SARS : How Much of a Threat ?
Amit Sen Gupta 18/05/2003
THE SARS (Sudden Acute Respiratory Syndrome) epidemic has struck fear in country governments, practitioners and whole populations across the globe. It has made global headlines and seems to have even overshadowed the human tragedy that is unfolding in Iraq. While we debate on how large a threat SARS is we should not lose sight of the fact that, till the beginning of May, there have been 5,600 reported cases and 372 deaths due to the epidemic. Contrast this with over 2,000 or almost six times the number of deaths taking place in India alone in a single day due to Tuberculosis. Further, in this one day 3,500 people would die of Malaria, most of them children in Africa. How the SARS epidemic will progress is open to speculation, as is the question how large a public health threat SARS will be in the future. What we do know is that it is a new infection, which can be extremely virulent, and can cause deaths in over 5 per cent of those who are infected. While SARS needs to be tackled with caution and speed we should also not lose sight of the fact that influenza epidemics caused by mutant starins (also caused by the same family of viruses called coronavirus that causes SARS) have been known to appear suddenly, cause a large number of deaths, and then lose steam.
How such epidemics appear suddenly is explained by the capacity of viruses to mutate that is to change their genetic characteristics. The human body, when infected by a certain virus, fights the virus by producing what are called antibodies against the infection. These antibodies remain in the system and confer partial or total immunity against subsequent infections by the same virus. Thus, if a virus has been around for a long time, most of the people in the community have some form of immunity against the virus – like immunity against the common cold. So even if infections occur, they are not very serious and such viruses do not cause epidemics.
This phenomenon, where most people in a community have immunity to a certain disease-causing germ is called "herd immunity". In the case of a new mutant virus, such herd immunity does not exist. As a result the disease is able to spread and assume epidemic proportions. Over time, as more people get infected, herd immunity develops in the community and the epidemic dies down and the disease expresses itself as isolated cases.
WHAT IS SARS?
Lets us now turn to what we know about the epidemic. In November, 2002, an outbreak of atypical pneumonia (i.e. pneumonia that is not caused by known causative organisms and has atypical features) was reported in Guangdong province in southern China. In late February, 2003, such cases were first reported outside China, in Hanoi, Vietnam. In March, 2003, a WHO officer Carlo Urbani first drew global attention to the outbreak after examining cases in Vietnam and coined the name sudden acute respiratory syndrome or SARS. Carlo Urbani himself died of the infection within 3 weeks of his drawing the world's attention to the epidemic.
We know now that the illness caused by SARS usually begins with a fever, sometimes associated with chills or other symptoms, including headache, general feeling of discomfort and body aches. After 2 to 7 days, SARS patients may develop a dry cough that might be accompanied by or progress to the point where insufficient oxygen is getting to the blood. In 10-20 per cent of cases, patients will require mechanical ventilation with a machine. The incubation period (i.e. the period between the time of infection and the manifestation of symptoms) is typically 2 to 7 days though isolated reports have suggested an incubation period as long as 10 days. SARS is spread by close person-to-person contact including through touching the skin of other people or objects that are contaminated with infectious droplets and then touching one's eye(s), nose, or mouth. This can happen when someone who is sick with SARS coughs or sneezes droplets onto themselves, other people, or nearby surfaces. People are most likely to be infectious (i.e. capable of infecting others) when they have symptoms, such as fever or cough. However, it is not known how long before or after their symptoms begin that patients with SARS might be able to transmit the disease to others.
We also know now that SARS is caused by a previously unrecognised coronavirus. Coronaviruses are a group of viruses that have a halo or crown-like (corona) appearance when viewed under a microscope. These viruses are a common cause of mild to moderate upper-respiratory illness in humans and are associated with respiratory, gastrointestinal, liver and neurological disease in animals. These viruses do not last a long time outside the body – generally not more than three hours.
Several new laboratory tests can be used to detect the SARS-associated coronavirus (SARS-CoV). These include the detection of antibodies to the virus in the patient's blood, detection of DNA of the virus in samples taken from the patient's blood, sputum, etc and culture of the virus. All these tests are expensive and they are not always conclusive. So the diagnosis of SARS depends on a combination of such tests, identifiable symptoms in the patient, and a history of contact with someone known to have SARS.
GLOBALISATION AND SARS
The SARS epidemic and its subsequent handling, curiously, points to both the threats posed by globalisation and its potential advantages. Globalisation leads to transnationalisation of public health risks. A major effect, in recent years, has been the resurgence of communicable diseases across the globe – the most recent expression being SARS. Every phase of human civilisation that has seen a rapid expansion in exchange of populations across national borders has been characterised by a spread of communicable diseases. The early settlers in America, who came from Europe, carried with them small pox and measles that decimated the indigenous population of Native Americans. Plague travelled to Europe from the orient in the middle ages, often killing more than a quarter of the population of cities in Europe (like the plague epidemic in London in the fifteenth century). This is a natural consequence of exposure to local populations to exotic diseases, to which they have little or no natural immunity.
