HIV subtypes on the rise in the US

Scientists are warning that the growing number of immigrants heading to the US could cause a significant rise in the various subtypes of the HIV virus in the country.

The US Centres for Disease Control and Prevention (US-CDPC) estimates that the prevalence of HIV subtypes in the country is currently at five per cent.

It also claims that strains of the virus which are normally seen in Africa, Asia and Latin America are increasingly being detected in the US.

Scientists are concerned that the various subtypes of the HIV virus could elude detection as most tests for the disease only search for the common HIV subtype B.

A recent study by researchers at the University of Columbia, published in the New England Journal of Medicine, said: "The continuing spread of HIV is causing a world pandemic of unprecedented genetic and geographic complexity."

The US-CDPC estimates that at the end of 2003, the latest year for which figures are available, over one million people were infected with HIV in the country.