Unicef goodwill ambassador Angelique Kidjo with an HIV-positive child in Nairobi. (AFP file picture)

New Delhi, Dec. 18: Scientists have cautioned that circumcision as a “shield” against HIV in men is imperfect despite mounting evidence and it’s unclear how widely it would be accepted across different cultures.

Preliminary results from the latest study in Kenya — released by US researchers earlier this week — indicates that medical circumcision of men reduces their risk of acquiring HIV during heterosexual intercourse by 53 per cent.

Doctors found that 47 among 1,391 uncircumcised men in the study had picked up HIV, while only 22 among 1,391 circumcised men became HIV positive. “Circumcision is now a proven, effective prevention strategy to reduce HIV infections in men,” said Robert Bailey, the principal investigator of the study at the University of Illinois, Chicago.

Last October, French and South African researchers had also found that circumcision reduced the rate of new female-to-male HIV infection by about 60 per cent. Experts monitoring the South African trial had found the protective effect to be so large that they stopped the trial and offered uncircumcised men circumcision as a preventive measure.

Earlier this week, the US scientists also halted the Kenyan trial and offered men in the study circumcision as a risk-reducing intervention.

But Indian medical researchers have cautioned that a question mark hangs over the acceptability of such preventive measures in different cultures.

“We would need to do exploratory studies to evaluate the likely public acceptance of such a preventive intervention,” said Sanjay Mehendale, a senior scientist at the National AIDS Research Institute (NARI) in Pune.

A study by Mehendale and his colleagues at NARI and the US two years ago had suggested that circumcised men could be six times less likely than uncircumcised men to acquire HIV infection.

But the Pune study merely observed rates of HIV in circumcised and uncircumcised men over many months. In the South African and Kenyan studies, circumcision was offered to men as a risk-reducing intervention.

The reduced risk from circumcision is attributed to the removal of thin tissue in the foreskin — a likely target for HIV activity because it has a high density of cells easily accessible by HIV.

“We’ve known for years that the risk of human papilloma virus infection is much lower among women whose partners are circumcised,” said Bhudev Das, director of the Institute of Cytology and Preventive Oncology near New Delhi. The human papilloma virus (HPV) can lead to cervical cancer.

“But I think it would be unrealistic to expect men here to go in for circumcision to reduce the risk of HPV for their partners or even to reduce the risk of HIV to themselves,” Das said.

Researchers also point out circumcision does not offer 100 per cent protection. “It’s not a foolproof strategy against either the human papilloma virus or HIV,” said Das.