title: Brief report: HIV-1 transmissions during asymptomatic infection: exploring the impact of changes in HIV-1 viral load due to coinfections.
abstract: High HIV-1 plasma viral loads (PVLs) in sub-Saharan Africa, partly because of high rates of coinfection, may have been one of the drivers of the "explosive" epidemics seen in that region. Using a previously published framework of infectiousness and survival, we estimate the excess onward HIV-1 transmission events (secondary infections) resulting from coinfection-induced changes in PVL during asymptomatic HIV-1 infection. For every 100 HIV-infected people, each suffering 1 episode of tuberculosis infection, there are 4.9 (2.7th-97.5th percentile: 0.2-21.5) excess onward HIV-1 transmission events attributable to this coinfection. Other estimates are malaria 0.4 (0.0-2.0), soil-transmitted helminths 3.1 (0.1-14.9), schistosomiasis 8.5 (0.2-38.6), filariasis 13.3 (0.3-89.2), syphilis 0.1 (0.0-1.6), herpes simplex virus 4.0 (0.0-24.2), and gonorrhea 2.1 (0.1-8.0) transmissions. If these higher PVLs confer a shorter life expectancy and higher infectiousness, then their impact on transmission is, in general, reduced. For most HIV-1 coinfections, the duration of a single infection is too short and/or the associated PVL elevation is too modest to contribute substantially to onward HIV-1 transmission.
authors.affiliation: *Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom; †Mathematics Institute, University of Warwick, Coventry, United Kingdom; ‡School of Life Sciences, University of Warwick, Coventry, United Kingdom; and §Department of Clinical Sciences, Liverpool School of Hygiene and Tropical Medicine, Liverpool, United Kingdom.
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Baggaley
authors.forename: T Déirdre
authors.initials: TD
authors.lastname: Hollingsworth
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara; D058345:Asymptomatic Infections; D001424:Bacterial Infections / Q000453:epidemiology / Q000635:transmission*; D060085:Coinfection / Q000453:epidemiology*; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000635:transmission*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D010272:Parasitic Diseases / Q000453:epidemiology / Q000635:transmission*; D019562:Viral Load