This editorial represents a plea to retrovirologists to attend the XVI International Conference on AIDS that will take place in Toronto, Canada between August 13–18, 2006. In short, it is vital that politicians and opinion leaders understand that basic scientists are no less committed to the worldwide battle against HIV than community activists or non-basic scientists, and the best way to demonstrate this is by showing up. The XVIth International Conference on AIDS will take place in Toronto, Canada between Aug. 13–18, 2006. It is vital that this meeting be attended by basic retrovirologists working in the field of HIV as well as by clinicians, epidemiologists and social scientists concerned with preventive and other aspects of HIV research. The reasons for this are simple. The International Conference on AIDS is the most media-intensive event in the world in regard to dissemination of information about the HIV epidemic. In addition, the International Conference on AIDS is the only one of its type that attempts to bring together scientists working on all aspects of the HIV epidemic together with members of industry, community representatives, and their supporters. As such, this is probably the only conference in the world that attempts to appeal to a broad spectrum of attendees and, in a sense, attempts to be "all things to all people". Although such a lofty objective can never be completely achieved, the efforts involved in trying are both noble and worthwhile.Quite simply, the International Conference on AIDS probably does more to promote HIV awareness and education throughout the world than any other conference or group of scientific papers can currently achieve. In order to sustain this level of interest and support, it is vital that the conference attracts a critical mass of compelling papers that can articulate hope for the future in regard to an improved understanding of the HIV replication cycle, development of novel targets for drug development, and more appropriate use of both current and future drugs in a therapeutic setting. Moreover, these considerations apply as much in the context of developing countries as they do in countries such as the United States, Canada, and the nations of Western Europe. For example, it will be important to discuss the initial results of the PEPFAR program of the US government for purchase and distribution of antiretroviral drugs in Africa, which currently reaches at least 400,000 people. The latter is by far the most generous program of its type in the world and it is appropriate that the Conference make it a focal point in regard to expanded access to these life-saving drugs.Scientists throughout the world who work on HIV should consider it their obligation to submit abstracts to the International Conference and to attend. We, who work in this field, have been the beneficiaries of major grant support as a result of increased levels of funding that are now available in the field. These increased levels of funding have come about, in part, because of political pressure brought to bear by community groups who have lobbied for the accomplishment of research that will make a difference. In addition, there are obvious political and economic factors that have also resulted in increased levels of funding in recent years. Major philanthropic organizations, such as the Gates and Soros Foundations, etc have also channeled more money into HIV research because of the global catastrophic situation.Against this background, it is important that all scientists show solidarity in regard to the HIV crisis. It is not sufficient for any of us to want to work on problems that relate to the ideas in our grant applications without considering the global dimensions of the pandemic at the same time. The Toronto Conference organizers hope that we will attract a large number of first-rate abstracts that will make ours a first-rate scientific conference. Of course, we also want to organize a conference that will result in antiretroviral drugs becoming available to the millions of people around the world who are so desperately at need. Basic scientists as well as others in the field can vote with their feet by coming to Toronto and ensuring that the Conference is a major success.All of this recognizes that basic scientists often derive more direct benefit by attending specialized meetings. The International Conferences on AIDS cannot compete in this regard. Nevertheless, it seems also important for basic scientists to interact with other disciplines and to meet industry as well as community representatives. The International Conference on AIDS provides the best podium for this.Retrovirology to Toronto for what will be a stimulating and challenging conference that will provide specific information to those who attend specialty sessions as well as more general information to those who want to learn how they personally can play a role in the global fight against HIV/AIDS.We look forward to welcoming the readers of


The article on HIV/AIDS infection by Singh and colleagues outlines an alarming fact about the spread of this deadly virus in Nepal . We woulThe first report of HIV/AIDS infection in India was in 1986, and since then the virus has spread rapidly throughout the country. Both HIV serotypes 1 and 2 exist in India, and HIV-1 C is the most common subtype reported. Sexual transmission of HIV is the predominant route of transmission in India . AccordiAIDS is a sexually transmitted disease, and as long as people are educated thoroughly and warned about the dangerous consequences of unsafe sex, there is less to fear. Unfortunately, the intervention program launched by the NACO had very little impact in controlling the spread of the epidemic in India . The curAccording to the Asia Pacific Network of People Living with AIDS, a considerable number of people were refused treatment or delayed provision of treatment or health services after being diagnosed with HIV/AIDS. Breaches of confidentiality by health workers were common in Asian countries. Within families and communities, women were discriminated against more than men—including ridicule, harassment, and physical assault—and they were often forced to change their place of residence because of their HIV status .Although politicians and policymakers are increasingly committed to AIDS prevention and control efforts in countries such as India, a multidisciplinary approach such as early identification and treatment of sexually transmitted diseases, promotion of condom usage, rapid blood screening to test for HIV in rural areas, public awareness campaigns, poverty eradication, and development of prevention interventions have to be considered for effective control of the spread of this virus in the Indian subcontinent.Moreover, people from all walks of life must take an active role to promote AIDS awreness and prevention across the Indian subcontinent. It is time for the local and regional celebrities, such as political leaders, movie stars, and beauty pageant winners, in the Indian subcontinent to get involved in helping people with HIV and in educating the public, which would certainly raise awareness among the rural public more quickly than current efforts. It is time to remember how the late Princess of Wales reached out to people with AIDS, shook hands to console them, and also raised millions of dollars for their welfare. Countries in the Indian subcontinent have experienced and handled the outbreak of deadly epidemics in the past , and we


