Nguyen Thi Thanh Thuy*, Vo Tuyet Nhung*, Mai Hoang Anh**, Truong Xuan Lien*, Ha Ba Khiem*
* Pasteur Institute in
** Center for Preventive Medicine of Angiang province,
To determine HIV-1 seroprevalence and to
identify HIV transmission modes in a border area of the southern
During 1995-1996, consecutive collection of blood samples
was performed in the frame of HIV sentinel surveillance among commercial sex
workers (CSWs), intravenous drug users (IDUs), sexually transmitted diseases
(STD) clinic attendees, tuberculous patients and pregnant women, in An Giang, a
province bordering
The highest HIV-1 seroprevalence was found among CSWs in 1995 and 1996 with 4.8% (n=416) and 4.09% (n= 660) respectively. That in STDs patients was of 1.32% (n=830) and 1.32% (n=909) during the same period. The infection among IDUs remained lower 1.15% (n=432) in 1995, but a rise to 4.6 % (n= 665) in 1996 needs to be further monitored. 10/11 isolates from CSWs were identified as Thai sub-type E, 1 as sub-type B. The migration of sex workers is a concern with 16.8 % coming from other provinces. 82.2 % showed a low education level as never having been in school or primary school. 38% were brothel-based CSWs. The majority of clients were men relevant to the movement across the frontier such as traders or businessmen (56%) including smugglers, or drivers (22.7%). 76.2% women reported their clients as non-regular clients. 80.2% women showed an inconsistent condom use (44.4% sometimes and 35.8 % never). Signs of genital ulcers, venereal warts were seen in 0.5%, and 1.1% respectively. Trichomoniasis (direct examination), chlamydial infection (IFD) and gonorrhea (culture) were detected in 9.4%, 8.1% and 0.3% respectively. HbsAg seroprevalence was of 7.6%. That of syphilis was particularly high 48.2% (TPHA) which was associated with low educational level (p=0.017), but all the syphilis patients were unaware of their infection status. 86.6% STD patients received no treatment or had self- medication. Only 0.5% had sex with drug users and 0.8 % injected drugs.
Heterosexual spread is the main transmission mode in this area. Population movements across the border were related to expansion of prostitution. High frequency of low socio-economic status led to lack of awareness of CSWs on protected sex showed by low rate of condom use. Poor detection and treatment of STDs contributed to increase risks in HIV heterosexual transmission. These features need to be taken in account for special intervention measures in this border area.