The epidemiology of HIV infection and AIDS in Thailand

Social network influences on reproductive health behaviors in urban northern Thailand

Prevention approaches for reproductive health have evolved from an emphasis on individually focused models of behavior change to a recognition that risk reduction occurs within a context of social norms. Prevention programs can be improved by understanding how social structure influences sexual behavior and using that understanding to develop strategies for positive change. In a dynamic, urban context, communities are better conceptualized as informal networks of ties. These network structures may help to protect, or conversely, expose members to reproductive risk behaviors. Using data from a study of social and sexual networks conducted in northern Thailand, this article describes partner relations and social structure in the modern, urban context, and illustrates the links between individual, relational and structural properties and reproductive risk behaviors. Triangulation of ethnographic, survey and social network data collection and analytic tools provide an opportunity to interpret individual behaviors, meanings of relationships and structural properties of networks. Intervention approaches should build on existing networks, and address the complex meanings of romantic and sexual partnerships.

Differences in sexual behaviour between HIV-infected pregnant women and their husbands in Bangkok, Thailand

In a Bangkok antenatal clinic, we interviewed 102 HIV-infected pregnant women and their husbands, 30% of whom were HIV-negative. We evaluated these data by matched and unmatched analysis, compared men and women in stable couple relationships on a number of sociodemographic and risk factor indicators and investigated further whether there were any differences in sociodemographic or risk factor profiles between HIV-serodiscordant couples and seroconcordant couples. When compared to wives, more of the husbands were working (p = 0.001), earning more money (p = 0.001), had had more than two sex partners (p = 0.001) and had had syphilis (p = 0.001). Serodiscordant couples did not differ greatly from seroconcordant couples except that women married to HIV-negative men were more likely to have been divorced or separated than their husbands which was not the case for women married to HIV-positive men (p = 0.02). There was poor agreement between husband and wife reports of husband risk behaviour and this did not differ between concordant and discordant couples. These findings suggest that assessment of risk and counselling of Thai women is incomplete without information on the HIV status and risk behaviour of her partner. Prevention strategies to decrease heterosexual transmission among couples need to target both the man and the woman.

Seroprevalence of HIV among female sex workers in Bangkok: evidence of ongoing infection risk after the "100% condom program" was implemented

BACKGROUND

After implementation in 1991 of a nationwide campaign to promote condom use during commercial sex, HIV-1 seroprevalence among young men began to decrease in 1994. However, it is unknown to what degree female sex workers (FSWs) have been protected from infection.

METHODS

FSWs attending a government clinic in Bangkok in 1997 and 1998 were interviewed, counseled, and tested for evidence of prior syphilis by Treponema pallidum hemagglutination assay (TPHA) and for HIV-1 antibodies.

RESULTS

Among the 500 participants, women who began sex work more recently reported less risky sex behavior when they were first potentially exposed to HIV infection, and TPHA reactivity rates were lower among these women. However, their HIV infection rates were higher. HIV seroprevalence was 5.5% among 91 women who began sex work before 1989, 8.0% among 87 women who began during 1990 to 1993, and 12.5% among 322 women who had begun since 1994.

CONCLUSIONS

Although condom use is critical to HIV prevention, women in this study who began sex work after the condom promotion campaign was implemented were still at high risk for HIV infection. Additional measures are needed to prevent HIV infection among the many young women who initiate or continue to engage in commercial sex.

HIV monitoring in Vietnam: system, methodology, and results of sentinel surveillance

OBJECTIVE

To measure the prevalence of and trends in HIV infections in populations defined by sentinel surveillance in Vietnam.

METHODS

Surveillance was conducted in eight provinces in 1994, expanded to 12 in 1995 and to 20 in 1996. Sentinel populations were sexually transmitted disease (STD) patients, female sex workers (FSW), injecting drug users (IDU), tuberculosis (TB) patients, pregnant women, and military conscripts. Samples were collected twice yearly for high-risk populations and once yearly for low-risk populations.

RESULTS

The overall HIV epidemic in Vietnam comprises several different smaller epidemics. It is primarily associated with injecting drug use, but its extent varies widely throughout the country. In 1998, HIV prevalence rates ranged from 0 to 85% (median, 13.1%), with an aggregate prevalence rate (APR; i.e., the sum of HIV-positive study subjects divided by the sum of all study subjects tested in sentinel provinces) of 17% among IDUs; this ranged from 0 to 14.7% (median, 0.8%), with the APR of 2.4% among FSWs; and from 0 to 6% (median, 0%), with the APR of 0.9% among STD patients. The APRs among antenatal women and army conscripts were less than 0.15%. APRs increased significantly from 1994 to 1998 among STD patients (p < .001), FSWs (p < .001), TB patients (p < .001), and pregnant women (p < .05) in original sentinel provinces. HIV prevalence also increased significantly among younger age groups of IDUs and FSWs.

CONCLUSION

Vietnam's HIV epidemic is increasing predominantly and most rapidly among IDUs. However, prevalence rates among FSWs and STD patients are rising but are still low among pregnant women and army conscripts. Vietnam, at present, is still in the early phase of the HIV epidemic and has time to take effective and appropriate actions.

Clinical presentation of hospitalized adult patients with HIV infection and AIDS in Bangkok, Thailand

OBJECTIVE

To characterize the clinical spectrum of disease and immune status of adult HIV-1-infected patients in Bangkok.

DESIGN

Cross-sectional survey of hospital admissions.

METHODS

From November 1993 through June 1996, demographic, clinical, and laboratory data were collected from HIV-infected inpatients (> or =14 years old) at an infectious diseases hospital.

RESULTS

Of 16,717 persons admitted, 3112 (18.6%) were HIV-seropositive, 2261 of whom were admitted for the first time. Of 2261, 1926 (85.2%) were male, 1942 (85.9%) had been infected heterosexually or by means not related to drug use, 319 (14.1%) were injection drug users (IDUs), and 1553 (68.7%) had AIDS. The most common AIDS-defining conditions were extrapulmonary cryptococcosis (EPC; 38.4%), tuberculosis (TB; 37.4%), and wasting syndrome (WS; 8.1%). IDUs were more likely (p < .05) to have TB or WS but less likely (p < .05) to have EPC or Pneumocystis carinii pneumonia than patients with no history of injection drug use. Lymphocyte counts were measured for 2047 (90.5%) patients; 81.8% had < or =1500 lymphocytes/microl.

CONCLUSION

These HIV-infected patients were admitted with severe immunosuppression. Cryptococcosis and TB are major problems and differ in prevalence among IDUs and persons infected sexually. Clinical and immunologic information is critical in improving the lives of HIV-infected persons in Asia through prevention, treatment, and prophylaxis.