This easy-to-read, scrupulously researched, and fascinating book addresses two critical, but stubborn problems which threaten to reduce the effectiveness of many externally-funded HIV/AIDS prevention and treatment programs in Africa. First is the reluctance by biomedical and public health practitioners to recognize the essential value of qualitative and ethnographic data for the success of AIDS intervention programs in Africa. Second is the challenge of explaining the culturally coherent logic behind the seemingly irrational and contradictory views of Africans who blame sorcery and witchcraft for the HIV/AIDS epidemic. While this book will not completely solve both of these entrenched problems, it is a powerful statement about the value of systematically studying local explanatory models of the AIDS epidemic and offers a convincing and fine-grained analysis of the African quest to explain and account for personal misfortune in a time of significant social and economic uncertainty.Rodlach's description of AIDS-related sorcery accusations and conspiracy theories is rooted in over a decade of work and research in rural and urban Zimbabwe. Although the book focuses specifically on Zimbabwe, there are many similarities to accounts of the AIDS epidemic elsewhere throughout southern and central Africa. His methodology draws on the usual skill-set of a qualitative researcher  and his theoretical framework rarely veers far from the standard anthropological literature on witchcraft in Africa ; but his extended residence in Zimbabwe as a practicing priest in the local Catholic Church clearly distinguishes him from other social scientific researchers. Fluent in Ndebele, Rodlach gained the confidence of his informants as he ministered to their suffering; this trust made possible his frank discussions about deeply-held and often hidden explanations of AIDS misfortune.The chapters on conspiracy theories will be of most interest to clinicians, medical researchers, and other healthcare providers as these professionals feature prominently in local explanations of the origin of HIV and the spread of AIDS. In fact, these are Rodlach's strongest chapters because they are based on a broad and diverse range of evidence and, unlike accusations of sorcery and witchcraft, conspiracy theories are publicly discussed thus revealing a shared consensus and logic. The origin of HIV is sometimes attributed to "clever" (meaning selfish) western researchers and their Zimbabwean colleagues whose experiments on HIV in primates went awry and infected the human population. Rodlach suggests that this local disgust of biomedical research originates in strong taboos against transgressions of primate-human boundaries, the researchers' failure to adhere to other local knowledge and traditions, and the suspect intentions of anyone who is personally enriched by biomedical research. Clearly, this is fertile ground for the emergence of a conspiracy theory that holds biomedical research responsible for the spread of HIV. Rodlach then situates these seemingly irrational beliefs in the context of colonial medical practices during the Spanish Influenza epidemic of 1918–1919, rampant iatrogenic morbidity and mortality, and the poisoning of maize flour by white Rhodesian farmers. This serves to demonstrate that that which is seemingly irrational is, in fact, a logical interpretation of the origin of HIV/AIDS against these historical circumstances.Also of interest to healthcare practitioners is an explanation of why even literate and educated Zimbabweans can simultaneously hold both biomedical and conspiracy explanations for the origin and transmission of HIV. Elite and healthy civil sector professionals who initially discredit sorcery charges may later invoke these same explanations to account for why they are diagnosed with AIDS when others are not. To explain this, Rodlach argues that causality is ambiguous. Because a variety of biomedical and social factors can lead to the symptoms of AIDS, and these causal factors can be variously categorized as remote, intermediate, proximate, or ultimate, it is therefore possible for people to hold multiple and even contradictory explanations of HIV. Clearly, the most effective AIDS education programs engage with, rather than deny, these multiple explanations. However, the link between beliefs and behaviors was not substantially addressed in the book, and the cursory discussion of the A-B-C controversy needed more critical attention. Despite these small shortcomings, Witches, Westerners, and HIV is an engaging discussion of a difficult and complex topic, and as a result, this book is an important contribution to the literature on explanatory models of HIV/AIDS in Africa.


The aim of this study was to investigate and present some pertinent comments concerning Acquired Immunodeficiency Syndrome (AIDS) knowledge, attitudes and misconceptions among the general population in a city of west Turkey. This study was deemed important and relevant due to the increasing importance of AIDS in Turkey and the other countries.Using a multistage area sampling method, a random sample of individuals aged 11–83 years, living in 65 different quarters in the city of Eskisehir, Turkey during September, October and November 2004 were interviewed.In all, 1048 respondents completed the survey. In most items, respondents displayed a fairly good to excellent degree of knowledge about HIV/AIDS. Individuals with higher degrees of education indicated more correct responses in all items relating to knowledge of HIV/AIDS.In general, the respondents' attitudes towards AIDS and people with AIDS were found to be tolerant and positive, with one answer choice showing that the majority of the respondents agreed with the statement that those with HIV/AIDS must be supported, treated and helped (90.7%). Moreover, the proportions of the respondents' misconceptions were found to be significantly low for all the items. However, nearly one fourth of the respondents agreed with the misconceptions 'AIDS is a punishment by God' and 'One is not infected with HIV/AIDS if engaged in sport and well nourished'.In general HIV/AIDS related knowledge was high and people showed positive attitudes. However, people continue to hold misconceptions about AIDS and these need to be addressed by health education programs targeting those at higher risk. The Acquired Immunodeficiency Syndrome (AIDS), one of the most complex health problems of the 21 st century, is in its third decade and has become a pandemic disease that threatens the world population. Moreover, with no treatment or cure in sight, the disease continues to spread at an alarming rate . Recent In Turkey, the importance of AIDS started with the diagnosis of two patients in the year 1985, and still continues to be on the agenda up to the present day. The number of AIDS cases increases every year: 34 new cases in 1990, 91 new cases in 1995, and 119 new cases in 1999. According to the June 2004 statistics of the Ministry of Health (MoH) the cumulative number of HIV positive patients is 1802, 76% of which are sexually active and social individuals aged between 15–49 years. Approximately 800 of these were AIDS patients [This article presents data from a study of the general population of Eskisehir, a city in western Turkey. Several studies, conducted among selected target populations, have evaluated HIV/AIDS knowledge and the attitudes of certain groups such as university students , health Eskisehir is a semi rural province situated in the western part of Turkey, with a population of about 460,000. The socio-economical level of the city is average compared to other cities of the country. There are significant disparities in the socio-economic characteristics between the quarters of the city. It includes two universities, and also has a cosmopolitan structure.The questionnaire used in this survey, based on the WHO AIDS programme knowledge, attitudes, beliefs and practices (KABP) survey in 1988  as well 1048 people were interviewed face-to-face between September and November 2004 for a study on the KABP relating to HIV/AIDS of the population in a city of western Turkey.Due to the questionnaire being rather long, the survey being conducted on a general population and there being a possibility that some people in the city are illiterate, trained interviewers  helped to explain any questions that the respondents found incomprehensible. 