Worm may be key to curbing HIV
APARASITIC worm which affected millions of the world’s poorest people might hold the key to cutting the spread of HIV, researchers said before a conference on the issue in London.
Schistosomiasis affects at least 250 million people. It is caused by parasitic worms, picked up in infested waters, which drill through people’s skin and lay eggs in their bodies.
If the worms laid eggs in a woman’s genital areas, including the vagina and cervix, they could cause lesions which made women more vulnerable to HIV, experts in the tropical disease said.
Women were three times more likely to be infected with HIV if they had female genital schistosomiasis, studies carried out in Zimbabwe, Tanzania, South Africa and Mozambique had found.
“It’s going completely under the radar,” Marianne Comparet, director of the London International Society for Neglected Tropical Diseases, said. “Treating one could really impact on the other.”
Men with the worms in their genitals showed a sharp increase in the amount of HIV virus in their semen, researchers said.
The treatment for schistosomiasis wass cheap – the drug had been donated for years to the World Health Organisation, so this could be a relatively easy way to help cut the spread of HIV, experts said.
“In the same way that circumcision came out as something that really changed the way people approached HIV transmission, this could be the next big thing in controlling HIV transmission,” Comparet said.
Circumcision has been found to cut the spread of HIV among heterosexuals and is recommended by the WHO as a means of prevention.
Nearly 37 million people live with HIV, most in Africa. It is not known how many people have female genital schistosomiasis, but estimates range from 20 million to 80 million, most again in Africa.
Undiagnosed
According to the WHO, most cases of female genital schistosomiasis are undiagnosed and few medical staff are aware of its existence.
It gets no mention in medical textbooks or nursing curricula in any of the countries where schistosomiasis is endemic.
The UN agency recommends the regular treatment of young girls through mass drug administration in schools and communities to prevent female genital schistosomiasis from developing.
Treatment kills adult worms but cannot reverse damage to organs and tissues.
“It starts early, and then when you are a young woman, without any treatment it becomes really serious, and when women become sexually active they are very vulnerable to HIV,” said Jutta Reinhard-Rupp at Merck Serono.
Merck Serono produces praziquantel, the only treatment available for schistosomiasis. Female genital schistosomiasis can also cause infertility and ectopic pregnancies.
The link between female genital schistosomiasis and HIV was difficult to prove in a clinical study because it was not possible to have a control group that was left untreated, Reinhard-Rupp said.
Another possible link is between schistosomiasis in men’s genitals and the spread of the HIV. Men with both diseases had an HIV viral load in their semen 10 times bigger than that of men without schistosomiasis, according to initial findings from a smallscale study carried out in Zimbabwe last year.
After treatment for schistosomiasis, the viral load returned to normal levels.
The findings will be made public at the International Society for Neglected Tropical Diseases’s Coinfections conference in London today.
Many countries in southern Africa were seriously affected by both schistosomiasis and HIV, Peter Leutscher, a professor at Aarhus University Hospital, who helped carry out the research, said in a telephone interview.
“This overlap of HIV and schistosomiasis is really striking. It’s a neglected risk factor in the fight against HIV,” he said. Leutscher wants genital schistosomiasis to be included alongside other risks involved in the spread of HIV. – Reuters