Plan to breed mozzies that fire blanks

05 December 2013 - 02:01 By KATHARINE CHILD

A factory that will breed malaria-carrying mosquitoes will be built in Johannesburg next year.

Researchers hope to sterilise up to a million male mosquitoes with a zap of radiation at the breeding centre at the National Institute for Communicable Diseases, Sandringham.

The males will be released to mate with female mosquitoes, the carriers of malaria.

Coetzee said most species of mosquitoes mate only once. So, if a female mosquito mates with a sterilised male, she will never have offspring.

This is one of the projects launched under the auspices of the Wits Malaria Institute last week.

The institute is co-headed by professor of medical entomology Maureen Coetzee, who has a mosquito species named after her, the Coetzeemyia, to honour her contribution to science.

If the project succeeds, the population of malaria-carrying mosquitoes will decrease. The programme is to start in 2015.

Coetzee said researchers are targeting only the four species of mosquito that carry malaria in Africa. There are about 150 species of mosquito in all.

In another project run by the institute, the head of the Wits department of pharmacology, Professor Robyn van Zyl, is testing plants used by traditional healers to find a cure for malaria.

One of the current treatments for malaria, artemisinin, is derived from a Chinese traditional medicine. It was discovered in the 1970s after Chinese researchers tested 5000 plant extracts.

Van Zyl said she had tested 308 plants in the past eight years and 570 chemicals from the plants. Some of the chemicals tested killed mosquitoes in a test tube. Further tests are being done.

Van Zyl said she sourced the plants from traditional healers who used them to treat symptoms of malaria, such as fever.

"Western medicine wants to isolate one compound that can be taken orally. Traditional medicine might use four plants to treat one disease. It's a very different system of therapy," she said.

Malaria kills about 655000 people every year. There is currently no vaccine available that offers full protection.

The incidence of malaria in South Africa dropped from 60000 in 2000 to less than 7000 last year .