274 houses and 108 workplaces situated in the 65 quarters of the city, each having approximately equal populations, were determined using a stratified random sample method. During the study period, a total of 1,621 people were working or living in these places, with 479 people living in houses, and 1,142 people working in workplaces. The study was conducted at the participants' work place or home. Our objective was to contact the whole population of subjects in the aforementioned places. Criteria for inclusion in the study was having the ability to complete the questionnaire and completion of education to at least primary school level, working on the presumption that this would ensure that all participants had a basic knowledge level of sexuality, a basic level of maturity with regard to answering sexually related questions, or the ability to communicate with one another. Those who came to visit the city from other cities and those with hearing impairments were excluded from the study. In addition, children and those not willing to participate were also excluded. The sample was representative. It did not differ from the general population in terms of age or sex.All subjects  were told that participation in the investigation was strictly voluntary and were told that the data collected would not be used for anything except the research aim. Those who agreed to participate were given the questionnaire to complete. The duration for completing the questionnaire was between 20–25 minutes per subject. The principal investigator met weekly with the data collectors to ensure the quality of data collected.Ethical permission for the study was obtained prior to collect data, by contacting and receiving approval from the appropriate management authority, the health directorship of the city involved. Participants were assured of the confidentiality of their responses and provided informed verbal consent.2) and t tests. The measure for statistical significance was established a priori as P < 0.05.The statistical package for social sciences (SPSS) version 10.0  was used to enter and analyze the data on a personal computer. Obtained data were evaluated by frequency and percentages ratios, Chi-square (xThe mean (± SD) age of the respondents n = 1048) was 29.9 ± 10.6, 95% CI  of 29.3–30.6, ranging from 11 to 83 years. It was significantly lower in women than in men , . Age ranged from 11 to 83 in men and from 12 to 76 in women. More respondents (56.7%) were male and single (48.1%) or married (46.9%), had attained the level of secondary education or above (86.2%). Most participants (64.8%) were working in a job and believed in God (87.9%). Household income levels were average or higher (71.6%). The characteristics of the participants are presented in Table 048 was 2Sixty two percent of the sample believed they were not at any risk of contracting HIV (Unshown data).The analysis of data indicated that in most items respondents had a fairly good to excellent knowledge about HIV/AIDS. The percentages of 'true' responses for all the knowledge items were higher than 'false' and 'don't know' responses, with the exception of the response for item 7. The vast majority had correct knowledge about items 2 (92.0%), 25 (94.3%), 28 (93.6%), 29 (91.5%), and 30 (90.6%). However, over 30% of the respondents thought that AIDS is a hereditary disease (37.6%); that AIDS is not generally seen in developing or underdeveloped countries (38.5%); that a person infected with HIV usually shows some symptom of the disease (39.2%); and that urine, X-ray, total blood count and biochemistry analyses are the tests used to check for the HIV virus in the blood (30.0%). Further misconceptions held were that HIV/AIDS can be contracted through sharing public toilets and swimming pools with an infected person (33.4%); using an infected person's belongings such as clothes, comb, underwear and towels (33.7%); sharing the food utensils of an infected person (37.7%); and exposure to an infected person who coughs or spits (34.9%), or the urine of an infected person (31.2%).There was an important evidence of sex differences in responses regarding knowledge about HIV/AIDS for 13 items out of the 34. In statements relating to knowledge on items 1., 2., 3., 4., 6., 9., 11., 21., 22., 23., 29., 32., and 33, males gave significantly more correct responses than did female respondents.Age groups were found to be significantly associated with AIDS related knowledge for 16 of the items. Younger respondents 24 years) responded better to items 6., 16., 17., and 31., whereas older respondents (45 years) responded better to items 5., 7., 8., 26., and 35. On the other hand, those in age group 25–34 years old had more correct responses for items 4., 9., 10., 12., and 20., and those in age group 35–44 years old had significantly more correct responses for items 19., and 27. The detailed data are presented in Table 4 years rTable In general, the respondents' attitudes towards AIDS and people with AIDS were found to be significantly tolerant and positive, with the exception of items 7 and 8. The majority of the respondents positively agreed with statement 5 (70.5%) and statement 9 (90.7%). On the other hand, a large number of the respondents agreed with the stigmas 1., 2., 3., 4., 6., 7., 8 and 10 with proportions of between 30% and 50%. These results are shown in Table Women were more positive in their attitudes towards HIV/AIDS or AIDS victims when answering all the items compared to men, and those attitudes were statistically significant for items 1., 3., 5., 8., and 10.There were significant differences for items 2., 3., 4., and 7 between different age groups with regard to their attitudes towards AIDS and AIDS victims. Those in the age group 45 years old and above had significantly more positive attitudes to items 2., and 7., whereas those aged 24 years old and under had significantly more positive attitudes to items 3., and 4.Upon comparison of people with different educational levels, it was found that there were significant differences between individuals with different levels of education for 8 items out of 10. Those with higher education were significantly more positive in their attitudes to items 1., 2., 3., 9., and 10., compared to less educated respondents, whereas illiterate individuals had significantly more positive attitudes to items 4., 5., and 7 when compared to higher educated respondents.In general, the proportions of the respondents' misconceptions were found to be significantly low for all the items. The majority of the respondents disagreed with all the statements. However, 23.2% and 24.2% agreed with misconceptions 2., and 6., respectively. The results are shown in Table Women more disagreed with the vast majority of the misconceptions, with the exception of item 4., where men more disagreed. There were significant differences between men and women to the misconception items 4., and 5..Significant differences between different age groups were seen for only 2 of the items  with regard to their misconceptions towards AIDS and AIDS victims. Those in the age group 24 years old and under disagreed more significantly with misconception item 2., whereas those in the age group 35–44 disagreed more significantly towards misconception item 6. However, no difference was observed between the other items  and different age groups.The proportions of those who neither agreed nor disagreed were higher for those agreeing with all items; however, there were no significant differences between religious belief and misconceptions, except for item 6.Although the proportions of those who agreed with all the items were higher in men than in women, there were significant