Predicting the extinction of HIV-2 in rural Guinea-Bissau.
OBJECTIVE
This article predicts the future epidemiology of HIV-2 in Caió, a rural region of Guinea Bissau; and investigates whether HIV-2, which has halved in prevalence between 1990 and 2007 and is now almost absent in young adults in Caió, can persist as an infection of the elderly.


METHODS
A mathematical model of the spread of HIV-2 was tailored to the epidemic in Caió, a village in Guinea-Bissau.


METHODS
An age-stratified difference equation model of HIV-2 transmission was fitted to age-stratified HIV-2 incidence and prevalence data from surveys conducted in Caió in 1990, 1997 and 2007. A stochastic version of the same model was used to make projections.


RESULTS
HIV-2 infection is predicted to continue to rapidly decline in Caió such that new infections will cease and prevalence will reach low levels (e.g. below 0.1%) within a few decades. HIV-2 is not predicted to persist in the elderly.


CONCLUSIONS
HIV-2 is predicted go extinct in Caió during the second half of this century.
aDepartment of Zoology, The Institute for Emerging Infections, The Oxford Martin School, Oxford University bNuffield Department of Medicine, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom cMedical Research Council Laboratories (UK), Fajara, The Gambia dDepartment of Infection and Immunity, The University of Sheffield Medical School, Sheffield, United Kingdom eErasmus Medical Centre, Medical Microbiology and Infectious Diseases, Rotterdam fHealth Service of Amsterdam (GGD) and Academic Medical Center gDepartment of Internal Medicine, Division of Infectious Diseases, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Meibergdreef, Amsterdam, The Netherlands hProjecto de Saúde de Bandim, Apartado 861, Bissau Codex, Guinea-Bissau iFaculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Helen R
HR
Fryer
Carla
C
Van Tienen
Maarten Schim
MS
Van Der Loeff
Peter
P
Aaby
Zacarias J
ZJ
Da Silva
Hilton
H
Whittle
Sarah L
SL
Rowland-Jones
Thushan I
TI
de Silva
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060740:Disease Eradication; D005260:Female; D006169:Guinea-Bissau / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015498:HIV-2 / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015995:Prevalence; D012424:Rural Population; D055815:Young Adult