Durban - Mosquitoes are becoming more resistant to the chemical poisons commonly used to control malaria, raising fears that another 120 000 people could die from the disease every year.
This was the warning from Professor Hillary Ranson of the Liverpool School of Tropical Medicine at the opening of the sixth Pan-African Malaria Conference at the Durban ICCon Monday.
Ranson said global progress in controlling malaria was at risk of being eroded and the impact of insecticide resistance could be “devastating”.
The bad news was that no new insecticides to combat malaria would be available before the end of the decade.
“Populations of mosquitoes resistant to all available insecticide (including DDT) are being increasingly reported,” she told the world’s largest gathering of malaria experts.
In the absence of new anti-malaria insecticides, governments in Africa and other malaria belts should step up efforts to monitor insecticide resistance and to rotate the variety of insecticides used to reduce the spread of the disease.
Malaria affects about 219 million people every year, and kills up to 660 000.
According to Dr Robert Newman of the World Health Organisation, about 70 percent of malaria deaths every year are in Africa (with deaths in Nigeria and the Democratic Republic of Congo making up nearly 40 percent of global malaria deaths).
Newman suggests that one of the biggest threats is the lack of funding, with several case studies showing that malaria often re-appears where disease control measures are not sustained.
Nevertheless, a new range of eight new chemical compounds is being tested, and three could be developed and lead to the release of new malaria insecticides by 2020.
The International Vector Control Consortium announced on Monday that it was hoping to choose three of the eight candidate anti-malaria compounds and bring some to market, possibly in 2020.
The consortium, which has received funding from the Bill and Melinda Gates Foundation, works closely with chemical giants Dow, Bayer, DuPont, Syngenta and Sumitomo.
Consortium chief executive Nick Hamon said they were committed to providing products at a price that would be affordable in Africa, and to meeting environmental and regulatory processes.
Later, a group of South African researchers will present the latest malaria statistics and surveillance projects in this country.
According to a draft summary, there has been a reduction of more than 90 percent in malaria cases since the 1999/2000 epidemic, when 63 100 cases were reported in South Africa.
KwaZulu-Natal had the highest number of cases during that epidemic when more than 41 000 cases were reported. This figure had dropped to just 476 cases last year.
In Botswana, the cases have dropped by more than 97 percent over the past decade.
Later this week, malaria experts from the US and Switzerland will discuss progress in the development of a vaccine.
Christopher Plowe of the University of Maryland School of Medicine noted in a preview paper that vaccines have been developed to eradicate smallpox and to eliminate polio and measles – yet a malaria vaccine remains in the early stages of development. - The Mercury