Treatment delay and reliance on private physicians among patients with sexually transmitted diseases in China

We examined health-care seeking practices among patients with sexually transmitted diseases (STDs) in south China. In 1995, we recruited a consecutive sample of 939 STD patients attending the STD clinics of the Municipal STD Control Centers of Guangzhou and Shenzhen, 'special economic zones' near Hong Kong. Attending physicians interviewed patients face-to-face using a standard survey questionnaire. Twenty-seven per cent of all subjects had sought treatment elsewhere for their presenting complaints, before visiting a study clinic. The main sources of prior treatment were private physicians followed by public clinics and drugstores. Women were more likely than men to delay in presenting their current symptoms to a study clinic (32% vs 25%, P=0.046). Factors associated with treatment delay differed by gender. Among men, seeking prior treatment from private physicians (OR=3.31; 95% CI=1.70, 6.43), having no urethral discharge (OR=4.00; 95% CI=2.33, 6.85), having engaged in sex trade (OR=1.64; 95% CI=1.03, 2.63), or being a resident in Shenzhen (OR=1.80; 95% CI=1.12, 2.89) were more likely to delay seeking treatment. Among women, only living in Shenzhen (OR=2.86; 95% CI=1.56, 5.25) was associated with treatment delay. Promotion of appropriate health-seeking behaviours and better management of STDs must be a top priority to slow a rapid spread of STD/HIV in China. Health education, improvement of STD care in the public and private sectors, and regulations of unauthorized private physicians, may help with STD control and HIV prevention.

Predominance of CCR5-dependent HIV-1 subtype E isolates in Cambodia

To investigate the genetic and biologic features of HIV-1 strains circulating in Cambodia, viruses from 95 HIV-1-seropositive individuals were subtyped by heteroduplex mobility assay (HMA) and 23 were further analyzed for their biologic characteristics. Eighty-nine individuals were clearly infected by HIV-1 subtype E. The other six samples were sequenced, together with 17 HMA subtype E samples. All but one of the 23 Cambodian env sequences clustered with previously described Thai and Vietnamese subtype E sequences, bearing a GPGQ motif at the tip of the V3 loop; the last had a GPGR motif and was phylogenetically equidistant from Asian and African subtype E viruses. Nonsyncytium-inducing, CCR5-dependent viruses predominated in patients of clinical stage B even in some with a high viral load and were detected in about 50% of the patients of stage C. All syncytium-inducing strains, mostly from AIDS patients, used both CCR5 and CXCR4. The presence of syncytium-inducing viruses did not correlate with the plasma viral load. These data show that CCR5-dependent HIV-1 subtype E is currently predominant in Cambodia. The analysis of clinical and virologic markers strongly supports the idea that dynamics of the viral population during subtype E infection in Southeast Asia is similar to that of subtype B infection in Europe and the United States.

HIV/AIDS surveillance system and reported cases of human immunodeficiency virus infection and acquired immunodeficiency syndrome in Japan (1983-1993)

The Ministry of Health and Welfare forms the AIDS Surveillance Committee, which publishes HIV infection at two-month intervals. As at December 1993, the Ministry of Health and Welfare reported 267 AIDS cases and 1,143 HIV infection cases. Epidemiological data in Japan showed a rapid increase of cases of transmission through heterosexual contact since 1991, before which cases of transmission due to homosexual contact were relatively large in number according to reports. Sporadic cases of mother-to-child transmission and some cases due to injection of drug use were also reported. However, others/unknown cases were 449 (31.8%). Although the reported number of AIDS cases and HIV infection cases in Japan is still small, a rapidly increasing HIV epidemic is feared. It is predicted that the primary mode of transmission will be heterosexual contact and that another epidemiological characteristics will be diversified modes of transmission. Therefore, the present surveillance should continue and actively track the epidemic and provide useful information for planning prevention strategies in Japan.

Herpes in the time of AIDS: a comparison of the epidemiology of HIV-1 and HSV-2 in young men in northern Thailand

OBJECTIVES

To compare the epidemiologic pattern of HIV-1, a recently introduced sexually transmitted disease (STD) agent in Thailand, with the pattern of HSV-2, a well-established STD agent, so that future trends for both viruses can be better understood.

METHODS

We obtained questionnaire data and determined HSV-2 (by specific gG-2) and HIV-1 seroreactivity in a cohort of 1,115 young male army conscripts who entered service in northern Thailand in 1991.

RESULTS

Seroprevalence of HIV-1 and HSV-2 was 6.9% and 14.9%, respectively. For HSV-2-seropositive men who reported previous genital ulcers, HIV-1 seroprevalence was 32%. For most variables, there was a close correspondence between the prevalence ratios for HIV-1 and for HSV-2, except that prevalence ratios for HIV-1 tended to be greater than the corresponding ratios for HSV-2. The seroprevalence of both viruses was strongly related to early and frequent contact with female sex workers (FSWs), infrequent use of condoms with FSWs, and residence in the upper north region of Thailand. When differences in sexual behavior between the upper north and lower north were controlled for, the seroprevalence of both viruses still differed significantly by region.

CONCLUSIONS

Although the seroprevalence levels of HSV-2 and HIV-1 were quite different in this cohort of Thai army conscripts in 1991, the patterns of infection in terms of demographic, residential, and behavioral variables were similar. Seroprevalence studies of HSV-2 in other populations, particularly where the HIV-1 epidemic is just beginning, may be useful in predicting which subgroups might be most vulnerable to the epidemic and could therefore benefit the most from public health intervention. Where differences in the patterns of the two viruses have been noted, we hypothesize that the pattern for HIV-1 will evolve toward that seen for HSV-2.

HIV-1 and other sexually transmitted infections in a cohort of female sex workers in Chiang Rai, Thailand

OBJECTIVES

To determine demographic and behavioural factors and sexually transmitted infections (STIs) associated with prevalent HIV-1 infection among brothel based and other female sex workers (FSWs) in Chiang Rai, northern Thailand.

METHODS

Data were collected from questionnaires, physical examinations, and laboratory evaluations on Thai FSWs enrolled in a prospective cohort study in Chiang Rai, Thailand, from 1991 to the end of 1994.

RESULTS

HIV-1 seroprevalence was 32% among 500 women: 47% for 280 brothel workers and 13% for 220 other FSWs (p < 0.001); 96% of infections were due to HIV-1 subtype E. At enrolment, other STIs were common: chlamydia, 20%; gonorrhoea, 15%; active syphilis (serological diagnosis), 9%; genital ulcer, 12%; seroreactivity to Haemophilus ducreyi, 21%, and herpes simplex virus type 2 (HSV-2), 76%. On multiple logistic regression analysis, HIV-1 was associated with brothel work, birth in upper northern Thailand, initiation of commercial sex at < 15 years of age, syphilis, HSV-2 seropositivity, and genital ulcer.

