The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Leishmaniasis <s> Leishmaniases are a complex of world-wide diseases with a range of clinical and epidemiological features caused by Leishmania spp. of protozoan parasites. Among 15 well-recognised Leishmania species known to infect humans, 13 have zoonotic nature, which include agents of visceral, cutaneous and mucocutaneous forms of the disease in both the Old and New Worlds. Currently, leishmaniases show a wider geographic distribution and increased global incidence of human disease than previously known. Environmental, demographic and human behavioural factors contribute to the changing landscape of leishmaniasis, which includes increasing risk factors for zoonotic cutaneous leishmaniases and new scenarios associated with the zoonotic visceral leishmaniases. The latter consist of the northward spread of Leishmania infantum transmission in Europe and America, the identification of unusual mammal hosts, and the decline of HIV-Leishmania co-infections in southern Europe following the introduction of the highly active antiretroviral therapy. Few advances have been made in the surveillance and control of the zoonotic leishmaniasis, however a number of tools have been developed for the control of the canine reservoir of L. infantum. These include: (i) several canine vaccine candidates, in particular an FML Leishmania enriched fraction showing good clinical protection, has been registered in Brazil for veterinary use; (ii) a number of insecticide-based preparations have been specifically registered for dog protection against sand fly bites. Laboratory and field studies have shown improved efficacy of these preparations for both individual and mass protection. <s> BIB001 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Leishmaniasis <s> First generation candidate vaccines against leishmaniasis, prepared using inactivated whole parasites as their main ingredient, were considered as promising because of their relative ease of production and low cost. These vaccines have been the subject of many investigations over several decades and are the only leishmaniasis vaccine candidates which have undergone phase 3 clinical trial evaluation. Although the studies demonstrated the safety of the vaccines and several studies showed reasonable immunogenicity and some indication of protection, an efficacious prophylactic vaccine is yet to be identified. Despite this overall failure, these trials contributed significantly to increasing knowledge on human leishmaniasis immunology. To provide a collective view, this review discusses the methods and findings of field efficacy trials of first generation leishmaniasis vaccine clinical trials conducted in the Old and New Worlds. <s> BIB002 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Leishmaniasis <s> The need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called "neglected" diseases. The list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. Leishmaniasis, in particular, is a parasitic disease caused by Leishmania spp. transmitted by infected phlebotomine sandfly, which remains a public health concern in developing countries with ca. 12 million people infected and 350 million at risk of infection. Despite several attempts, methods for diagnosis are still noneffective, especially with regard to specificity due to false positives with Chagas' disease caused by Trypanosoma cruzi . Accepted golden standards for detecting leishmaniasis involve isolation of parasites either microscopically, or by culture, and in both methods specimens are obtained by invasive means. Here, we show that efficient distinction between cutaneous leishmaniasis and Chagas' disease can be obtained with a low-cost biosensor system made with nanostructured films containing specific Leishmania amazonensis and T. cruzi antigens and employing impedance spectroscopy as the detection method. This unprecedented selectivity was afforded by antigen-antibody molecular recognition processes inherent in the detection with the immobilized antigens, and by statistically correlating the electrical impedance data, which allowed distinction between real samples that tested positive for Chagas' disease and leishmaniasis. Distinction could be made of blood serum samples containing 10(-5) mg/mL of the antibody solution in a few minutes. The methods used here are generic and can be extended to any type of biosensor, which is important for an effective diagnosis of many other diseases. <s> BIB003 </s> The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review <s> Leishmaniasis <s> BACKGROUND ::: Cutaneous leishmaniasis (CL) has traditionally been underrecognized and underreported. Improved awareness is warranted as the number of cases has increased as a result of increased travel to endemic countries, the HIV/AIDS pandemic, and the larger number of military and contract workers deployed overseas. ::: ::: ::: OBJECTIVE ::: We sought to present a systematic review of evidence from a gamut of research trials on the treatment efficacy of different regimens and aggregate this knowledge for use as a guide for clinical practice decisions. ::: ::: ::: METHODS ::: We performed a comprehensive search of print and electronic sources to identify the accumulated research information on New World CL. ::: ::: ::: RESULTS ::: Topical treatment of New World CL lesions is generally not recommended. Findings support the systemic administration of pentavalent antimonials as first-line treatment. Exception to this is infection with L guyanensis in French Guiana where systemic pentamidine is suggested as first-line treatment. ::: ::: ::: LIMITATIONS ::: The reliability of the findings of this review of research evidence is dependent on the individual quality and potential bias in its component principal trials. There was a conscious attempt to only include evidence derived from randomized controlled studies, with adequate randomization, adequate patient numbers, and complete follow-up information. However, because of the relatively small number of such studies on New World CL, evidence from nonrandomized studies and case series studies was also considered. ::: ::: ::: CONCLUSIONS ::: The pentavalent antimony compounds remain the first-line treatment choice for the treatment of New World CL. Concerns with cost, availability, poor compliance, and systemic toxicity, however, may compel clinicians to opt for alternative treatment modalities. Some advances in the development of an antileishmanial vaccine have been made but none is yet available for clinic use. The increase, over recent years, in the incidence of CL warrants an enhanced effort to increase awareness of the disease, assure timely diagnosis, and implement effective management and treatment strategies. <s> BIB004
Leishmaniasis is a neglected parasitic disease that is caused by the protozoan parasite of the Leishmania genus and spread by the bite of female phlebotomine sand flies BIB003 BIB001 . These flies inject the infective stage of promastigote parasites into human hosts BIB004 . These are then phagocytized by macrophages and transformed into amastigotes which will develop in the infected cells and cause skin lesions that will take months or even years to heal BIB004 or which if left untreated, may be fatal BIB001 . Leishmaniasis is a public health problem that has being reported to have a 500% increasing incidence in the most endemic areas in Africa, Asia, the Middle East, and the Mediterranean BIB004 BIB002 . The established gold standards for Leishmaniasis detection involve the isolation of parasites either microscopically or by culture BIB003 . Existing available diagnostic tests include histology, culture, molecular techniques, Leishmanin skin test and serologic skin tests. Never the less those diagnostic tests have their own limitations particularly due to false positives with Chagas disease and also to a lesser extent to tuberculosis and leprosy BIB004 BIB003 .