Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 23357-23360 413

2.2 to 3.4 for women, and OR = 3.0, 95% CI 2.3 to 3.8 for men), 17% among
women reporting vaginal discharge (OR = 2.0, 95%CI 1.4-2.0) and 19% among
men reporting urethral discharge (OR = 2.0, 95%CI 1.3-3.0). HIV prevalence
increased significantly with number of lifetime sexual partners: having 10 or more
lifetime sexual partners was associated with a two-fold higher HIV prevalence
compared to those with 2-4 partners (OR = 2.1, 95%CI 1.4 to 3.1 for women and
OR = 2.1, 95%CI 1.5 to 2.9 for men). Women who had ever had a casual partner
had 1.6 times (95%CI 1.3 to 2.0), and men 1.5 times (95%CI 1.1 to 2.0), the
risk of those who had not. Prevalence was not significantly related to education,
frequency of travel outside the village or age at first sex.
Conclusions: These data provide the most precise estimates available of the
effects of a range of risk factors on HIV infection among adults in rural sub-Saharan Africa. Associations were strongest with reported recent infection with
sexually transmitted diseases, supporting the importance of condom use and
prompt and effective treatment for STDs in preventing the spread of HIV infection
in these communities.
S23357 HIV-1 heterosexual transmission: relationship with HIV-1
subtypes in Uganda
Pontiano Kaleebu1, D. Morgan1, J. Oram2, A. Rutebemberwa1, F. Lyagoba1,
B. Biryahwaho1, J. Whitworth1. MRC/UVRI PO. Box 49 Entebbe, Uganda;
2Camp Porton Down Salisbury, UK
Objective: To determine whether HIV-1 subtype affects the rate of heterosexual
transmission in couples in a rural population in Uganda.
Methods: In a natural history cohort in rural south-west Uganda, HIV-1 subtyping has been done on 103 individuals using both HMA and sequencing in the
V3 and p24 gag regions. In this cohort, 27 couples were identified, 11 were HIV-1
serologically discordant and 16 were concordant positive.
Results: There were 38 subtype A, 59 subtype D, 1 each subtype B and C in the
envelope region, four individuals had A/D. Seven (64%) of the positive discordant
partners and both partners for 13 (81%) seroconcordant couples were subtyped.
In the discordant couples 2 out of 7 (29%) were infected with HIV-1 subtype A
and 5 (71%) with subtype D, while of the concordant couples, both partners were
infected with subtype A in 8 and with subtype D in 4 and the partners for one
couple had different subtypes. In four couples where p24 gag sequences were
available, the sequences were closely related suggesting transmission between
the partners. The chance of transmission having occurred if infected with subtype
A was 8/10 (80%) and only 4/9 (44%) if infected with subtype D (p = 0.17; 2 tailed
Fisher Exact).
This preliminary study suggests that HIV-1 envelope subtype A may be more
efficiently transmitted than subtype D between heterosexual couples. We are
planning to extend the size of the study to confirm this finding.
23358 Travel, sexual behaviour and risk to HIV infection
Abdullah Abu Saleh, A.J. Hedley, R. Fielding. The University of Hong Kong, Dept
of Community Medicine, The University Patrick Hanson, Bldg 7 Sassoon Road,
Hong Kong, PR China
Aim: To estimate high risk sexual behaviour among travellers departing from
Hong Kong and to develop a profile of risk behaviour during travel to support the
design of interventions in continuing health promotion.
Methods: Travellers were interviewed by five trained interviewers covering
eight languages (Cantonese, Mandarin, Japanese, English, French, German,
Hindi and Bengali) in the departure lounge of Kai Tak International Airport, Hong
Kong, between May and June 1996 using a structured pre-tested questionnaire.
A systematic sampling method was used to select the samples. Additional information about respondents and non-respondents was obtained from interviewers
during debriefing sessions.
Results: Among 438 subjects interviewed 23% were ethnic Chinese, 44%
Caucasian, 31% other Asians and 1% Africans. Seventy five percent of the travellers were male; 57% were married and 91% had travelled at least once within
the previous year. Forty four percent (168/383) of those who travelled within the
previous year had sex during their travel either with a local person, another tourist
or with prostitutes. Having sex during travel was associated with ethnicity, age,
gender and sexual attitude including having multiple sexual partners and people
who travel solely for sex. Thirty seven percent (139/376) of the respondents reported they do not use condoms at all during sexual intercourse. Using condoms
during sexual intercourse was associated with age, marital status and perceived
risk for human immunodeficiency virus (HIV) infection. Middle aged and married
travellers were more likely to be in the higher risk group.
Conclusion: The high rates of higher risk sexual activity and the low rates
of condom use among travellers indicate a high potential risk for sexually transmitted diseases (STDs) including HIV infection among travellers in this region.
Besides the threat to themselves, travellers may pose a potential threat both to
their families and home community and the territories they visit by transmitting
STDs. In Hong Kong and the Asia Pacific there is an urgent need to target
travellers effectively in any strategy designed to prevent the spread of STDs in

the region.

