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

114 Abstracts 13143-13147

12th World AIDS Conference

Results: The response rate was 65% (229, male; 105, female; 123 mean age
= 40.0) for Okayama and 83%(156, male; 77, female; 79 mean age = 40.0) for
Komoro. The table presents the prevalence (95% confidence interval) of respondents aged 20-59 years reporting multi penis-vagina intercourse partners among
those who reported any heterosexual experience in the last year, and that of the
18-59 age group in Britain and France (AIDS 1995, 9: 735-743).
Table. Prevalence of multi heterosexual-partners in the last year
Location Britain France Okayama (Japan) Komoro (Japan)
Respondents 15322 25020 166 112
Response rate (%) 63 61 65 83
Reporting multiple partners (%)
Male 15.4 13.7 22.3 (13.5-31.3) 25.0 (13.2-36.8)
Female 7.2 6.2 14.8 (7.1-22.5) 5.0 (0.5-10.5)
Conclusion: Prevalence of reported multi heterosexual-partners was similar
for men in these two Japanese cities and it was higher amongst women in the
larger city than in the smaller one. The prevalence in Japan was estimated as
being higher than in Britain and France. Therefore behavioral risk for heterosexual
transmitted HIV in Japan may be higher than these two developed countries.
S13143 Declining seroprevalence of HIV-1 among child-bearing
women in upper northern Thailand
Peter H. Kilmarx1, S. Yanparsan'2, R.E. Bunnell3, K. Limpakarnjanarat1,
P. Rhodes.3, TD. Mastro1, M.E. St. Louis3. 1 US CDC & HIV/AIDS Collaboration,
Nonthaburi 11000; 2Chiang Rai Hospital, Chiang Rai, Thailand; 3CDC, Atlanta
GA, USA
Background: The highest rates of HIV-1 infection in Thailand are in the upper
northern part of the country. Prevalence among young men has declined since
1994 after an increase in condom use during commerical sex, but trends among
women are not well characterized.
Methods: Since 1990, pregnant women have been routinely tested for HIV
infection by enzyme immunoassay at Chiang Rai Hospital, a public hospital at
which the greatest number of deliveries in the province are performed. Data
through mid-1997 were abstracted from delivery ward log books and analyzed to
determine trends in prevalence and risk factors for infection.
Results: Among the 40,723 deliveries, HIV seroprevalence increased from
1.6% in 1990 to 6.4% in 1994 and then decreased to 4.6% in 1997. Overall prevalence was 6.8% among women <19 years of age (relative risk [RR] 3.2; 95%
confidence interval [CI] 2.7-3.8) and 5.1% among women aged 20-29 years (RR
2.4; Cl 2.1-2.8), compared with 2.1% among women aged >30 years. Maternal
HIV infection was also independently associated with first pregnancy (adjusted
odds ratio [AOR] 1.6; Cl 1.4-1.7), public antenatal care (compared with private
care; AOR 2.4; CI 2.1-2.7) and positive syphilis serology results (AOR 3.7; CI
3.0-4.6). The recent decline in prevalence was most marked among younger
women and primigravidas.
Conclusion: Young childbearing women in upper northern Thailand are at a
particularly high risk for HIV infection. The observed decline in prevalence since
1994 may be due to a true decline in the rate of infection or to a decreasing
likelihood of HIV-infected women to deliver at the study hospital. Further prevention measures for women in the general population are needed, and substantial
resources will be required to care for those who are already infected.
13144 1 Similar risk factors for new infection with HIV-1 subtypes
B' and E among injecting drug users (IDUs) in Bangkok,
Thailand
Dwip Kitayaporn', S. Vanichseni2, T.D. Mastro1, K. Choopanya2, D.C. Des
Jarlais3, C. Wasi4, S. Raktham2, N.L. Young1, P. Mock1, W.L. Heyward5,
J. Esparza6. 1HIV/AIDS Collaboration (PO Box 139) Nonthaburi 11000;
2Bangkok Metropolitan Administration, Bangkok; 4Mahidol University, Bangkok,
Thailand; 3Beth Israel Medical Center, New York, NY; 5CDC, Atlanta, GA, USA;
6UNAIDS, Geneva, Switzerland
Background: Bangkok IDUs experienced an epidemic of HIV-1 subtype B' (Thai
B) in 1988. Recent cross-sectional surveys have identified an increase in subtype
E. Since 05/95, in a prospective cohort of 1,208 IDUs attending 15 methadone
treatment clinics of the Bangkok Metropolitan Administration, HIV-1 incidence
was 8.1 per 100 person-years. We evaluated demographic and behavioral factors
associated with incident infection with these two subtypes.
Methods: Data on seroconverters were obtained from enrollment and follow-up questionnaires. Incident HIV-1 strains were characterized by direct DNA
sequencing of the C2-V4 envelope region.
Results: By 12/15/97, 101 IDUs became HIV-1 infected, and 82 were available
for this analysis. Of these, 87% still injected heroin despite treatment, and needle
sharing was reported by 28%. However, reported sexual activity in the four months
before seroconversion was limited: 59% had no sex, only 2.4% had sex with a
non-regular partner, and none had sex with a commercial sex worker. Infection

was due to subtype E for 67 (82%) and subtype B' for 15 (18%). IDUs with
subtype E tended to be younger than those with B' (mean age: 30 vs. 32 years, p
= 0.2). Yet, other demographic and behavioral factors (gender, education, marital
status, age of first drug use, incarceration, needle sharing, history of casual sex,
and reported STDs) were similar for those with subtypes B' and E (p > 0.1 for
any variable).