differences between religious beliefs and sex differences, with the exception of items 4., and 5.There were no significant differences between different age groups and those who agreed with misconceptions towards AIDS and AIDS victims, barring item 2 where the proportion of those agreeing with item 2 was higher in those aged 45 years and over when compared to the other age groups.While comparing people with different educational levels, it was found that there were significant differences between individuals with different levels of education in all of the misconception items.Those with higher education disagreed significantly more with all the misconceptions, compared to less educated respondents.The majority of the respondents indicated that their level of information about HIV/AIDS was average (49.3%). Most respondents reported that mass media  was the major sources of their information about HIV/AIDS, followed by school and friends . However, most indicated that they desired to learn more (86.6%). These results are shown in Table 6This paper reports data from a population-based study on AIDS knowledge, attitudes and misconceptions among the general population in Eskisehir, Turkey. The findings indicated that people in Turkey reported good knowledge about AIDS. However, nearly 40% and 30% of the respondents believed that AIDS is a hereditary disease and that there is an active treatment for AIDS, respectively. They also indicated that they believed that AIDS is not generally seen in the developing or underdeveloped countries, countries that would be least able to afford to care for infected people (38.5%), that people infected with HIV usually show some symptom of the disease 39.2%), and that 23.1% of them believed that AIDS patients differ from the normal population in their appearance (23.1%). Furthermore, respondents demonstrated a limited knowledge of how HIV/AIDS cannot be transmitted whereas a rather high rate said that AIDS could be contracted through items 13 (33.4%), 14 (33.7%), 17 (37.7%), 18 (34.9%), 20 (29.8%), and 31 (31.2%). It appears that a number of respondents in the city do not know about the risk of transmission of AIDS or HIV infection from different sources. These findings are consistent with other results in both our country and other countries .2%, and ,17,21.The findings suggested that gender was not associated with the correct answering of questions on AIDS-related knowledge, excluding those of 13 items  where males preformed better. In contrast, as expected, those who had higher levels of education and younger respondents (those aged 34 and under) generally had more correct answers on questions relating to knowledge about AIDS. A study from the US among the general population also showed significant differences in AIDS-related knowledge with less-educated and older respondents being less likely to respond correctly to general AIDS knowledge questions [The most interesting finding from this survey was the fact that people in the city showed a more positive attitude towards AIDS and those with AIDS than expected, with the exception of a few items . For example only a small number of the respondents disagreed with the attitude that people with AIDS must be supported, treated and helped (4.8%) or agreed with the attitude that people with AIDS should be locked up or isolated in a special center (17.8%). Furthermore, when taking into consideration that the majority of the respondents' educational levels were high school and above (74.8%) and that their levels of information about HIV/AIDS were average or above (57.4%) our study, in line with the study of Maswanya et al (2000) , may conOn the other hand, there was a substantial negative attitude towards HIV and AIDS positive patients. A proportion of about 30% and 50% of the respondents, excluding item 5 where the proportion of negative attitude was only 17.8%, expressed negative attitudes. These findings are consistent with the findings of some studies conducted in Iran and Indian . This caIn our study, 17.8% of the respondents agreed with the statement suggesting that people with AIDS should be locked up or isolated in a special center. This result was in line with the study by Moatti et al (1998) , where tIn this study, women were more positive in their attitudes towards HIV/AIDS or AIDS victims in all the items when compared to men. This finding is compatible with the study by Lester (1989) . This maThis survey demonstrated that in general only a small number of the respondents harbored misconceptions. For instance, only 23.2% of people in a Muslim country such as Turkey agreed with the statement that AIDS is a punishment from God. In parallel, this proportion was 14.2% in Montazeri 2004)'s study 04's stud in TunisIn the current study, those having attained a higher education level disagreed significantly more with all the misconceptions, compared to less educated respondents. This is compatible with the study of Eshetu et al (2004) . This inIn this study, the most important AIDS related knowledge source for the majority of the respondents was the mass media such as television 68.9%) and newspapers (47.6%), followed by magazines 23.6%). It appears that the mass media, especially television, has an important role in raising AIDS awareness within the Turkish community. In contrast, institutions such as school (18.8%) and the AIDS Association (0.7%) where better information about AIDS can be found, or from specialist persons such as doctors (8.1%), teachers (7.8%) and nurses (4.5%) had less importance. These should be more involved in AIDS education. In addition, only 4.5% said that their family informed them about the disease. The sources of knowledge of HIV/AIDS for the general population reported here are similar to those previously reported % and new,16,28. T.6%. It aIn the present study, the respondents desired to learn more about HIV/AIDS (86.6%). This indicates that reports dealing with the rapid spread of AIDS in various populations, as well as in the Turkish population, have increased the level of anxiety over contagion among the respondents.Sixty two percent of the sample believed they were at no risk of contracting HIV. This figure is comparable to the 2003 National HIV/AIDS and Reproductive Health Survey that reported 72% of the civilian population  and alsoThe level of HIV/AIDS related knowledge was relatively high throughout our study, with most people showing positive attitudes. Misconceptions about AIDS still exist and need to be addressed by health education programs targeting those at higher risk. It has previously been shown that health education and sustained prevention efforts, such as the introduction of HIV/AIDS education into schools, mass-media campaigns promoting the use of condoms, and the wearing down of individuals' ability to deny risk towards patients with HIV or AIDS positive can be effective in changing people negative attitudes or misconceptions towards AIDS -33.Being in total agreement with the opinion reported by Tebourski and Ben Alaya (2004) in their study , we woulThe author(s) declare that he has no competing interestsThe pre-publication history for this paper can be accessed here:


