Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

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.

Original publication




Journal article


Journal of acquired immune deficiency syndromes (1999)

Publication Date





594 - 598


*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.


Humans, HIV-1, Bacterial Infections, HIV Infections, Parasitic Diseases, Viral Load, Adult, Africa South of the Sahara, Female, Male, Asymptomatic Infections, Coinfection