Conclusion: Recently infected Bangkok IDUs with subtype B' or E infection are
similar with regard to demographic and behavioral factors. These data suggest a
similar parenteral mode of infection for both subtypes B' and E.
S13145 HIV sentinel surveillance in China in 1997
Shuquan Qu1, Xin Hua Sun2, Xiwen Zheng1, Jie Shen2. Group of National HIV
Sentinel Surveillance; 1 Center for AIDS Surveillance CAPM, 27 Nanwei Road,
Beijing; 2Dept. of Diseases Control MOH, Beijing, People's Republic of China
Objective: To provide the accurate information for policy-making on AIDS prevention and control program and to monitor HIV epidemic trends more scientifically
and efficiently.
Design: Cross-sectional study.
Methods: A consecutive samples of 250-400 are recruited on four high risk
groups, people attending STDs clinic, underground prostitutes, drug users and
long distance truck drivers in 42 sentinel sites twice a year since 1995 in China.
There adds to the 60 sentinel sites in 27 provinces in 1997. HIV antibody is tested
by using two different ELISA methods.
Results: Very few HIV infected persons were reported among people attending STDs clinic, no HIV infected persons were found among long distance truck
drivers in the first round surveillance in 1997 and before. About 1% to 2% HIV
infected persons were found among underground prostitutes in 3 sentinel sites in
1997, compared to only below 0.5% in the previous years before 1997. HIV infected persons were reported in 7 (include 2 new sites) sentinel sites of 12 among
the drug users in 1997, compared to only 3 of 8 in the same time before. 1997. In
Xinjiang autonomous region 83 (20.8%) HIV infected person were reported, only
32 (8.0%) reported in the same sentinel sites at the same time in previous years.
The ratio of IDU among the drug users is increasing steadily or remains high level
in most sentinel sites. It's reported that nearly 60% of underground prostitutes
never use condom during sex.
Conclusion: The results show that the HIV epidemic spreads faster and more
extensively in China. There are many risk factors that can cause wide HIV
epidemic in China.
131316 Rapid detection of HIV-1 subtype E infection by
polymerase chain reaction (PCR) in Taiwan
Mao-Yuan Chen. No. 7 Chung-Shang South Road, Taiwan
Objective: To check the sensitivity and specificity of a nested PCR method
specific for identification of subtype E HIV-1 infection in Taiwan.
Design: Restrospective study.
Methods: A total of 187 samples were tested. The viral subtypes of HIV-1 had
been identified in 130 patients by DNA sequencing of v3 and/or gag genes. The
other 57 samples were newly collected, their viral subtypes were unknown prior
to the test but were later studied by phylogenetic analysis. Genomic DNA was
extracted from PBMC by standard phenol/chloroform method. The nested PCR
was performed by using a common outer primers (sense nt. 5855-80 & antisense 6435-56). Two different pairs of inner primers were used in second round,
they were (1) common vpu primers; sense nt. 5956-92 & antisense 6338-62 (2)
E-specific primers derived from our sequence data of subtype E vpu gene.
Results: PCR products of expected size were present in all 59 subtype E
infected samples but were absent in 118 samples of subtype B infection by using
subtype E specific primers. In three patients with subtype A infection and in one
of three patients with subtype C infection a fainter band was seen on agarose
gel. In all four patients with subtype G infection, the E-specific nested PCR were
positive.
Conclusion: Subtype E-specific nested PCR is a rapid and reliable method for
differentiating two prevalent HIV-1 subtypes; B and E; in Taiwan.
131471 HIV-1 seroprevalence and distribution of serotypes in
young Thai men
Achara Jugsudee1, P. Chanbacherd1, S. Kitsiripornchai2, S. Tanomkolm1,
P. Tienamporn1, P. Julananto1, T. Supapongse2, K. Torugsa2, M. De Sousa3,
C. Mason2, L.E. Markowitz2. 1Army Institute of Pathology, 315 Rajvithi Rd.,
2RTAMC-AFRIMS; 3 HMJF-USA-AFRIMS, Bangkok, Thailand
Objectives: To determine HIV-1 seroprevalence and serotypes in young Thai
men entering the Royal Thai Army.
Methods: Each year over 50000 young Thai men are selected by lottery and
inducted in May and November. All inductees are routinely screened for HIV-1
antibody by ELISA and confirmed by Western blot. In November 1996 and May
1997, serotyping by a V3 ELISA, utilizing peptide sequences based on genotype
B and E isolates from Thailand, was performed on Western blot + sera.
Results:
HIV-1 seroprevalence (%) by region of service in the RTA and year
Region 1989 1990 1991 1992 1993 1994 1995 1996 1997

Central 0.4 1.3 2.2 2.9 3.0 2.6 2.5 2.0 1.8
Bangkok 0.2 1.2 2.8 3.3 3.2 2.9 2.6 1.7 2.2
Northeast 0.4 0.9 1.8 2.4 2.6 2.5 1.6 1.6 1.1
North 1.4 6.1 6.5 7.5 7.3 5.0 3.4 3.3 2.5
South 0.9 1.6 2.2 2.7 2.8 2.2 2.1 2.1 2.6
Total 0.5 1.9 2.9 3.5 3.6 3.0 2.4 2.1 1.9