Young people aged 15–24 years account for fifty percent of all new AIDS cases worldwide. Moreover, half of all new HIV infections are associated with injection drug use. The average age for initiation into injecting drug use is 20 years of age. This paper investigates whether HIV prevention programs have reduced risk behaviours in young people. Young people are at the forefront of the HIV/AIDS epidemic as it continues to spread worldwide. An estimated 12 million people aged between 15 and 24 years are living with HIV or AIDS around the world. Of the five million new HIV infections in 2001, over half were among youth aged 15–24  and The target population varied in each of the HIV program studies. Firstly the definition of a young person varied, from under 26 years old to 12–23 years. However the most common definition of youth in the literature is between the ages of 15 and 24 years . SecondlThe sample sizes of the studies varied from 13 to 1,146 young IDUs. Sample size will impact on the statistical power of the study. Small sample sizes are unlikely to allow differences to be detected. Also, the assessment periods of the studies differed. Three studies were cross-sectional -11 whereThe United Nations aims to reduce HIV prevalence among 15–24 year olds by a quarter in the most affected countries by 2005 and globally by 2010 [The studies presented in Table 1 employed disparate methodologies, making a comparison of relative effectiveness impossible. According to the authors, all studies had some positive benefit for reducing HIV-related outcomes in the sample, whether it be increasing participant knowledge of HIV or other BBVIs or reducing needle and syringe sharing. However, they all differed in outcomes measured, instruments used, target population and study design. Due to differences in the programs' nature and length and other practical constraints such as budgetary factors, it is unrealistic to expect a good level of consistency. Nonetheless, it is not unrealistic to expect better consistency than that presented in Table 1 . As outlined in the Introduction, standardisation is now recognized as crucial and is in urgent need of implementation. The need for standardisation still needs to be emphasised, as standardized program findings are critical to informing and guiding appropriate prevention responses . MoreoveThe studies presented in Table 1 only measured behavioural outcomes and did not contain biological data. Biological data  are an The studies presented in Table 1 additionally lack cost-benefit data, crucial information to aid policy makers and program managers in allocating resources, particularly in resource poor settings. Random sampling was not conducted in any of the studies, thus biases in the results may exist. Although random sampling of individuals in one location for example may not be feasible, random allocation of the intervention to certain clinics may be one solution. Two studies did conduct assessments at an intervention site as well as one or more comparison sites, although these studies did not measure the same participants pre and post intervention, and so were unable to determine the effect of the prevention program on HIV-related outcomes. These short comings resulted in less conclusive data. However the desire to obtain accurate information and the costs and practical issues in collecting such information need to strike a balance and although the ideal should be strived for, it is not always possible. Another reason for the lack of research on youth has been the restrictions imposed by many ethics committees on researchers accessing young people.UNAIDS proposes that HIV prevention programs for youth should have the following characteristics for effectiveness:• To succeed they should respect and involve young people, while being sensitive to their cultures.• Young people need a safe and supportive environment, with sensitive attitudes, policies and legislation at family, community and national levels.• The stigma and discrimination associated with HIV/AIDS needs to be diffused.• Strong and effective education systems are important, yet in many countries education systems are clearly in disarray.• Outreach and peer education programs among young drug users should be expanded, and include steps to improve access to information and prevention equipment such as condoms and needles and syringes and HIV/AIDS care services.Upon searching the literature for recommendations of standardized instruments and study designs to integrate in a new evaluation study of a HIV prevention program, no clear guidelines were found. If standardised, valid and reliable instruments were in the literature, then program managers would be more likely to adopt them in practice. An important confounding concern is that although standardized indicators are needed that can be compared across countries and regions of the world, failure to adapt these indicators to the local setting can weaken our ability to obtain valid information. Key experts in the field need to make clear recommendations of evaluation study design and instruments to use, preferably at a global level. The following recommendations are a result of this review, with respect to study design, outcomes and instruments to use:(1) Randomise (2) Collect baseline, post-intervention and follow-up data on the same clients(3) Use control or comparison group(4) Collect behavioural and biological data(5) Use standardized instruments to measure HIV outcomes.The author(s) declare that they have no competing interests.Summary of Studies of programs for young and new injecting drug usersClick here for file


HIV/AIDS-related stigma and discrimination are significant determinants of HIV transmission in the Caribbean island nation of Trinidad and Tobago (T&T), where the adult HIV/AIDS prevalence is 2.5%. T&T is a spiritually-aware society and over 104 religious groups are represented. This religious diversity creates a complex social environment for the transmission of a sexually transmitted infection like HIV/AIDS. Religious leaders are esteemed in T&T's society and may use their position and frequent interactions with the public to promote HIV/AIDS awareness, fight stigma and discrimination, and exercise compassion for people living with HIV/AIDS (PWHA). Some religious groups have initiated HIV/AIDS education programs within their membership, but previous studies suggest that HIV/AIDS remains a stigmatized infection in many religious organizations. The present study investigates how the perception of HIV/AIDS as a sexually transmitted infection impacts religious representatives' incentives to respond to HIV/AIDS in their congregations and communities. In correlation, the study explores how the experiences of PWHA in religious gatherings impact healing and coping with HIV/AIDS.Between November 2002 and April 2003, in-depth interviews were conducted with 11 religious representatives from 10 Christian, Hindu and Muslim denominations. The majority of respondents were leaders of religious services, while two were active congregation members. Religious groups were selected based upon the methods of Brathwaite. Briefly, 26 religious groups with the largest followings according to 2000 census data were identified in Trinidad and Tobago. From this original list, 10 religious groups in Northwest Trinidad were selected to comprise a representative sample of the island's main denominations. In-depth interviews with PWHA were conducted during the same study period, 2002–2003. Four individuals were selected from a care and support group located in Port of Spain based upon their perceived willingness to discuss religious affiliation and describe how living with a terminal infection has affected their spiritual lives. The interviewer, a United States Fulbright Scholar, explained the nature and purpose of the study to all participants. Relevant ethical procedures associated with the collection of interview data were adopted: interviews were conducted in a non-coercive manner and confidentiality was assured. All participants provided verbal consent, and agreed to be interviewed without financial or other incentive. Ethics approval was granted on behalf of the Caribbean Conference of Churches Ethics Committee. Interview questions followed a guideline, and employed an open-ended format to facilitate discussion. All interviews were recorded and transcribed by the interviewer.Religious representatives' opinions were grouped into the following categories: rationale for the spread of HIV/AIDS, abstinence, condom