CONCLUSIONS

Young Thai FSWs working in brothels in northern Thailand in the early phase of the HIV epidemic have been at very high risk for HIV-1 infection and several other STIs. Programmes are needed to prevent girls and young women from entering the sex industry and to reduce the risk of infection with HIV-1 and other STIs.

HIV related knowledge and prevention among Thai female commercial sex workers in Japan

A survey of 87 Thai female commercial sex workers (TCSW) was conducted in Tokyo and surrounding areas to investigate their: 1) living conditions, 2) knowledge about HIV/AIDS and sources of information, and 3) working conditions and dealings with clients. Data were mainly collected by "snowballing" with semi-structured interviews. The results showed a majority of participants knew HIV could be contracted through sexual intercourse and that condom use could protect against HIV infection. However, some TCSW reported failing to use condoms despite having requested clients to do so. Reasons for client compliance with condom use were discussed. Although a majority of the participants underwent HIV testing at least once every 3 months, they did not learn much about HIV prevention through public information and education. The results suggest that workers and clients need more detailed information concerning HIV prevention as well as a greater accessibility.

Infection with HIV-1 subtypes B and E in injecting drug users screened for enrollment into a prospective cohort in Bangkok, Thailand

From May through August 1995, a cross-sectional survey was conducted among injecting drug users (IDUs) drawn from 15 drug treatment clinics in Bangkok and who were not known to be HIV-seropositive, to determine the prevalence of HIV-1 subtypes B and E and related risk behaviors, and to offer enrollment in a prospective cohort study. IDUs who voluntarily consented were interviewed, and blood specimens were tested for the presence of HIV antibodies. HIV-1-seropositive specimens were tested for subtypes B' (Thai B) and E by using V3 loop peptide enzyme immunoassays specific for these HIV-1 genetic subtypes. Of 1674 IDUs studied, the mean age was 31.2 years (interquartile range, 25-37 years), 94.8% were men, and 29.3% were HIV-1-seropositive. On multiple logistic regression analysis, HIV-1 seropositivity was associated with older age, not being married, less education, needle sharing, and incarceration. HIV-1 subtype B' accounted for 65% of prevalent infections and subtype E, 35%. Infection with subtype E was associated with younger age and did not seem to be associated with sexual risk behaviors, which were uncommon in general. Bangkok IDUs continue to be at high risk for HIV-1 infection related to needle sharing and incarceration. Although HIV-1 subtype B' accounts for most prevalent infections, subtype E seems to be more prevalent among younger IDUs, and most infections seem likely to result from parenteral transmission.

Genetic and serologic characterization of HIV type 1 prevailing in Myanmar (Burma)

To study the molecular epidemiology of HIV-1 spread in Myanmar and the interplay with the epidemic in surrounding Southeast Asian countries, we determined the HIV-1 subtypes prevailing in Myanmar. Thirty HIV-positive blood specimens were sampled in the capital city, Yangon, and an additional 459 sera were collected nationwide in 1995. Genetic subtyping based on the env C2/V3 sequence and serologic data, using a V3 peptide enzyme immunoassay (PEIA), revealed three patterns of HIV spread in different geographic regions in Myanmar: (1) in the capital city, Yangon, HIV-1 subtype B' ("Thai-B" cluster within subtype B) predominated both in IDUs and heterosexuals; (2) in the cities near the border with Thailand, including Tachelaik and Kawthaung, where heterosexual transmission is a major pathway of HIV-1 spread, HIV-1 subtype E was predominantly distributed among the commercial sex workers and heterosexuals; (3) in central and northeast Myanmar, both HIV-1 subtypes B' and E occurred in a mixed distribution, without showing any significant segregation by risk group. In addition, the PEIA data implied the occurrence of other subtype(s) in these areas. The interperson nucleotide sequence variations in env C2/V3 regions of B' and E, prevailing in Yangon, were 6.7 +/- 2.1 and 7.1 +/- 0.7%, respectively. They were similar to those levels observed in Thailand. These findings are consistent with the view that HIV spread in Myanmar might have taken place at about the same time as that in Thailand, and that multiple entries and exchanges of HIV-1 with neighboring countries are important factors contributing to the current distribution of subtypes in Myanmar.

HIV-1 seroconversion in a prospective study of female sex workers in northern Thailand: continued high incidence among brothel-based women

OBJECTIVES

To determine the incidence of HIV-1 infection, temporal trends in incidence, and risk factors for seroconversion in a cohort of female commercial sex workers (CSW) in upper northern Thailand, the region of Thailand with the highest rates of HIV-1 infection.

METHODS

CSW were enrolled from 1991 through 1994 and evaluated prospectively with interviews, physical examination, testing for sexually transmitted diseases (STD), and serologic testing for HIV-1 infection.

RESULTS

The incidence of HIV-1 seroconversion in the first year of follow-up was 20.3 per 100 person-years among 126 brothel-based CSW and 0.7 per 100 person-years among 159 other CSW who worked in other venues such as bars or massage parlors. Incidence remained elevated among brothel-based CSW who were enrolled later in the study compared with those who enrolled earlier. Through 1996, 30 women seroconverted. In a multivariable proportional hazards model, seroconversion was significantly associated (P < 0.05) with brothel-based sex work (adjusted risk ratio, 7.3) and Chlamydia trachomatis cervical infection (adjusted risk ratio, 3.3).

CONCLUSION

Despite national HIV control efforts and declining rates of infection among young men in Thailand, brothel-based CSW may continue to be at high risk for HIV-1 infection. Additional efforts are needed to provide alternative economic choices for young women, to ensure universal condom use during commercial sex, and to develop new prevention technologies.

Nationwide surveillance of HIV-1 prevalence and subtype in young Thai men

As part of routine surveillance, an HIV-1 serosurvey of 366,074 members of successive cohorts of young Thai men entering service with the Royal Thai Army (RTA) was conducted between November 1989 and November 1995. We analyzed regional and temporal trends in HIV-1 seroprevalence in young men in Thailand and determined the proportion of infections resulting from subtypes E and B in this population in 1992 and 1995. The prevalence in 1992 was compared with that in 1995 by region and demographic group. The HIV-1 subtype was determined in a random sample of HIV-1-positive specimens in 1992 and 1995 using a V3 peptide enzyme immunoassay. From a peak of 3.7% in 1993, overall seroprevalence declined to 3.0% in 1994 and further in 1995 to 2.5%. Between 1992 and 1995, the absolute decrease in seroprevalence was greatest in the upper North (from 12.5% to 5.3%), where the prevalence has been the highest. Overall, 96.9% and 95.9% of typable specimens were determined to be subtype E in 1992 and 1995, respectively. Decline in HIV-1 seroprevalence among young men in Thailand has continued, which suggests that HIV control programs in Thailand may have been successful in decreasing spread of HIV-1. Almost all HIV-1 infections resulted from subtype E.

