Have the explosive HIV epidemics in sub-Saharan Africa been driven by higher community viral load?

TitleHave the explosive HIV epidemics in sub-Saharan Africa been driven by higher community viral load?
Publication TypeJournal Article
Year of Publication2013
AuthorsAbu-Raddad LJ, Barnabas RV, Janes H, Weiss HA, Kublin JG, Longini IM, Wasserheit JN
Corporate AuthorsHIV Viral Load Working Group
JournalAIDS
Volume27
Issue6
Pagination981-9
Date Published2013 Mar 27
ISSN1473-5571
KeywordsAfrica South of the Sahara, Female, HIV Infections, HIV-1, Humans, Male, Models, Theoretical, Pregnancy, RNA, Viral, Viral Load
Abstract

OBJECTIVE: The HIV epidemic has carved contrasting trajectories around the world with sub-Saharan Africa (SSA) being most affected. We hypothesized that mean HIV-1 plasma RNA viral loads are higher in SSA than other areas, and that these elevated levels may contribute to the scale of epidemics in this region.

DESIGN AND METHODS: To evaluate this hypothesis, we constructed a database of means of 71,668 viral load measurements from 44 cohorts in seven regions of the world. We used linear regression statistical models to estimate differences in viral load between regions. We also constructed and analyzed a mathematical model to describe the impact of the regional viral load differences on HIV epidemic trajectory.

RESULTS: We found substantial regional viral load heterogeneity. The mean viral load in SSA was 0.58 log(10) copies/ml higher than in North America (95% confidence interval 0.45-0.71); this represents about a four-fold increase. The highest mean viral loads were found in Southern and East Africa, whereas in Asia, Europe, North America, and South America, mean viral loads were comparable. Mathematical modeling indicated that conservatively 14% of HIV infections in a representative population in Kenya could be attributed to the enhanced infectiousness of patients with heightened viral load.

CONCLUSION: We conclude that community viral load appears to be higher in SSA than in other regions and this may be a central driver of the massive HIV epidemics in this region. The elevated viral loads in SSA may reflect, among other factors, the high burden of co-infections or the preponderance of HIV-1 subtype C infection.

DOI10.1097/QAD.0b013e32835cb927
Alternate JournalAIDS
PubMed ID23196933
PubMed Central IDPMC3725236
Grant List5 KL2 RR025015 / RR / NCRR NIH HHS / United States
AI 38855 / AI / NIAID NIH HHS / United States
AI 38858 / AI / NIAID NIH HHS / United States
AI 68634 / AI / NIAID NIH HHS / United States
AI 68636 / AI / NIAID NIH HHS / United States
KL2 TR000421 / TR / NCATS NIH HHS / United States
P30 AI027757 / AI / NIAID NIH HHS / United States
P30 AI027757 / AI / NIAID NIH HHS / United States
U01 AI038855 / AI / NIAID NIH HHS / United States
U01 AI068634 / AI / NIAID NIH HHS / United States
U01 AI068636 / AI / NIAID NIH HHS / United States
UM1 AI068635 / AI / NIAID NIH HHS / United States