|Acting Early to Prevent AIDS: The Case of Senegal (UNAIDS, 1999, 28 p.)|
|Has the response made a difference?|
With such low rates of casual sex, falling rates of STD infection and high levels of condom use, it might be expected that HIV infection in Senegal has remained low. A possible exception might be among sex workers, whose levels of STDs suggest a rather high cumulative risk of HIV infection, even when the majority of their sexual contacts are protected by condom use.
And indeed, the available HIV surveillance data bear out these expectations. National AIDS programme data show that HIV prevalence among pregnant women was 1.41 percent at the end of 1996. There has been no significant trend over time in this population. Figure 4 shows HIV-infection rates among pregnant women in the capital Dakar. There are also sentinel surveillance sites at antenatal clinics in three other major urban areas - Saint-Louis, Kaolack and Ziguinchor; they all show much the same rates, with HIV infection below two percent in pregnant women most years between 1989 and 1996, and no upward trend in HIV prevalence over time.
Figure 4. HIV prevalence among pregnant women, Dakar, Senegal
In male STD patients, generally thought to be a group representing high risk of infection, HIV infection rates have remained more or less consistently below 5 percent over time in all sites. It is only among female sex workers, probably the group at highest risk of infection, that HIV prevalence levels have risen significantly over time. They are highest in the south of the country - HIV infection among registered sex workers in the southern city of Ziguinchor reached close to 35 percent in 1996. In the capital, Dakar, HIV infection among sex workers appears to have remained stable at around 17 percent since 1993.
Stable HIV prevalence does not, of course, mean there are no new infections. For every person who drops out of the group tested for HIV - because they have died, are too sick to present at health facilities, are no longer fertile or for any other reason - there must be one new infection to keep prevalence stable. But in the case of Senegal, it does not appear that stable prevalence is masking rising incidence. An incidence study of sex workers in Dakar registered new HIV infections at around 1.1 per 100 person years of observation in the decade between 1985 and 1995, with no significant rise in infection levels over time.
Among pregnant women, too, there seems to be no evidence of high infection rates in the youngest age group - the age group where prevalence levels are most likely to reflect incidence, or new infections. Between 1989 and 1996, only one out of more than 400 pregnant teenagers screened for HIV was found to be infected with the virus.