Mo.C.1577

Seven Years of Sentinel Surveillance
of HIV2 and HIV1 Infection:
The Use of an HIV1 model to estimate the
spread of the epidemic

Objectives

To use seven years (1989-95) of sentinel surveillance data to establish projections for both viruses in a HIV2 endemic area; To give decision makers a tool to evaluate the future impact of HIV/AIDS and to plan preventive actions.

Methods

A meta-analysis on main epidemiologic findings was conducted and correction factors on gender, HIV ( %HIV2 = HIV1+0.2) and urban/rural ( %R=0.3 U) distribution were calculated. We modified a number of factors, including the progression rate from HIV to AIDS and the perinatal transmission rate from mother to children for HIV2. This approach seemed most accurate in accoun ing for HIV2 specificities.

Results

Seroprevalence varies from 0.5% in Dakar to 1.6% in Ziguinchor among pregnant women and from 16.4% to 39% among commercial female sex workers in the same locations. Our model suggests that from 1994 to 1998, the number of persons infected in the general population will increase by 162%, AIDS cases by 185% and deaths by 158%. Our projections revealed a variation in seroprevalence from 0.13% to 2.88% in 5 years among adults (15 - 49 years). In 1997, 60613 individuals will be infected by HIV.

Conclusions

Existing models of HIV1 progression can be modified for use with HIV2 if taking into account the natural history of this virus. Those data are helpful to build an efficient health information system and will allow decision makers to improve their understanding of the AIDS crisis and better monitor the dynamics of the epidemics.

Pape Ousmane
DIAW Laboratoire de Bacteriologie-Virologie
HALD BP 7318 Dakar Senegal
Tel.: (221) 21.64.20; Fax: (221) 21.64.42