People being infected with more than one strain of HIV is becoming increasingly common, the South African Aids conference in Durban heard on Tuesday.
A paper delivered on behalf of the Institute of Molecular Medicine and Infectious Diseases in Durban said that those infected with more than one type of HIV tended to become ill with Aids sooner.
There are two main types of HIV (HIV1 and HIV2) with 11 main subtypes or clades of HIV. However, there are increasing numbers of mutations.
Aids is not like flu — each time a person is exposed to HIV they are reinfected, which is why HIV-positive people have to use condoms, particularly if having sex with another HIV-positive person.
In a study conducted by the institute among sex workers and their clients in Kwazulu-Natal, 60% of the sex workers were infected and 56% of their clients.
On average less than a fifth of clients or sex workers used condoms. And the average sex worker had 15 partners a week.
Twelve percent of those studied had more than one subtype of HIV circulating in their body, and all of that group had mutant or recombinant HIV and had significantly higher viral loads — which means life expectancy is shorter — than those infected with only one type of HIV.
”Dual infection can be a consequence of either co-transmission (infection with two strains at, or close to, seroconversion — the time when a person becomes HIV-positive) or superinfection (subsequent HIV1 infection of an already infected individual) with the same subtype or different subtypes,” the report noted.
It observed that dual infection can result in recombination (mutation), ”which, in primates has been shown to occur within 15 days of co-infection.
”The high numbers of unique circulating recombinant forms suggest that dual infection and recombination occur frequently.”
What this means is that the body develops a unique form of HIV, or carries more than one subtype of HIV.
It is difficult to treat a person with more than one type of the virus inside their body.
The challenges of more than one subtype or clade of HIV is what is obstructing the development of an effective vaccine.
It is considered unlikely, for example, that a vaccine developed for subtype B, which predominates in the USA, as an example, would be effective in southern Africa where subtype or clade C predominates. – Sapa