Today, what incubates in a tropical rainforest can emerge in a temperate suburb in affluent Europe, and likewise what festers in a metropolitan ghetto of the global North can emerge in a sleepy village in Asia – within weeks or days. The SARS epidemic, for example, which started from China, may have festered in its place of origin and run out its course if the rapid exchange of people across countries had not taken place. When such rapid spread takes place, those that are most badly affected are the poorest that live in developing countries, because their immunity is compromised by under nutrition and because they have little or no access to health facilities. We must not forget the backdrop-in the last twenty years IMF/WB mandated policies have devastated public health facilities in virtually every developing country. It is a moot point whether this epidemic would have reached current proportions if China had not chosen to drastically privatise its health facilities in the last decade. In fact China's privatisation of the Health Sector, today, is almost as widespread as in India.
In the 1960s scientists were exulting over the possible conquest to be achieved over communicable diseases. Forty years later a whole new scenario is unfolding. AIDS is its most acute manifestation. We also have resurgence of cholera, yellow fever and malaria in Sub-Saharan Africa, malaria and dengue in South America, multi-drug resistant TB, plague, dengue and malaria in India. We also see the emergence of exotic viral diseases, like those caused by the Ebola and the Hanta virus and now SARS. We thus have a resurgence of "old diseases" compounded by the emergence of new ones. Globalisation that forces migration of labour across large distances, that has spawned a huge "market" on commercial sex, that has changed the environment and helped produce "freak" microbes, has contributed enormously to the resurgence. We talked of the random mutations that produce new viruses. The pace of such mutations is increasing due to environmental degradation as microbes are exposed to hitherto unknown conditions.
RESPONSE OF THE SCIENTIFIC COMMUNITY
The response of the global scientific community to the SARS epidemic also points to the potential that true globalisation has in tackling human misery. In 2001, the World Health Organization (WHO) established an epidemic alert and response programme to enable coordinated responses to emerging epidemics, and in early March of this year, the WHO used this program to start an international collaborative investigation into the nature of SARS. The results of this international collaboration have been the astoundingly rapid identification of a likely etiologic agent (i.e. identification of the virus that causes SARS) and the dissemination of clinical information with unprecedented speed. The information already gleaned about the SARS virus will help in the development of an accurate diagnostic test and antiviral drugs. A speedy test could be available soon, according to the WHO, which coordinated the work of 13 laboratories around the world. "The pace of SARS research has been outstanding," said Dr David Heymann, WHO's executive director of communicable diseases. The work of the laboratories and WHO has been dedicated to Dr Carlo Urbani, the WHO scientist who first identified the virus in Hanoi and subsequently died of SARS.
The speedy response to SARS shows what can be achieved by global scientific collaboration. It also shows that such collaboration is manifest today only when the developed world sees a threat to its own population. The potential exists, but under imperialist globalisation this potential is fettered by the narrow interests of developed countries. Why else have we not seen such a high degree of collaboration when it comes to diseases that continue to plague the developing countries – like Malaria or Tuberculosis.
COMIC SPECTACLE IN INDIA
The handling of the threat of a SARS epidemic in the country has been typically inept. We see a comic spectacle unfold before us as the Indian government blunders along. First there was a flurry of "positive" SARS cases reported from across the country. We were told that these cases had been "confirmed" by the National Institute of Virology. Then, suddenly, Mrs Sushma Swaraj gleefully announced that we had been mistaken all this while because the WHO now says that none of these "confirmed" cases are actually cases of SARS. Did we require the WHO to tell us this? The WHO has no surveillance, treatment or diagnostic facilities in the country. It relies on data provided by the Indian health authorities. How is it that the same data told two entirely different stories? It is obvious that the handling of the suspected cases ignored standard practices, which any competent medical practitioner should be aware of. If the National Institute of Virology (NIV) had "confirmed" cases, how did they suddenly turn out to be SARS free after the WHO declared them to be so? It is clear that what the NIV had declared as confirmed were not confirmed cases. The NIV had not followed standard protocol – now available globally and even accessible to anyone who has access to the internet – while labelling cases to be SARS positive.
If we can misdiagnose patients as "SARS positive" we are equally capable of misdiagnosing patients as "SARS negative". In other words, we are by no means geared to tackle the SARS epidemic if and when it reaches India. Epidemic control is not achieved by holding press conferences and stationing masked doctors at airports. Epidemic control requires a high level of preparedness of the public health infrastructure. This infrastructure has been systematically dismantled in the last 12 years of economic liberalisation. The government has taken the lead in delegitimising this infrastructure and today very few people have faith in the public health system. In such a situation do not expect SARS cases to be detected and treated by the public health system. We can only hope that the doddering edifice of our public health infrastructure is not called upon to deal with a real SARS epidemic. If that happens, it is doomed to fail.
Categories Public Health Post navigation
The Electricity Bill 2003 – From Crisis To Disaster
Telecom, Power And GATS