use, sexuality and homosexuality, compassion, experiences with PWHA, recommendations and current approach to addressing HIV/AIDS in congregations. Religious representatives expressed a measure of acceptance of HIV/AIDS and overwhelmingly upheld compassion for PWHA. Some statements, however, suggested that HIV/AIDS stigma pervades Trinidad's religious organizations. For many representatives, HIV/AIDS was associated with a promiscuous lifestyle and/or homosexuality. Representatives had varying levels of interaction with PWHA, but personal experiences were positively associated with current involvement in HIV/AIDS initiatives. All 4 PWHA interviewed identified themselves as belonging to Christian denominations. Three out of the 4 PWHA described discriminatory experiences with pastors or congregation members during gatherings for religious services. Nonetheless, PWHA expressed an important role for faith and religion in coping with HIV.Religious groups in Trinidad are being challenged to promote a clear and consistent response to the HIV/AIDS epidemic; a response that may reflect personal experiences and respect religious doctrine in the context of sex and sexuality. The study suggests that (1) religious leaders could improve their role in the fight against HIV/AIDS with education and sensitization-specifically aimed at dismantling the myths about HIV transmission, and the stereotyping of susceptible sub-populations, and (2) a consultative dialogue between PWHAs and religious leaders is pivotal to a successful faith-based HIV intervention in Trinidad. The HIV/AIDS epidemic in the Caribbean region is fuelled by stigma and discrimination, which are the most significant determinants of HIV infection and death from AIDS-related complications . TrinidaStigma and discrimination create barriers to HIV testing and treatment, care and support networks for people living with and affected by HIV/AIDS ,9. In TrT&T is a spiritually-aware society where the majority of the population belongs to at least 1 of over 104 religious groups . When th"Human Sexuality and HIV/AIDS in the Caribbean – A Theological Approach" [Religious leaders are esteemed, frequently exchange with the public and maintain an influential role in policy-making in Trinidad . They mapproach" . The conYet there are barriers to more active and widespread involvement in HIV/AIDS initiatives among religious groups in Trinidad. Debate over condom sales, for example, has hindered collaboration with public health organizations  and reliAll relevant ethical procedures associated with collection of interview data were adopted, and the methods approved on behalf of the Caribbean Conference of Churches Ethics Committee. The interviewer explained the nature and purpose of the study to the participants and conducted the interviews in a non-coercive manner, with the assurance of confidentiality. All respondents provided verbal consent, and agreed to be interviewed without financial or other incentive.Between November 2002 through April 2003, in-depth interviews were conducted with 11 consenting representatives from 10 religious organizations in Trinidad, including: Anglican, Open Bible, Pentecostal, Salvation Army, Unity School of Christianity, Seventh Day Adventists, Hindu, Jamaat al Muslimeen, Nation of Islam, and Roman Catholic (2 representatives). Selection of religious groups was based upon the methodology of Brathwaite . BrieflyP1–P4) were selected from an established HIV/AIDS support group in Port of Spain, Trinidad, based upon their perceived willingness to discuss sensitive issues and religious affiliation. Interview questions were open-ended, but followed a structured guideline , whose goals include the provision of necessary support within a holistic framework for those persons infected and affected by HIV/AIDS. These goals are currently undertaken by the newly-formed National AIDS Coordinating Committee [Regional conferences such as those led by the CCC indicate that religious groups are beginning to mobilize in confronting the HIV/AIDS epidemic. Since the completion of this study, in 2005, the CCC hosted another consultation with Faith Based Organizations to develop an HIV/AIDS policy and action plan, entitled, IV/AIDS" . The docommittee .Nonetheless, several religious representatives agreed that the pace of efforts on behalf of religious organizations has been too slow. The present research raises the following question: if HIV were not sexually transmitted, would religious organizations respond to the epidemic in the same way? The HIV/AIDS epidemic in Trinidad urgently calls upon religious groups to provide a clear and consistent response to issues of sex and sexuality that resonates with personal experience and respects religious doctrine. However, the present research highlights inconsistent attitudes and opinions on the moral and spiritual issues surrounding HIV/AIDS; such inconsistencies may serve as a barrier to a united faith-based initiative in Trinidad. Religious groups across all faiths and denominations are challenged to recognize that human beings are sexual beings; herein lays the dilemma for religious groups. A faith-based intervention must understand the complexity of preserving the central tenets of organized religion while embodying compassion for individuals as sexual beings.This study was limited by a small sample size and the geographic location of Northwest Trinidad; this may affect the generalization of results throughout Trinidad and Tobago. On average, only one representative from each religious organization was interviewed, and opinions expressed did not necessarily reflect those of the religious organization as a whole. Nonetheless, HIV/AIDS-related stigma and discrimination will continue to fester throughout Trinidad and Tobago until all the republic's religious leaders, esteemed in the public eye, possess accurate information about HIV transmission, which may then be conveyed to congregations; and until religious leaders are sensitized to the experiences of PWHA. Prior to involvement in community-based education, care and HIV/AIDS support initiatives, religious leaders must possess compassion that is reinforced by personal experiences with PWHA. PWHA are receptive to faith-based counseling and support provided by religious leaders and congregation members. Thus, a consultative dialogue between PWHA and religious leaders is pivotal to a successful faith-based HIV/AIDS initiative in Trinidad.AC: Anglican ChurchAIDS: Acquired Immuno-Deficiency SyndromeCAREC: Caribbean Epidemiology CenterHIV: Human Immunodeficiency VirusNOI: Nation of IslamPWHA: People Living with HIV/AIDSRC: Roman Catholic SA: Salvation ArmySDA: Seventh Day AdventistSTI: Sexually Transmitted InfectionThe findings and conclusions in this report are those of Dr. Brathwaite and Ms. Genrich and do not necessarily represent the views of the funding agency, the Institute for International Education and Fulbright Fellowship Program, nor the organizations where the authors currently work, the University of the West Indies and the Centers for Disease Control and Prevention, respectively. There were no competing interests, financial or otherwise, in the present investigation, and no incentive on behalf of the Institute for International Education to obtain the results found. No fees or funding were obtained from any organization that could gain or lose from the publication of the manuscript, and no stocks or shares are held in any organization that stood to gain or lose financially from publication.Dr. Brathwaite contributed to the design of the research method. Ms. Genrich carried out the in-depth interviews with the participants, religious representatives and individuals living with HIV/AIDS. Both Dr. Brathwaite and Ms. Genrich collaborated on the final analysis and manuscript preparation. Both authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:


