Regional differences in HIV trends in The Gambia: results from sentinel surveillance among pregnant women.
OBJECTIVE
To monitor HIV-1 and HIV-2 trends in The Gambia, West Africa.


METHODS
In 1993-1995 a nationwide survey among 29 670 pregnant women attending eight antenatal clinics estimated the seroprevalence of HIV-1 at 0.6%, and of HIV-2 at 1.1%. Five years later, sentinel surveillance in pregnant women was established, using unlinked anonymous testing in four clinics. A dried blood spot on filter paper was obtained and tested for HIV antibodies.


RESULTS
Between May 2000 and August 2001, 8054 analysable samples were collected at four sites. The prevalence of HIV-1 rose sharply in one rural area from 0.6 to 3.0% (P < 0.0001), but the increase was small and non-significant in two other rural sites and in the urban site. The prevalence of HIV-2 did not change significantly at any of the sites. The overall prevalence of HIV-1 was 1.0% [95% confidence interval (CI) 0.8-1.3%], and of HIV-2 0.8% (CI 0.6-1.0%). Site, nationality and higher age were significantly associated with HIV-1 infection, and higher parity and site were significantly associated with HIV-2 infection.


CONCLUSIONS
Fifteen years after the first case of HIV-1 was described in The Gambia, the epidemic is still at a low level. There is heterogeneity within the country, with one rural area experiencing a fivefold increase in 6 years. The prevalence of HIV-2 in The Gambia is stable.
Schim van der Loeff
Maarten F
MF
Medical Research Council Laboratories, The Gambia. maartin.schim@lshtm.ac.uk
Sarge-Njie
Ramu
R
Ceesay
Saihou
S
Awasana
Akum Aveika
AA
Jaye
Pa
P
Sam
Omar
O
Jaiteh
Kebba O
KO
Cubitt
David
D
Milligan
Paul
P
Whittle
Hilton C
HC
D000367:Age Factors; D005260:Female; D005714:Gambia / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology*; D015528:HIV Seroprevalence; D015497:HIV-1; D015498:HIV-2; D006801:Humans; D015999:Multivariate Analysis; D010298:Parity; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D018571:Sentinel Surveillance