Needle sharing and high-risk sexual behaviors among IV drug users in Southern Thailand

This study sought to determine the prevalence of needle sharing and high HIV risk sexual behaviors and to identify characteristics associated with these practices in southern Thailand. Data were obtained using a structured questionnaire from 298 male intravenous drug users (IVDUs) seen in a methadone clinic during the previous year. The prevalence of HIV was 37%, and that of needle-sharing in the preceding months was 45%, although only 10% claimed to have had unsafe sex with a casual partner or prostitute in the same period. Determinants for needle sharing included shorter duration of drug injection, diminished knowledge of HIV prevention, a carefree attitude toward risk of HIV infection, and lower levels of income. Young single IVDUs with a low knowledge of HIV prevention were most likely not to use a condom. In conclusion, needle sharing among the study subjects was still a common practice, whereas high HIV risk sexual behavior was not. Attitudinal change may be necessary to reduce needle-sharing behavior and not just information on disease transmission.

HIV-1 subtype E incidence and sexually transmitted diseases in a cohort of military conscripts in northern Thailand

OBJECTIVES

To determine the rate of and risk factors for HIV-1 seroconversion and describe sexually transmitted disease (STD) prevalence rates for young men in northern Thailand.

METHODS

Data were collected from self-administered questionnaires and serologic testing at enrollment in a prospective study in 1991 and at follow-up after 6, 17, and 23 months on a cohort of 1115 men selected by lottery for military conscription.

RESULTS

A total of 14 men seroconverted to HIV-1 envelope subtype E. The overall HIV-1 incidence rate was 1.1 (95% confidence interval [CI], 0.6-1.8) per 100 person-years (PY) of follow-up. However, the rate was 2.0/100 PY for conscripts from the upper northern subregion of Thailand compared with 0.5/100 PY from other regions (adjusted rate ratio [RR] = 2.69; 95% CI, 0.8-12.2). On multivariate analyses, the behavioral factors associated with HIV-1 seroconversion were frequency of sex with female sex workers (FSWs; p = .04), receptive anal sex (adjusted RR = 6.73; 95% CI, 1.8-21.7), and large amount of alcohol consumption (adjusted RR = 3.12; 95% CI, 1.0-10.9). Genital ulceration was the STD most strongly associated with seroconversion. The prevalence of serologic reactivity to syphilis, Haemophilus ducreyi, and herpes simplex virus type 2 increased with greater frequency of sex with FSWs and was generally higher for men from the upper north.

CONCLUSION

Young men in northern Thailand are at high risk for HIV-1, primarily through sex with FSWs; and other STDs are highly associated with HIV-1 incidence. As HIV-1 infection extends into the general population, intervention programs are needed to address the problem of sexual transmission apart from commercial sex venues.

Sexual behavior of young men in Thailand: regional differences and evidence of behavior change

An anonymous, self-administered behavioral survey was conducted in Royal Thai Army (RTA) conscripts from 19 provinces throughout Thailand in May 1996. All (to a maximum of 350) Thai men who entered the RTA in each province were selected. Data from 5474 men were included in this analysis. High-risk behaviors were reported nationwide; however, some regional differences were found. Men from the upper North were more likely to have had a commercial sex worker (CSW) as their first sexual partner (42%) than men from any other region. However, in the past year, reported sex with CSWs in the upper North (41%) was similar to or lower than those in other regions. Consistent condom use with CSWs was higher in the North than in any other region. Condom use at first sex with CSWs increased with later years at first sex in all regions. These data suggest that past higher-risk behavior among young men in the upper northern part of Thailand may have contributed to the concentration of the HIV epidemic in that region. Risk behaviors, particularly unprotected sex, appear to be decreasing nationwide.

A comprehensive panel of near-full-length clones and reference sequences for non-subtype B isolates of human immunodeficiency virus type 1

Non-subtype B viruses cause the vast majority of new human immunodeficiency virus type 1 (HIV-1) infections worldwide and are thus the major focus of international vaccine efforts. Although their geographic dissemination is carefully monitored, their immunogenic and biological properties remain largely unknown, in part because well-characterized virological reference reagents are lacking. In particular, full-length clones and sequences are rare, since subtype classification is frequently based on small PCR-derived viral fragments. There are only five proviral clones available for viruses other than subtype B, and these represent only 3 of the 10 proposed (group M) sequence subtypes. This lack of reference sequences also confounds the identification and analysis of mosaic (recombinant) genomes, which appear to be arising with increasing frequency in areas where multiple sequence subtypes cocirculate. To generate a more representative panel of non-subtype B reference reagents, we have cloned (by long PCR or lambda phage techniques) and sequenced 10 near-full-length HIV-1 genomes (lacking less than 80 bp of long terminal repeat sequences) from primary isolates collected at major epicenters of the global AIDS pandemic. Detailed phylogenetic analyses identified six that represented nonrecombinant members of HIV-1 subtypes A (92UG037.1), C (92BR025. 8), D (84ZR085.1 and 94UG114.1), F (93BR020.1), and H (90CF056.1), the last two comprising the first full-length examples of these subtypes. Four others were found to be complex mosaics of subtypes A and C (92RW009.6), A and G (92NG083.2 and 92NG003.1), and B and F (93BR029.4), again emphasizing the impact of intersubtype recombination on global HIV-1 diversification. Although a number of clones had frameshift mutations or translational stop codons in major open reading frames, all the genomes contained a complete set of genes and three had intact genomic organizations without inactivating mutations. Reconstruction of one of these (94UG114.1) yielded replication-competent virus that grew to high titers in normal donor peripheral blood mononuclear cell cultures. This panel of non-subtype B reference genomes should prove valuable for structure-function studies of genetically diverse viral gene products, the generation of subtype-specific immunological reagents, and the production of DNA- and protein-based subunit vaccines directed against a broader spectrum of viruses.

Rapid assessment of sexually transmitted diseases in a sentinel population in Thailand: prevalence of chlamydial infection, gonorrhoea, and syphilis among pregnant women--1996

OBJECTIVE

To determine the prevalence of sexually transmitted diseases (STDs) among pregnant women in Thailand, where case reporting suggests a marked decrease in STDs following a campaign promoting condom use during commercial sex.

DESIGN

Cross sectional study of women at their first visit to the study hospitals' antenatal clinics in Chiang Rai (n = 500) and Bangkok (n = 521).

METHODS

First catch urine specimens were tested for Chlamydia trachomatis and Neisseria gonorrhoeae using the Amplicor CT/NG polymerase chain reaction assay. Syphilis and HIV serological testing were performed in the study hospitals' laboratories.

