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Global Update Indian Pediatrics 2006; 43:925-926 |
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News in Brief |
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The story of malaria and DDT is long and complicated. In the early part of this century, malaria was endemic all over the world including Europe and America. DDT, once hailed as a "miracle" pesticide, was first used widely during World War II to help control everything from typhus to the body lice on U.S. soldiers. Within a few years, the U.S. was free of malaria. In 1955, the WHO endorsed DDT use for a global campaign that within 12 years freed developed countries, along with parts of Asia and Latin America, from risk of infection. In fact the inventor of DDT was even awarded the Nobel Prize. Then complaints from environmentalists started creeping in, including the famous book called Silent Spring by Rachel Carson nearly 40 years ago. When it was used in vast quantities in agriculture, DDT probably harmed reproduction in birds of prey - but this harm subsequently proved reversible. So DDT was removed from the malaria control programme in many developing countries. Concerns regarding the impact of DDT are not unfounded. There is little doubt within the scientific community that the chemical can cause serious environmental harm. However, its precise impact on humans is a subject of debate. Many countries have been put under pressure from international health and environmental agencies to give up DDT or face losing aid grants. In South Africa the government stopped using DDT in 1996 - and since then malaria rates have risen by around 1000 percent, because mosquitoes are becoming resistant to the new generation of pesticides. Other mosquito-borne diseases are also on the rise. Until the 1970s, DDT was used to eradicate the aedes aegypti mosquito from most tropical regions of the Americas. The reinvasion of aedes aegypti since then has brought devastating outbreaks of dengue fever, dengue hemorrhagic fever, and a renewed threat of urban yellow fever. After a reevaluation, WHO is now recommending the use of indoor residual spraying, not only in epidemic areas, but also in areas with constant and high rates of transmission of malaria, which includes all of Africa. "The scientific and programmatic evidence clearly supports this reassessment," said Dr Anarfi Asamoa-Baah, assistant director general at WHO for HIV/AIDS, tuberculosis, and malaria. "Indoor residual spraying is useful to quickly reduce the number of infections caused by malaria carrying mosquitoes. One subject on which there is little debate is DDT’s effectiveness is combating malaria. The Director of WHO’s Global Malaria Programme, Dr Arata Kochi, identified DDT as "one of the best tools we have against malaria. Of the dozens of chemicals WHO has approved, the most effective is DDT," he said. DDT is eight times cheaper than other insecticides, and has a nine month effectiveness. But it must be sprayed in more than 70% of the homes in targeted areas, and nearby regions also must be sprayed to halt mosquitoes there from reintroducing the disease. (The Wall Street Journal Online Sept 15, 2006, BMJ 2006; 333:622, 23 September 2006). The Polio crisis Top health officials in India held a meeting on 21 September in view of the surge of cases with poliomyelitis in India this year. In 2005 only 66 cases had been reported from India. This year atleast 297 cases have already been reported. The epidemic centers around Uttar Pradesh. This year 259 cases have been reported from UP while there were just 29 cases last year. Migrants from UP are spreading the disease not only to other states in India but to neighboring countries which had become polio free last year including Nepal, Bangladesh and 2 African countries – Angola and Namibia. In India Maharashtra, Haryana and Madhya Pradesh have documented cases this year originating from UP. Recently the health minister Anbumani Ramadoss vowed that India will eliminate polio by 2007. Will polio eradication also become another missed chance like malaria or will India rise to the challenge? (Reuters India Sept 14 2006). Gouri Rao Passi,
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