Does HIV Reinfection Increase My Risk of Illness?

The Association Between Superinfection and Disease Progression

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Question: Does HIV reinfection increase my risk of illness?

Answer: Many of the consequences of HIV reinfection, also known as superinfection, are well documented. They include such concerns as the acquisition of a drug-resistant virus, which can decrease the effectiveness of current or future drug therapies, as well as co-infections with any number of sexually transmitted diseases (STDs).  Both of these events have the potential to cause illness, either in the short or long term.

But does HIV reinfection, in and of itself, correlate to faster disease progression as measured by either

  • a significant increase in viral load;
  • a significant decline in CD4 count, or;
  • a significant increase in adverse clinical events?

The answer is both yes and no.

In October 2014, researchers at the Fred Hutchison Cancer Research Center conducted a prospective analysis of 146 female sex workers in Kenya, 21 of whom were confirmed to have been reinfected with a second HIV variant within the 15-year study period (1993 to 2008). It was largest cohort study to date into the impact of HIV superinfection, well designed to track disease progression among women roughly infected at the same time with similar baseline serologies.

When comparing the two groups, the superinfected women were seen to have a slightly higher rate of viral load increase over women who were singly infected (0.0009 log10/month), but no significant difference in the rate of CD4 decline.

Similarly, while 91 women in the study had experienced a clinical event (defined as having a CD4 count under 200 cells/mL; an illness requiring antiretroviral intervention; or death), the researchers could find no significant association between superinfection and the incidence of such events.

Computer modelling ultimately forecast that, over a five-year period, the superinfected women would have CD4 counts only 27 cells/mL lower than their singly infected counterparts, with marginally elevated viral loads (0.24 log10).

What Does All of This Mean?

While the small sample size limits the conclusions one can draw from the research, the lack of association between superinfection and disease progression is not insignificant. Common knowledge has often dictated that superinfection is associated poorer clinical outcomes, and research has increasingly shown that this is not the case.

In fact, some research has shown just the opposite, with one Swedish study suggesting that individuals infected with both HIV-1 and HIV-2 may actually have slower disease progression. As controversial as that may sound, if true, such findings could have significant impact on the development of HIV-1 vaccines and therapeutics.

None of this, of course, suggests that HIV reinfection should be of any less concern from an individual standpoint. Transmitted drug resistance remains of particular concern, especially if an HIV-positive partner is either not on therapy or unable to maintain an undetectable viral load while on therapy.

If you believe yourself to have been reinfected, advise your doctor so that any changes in CD4/viral load can be monitored and appropriate STD screenings be provided.

In the event of viral rebound, genetic resistance testing is recommended.

Sources:

Ronen, K.; Richardson, B.; Graham, S.; et al. "HIV-1 superinfection is associated with an accelerated viral load increase but has a limited impact on disease progression." AIDS. September 24, 2014; 28(15):2281-2286.

Esbjörnsson, J.; Månsson, F.; Kvist, A.; et al. "Inhibition of HIV-1 disease progression by contemporaneous HIV-2 infection." New England Journal of Medicine. July 19, 2012; 367(3):224-232.

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