RESULTS

The prevalence of chlamydial infection was 5.7%, gonorrhoea 0.2%, and syphilis 0.5% (all VDRL or RPR titres were < or = 1:4). The prevalence of HIV infection was 7.1% in Chiang Rai and 2.9% in Bangkok. In a multivariate logistic regression analysis, chlamydial infection was associated with younger age and with higher gestational age at first antenatal clinic visit, but was not associated with marital status, gravidity, city of enrollment, or HIV infection status.

CONCLUSIONS

There was a low prevalence of gonorrhoea and syphilis among these pregnant women in Thailand. Chlamydial infection was detected at a higher prevalence, especially among younger women and women registering later for antenatal care. Testing of pregnant women using easily collected urine specimens and a sensitive nucleic acid amplification assay is a feasible method of rapidly assessing chlamydial and gonococcal prevalence.

Demographic impact of the HIV epidemic in Thailand

OBJECTIVE

To assess the impact of the HIV epidemic on the demographic development of the Thai population.

METHODS

A deterministic mathematical model was used to predict simultaneously epidemiological and demographic processes. Partial differential equations express the relationships between biological, behavioural and demographic variables. The model allows the evaluation of different sexual mixing patterns, variable transmission probabilities and incubation times. Validity analysis was performed by generating antecedent HIV prevalence patterns among military recruits and pregnant women.

RESULTS

On the national level in Thailand we predict that the cumulative number of people in Thailand with HIV infection will exceed 1 million by 1999; the number of deaths from AIDS will be 555000 by the year 2000 but will not reach 1 million until after the year 2014. Without the HIV epidemic the population growth rate was estimated at 1.3% per annum until 1995, after which a decline to 0.9% by 2005 is predicted. The HIV epidemic started to affect the population growth rate by 0.026% per year in 1991, and the difference is predicted to rise to about 0.12% per year during the period 1995-2000, to decline to 0.06% in 2005 and then to disappear. In the mid-1990s HIV affected mainly the 15-35-year-old age group, but over time younger and older age groups have been affected as a result of perinatal transmission, and a decline in fertility as well as ageing of the 15-35-year-old birth cohort. Because of HIV, in 2000 there will be 612000 (1%) fewer people than expected and by 2010, 1140000 fewer (1.6%). We predict that the demographic impact of the HIV epidemic in the northern region will follow the same pattern, but with greater severity. Here, the effect on the population growth rate and the population age distribution is likely to be twice as high as at the national level.

CONCLUSIONS

It is estimated that 1 million Thais will be infected with HIV by the year 2000 and an almost equal number will have died of AIDS by the year 2014. Although these numbers seem high, their direct and indirect effects on the demographic structure of the Thai population are small. However, at a regional level, for example in the northern region, the effect of the HIV epidemic may be more severe.

Impact of HIV on families of HIV-infected women who have recently given birth, Bangkok, Thailand

The objective of this study was to assess changes in the family situation of HIV-infected women who have recently given birth. As part of a prospective perinatal HIV transmission study, interviews were conducted with a subset of HIV-infected women at 18 to 24 months postpartum, and answers were compared with baseline information obtained during pregnancy. Standardized scales were used to assess levels of psychosocial functioning. A convenience sample of 129 HIV-infected women enrolled during pregnancy was interviewed at 18 to 24 months postpartum. At delivery, the women were young (median age, 22 years), primiparous (57%), and asymptomatic (93%). When baseline and follow-up data were compared, more women were living alone (1% versus 6%; p = 0.03), fewer women were living with their partners (98% versus 73%; p < 0.001), and 30% of families had reduced incomes. At follow-up, 10% of partners had died, and more partners than wives had become ill or died (21% versus 4%; p = 0.02). Most children (78%) were living with their mothers, but only 57% of the HIV-infected women were the primary caretakers. Fewer women had disclosed their HIV status to others (e.g., family, friends) than to their partners (34% versus 84%; p < 0.001), largely because of fear of disclosure. The women appeared to have high levels of depression and worry. The women's greatest worries were about their children's health and the family's future. Within 2 years after childbirth, substantial change within the families of HIV-infected women was evident. These were manifest by partner illness or death, family separation, reduced family income, shifting responsibilities for child care, and signs of depression and isolation. Providing family support is a major challenge in Thailand as the perinatal HIV epidemic progresses.

Harm reduction in the hills of northern Thailand

The human immunodeficiency virus (HIV) pandemic has swept through injecting drug user (IDU) communities around the world. Once HIV is present in an IDU community, seroprevalence rates escalate rapidly unless immediate and comprehensive prevention methods are put in place. Such measures often include providing IDUs with sterile injecting equipment and dispensing methadone or other opiate substitution formulas. These measures fall under the rubric of harm reduction-an attempt to reduce the harm to drug users, their families, and communities, including preventing or limiting the transmission of HIV and other blood-borne viruses. In Thailand, HIV-1 spread rapidly among IDUs with seroprevalence rates jumping from 1 to 40% in the space of a year. Current incidence rates are estimated at 11 per 100 person years. This paper describes the establishment and implementation of needle and syringe exchanges among injecting drug users in nine Hilltribe communities in Northern Thailand. The exchanges have been operating for between 1 and 3 years and have been effective in limiting the transmission of HIV within these small communities. The needle and syringe exchanges are run by indigenous staff with the cooperation of the community and provide a good example of the feasibility of establishing locally-run, community-based harm reduction programs.

Emerging infectious diseases and travel medicine

International movement of individuals, populations, and products is one of the major factors associated with the emergence and reemergence of infectious diseases as the pace of global travel and commerce increases rapidly. Travel can be associated with disease emergence because (1) the disease arises in an area of heavy tourism, (2) tourists may be at heightened risk because of their activities, or (3) because they can act as vectors to transport the agent to new areas. Examples of recently recognized diseases with relationship to travel include HIV, Legionnaire's disease, cyclosporiasis, Vibrio cholerae O139 Bengal, hantavirus, and variant Creutzfeldt-Jacob disease. Reemerging diseases include dengue fever, malaria, cholera, schistosomiasis, leptospirosis, and viral hemorrhagic fevers. In addition, tuberculosis, drug-resistant shigellosis, and cholera have been major concerns in refugee and migrant populations. Because of the unique role of travel in emerging infections, efforts are underway to address this factor by agencies such as the CDC, WHO, the International Society of Travel Medicine, and the travel industry.

