Monkey HIV drug-resistant within days, dampening hopes for Aids cure

The monkey version of HIV can take refuge from anti-Aids drugs within days of entering the body, a study said, dampening hopes for a human cure.

If the same holds true for human beings, treatment may have to start "extremely early" after a person is infected with the virus that causes Aids, according to research published in the journal Nature.

The findings came just days after news that an American baby thought to have been cleared of HIV through a potent dose of antivirals given 30 hours after birth and continued for 18 months, tested positive for the virus after two drug-free years.

"The unfortunate clinical findings of viral rebound in the Mississippi baby appear to be concordant with the monkey data," said study co-author Dan Barouch of the Beth Israel Deaconess Medical Centre in Boston, Massachusetts.

"These data certainly raise important challenges for HIV eradication efforts."

A key challenge for curing HIV infection is the presence of viral reservoirs - infected immune cells in which virus DNA can lie dormant for years.

In the vast majority of people, the virus starts proliferating as soon as treatment is stopped, which means the drugs have to be taken for life.

The new study found that in rhesus monkeys infected with simian HIV, or SIV, the reservoir was established "strikingly early".