Ethnobotanical surveys were carried out to document herbal remedies used in the management of HIV/AIDS opportunistic infections in Bukoba Rural district, Tanzania. The district is currently an epicenter of HIV/AIDS and although over 90% of the population in the district relies on traditional medicines to manage the disease, this knowledge is impressionistic and not well documented. The HIV/AIDS opportunistic conditions considered during the study were Tuberculosis (TB), Herpes zoster (Shingles), Herpes simplex , Oral candidiasis and Cryptococcal meningitis. Other symptomatic but undefined conditions considered were skin rashes and chronic diarrhea.ic) was used to analyze the ethnobotanical importance of the plants.An open-ended semi-structured questionnaire was used in collecting field information. Descriptive statistics were used to analyze the ethnobotanical data collected. Factor of informant consensus (FIn the present study, 75 plant species belonging to 66 genera and 41 families were found to be used to treat one or more HIV/AIDS related infections in the district. The study revealed that TB and oral candidiasis were the most common manifestations of HIV/AIDS opportunistic infections affecting most of the population in the area. It unveils the first detailed account of ethnomedical documentation of plants focusing the management of HIV/AIDS related infections in the district.It is concluded that the ethnopharmacological information reported forms a basis for further research to identify and isolate bioactive constituents that can be developed to drugs for the management of the HIV/AIDS opportunistic infections. According to WHO , traditiMore than 60% of the population in Tanzania depends on traditional medicines for the management of various diseases including HIV/AIDS . Due to Even though there are a good number of reports on traditional uses of plants to treat various diseases in the country, knowledge on herbal remedies used to manage HIV/AIDS in particular is scanty, impressionistic and not well documented. Consequently, this paper presents the first detailed account of the status and use of traditional medicines in the management of HIV/AIDS opportunistic infections in Tanzania.Kihaya language. Agriculture is the economic mainstay of the district and accounts for 50% of the Region's Gross Domestic Product (GDP). The main crops are green bananas, coffee, beans, cotton and cassava. Other crops include sugarcane, sweet potatoes, vegetables, millet and sorghum  and Herpes simplex [Genital herpes] (Ebiere). The symptomatic conditions, skin rashes and chronic diarrhea are locally called Ubwere and Kuaruka respectively.During the interviews, the symptoms of various HIV/AIDS opportunistic infections were described to the healers so as to enable them give the appropriate plant species they usually use to manage the infections ,4-16 Ta. The OppCapparis erythrocarpos was used to treat all the seven reported disease conditions.A total of thirty herbal practitioners aged between 32 and 80 years of age were interviewed during the study. Twenty two out of the thirty respondents (73%) were above 50 years of age. Twenty one of these were women and only nine were men, constituting a percentage of 70% and 30% respectively. Majority of the respondents were peasant farmers and non- educated. It was found that most informants could unambiguously characterize symptoms of the targeted HIV/AIDS opportunistic infections without much problem. During the study, 75 plant species in 66 genera and 41 families were known to be used to treat one or more of the reported HIV/AIDS related infections in the district. The families Anacardiaceae, Asteraceae, Capparaceae, Clusiaceae, Euphorbiaceae, Papillionaceae, Rubiaceae, Myrtaceae, Mimosaceae and Lamiaceae constituted 52% of all the reported plant species, with each family having three or more species associated with the treatment of the opportunistic infections documented. The highest number of plant species used to treat the various conditions was recorded for TB which had 27 of the 75 documented species. It was followed by oral candidiasis with 25, Herpes zoster (23), H. simplex (23), skin rashes (23) chronic diarrhea (21) and cryptococcal meningitis (17) , stem or bark (26%) and other parts of plants like fruits or seeds 3%)  arrived at the value of 0.70. A high Fic value (close to 1) indicates that the informants use relatively few taxa to manage specific disease conditions as well as consistency in the use of plant species, while a low value indicates that the informants disagree on the taxa to be used in the treatment within a category of illness[The use of the Factor of informant consensus  derived suggests that there was a great agreement amongst the respondents on the use of different plant species to manage the reported disease conditions. On the other hand, it reflects the likelihood of presence of bioactive molecules to curtail the various HIV/AIDS opportunistic infections reported. A similar observation was made by Schlage et al. [ic to evaluate the ethnobotanical importance of the medicinal plants of Washambaa in Tanzania. Fic is also a crucial tool in establishing a comparative estimation of the level of informant consensus on the use of herbal remedies between culturally different communities [On one hand, the relatively high Fe et al.  who usedmunities .Ozoroa insignis, Rhus natalensis, R. vulgaris and Lannea schimperi in their respective treatment of skin rashes, Herpes simplex, H. zoster and chronic diarrhea as reported in Table The supremacy of the families Anacardiaceae, Asteraceae, Capparaceae, Clusiaceae, Euphorbiaceae, Lamiaceae, Mimosaceae, Myrtaceae, Papillionaceae and Rubiaceae in the management of the reported conditions could be associated with the presence of certain bioactive secondary metabolites. For example, the families Myrtaceae and Lamiaceae are rich in terpenoids which are biologically responsible for the general improvement and maintenance of body health , with a Harungana madagascariensis among the Igbos of southeastern Nigeria for the treatment of diarrhea has been reported by Okoli et al. [Psorospermum febrifugum by the Kamba of Kenya and the Washambaa of Tanzania in the treatment of skin infections [Garcinia huillensis and Securidaca longipedunculata to treat Cryptococcal meningitis is consistent with data reported by Mathias [The ethnomedical uses of some plants described here are consistent with data reported previously. For instance, the traditional use of i et al. . The usefections ,23 also  Mathias . Such a The information provided forms a strong basis for conservation of the reported remedies, considering that a greater percentage of the plant parts used were roots and stem/bark. Continuous unsustainable harvesting of these plant parts may eventually lead to disappearance of these invaluable resources if early conservation measures are not taken. In future, there would be a need to engage in value adding and standardization of the herbal preparations by developing the necessary dosages and packaging of the herbal formulations. The ethnopharmacological information reported forms a crucial lead for further research to identify and isolate bioactive constituents that can be developed to drugs for the management of the HIV/AIDS opportunistic infections.The author(s) declare that they have no competing interests.DPK was involved in the conception, acquisition and analysis of data, drafting and final revision of the manuscript. HVML designed the research layout, was involved in data analysis and interpretation, and critically revised the manuscript for important intellectual content. KMH and CCJ were involved in the conception, designing of the research and critical revision of the manuscript for important intellectual content. All authors read and approved the final manuscript.