HIV type 1 in Thailand, 1994-1995: persistence of two subtypes with low genetic diversity

Extensive transmission of human immunodeficiency virus type 1 (HIV-1) in Thailand began in 1988, resulting in an estimated 800,000 cumulative infections by 1994. During 1994 and 1995, we collected blood specimens from 215 asymptomatic HIV-1-infected people with various risk behaviors from nine locations in all four regions of Thailand. HIV-1 subtypes and genetic heterogeneity were determined for 214 strains by a combination of direct DNA sequencing (n = 95), subtype-specific oligonucleotide probe testing (n = 201), and V3-loop peptide enzyme immunoassay (PEIA) (n = 214). All strains were either env subtype E (175; 81.8%) or B (39; 18.2%). Of the subtype B isolates, 37 (94.9%) were B' and 2 (5.1%) were more typical North American-like B strains (most subtype B strains in Thailand are part of a distinct subcluster within the subtype B branch on phylogenetic trees, termed B'; formerly Thai B or BB). Of 149 viruses from people with sexual risk behaviors from all regions, 146 (98.0%) were subtype E. Of 65 viruses from injecting drug users (IDUs), 29 (44.6%) were subtype E and 36 (55.4%) were subtype B, including 35 B' strains. There was regional variation in the proportions of subtypes E and B' among IDUs. The intrasubtype nucleotide divergence within the V3 and flanking regions of the env gene (mid-C2 to the start of the V4 region) was low (5.7% for subtype E and 3.1% for subtype B') compared with other HIV-1 group M subtypes from different countries. These findings of two subtypes with low heterogeneity indicate that Thailand may be a desirable setting for evaluating candidate HIV-1 vaccines. The mix of subtype E and B' strains among IDUs also offers the opportunity to study phenotypic differences between the two subtypes.

Genetic subtypes of HIV-1 in the Philippines

OBJECTIVES

To determine the genetic variability of HIV-1 amongst infected Filipinos and to analyze phylogenetic relationships, temporal introductions and transmission dynamics of identified variants.

METHODS

Polymerase chain reaction amplification and direct sequencing of a 204 base-pair fragment of the env C2-V3 region from uncultured peripheral blood mononuclear cells obtained from 51 HIV-1-positive Filipinos infected from 1987 to mid-1996. Evolutionary distance and phylogenetic relationships among the DNA sequences were estimated.

RESULTS

The 51 Philippine strains were classified into five env V3 subtypes, namely subtype B (n = 37), subtype E (n = 8), subtype A (n = 3), subtype C (n = 2) and subtype D (n = 1). The overall env nucleotide divergence ranged from 11.7 to 32.2%. The nucleotide variation appeared to be random and no temporal ordering was observed. The variation of the sequences at the tip of the V3 loop was very broad. Subtypes B and C isolates did not show close genetic relationship to other Asian variants. Only three of the subtype E strains had close affinity to known Asian sequences. The majority (94%) of the subjects acquired the infection by sexual transmission. About two-thirds were presumably infected outside the Philippines, whereas the remaining were infected indigenously. Information was limited to allow segregation of the identified subtypes by mode of transmission or risk groups.

CONCLUSION

Our findings demonstrate the presence of multiple genetic subtypes of HIV-1 in the Philippines. The apparent geographic range of previously reported genotypes in South and South-east Asia was extended and has obvious implications for env-based antiviral interventions.

Evaluation of a targeted HIV prevention programme among female commercial sex workers in the south of Thailand

OBJECTIVE

To evaluate a targeted HIV prevention programme among female commercial sex workers (CSWs) in the south of Thailand.

SUBJECTS AND METHODS

A pretest-post-test comparison group study was carried out in Sungai Kolok and Betong between June and December 1994. In June 408 CSWs were entered in Sungai Kolok (the intervention area) and 343 CSWs were enrolled in Betong (the comparison area). In December 1994, 416 women were enrolled in Sungai Kolok and 342 in Betong. Of these women 37% (n = 283) also participated in the June survey. All women completed an oral interview and blood samples were collected for HIV serology. The intervention programme consisted of an informational and educational campaign and peer educator training.

RESULTS

Increase in knowledge and perceived vulnerability was more pronounced in the intervention area but did not translate into a greater increase in condom use. Refusal of customers unwilling to use a condom and manager support in doing so were the only factors independently related to positive changes in condom use. HIV prevalence (approximately 20%) and incidence (approximately 4.2 per 100 women years) were the same in both study locations. Women in the intervention area reported significantly fewer customers and income from sex work, possibly as a result of a coincidental police campaign to suppress (child) prostitution.

CONCLUSIONS

HIV incidence among CSWs in the south of Thailand is still high. Prevention programmes should focus on improvement of negotiation and refusal skills and manager support in using condoms.

Phylogenetic analysis of the nef gene reveals a distinctive monophyletic clade in Korean HIV-1 cases

To study the genetic variation of the HIV-1 strains prevalent in South Korea, we analyzed the nef sequences derived from 46 HIV-1-positive individuals living in various geographic regions in Korea. Phylogenetic analysis revealed four subtypes of HIV-1: A (3 patients), B (41 patients), D (1 patient), and a type that could not be clearly classified to any known subtype (1 patient). Thirty-five of the 41 Korean subtype B isolates formed a distinct monophyletic clade that is not related to any of the international sequences from the Los Alamos Database or GenBank as of June 1997. Indeed, the presence of unique conserved sequences was identified among the Korean isolates in this Korean subtype B group. The variations in the nucleotide sequences of a majority (32 of 35) subtype B samples within the Korean clade were 1.9% to 8.8%, and amino acid sequences varied from 3.9% to 15.5%. These results suggest that HIV-1 strains currently present in South Korea might have originated from a few sources or might be developing through a certain selective pressure. This is the first report on the molecular nature of the HIV-1 infection present in South Korea.

Epidemiology of HIV-1 infection in opiate users in Northern Thailand

Characterizing the epidemiology of HIV-1 infection in Northern Thai opiate users is important in developing control strategies in this ethnically diverse and culturally distinct region. A cross-sectional survey of drug users first admitted between 1993 and 1995 at the Northern Drug Dependence Treatment Center, Mae Rim, Thailand, was conducted. Patients (n = 4197) were interviewed at intake about their history of drug use when they provided serum specimens for HIV-1 antibody testing. The HIV-1 prevalence was 18.6%, with men having a fourfold higher prevalence than women. Wide diversity in HIV-1 prevalence was seen by ethnicity; the HIV-1 prevalence among Thai lowlanders was four times greater than that among ethnic minorities (hill tribes). Differences in HIV-1 prevalence were the result of differences in opiate use; hill tribes frequently smoked or ingested opium, whereas Thai lowlanders injected heroin. The high HIV-1 prevalence suggests that preventive interventions for risk reduction are urgently needed in these populations. Education about the risks of injection drug use (IDU) as well as information concerning needle disinfection and expansion of drug treatment are required to reduce the risk of HIV-1 transmission associated with sharing injection equipment. Further, increasing sources of sterile needles should be considered for active users, especially for those in more remote settings.

