Tuesday, February 3, 2009

Ode to a Mosquito

Amitabh Ghosh’s book, The Calcutta Chromosome reminds us in India of the country’s long association with Malaria. On 20 August 1897, in Secunderabad, Sir Ronald Ross, an Army doctor with the Indian medical service, in the course of experiments conducted in Kolkata’s Presidency General Hospital(PG Hospital to you and me !) and Secundrabad ,he found the malaria parasite and went on to prove the role of Anopheles mosquitoes in the transmission of malaria parasites in humans. Despite India’s historical association with malaria, (Sir Ronald Ross later went on to win the Nobel Prize for medicine), India’s tryst with malaria has far from ended. Malaria is endemic in all of India except at elevations above 1800 meters and in some coastal areas.

Two-thirds of all cases are reported from Gujarat, Karnatka, Madhya Pradesh, Orissa, Uttar Pradesh and Punjab.

- Orissa, Assam & Maharashtra account for 80 percent of all _plasmodium falciparum_ malaria which is potentially fatal

- Malaria is reported nationwide, including Delhi and Bombay; but not in Himachal Pradesh, Jammu & Sikkim, isolated coastal areas around Western Ghats, Andaman and Nicobar Islands. Transmission begins with the onset of the Monsoon season in mid-June.

- _P. vivax_ predominates until August, with _P. falciparum_ infection rising to a peak in September.

At the time of independence in 1947, there were an estimated 75 million malaria cases and 0.8 million deaths annually. National Malaria Eradication Programme was launched in 1958, based mainly on widespread DDT spraying. The number of reported cases was reduced to about 100,000 by 1965-66. After global eradication was called off in 1969, funding decreased steeply, and by 1976 reported cases peaked at 6.47 million. Malaria was nearly eradicated from India during the early 1960’s.

Malaria and poverty are intimately connected. Judged as both a root cause and a consequence of poverty, malaria is most intractable for the poorest countries in the world and it affects the health and economic growth of nations. Its epidemiology and its control are complicated by poverty as it is a dominant disease in poverty stricken societies. The economic loss due to the loss of man-days due to malaria was estimated to be at Rs. 10,000 million per year in 1935. The annual incidence of malaria was estimated at around 75 million cases in 1953 with about 8 lakhs deaths annually

The fact that malaria is fundamentally a disease of the poor has meant that malaria has received comparatively scant attention in recent times. By the early 1990s, worldwide funding on malaria research had practically dried up.

While older vaccines for diseases like mumps and measles are more widely and cheaply available, vaccines for malaria, tuberculosis and AIDS, the developing world's top killers, are so risky and costly to bring to market that little progress has been made in these areas. The malaria vaccine about to be tested has been under development for two decades -- and at one point it was nearly abandoned. Till the millennium development goals, once again put malaria on the world map, the disease was literally out of sight of the world. In recent years, the Bill and Melinda Gates foundation has been the most high profile philanthropist involved in malaria control. The Gates couple began handing out research grants for malaria in late 1998, even before they had formalized the structure of their foundation. Since then, they have poured more than $860 million into just malaria research and another $650 million into the Global Fund for fighting AIDS, tuberculosis and malaria.

The latest review of the national programme was carried out in early 2007 as an international collaborative Joint Monitoring Mission following a sample survey in households and health facilities of malaria control implementation carried out by the National Institute of Malaria Research, New Delhi. An interesting finding of the review was that the malaria burden in the country is unknown despite an elaborate surveillance system. The number of officially reported malaria deaths is about 1000 per year, but a study of medically certified deaths in the country suggest that the real figure is at least 40 times as high.

A hundred and ten years and more after Ronald Ross made his breakthrough discovery of the malarial parasite on Indian soil, there is still a lot that remains to be done in reducing malaria deaths and one can only hope that malaria will be the next disease selected for eradication after the long suffering polio.

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