Publications (5)21.68 Total impact
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Article: Changes in Seroadaptive Practices from before to after Diagnosis of Recent HIV Infection among Men Who Have Sex with Men.
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ABSTRACT: We assessed changes in sexual behavior among men who have sex with men (MSM), before and for several years after HIV diagnosis, accounting for adoption of a variety of seroadaptive practices. We collected self-reported sexual behavior data every 3 months from HIV-positive MSM at various stages of HIV infection. To establish population level trends in sexual behavior, we used negative binomial regression to model the relationship between time since diagnosis and several sexual behavior variables: numbers of (a) total partners, (b) potentially discordant partners (PDP; i.e., HIV-negative or unknown-status partners), (c) PDPs with whom unprotected anal intercourse (UAI) occurred, and (d) PDPs with whom unprotected insertive anal intercourse (uIAI) occurred. A total of 237 HIV-positive MSM contributed 502 interviews. UAI with PDPs occurred with a mean of 4.2 partners in the 3 months before diagnosis. This declined to 0.9 partners/3 months at 12 months after diagnosis, and subsequently rose to 1.7 partners/3 months at 48 months, before falling again to 1.0 partners/3 months at 60 months. The number of PDPs with whom uIAI occurred dropped from 2.4 in the pre-diagnosis period to 0.3 partners/3 months (an 87.5% reduction) by 12 months after enrollment, and continued to decline over time. Within months after being diagnosed with HIV, MSM adopted seroadaptive practices, especially seropositioning, where the HIV-positive partner was not in the insertive position during UAI, resulting in a sustained decline in the sexual activity associated with the highest risk of HIV transmission.PLoS ONE 01/2013; 8(2):e55397. · 4.09 Impact Factor -
Article: Differential persistence of transmitted HIV-1 drug resistance mutation classes.
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ABSTRACT: Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) mutations can become replaced over time by emerging wild-type viral variants with improved fitness. The impact of class-specific mutations on this rate of mutation replacement is uncertain. We studied participants with acute and/or early HIV infection and TDR in 2 cohorts (San Francisco, California, and São Paulo, Brazil). We followed baseline mutations longitudinally and compared replacement rates between mutation classes with use of a parametric proportional hazards model. Among 75 individuals with 195 TDR mutations, M184V/I became undetectable markedly faster than did nonnucleoside reverse-transcriptase inhibitor (NNRTI) mutations (hazard ratio, 77.5; 95% confidence interval [CI], 14.7-408.2; P<.0001), while protease inhibitor and NNRTI replacement rates were similar. Higher plasma HIV-1 RNA level predicted faster mutation replacement, but this was not statistically significant (hazard ratio, 1.71 log(10) copies/mL; 95% CI, .90-3.25 log(10) copies/mL; P=.11). We found substantial person-to-person variability in mutation replacement rates not accounted for by viral load or mutation class (P<.0001). The rapid replacement of M184V/I mutations is consistent with known fitness costs. The long-term persistence of NNRTI and protease inhibitor mutations suggests a risk for person-to-person propagation. Host and/or viral factors not accounted for by viral load or mutation class are likely influencing mutation replacement and warrant further study.The Journal of Infectious Diseases 04/2011; 203(8):1174-81. · 6.41 Impact Factor -
Article: Recent HIV type 1 infection among participants in a same-day mobile testing pilot study in Zimbabwe.