The association of herpes simplex virus type 2 (HSV-2), Haemophilus ducreyi, and syphilis with HIV infection in young men in northern Thailand

To evaluate the association between sexually transmitted diseases that commonly may cause genital ulceration and prevalent and incident HIV infections, we conducted three case control studies in a cohort of 21-year-old male military conscripts in northern Thailand. The men were evaluated at baseline in 1991 and semiannually until their discharge 2 years later. Serologic evidence of infection with herpes simplex virus type 2 (HSV-2), Haemophilus ducreyi, and HIV were more frequent at baseline in 83 men with a history of genital ulcer than in 97 men without such a history. Seropositivity to H. ducreyi (odds ratio [OR] = 3.46), HSV-2 (OR = 3.83), and syphilis (OR = 1.53) were more common in HIV-positive than HIV-negative men. Men (N = 45) who seroconverted to HIV while in the military were more often seropositive for H. ducreyi and HSV-2 before HIV seroconversion and also were more likely to seroconvert to HSV-2 and H. ducreyi during the same interval as their HIV seroconversion compared with men who remained HIV-negative. These data suggest that HSV-2 and H. ducreyi may be both markers for high-risk sexual behavior and risk factors for HIV infection among young men in Thailand.

Medication use by female sex workers for treatment and prevention of sexually transmitted diseases, Chiang Rai, Thailand

BACKGROUND

Female sex workers (FSWs) in Thailand are at high risk for sexually transmitted diseases (STDs). Although regular attendance at public STD clinics is required, FSWs may frequently use medications obtained in the community for STDs.

OBJECTIVES

To determine the frequency of use of medications for STDs from sources other than public STD clinics among FSWs in Thailand and to describe factors associated with such medication use.

METHODS

A cross-sectional survey of FSWs attending the public STD clinic in Chiang Rai, Thailand, was performed.

RESULTS

Of the 200 FSWs interviewed, 55% had ever used medications to treat or prevent STDs from a source other than a public STD Clinic, and 36% had done so in the prior year. Most use (79%) was to treat STD symptoms, and medication was most frequently obtained directly from a pharmacy (54%). This use of community medication for STDs was associated with younger age, non-Thai ethnicity, seeking STD treatment during the current clinic visit, and brothel-based sex work.

CONCLUSIONS

Use of medications from various sources in the community was common among these FSWs. Further research is needed to determine the appropriateness of this treatment. Innovative methods to ensure adequate quality STD care by community providers and to improve the health-care-seeking behaviors of these high-risk women are needed.

Langerhans cell tropism of human immunodeficiency virus type 1 subtype A through F isolates derived from different transmission groups

To test the hypothesis that some subtypes of human immunodeficiency virus type 1 (HIV-1), especially subtype E, are more likely to infect mature Langerhans cells (mLC), we titrated a panel of 26 primary HIV-1 isolates of subtypes A through F on peripheral blood mononuclear cells (PBMC) and mLC. The majority of HIV-1 isolates from heterosexually infected patients did not show a preferred tropism for mLC compared to homosexually transmitted HIV-1 isolates. Only 6 of 26 isolates, 2 from patients infected by homosexual contact and 4 from patients infected by heterosexual contact, showed a higher infectivity for mLC than for PBMC. Both syncytium-inducing and non-syncytium-inducing isolates were able to infect mLC which express mRNA for the chemokine receptors CCR3, CCR5, and CXCR4.

Human immunodeficiency virus type 1 strains of subtypes B and E replicate in cutaneous dendritic cell-T-cell mixtures without displaying subtype-specific tropism

A report that genetic subtype E human immunodeficiency virus type 1 (HIV-1) strains display a preferential tropism for Langerhans cells (epidermal dendritic cells [DCs]) compared to genetic subtype B strains suggested a possible explanation for the rapid heterosexual spread of subtype E strains in Thailand (L. E. Soto-Ramirez et al., Science 271:1291-1293, 1996). In an independent system, we applied subtype E and B isolates to skin leukocytes, since skin is a relevant model for the histologically comparable surfaces of the vagina and ectocervix. Isolates of both HIV-1 subtypes infected DC-T-cell mixtures, and no subtype-specific pattern of infection was observed. Purified DCs did not support the replication of strains of either subtype B or E. Our findings do not support the conclusion that subtype E strains have a preferential tropism for DCs, suggesting that other explanations for the rapid heterosexual spread of subtype E strains in Asia should be considered.

The molecular epidemiology of HIV-1 among male sex workers in northern Thailand

Male commercial sex workers (CSWs) in northern Thailand are at high risk for HIV-1 infection and may be exposed to multiple subtypes of HIV-1 through sexual contact with men and women from Thailand, other Asian nations, and the West. We studied 103 male Thai nationals working in gay bars and clubs in Chiang Mai city who participated in the 1994 sentinel surveillance of the Thai Ministry of Public Health using HIV serologic testing, DNA polymerase chain reaction methods, molecular cloning, differential colony hybridization, nucleotide sequencing, and a third hypervariable region (V3) peptide enzyme-linked immunoabsorbent assay to differentiate subjects infected with HIV-1 subtypes B, E, both, or neither. The majority (58%) reported heterosexual orientation, and 35 (34%) were married. Seventeen (16.5%) were HIV infected: 16 (94%) of 17 had HIV-1 subtype E; 1 had HIV-1 subtype B. Two subjects had dually reactive results by molecular techniques but colony hybridization sequencing revealed only HIV-1 subtype E. HIV-1 subtype E appears to be the predominant clade among male CSWs in northern Thailand. This may have important implications for the global kinetics of the HIV epidemic.

Association of contraceptives and HIV-1 infection in Thai female commercial sex workers

We conducted a case-control study to evaluate the association between contraceptive methods and HIV infection among Thai female commercial sex workers in Khon Kaen and Lumpang provinces, Thailand; 118 cases of HIV-1 infected sex workers were eligible for inclusion and 258 HIV-1 negative women were recruited as controls during the period of October 1, 1993 to December 31, 1994. Cases and controls were matched by age, education, parity, age at first exposure to commercial sex, number of clients per night, duration of work and sexual practice during menstruation. The ratio of case per control was 1:2. Both cases and controls were interviewed and underwent blood testing by a team of investigators. The study revealed no significant association between oral pill, injection, other contraceptives and HIV-1 infection. However, condom usage showed a significant protective effect. It is suggested that these contraceptives in this high-risk group of women do not increase the risk of HIV infection. In contrast, the use of condoms could reduce the risk of HIV infection.