23359 1 Factors associated with HIV infection in heterosexuals
attending anonymous test sites in Switzerland
Martin D. Gebhardt, W.J. Paget. Swiss Federal Office of Public Health, PO Box
3003, Bern, Switzerland
Background: Since July 1985, anonymous HIV testing and counselling has
been available for the general population at the five university hospital centers
of Switzerland. The objective of the present study was to determine factors
associated with HIV infection in heterosexuals.
Methods: All test sites have used the same questionnaire since July 1993
to collect data on the demographic characteristics of persons requesting the
test, reasons for testing, history of injecting drug use, sexual preference, sexual
partners, previous episodes of sexually transmitted diseases (STDs) and previous HIV test results. We analysed reports on heterosexuals, i.e. persons with a
preference for or sexual contacts with partners from the opposite sex, excluding
injecting drug users and men who also had sex with men. Multivariate logistic
regression was used to estimate the odds ratios (OR) for HIV infection. Risk
factors (protective factors) were defined as factors with a lower (upper) bound of
the 95%-confidence interval greater (smaller) than 1.
Results: During the four years from July 1993 to June 1997, the five centers
sent 51826 test reports to the Swiss Federal Office of Public Health. 45753 reports
(88.3%) concerned heterosexuals, of which 45650 could be analysed (103 cases
with insufficient information were excluded). 144 tests (0.32%) were positive.
Risk factors were: nationality in a country with predominantly heterosexual HIV
transmission (HTC) versus other nationality (OR = 14.1); sex with an HIV positive
person (OR = 5.20); sex with partners from an HTC (OR = 2.09); and having had
at least one STD (OR = 1.82). Protective factors were: age under 25 (OR = 0.38);
having had at least one previous HIV test (OR = 0.56); a new sexual partner
versus having had a risk situation as the reason for testing (OR = 0.63); male sex
(OR = 0.68); and (marginally significant) sex with commercial sex workers (OR =
0.49).
Conclusions: The anonymous HIV test sites in Switzerland allow the prevalence of HIV to be monitored in heterosexuals who seek an HIV test on their
own initiative. Although this group may not be representative of heterosexuals in
the general population, these data are an important part of HIV surveillance in
Switzerland. They provide information on differences in HIV prevalence among
different groups of heterosexuals which can help to plan targeted prevention
activities or to design specific studies on the spread of HIV.
S23360 1 Prevalence of STDs among HIV infected patients in
Yaounde: The need for an improved prevention and
strategies
Henriette Kenfack1, L. Zekeng2, C.B. Ndongmo2, A.C. Nzoung Kaniy Bisseck3,
G. Afana Ngaska3, E. Kembou4, L. Kaptue2. 1Hemato-lmmuno Laboratory, Chu
Yaounde; 2lmmuno-Hematology Laboratory, Chu Yaounde, Yaounde;
3Dispensaire Antivenerien Elig Essono, Yaounde; 4Sidalerte Cameroon,
Yaounde, Cameroon
Objective: To determine the prevalence of STDs among HIV infected patients and
the implication on the management strategies (diagnosis, treatment, counselling)
Design: Transversal study
Methods: All STD clinic attendants are submitted to a questionaire and after
diagnosis (clinical diagnosis of STD), blood specimens were collected in EDTA
tubes. Plasma fractions were further obtained and screened for HIV antibodies
by ELISA techniques using Enzygnost anti HIV 1/2 plus (Berhing), Welcozyme
HIV-1 (Murex). Reactive samples were confirmed by Western Blot (Novapath
HIV1 Immunoblot (Bio-rad). VDRL and TPHA tests were also run on samples for
confirmation of syphilis, the statistical analysis has been done by Epi info5.
Results: A total of 200 blood specimens were collected between June 1996
and January 1997 from patients in whom a STD was suspected. Ninety-eigth
(49%) were male aged 19-71 years, (51%) female (aged 15-63 years). Thity-two
(16%) specimens were positive for HIV antibodies while 61 (30.5%) tested positive by VDRL and TPHA. There was no sex difference. The most HIV infected
age range was 21-39 years. Out of the 32 HIV infected patients 14 (43.75%) had
syphilis as compared to the 47 (28%) of the 168 control HIV negative patients.
The Chi square value was 3.84 and a P = 0.04 (P < 0.05).As concerning STDs
with discharge, there were 11 cases (34.37%) among the 32 HIV positive patients
while against 46 cases (27.38%) among the 168 senegative patients. The P value
was 0.0006 (P < 0.05). These figures show that there is a definite correlation
between STDs and HIV infection.
Conclusion: The seroprevalence of STD infection remains high among HIV
infected patients; these results reiterate again the fact that individual who have
a STD are more proned to HIV infection. More emphasis should be put on the
STD prevention, management (early diagnosis and treatment) and counselling in
order to reduce the reinfection and the incidence of new HIV infections.
S23361 HIV-seropositive men's perceived responsibility for
preventing the transmission of HIV to others

Richard Wolitski1, C.A. Gomez2, J.T. Parsons3, T. Ambrose4, R.H. Remien5.
'CDC, 1600 Clifton Road (MS E-37), Atlanta, GA 30333; 2University of
California, San Francisco, San Francisco, CA; 3Jersey City State College, Jersey
City, NJ; 4Rutgers University, New Brunswick, NJ;5 Columbia University New
York City, NY USA
Background: This study examines the relationship between HIV-seropositive gay