Herpes zoster (the virus which causes shingles), occurs with greater frequency in HIV-positive women than HIV-negative women, even in the HAART era, according to a US study published in the December 15th 2004 edition of the Journal of Acquired Immune Deficiency Syndromes. The American investigators also established that, although herpes zoster was most common amongst women with low CD4 cell counts, it still occurred with increased frequency in HIV-positive women, even when they had a high CD4 cell count.
Herpes zoster is an opportunistic infection that occurred in HIV-positive individuals with increased frequency, regardless of CD4 cell count, in the pre-HAART era. The impact of HAART on the epidemiology of herpes zoster is not well understood, with some studies suggesting that immune reconstitution after the commencement of anti-HIV treatment leads to an increased incidence of herpes zoster.
Study design
Investigators from the US Women’s Interagency HIV Cohort Study (WIHS) wished to describe the long-term epidemiology of herpes zoster in HIV-positive women in the HAART era. Data were collected from 1832 HIV-positive and 489 HIV-negative women at six-monthly visits. At each visit study participants were asked to say if they had been diagnosed with herpes zoster (shingles) since their last visit. HIV-positive women were also asked to report if they had been prescribed HAART.
Demographic data were obtained for all individuals, and both HIV-positive and HIV-negative women provided blood samples for the measurement of CD4 and CD8 cell count. HIV-positive women also provided blood for HIV viral load measurement.
Investigators calculated the probability of herpes zoster for both HIV-positive and HIV-negative women and then adjusted this according to CD4 and CD8 cell count, HIV viral load and the use of HAART.
Results
Just over 30% of the HIV-positive women enrolled to the study reported an AIDS-defining event prior to baseline, and an additional 26% of women developed AIDS during follow-up.
Over two-thirds (68%) of HIV-positive women started HAART during the study period, the median CD4 cell count at the study visit before HAART initiation being 270 cells/mm3, median CD8 cell count 771 cells/mm3 and median viral load 10,000 copies/ml.
At baseline significantly more HIV-positive women than HIV-negative women reported a history of herpes zoster (6% versus 0.6%). During follow-up, 337 HIV-positive women (18%) reported at least one episode of herpes zoster compared to only seven (1%) HIV-negative women.
Data were available for 334 of the HIV-positive women reporting herpes zoster. The women has a median age of 40 years, 61% were white and 39% were African American, the CD4 cell count closest to the reporting of herpes zoster was 262 cells/mm3 and median CD8 cell count was 818 cells/mm3.
Amongst HIV-positive women the incidence of herpes zoster varied by CD4 cell count and was highest amongst women with the lowest CD4 cell count. The probability of reporting herpes zoster since the last study visit was 1.2% for women with a CD4 cell count above 750 cells/mm3, 1.7% for women with a CD4 cell count between 749 – 750 cells/mm3, 2.07% for women with a CD4 cell count between 350 – 499 cell/mm3, 3.2% for those with a CD4 cell count between 200 – 349 cells/mm3, and 4.2% for individuals whose CD4 cell count was below 200 cells/mm3.
At all CD4 cell counts, the probability of reporting herpes zoster was significantly greater amongst HIV-positive women than HIV-negative women (0.14%).
In multivariate analysis CD4 cell count was significantly associated with herpes zoster (p
“We found a strong relationship between herpes zoster incidence and the degree of immunosuppression” write the investigators, who add, “even HIV-infected women at the highest CD4 cell count stratum were at a nearly 9-fold higher risk of developing zoster compared to HIV-negative women.”
The investigators note that they did not observe the increased incidence in herpes zoster amongst individuals who recently started HAART seen in earlier studies.
“These available data suggest that herpes zoster occurs at all stages of HIV disease but at higher rates with more advanced immunosupression. Unlike many other opportunistic infections, herpes zoster is likely to remain a common complication of HIV disease even in those who are treated with HAART”, conclude the investigators.
Glesby MJ et al. Herpes zoster in women with and at risk for HIV. J Acquir Immune Defic Syndr 37: 1604 – 1609, 2004.