Herpes simplex virus type 2 infection is important in the HIV epidemic and may contribute to increased HIV transmission. We evaluated the effect of suppressive acyclovir therapy on cervicovaginal HIV-1 shedding.
HIV-1- and herpes simplex virus type 2-coinfected women aged 18-49 years with CD4 counts >200 cells/microL were enrolled in a randomized crossover trial of suppressive acyclovir therapy (NCT00362596, http://www.clinicaltrials.gov). For each woman, monthly plasma and weekly cervicovaginal lavage specimens were collected; the mean of the monthly median cervicovaginal lavage HIV-1 viral load and plasma HIV-1 viral load was compared.
Sixty-seven women were enrolled; at baseline, median CD4 count was 366 cells/microL, and median HIV-1 plasma viral load was 4.6 log10 copies/mL. The mean cervicovaginal lavage HIV-1 viral load was 1.9 (SD 0.8) log10 copies/mL during the acyclovir month and 2.2 (SD 0.7) log10 copies/mL during the placebo month (P < 0.0001); the mean decrease in HIV was 0.3 log10 copies/mL. The mean plasma HIV viral load during the acyclovir month (3.78 log10 copies/mL) was reduced compared with the placebo month (4.26 log10 copies/mL, P < 0.001).
Acyclovir reduced HIV genital shedding and plasma viral load among HIV-1- and herpes simplex virus type 2-coinfected women. Further data from clinical trials will examine the effect of suppressive therapy on HIV transmission.
[Show abstract][Hide abstract] ABSTRACT: To assess the long-term effects of population-level HSV-2 infection on HIV incidence.
Data from a population-based cohort in south-western Uganda were used to estimate HIV incidence from 1990 to 2007. Stored blood samples were tested for HSV-2, and the impact of HSV-2 prevalence and incidence on HIV incidence was estimated by calculating population attributable fractions (PAFs). The association between population-level annual HIV incidence and annual HSV-2 incidence/prevalence was analysed using linear regression.
HIV incidence declined over time among men, from 8.72/1000 person-years (pyr) in 1990 to 4.85/1000 pyr in 2007 (P-trend <0.001). In contrast, there was no decline in HIV incidence among women (4.86/1000 pyr in 1990 to 6.74/1000 pyr in 2007, P-trend = 0.18). PAFs of incident HIV attributable to HSV-2 were high (60% in males; 70% in females). There was no evidence of an association between long-term trends in HIV incidence and HSV-2 prevalence or incidence.
Assuming a causal relationship, a substantial proportion of new HIV infections in this population are attributable to HSV-2. The study did not find an effect of HSV-2 prevalence/incidence on trends in HIV incidence. HIV incidence did not vary much during the study period. This may partly explain the lack of association.
Tropical Medicine & International Health 10/2013; 18(10):1257-66. DOI:10.1111/tmi.12176 · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Herpes simplex virus type 2 (HSV-2) infection increases acquisition and transmission of HIV, but the results of trials measuring the impact of HSV-2 therapy on HIV genital shedding and HIV acquisition are mixed, and the potential impact of HSV-2 therapy on the incidence of HIV at the population level is unknown.
The effects of episodic and suppressive HSV-2 therapy were simulated using the individual-level model STDSIM fitted to data from Cotonou, Benin (relatively low HIV prevalence) and Kisumu, Kenya (high HIV prevalence). Clinician- and patient-initiated episodic therapy, started when symptomatic, were assumed to reduce ulcer duration. Suppressive therapy, given regardless of symptoms, was also assumed to reduce ulcer frequency and HSV-2 infectiousness.
Clinician-initiated episodic therapy in the general population had almost no effect on the incidence of HIV. The impact of patient-initiated therapy was higher because of earlier treatment initiation, but still low (<5%) unless symptom recognition and treatment-seeking behaviour were very high. Suppressive therapy given to female sex workers (FSW) in Kisumu had little effect on population HIV incidence. In Cotonou, suppressive therapy in FSW with high coverage and long duration reduced population HIV incidence by >20% in the long term. Impact was increased in both cities by also treating a proportion of their clients. Long-term suppressive therapy with high coverage in the general population could reduce HIV incidence by more than 30%.
These results show that HSV-2 therapy could potentially have a population-level impact on the incidence of HIV, especially in more concentrated epidemics. However, a substantial impact requires high coverage and long duration therapy, or very high symptom recognition and treatment-seeking behaviour.
[Show abstract][Hide abstract] ABSTRACT: For most viruses, there is a need for antimicrobials that target unique viral molecular properties. Acyclovir (ACV) is one such drug. It is activated into a human herpesvirus (HHV) DNA polymerase inhibitor exclusively by HHV kinases and, thus, does not suppress other viruses. Here, we show that ACV suppresses HIV-1 in HHV-coinfected human tissues, but not in HHV-free tissue or cell cultures. However, addition of HHV-6-infected cells renders these cultures sensitive to anti-HIV ACV activity. We hypothesized that such HIV suppression requires ACV phosphorylation by HHV kinases. Indeed, an ACV monophosphorylated prodrug bypasses the HHV requirement for HIV suppression. Furthermore, phosphorylated ACV directly inhibits HIV-1 reverse transcriptase (RT), terminating DNA chain elongation, and can trap RT at the termination site. These data suggest that ACV anti-HIV-1 activity may contribute to the response of HIV/HHV-coinfected patients to ACV treatment and could guide strategies for the development of new HIV-1 RT inhibitors.
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