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ABSTRACT: We estimated HIV-1 incidence and characterized risk factors associated with recent infection among participants of a mobile HIV voluntary counseling and testing (VCT) pilot program in two communities in Zimbabwe (N = 1096). HIV-1 infection was diagnosed using a parallel rapid testing algorithm. Recent HIV-1 infections were characterized using the BED immunoglobulin G capture enzyme immunoassay (BED-CEIA). HIV prevalence was 28.9% overall and nearly twice as high in women compared to men (39.5% vs. 21.4%, p < 0.001). HIV-1 incidence was 1.91% and was comparable between men and women (1.99% vs.1.88%; p = 0.626). Although not significant, the proportion of recent infections among all infections was highest among persons ages 25 to 34 years old (10.5%) for both men (11.9%) and women (9.2%). Persons recently infected compared to those with long-term infections were more likely to report STD symptoms (33% vs. 13%; OR = 3.2; p = 0.075) and prior STD treatment (13% vs. 6%; OR = 3.4; p = 0.187) in the previous 6 months. There were no associations found between recent versus long-term HIV infection status and perceived risk or expectation of negative test results. Recent HIV-1 infection detection among mobile VCT participants is a valuable measure for tracking the spread of the epidemic among persons who might otherwise not have access to HIV testing due to practical and logistical barriers. Mobile VCT presents opportunities to expand HIV testing services and evaluate at-risk populations within community settings. Given the challenges of longitudinal cohort studies, recent infection may be a practical endpoint for community-based prevention intervention trials employing mobile testing.AIDS research and human retroviruses 11/2010; 27(6):593-5. · 2.18 Impact Factor -
Article: HIV RNA level in early infection is predicted by viral load in the transmission source.
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ABSTRACT: HIV-1 viral load in early infection predicts the risk of subsequent disease progression but the factors responsible for the differences between individuals in viral load during this period have not been fully identified. We sought to determine the relationship between HIV-1 RNA levels in the source partner and recently infected recipient partners within transmission pairs. We recruited donor partners of persons who presented with acute or recent (<6 months) HIV infection. Transmission was confirmed by phylogenetic comparison of virus sequence in the donor and recipient partners. We compared viral load in the donor partner and the recipient in the first 6 months of HIV infection. We identified 24 transmission pairs. The median estimated time from infection to evaluation in acutely/recently infected recipient individuals was 72 days. The viral load in the donor was closely associated with viral load at presentation in the recipient case (r = 0.55, P = 0.006). The strong correlation between HIV-1 RNA levels within HIV transmission pairs indicates that virus characteristics are an important determinant of viral load in early HIV infection.AIDS (London, England) 02/2010; 24(7):941-5. · 4.91 Impact Factor -
Article: Transmitted drug resistance in persons with acute/early HIV-1 in San Francisco, 2002-2009.
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ABSTRACT: Transmitted HIV-1 drug resistance (TDR) is an ongoing public health problem, representing 10-20% of new HIV infections in many geographic areas. TDR usually arises from two main sources: individuals on antiretroviral therapy (ART) who are failing to achieve virologic suppression, and individuals who acquired TDR and transmit it while still ART-naïve. TDR rates can be impacted when novel antiretroviral medications are introduced that allow for greater virologic suppression of source patients. Although several new HIV medications were introduced starting in late 2007, including raltegravir, maraviroc, and etravirine, it is not known whether the prevalence of TDR was subsequently affected in 2008-2009. We performed population sequence genotyping on individuals who were diagnosed with acute or early HIV (<6 months duration) and who enrolled in the Options Project, a prospective cohort, between 2002 and 2009. We used logistic regression to compare the odds of acquiring drug-resistant HIV before versus after the arrival of new ART (2005-2007 vs. 2008-2009). From 2003-2007, TDR rose from 7% to 24%. Prevalence of TDR was then 15% in 2008 and in 2009. While the odds of acquiring TDR were lower in 2008-2009 compared to 2005-2007, this was not statistically significant (odds ratio 0.65, 95% CI 0.31-1.38; p = 0.27). Our study suggests that transmitted drug resistance rose from 2003-2007, but this upward trend did not continue in 2008 and 2009. Nevertheless, the TDR prevalence in 2008-2009 remained substantial, emphasizing that improved management strategies for drug-resistant HIV are needed if TDR is to be further reduced. Continued surveillance for TDR will be important in understanding the full impact of new antiretroviral medications.PLoS ONE 01/2010; 5(12):e15510. · 4.09 Impact Factor
