Extended high viremics: A substantial fraction of individuals maintain high plasma viral RNA levels after acute HIV-1 subtype C infection
ABSTRACT The present study addressed two questions: what fraction of individuals maintain a sustained high HIV-1 RNA load after the acute HIV-1C infection peak and how long is a high HIV-1 RNA load maintained after acute HIV-1C infection in this subpopulation?
Plasma HIV-1 RNA dynamics were studied in 77 participants with primary HIV-1C infection from African cohorts in Gaborone, Botswana, and Durban, South Africa. HIV-infected individuals who maintained mean viral load of at least 100,000 (5.0 log(10)) copies/ml after 100 days postseroconversion (p/s) were termed extended high viremics. Individuals were followed longitudinally for a median [interquartile range (IQR)] of 573 (226-986) days p/s.
The proportion of extended high viremics was 34% [95% confidence interval (CI) 23-44%] during the period 100-300 days p/s and 19% (95% CI 9-29%) over the period of 200-400 days p/s. The median (IQR) duration of HIV-1 RNA load at least 100,000 copies/ml among extended high viremics was 271 (188-340) days p/s. For the subset with average viral load at least 100,000 copies/ml during 200-400 days p/s, the median (IQR) duration was 318 (282-459) days. The extended high viremics had a significantly shorter time to CD4 cell decline to 350 cells/μl (median: 88 vs. 691 days p/s for those not designated as extended high viremics; P < 0.0001, Gehan-Wilcoxon test).
A high proportion of extended high viremics - individuals maintaining high plasma HIV-1 RNA load after acute infection - have been identified during primary HIV-1 subtype C infection. These extended high viremics likely contribute disproportionately to HIV-1 incidence.
- SourceAvailable from: Laith J Abu-Raddad
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- "Different circulating virus sub-types are another potential biological cofactor. HIV-1 subtype C is found predominantly in areas of high HIV prevalence in SSA and appears to be linked to extended high viremia (Kaul et al., 2011; Novitsky et al., 2011). Other potential biological cofactors include STIs such as herpes simplex virus type 2 (Abu-Raddad et al., 2008; Korenromp et al., 2001), tropical co-infections increasing HIV viral load (Abu-Raddad et al., 2006, 2013), hormonal contraception (Heffron et al., 2012), and host genetics and immunology (Kaul et al., 2011). "
ABSTRACT: Background Representative and precise estimates for the annual risk of HIV transmission (ϕ) from the infected to the uninfected partner in a stable HIV-1 sero-discordant couple (SDC) are not available. Nevertheless, quantifying HIV infectiousness is critical to understanding HIV epidemiology and implementing prevention programs. Materials and methods We estimated ϕ and examined its variation across 23 countries in sub-Saharan Africa (SSA) by constructing and analyzing a mathematical model that describes HIV dynamics among SDCs. The model was parameterized using empirical measures such as those of the nationally representative Demographic and Health Surveys. Uncertainty and sensitivity analyses were conducted to assess the robustness of the findings. Results We estimated a median ϕ of 11.1 per 100 person-years across SSA. A clustering based on HIV population prevalence was observed with a median ϕ of 7.5 per 100 person-years in low HIV prevalence countries (<5%) compared to 19.5 per 100 person-years in high prevalence countries (>5%). The association with HIV prevalence explained 67% of the variation in ϕ, and suggested an increase of 0.95 per 100 person-years in ϕ for every 1% increase in HIV prevalence. Conclusions Empirical measures from cohort studies appear to underestimate HIV infectiousness in SSA. The risk of HIV transmission among SDCs appears also to vary across SSA, and this may have contributed to the contrasting HIV epidemic trajectories in this continent.Epidemics 11/2013; 6. DOI:10.1016/j.epidem.2013.11.001 · 2.38 Impact Factor
- "Rather, we hypothesize that a combination of sexual mixing in a high-prevalence setting, structural factors that put young people at increased risk of exposure and unique biological factors, such as the predominance of clade C HIV  , is driving the epidemic in sub- Saharan Africa over and above individual sexual behaviors. Kenyon et al assert that we dismiss the role of behavior, in particular concurrency, and also race in explaining differences in the epidemics observed in South Africa and the United States. "
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- "Concurrency particularly enhances population spread of HIV because of the virus's long duration of infectiousness (Garnett & Johnson, 1997), and it increases the opportunities for transmission during acute HIV infection when the transmission probability is greatest (Pilcher et al., 2004; Pinkerton, 2008). Although acute infection is time limited, there is some evidence that a subset of HIV-1 subtype C-infected individuals maintains high plasma HIV-1 levels for an extended period of time (Novitsky et al., 2011). The estimates from several mathematical modeling studies suggest that from 9% to 50% of HIV transmissions in a sub-Saharan African setting were attributable to sexual contact with individuals with early infection (Abu-Raddad & Longini, 2008; Cohen & Pilcher, 2005; Hayes & White, 2006; Hollingsworth, Anderson, & Fraser, 2008; Powers et al., 2011). "
ABSTRACT: In the United States, Blacks are disproportionately impacted by HIV/AIDS. Sexual networks and concurrent relationships have emerged as important contributors to the heterosexual transmission of HIV. To date, Africa is the only continent where an understanding of the impact of sexual concurrency has been conveyed in HIV prevention messaging. This project was developed by researchers and members of the Seattle, Washington, African American and African-Born communities, using the principles of community-based participatory research (CBPR). Interest in developing concurrency messaging came from the community and resulted in the successful submission of a community-academic partnership proposal to develop and disseminate HIV prevention messaging around concurrency. The authors describe (a) the development of concurrency messaging through the integration of collected formative data and findings from the scientific literature; (b) the process of disseminating the message in the local Black community; and (c) important factors to consider in the development of similar campaigns.AIDS education and prevention: official publication of the International Society for AIDS Education 12/2012; 24(6):527-48. DOI:10.1521/aeap.2012.24.6.527 · 1.51 Impact Factor