In a recent article, Six weeks after DMAB exposure, we found that the patient was still confused about time . FourteeThe patient developed a progressive distal numbness and limb weakness 5 days after DMAB intoxication, and neurologic examinations showed generalized hyporeflexia; decreased sensation in pin-prick, temperature, touch, vibration, and position sensations; and weakness in the distal limbs, particularly in both feet . The datOur time course of DMAB-induced polyneuropathy indicated an acute axonal polyneuropathy . However


This paper critically discusses two previous studies concerned with predictions of HIV/AIDS in the United States and Japan during the early 1990s. Although the study in the US applied a historical theory, assuming normal distribution for the epidemic curve, the underlying infection process was not taken into account. In the Japan case, the true HIV incidence was estimated using the coverage ratio of previously diagnosed/undiagnosed HIV infections among AIDS cases, the assumptions of which were not supported by a firm theoretical understanding. At least partly because of failure to account for underlying mechanisms of the disease and its transmission, both studies failed to yield appropriate predictions of the future AIDS incidence. Further, in the Japan case, the importance of consistent surveillance data was not sufficiently emphasized or openly discussed and, because of this, revision of the AIDS reporting system has made it difficult to determine the total number of AIDS cases and apply a backcalculation method. Other widely accepted approaches can also fail to provide perfect predictions. Nevertheless, wrong policy direction could arise if we ignore important assumptions, methods and input data required to answer specific questions. The present paper highlights the need for appropriate assessment of specific modeling purposes and explicit listing of essential information as well as possible solutions to aid relevant policy formulation. Although numerous mathematical and statistical approaches have been proposed to predict the future course of infectious diseases, various assumptions are required to account for the intrinsic and extrinsic dynamics of disease spread -3, and cBefore entering into discussion on the details of the case studies, two widely accepted models of HIV/AIDS epidemiology are briefly discussed. Whereas there is no single best method for AIDS prediction, these two approaches, both of which were initially proposed during the late 1980s, are widely employed -10.The first approach is based on a mathematical model that explores the population dynamics of HIV/AIDS ,11. The The second model, referred to as backcalculation, is a more statistically motivated approach to estimating HIV prevalence -10. BackNeither the US nor Japan case studies used the above methods, and further, whereas the above two approaches account for underlying mechanisms of the disease, the two case studies focused almost entirely on extrapolation of the epidemic curve.The approach employed in the US case study assumed a normally distributed epidemic curve . The undAs the Japan case study, the series of studies by the Working Group on prediction of HIV-infected cases and AIDS patients, organized by the Ministry of Health, Labor and Welfare (MHLW), Japan, are discussed -31. FromHu, Hd, Au, and Ad are the cumulative number of unreported and reported HIV infections and unreported and reported AIDS cases, respectively. The ratio has been revised several times, but the most recent studies adopt an estimate of 1/5.1 (reported/unreported), because approximately 19.6% of the AIDS cases reported up until the mid-1990s were previously diagnosed as being infected with HIV [where with HIV ,32.The ratio should be implicitly assumed to be independent of time. Using the estimated HIV prevalence based on this ratio, it is assumed that HIV-infected individuals develop AIDS according to a fixed incubation period distribution that follows Weibull distribution -30. BaseAs shown in Fig. The original study did not take into account the reason behind the assumption of a normal curve ,35. Non-Figs. A number of professionals immediately and sharply criticized the US projection ,33,36,37Some publications, which did not follow the widely discussed theoretical concepts, investigated the original study as an accepted theory or extended the discussion concerning predictability. Shortly after publication of the original study and more recently ,40, the In Japan, the Committee of AIDS Trends, formed by MHLW, expressed their standpoint with respect to interpretation of such estimations as follows : "BecausThe Japan case study also indirectly influenced the AIDS notification method. Prior to revision of the surveillance system in 1999, HIV/AIDS notifications among Japanese nationals were classified into one of three categories: (1) HIV infection, (2) AIDS without a previous diagnosis of HIV infection (= 'First Report'), and (3) AIDS with a previous HIV diagnosis (= 'Second Report'). Since implementation of the Law Concerning the Prevention of Infectious Diseases and Medical Care in 1999, replacing the previous law for HIV/AIDS in Japan, it has become difficult to link individuals initially categorized as (1) and later as (3) due to the altered administrative system . MoreoveThe two case studies discussed here employed rather different approaches compared to widely accepted methods. In the US, experts in relevant fields criticized the original study and the flawed prediction has become relatively well known, at least among specialists. Although there were few public health impacts (including the data collection method), a few non-experts, who seem not to recognize the importance of intrinsic dynamics, continue to reference and extend the original theory. Moreover, the predictions obtained based on the original Japan case study have been largely adopted as official, and unfortunately, only one study has so far criticized the technical flaw . The folIt should be accentuated that intrinsic dynamics are one of the most important factors offering valid and sound answers to the specific question addressed by the model  . TransmiIt should be emphasized that even if a model has good predictability it does not necessarily mean it's a good model for prediction. It should also be noted that good models are essentially accompanied by valid basic assumptions of the spread of disease and pay close attention to the input parameters; the widely accepted approaches take particular care to heed this point. As in the above two case studies, the majority of flawed predictions employ simple extrapolation of an epidemic curve, the most uncertain component of modeling, frequently focusing on the predicted value itself or simple residual variance alone.One of the biggest challenges facing modelers and policy makers is how to communicate and share these points effectively . Many reThe criticisms presented here do not blame the authors of the presented case studies, but rather attempt to give general suggestions for improvement. As a possible remedy for modeling frameworks, to make them truly useful for policy making, I suggest the following potential solutions. These apply not only to the above discussed extreme cases in the US and Japan but also to most quantitative models.The model structure depends on investigation of a specific question. Even if based on valid assumptions, it must be remembered that models may not provide any insights other than their main purpose. Thus, what can and cannot be learned from each study must be explicitly documented for the reader to assess. If more than two quantitative approaches are applied to the same data, the purposes and information obtained could be different. It is not uncommon for various approaches to be applied to the same data, with the generated findings enhancing our understanding of the validity of the assumptions made. Thus, where possible, various approaches that differ from each other in their purposes should be applied to the same data.As discussed above, the validity of estimations and/or predictions largely depends on the assumptions made. Thus, it would be very useful if all publications documented the assumptions, limitations and input parameters in an explicit manner . AltMost modeling frameworks are accompanied by a certain number of unrealistic assumptions. Despite efforts to make a model as realistic as possible, it is often the case that the data is limited, e.g., as a result of future improvements in treatments or behavioral changes. It should be noted, however, that incorporation of numerous details is not necessarily a remedy for inappropriate description of the reality. Depending on the question being addressed, an accurate yet simplistic model may be desirable; a simple model often better reflecting the reality than complex simulations . In lineModelers should fully understand the intrinsic dynamics of the disease and/or work closely with specialists who can offer detailed disease information. Since it is not uncommon for the findings of a model to be misinterpreted (as in the above case studies), it is crucial that modelers, policy makers, and clinicians work together when creating and utilizing such models. Through such practice, modeling experts should share their knowledge in assessing the validity of a model and translating the implications for policy makers. Further, if public health officials are unable to assess the findings of model-based predictions, modelers should be on hand for consultation. These experts should also employ their knowledge to disease monitoring systems.The present study critically discussed two predictions of AIDS incidence with the aim of understanding how such estimates are interpreted by the general public and exploring possible improvements in policy making. It should be emphasized that ignoring how a disease spreads, and related assumptions, as well as neglecting key input information could lead to wrong policy direction. The need for appropriate assessment of specific modeling purposes, and explicit listing of assumptions, limitations and parameter inputs as well as possible solutions to aid relevant policy formulation was therefore highlighted.The author(s) declare that they have no competing interests.HN carried out paper reviews, proposed the study, performed mathematical analyses and drafted the manuscript. The author has read and approved the final manuscript.Additional methods. Mathematical details are provided in pdf format.Click here for file