Contexts and patterns of men's commercial sexual partnerships in northeastern Thailand: implications for AIDS prevention

Results of an exploratory research project elaborating the contexts, patterns and specific scenarios of the commercial sexual activity of northeastern Thai men are reported. Data were collected using face-to-face surveys, focus groups, key informant interviews and observations in 32 northeastern villages (n = 744 men), 18 migrant labour camps housing sugarcane workers (n = 219 men), and five cattlemarkets in northeast Thailand. Fifty percent of married men and 43% of single men had visited female sex workers (FSW). Female sex worker visits occurred primarily prior to marriage, though 13% of married men had purchased sexual services within the past year. Nonmarital sexual activity was set within the socio-cultural frameworks of poverty, circular migration, a large commercial sex sector, and a belief system about men's sexuality and men's and women's gender roles. Sexual services were typically purchased as part of friendship group partying (paiy tiaow) and generally included heavy alcohol consumption. The most common scenario for visiting FSWs involved brothels, though cattlemarkets, festivals, and migrant labour situations were also scenarios for FSW contact. These each had unique characteristics that affected the likelihood that condoms would be used. The further the specifics of a scenario (as evaluated by men) diverged from those of brothel contact with an FSW, the less likely men were to identify this as having the potential for HIV transmission and the less likely they were to use a condom. AIDS prevention campaigns must be developed that are sensitive to the socio-cultural framework, contexts and specific scenarios within which nonmarital sexual contacts occur.

Descriptive epidemiology of HIV/AIDS in Japan, 1985-1994

The HIV epidemic in Japan appears to be following a unique course, with no predominance of homosexual contact over heterosexual contact in reported cases and relatively little transmission by injection drug users and commercial sex workers. Infection rates are still low compared with those in southeast Asia and Western countries: 404 cases of nonhemophiliac AIDS (287 Japanese, 117 foreigners) and 1,441 cases of nonhemophiliac HIV infection (634 Japanese, 807 foreigners) were reported as of the end of 1994. Nevertheless, the numbers are increasing and the importance of targeted prevention programs is clear, particularly among those at higher risk because of sexual practices, such as homosexual men and commercial sex workers and their clients, or because of injection drug use. More data are needed to assess the impact of HIV/AIDS in Japan. These should include surveillance data as well as results from epidemiologic and behavioral studies.

A Tale of Two Countries: Attempts to Control HIV among Injecting Drug Users in Australia and the United States

Prevalence of injectable drug use is surprisingly similar in Australia and the United States. HIV prevalence among injection drug users (IDUs) is less than 5% in Australia and about 14% in the United States. IDUs accounted for 2.5% of AIDS cases in Australia in 1994 and 28% in the United States in 1993. Harm reduction was officially adopted in Australia in 1985 but has been explicitly rejected by the U.S. government. In 1994, needle programs exchanged over 10 million syringes from over 4,000 outlets in Australia while 55 needle exchange programs in the United States exchanged almost eight million syringes. Since 1985, methadone maintenance expanded almost ten-fold in Australia but barely increased in the United States. Timely and vigorous adoption of harm reduction strategies in Australia and the relative lack of such programs in the United States is the most plausible explanation for the good control of HIV among IDUs in Australia and poor control in the United States.

Correlation of genetic and serologic approaches to HIV-1 subtyping in Thailand

The aim of this study was to compare the performance of differential polymerase chain reaction (PCR) typing and peptide enzyme-linked immunosorbent assay (V3-EIA) for human immunodeficiency virus type 1 (HIV-1) subtyping in Thailand using heteroduplex mobility assay (HMA) as the reference standard. Paired peripheral blood mononuclear cells (PBMC) and sera were collected from 38 HIV-1 seropositive persons in Thailand. HMA was done by standard methods; differential PCR employs primer pairs that differentially amplify either subtype E or B. V3-EIA used peptides specific for subtypes E or B. Thirty-two cases (84%) were found by HMA to be infected with subtype E: and six with (16%) subtype B. The results obtained with differential PCR were 100% concordant with those of HMA; V3 EIA correctly predicted the subtype in 95% (36 of 38). Six samples that molecularly subtyped as E were repeatedly dual reactive by screening V3-EIA, but these resolved to subtype E using an antigen-limiting EIA. Two samples were serologically nontypeable because of overall low levels of V3 antibody. Using HMA as the standard, differential PCR was shown to subtype HIV-1 reliably from patient PBMC samples. V3-EIA correctly predicted HIV-1 subtype in most (95%) of our cases. Because of the less rigorous sampling requirements, specimen processing, and logistical and technical requirements of serotyping compared with molecular techniques, it appears to be practical for screening purposes in a field environment. Samples that cannot be definitively subtyped serologically should undergo differential PCR and antigen-limiting V3 EIA. These approaches to HIV-1 subtyping should be used in complementary fashion in Thailand, where subtypes B and E are currently known to cocirculate.

Travel-Related AIDS Awareness Among Young Gulf Arab Men

Background: The Federal Ministry of Health of the United Arab Emirates (UAE) has a vigorous AIDS control programme that conforms to international guidelines. Available information on HIV infection in the Al Ain district (UAE) shows a low incidence among its citizens and a low frequency of spread by the sexual route. This is in keeping with cultural factors perceived to have withstood the potential for sexual spread in the Arabian Gulf area. However, there is an acknowledged concern for the risk to young male citizens while traveling abroad to popular destinations such as India, Thailand, and the Philippines. Methods: The authors attempted to determine the knowledge and attitude about AIDS among Emirati males (aged 18-25 years) by confidential, self-administered questionnaire (modification of a tested approach in the UK). A total sample of 298 subjects participated (94% response), comprising 47 medical students (16%), 194 nonmedical students (65%), and 57 school graduates (19%). Of all participants, 253 (85%) were unmarried. Results: Salient discriminatory findings were that medical students significantly differed from the other two groups in stating that AIDS could not be identified in a person by appearance (p=.003) and that the use of condoms was protective while traveling abroad (p<.001). The latter issue also reflected a significant difference between married and unmarried subjects, in that marital status influenced a positive response to the protective role of condoms. Among all subjects, 41% had visited Asian countries outside the Gulf region and 20% intended to visit. Conclusion: This study demonstrated a prevailing uncertainty about AIDS knowledge and a possible fear of AIDS, both of which tend to increase acceptance of special education programmes.

Detection of HIV type 1 env subtypes A, B, C, and E in Asia using dried blood spots: a new surveillance tool for molecular epidemiology

Global surveillance of HIV-1 subtypes for genetic characterization is hampered by the biohazard of processing and the difficulties of shipping whole blood or cells from many developing country regions. We developed a technique for the direct automated sequencing of viral DNA from dried blood spot (DBS) specimens collected on absorbent paper, which can be mailed unrefrigerated in sturdy paper envelopes with low biohazard risk. DBS were collected nonrandomly from HIV-1-infected, mostly asymptomatic, patients in five Asian countries in 1991, and shipped via airmail or hand carried without refrigeration to Bangkok, and then transshipped to North America for processing. After more than 2 years of storage, including 6 months at ambient temperatures, proviral DNA in the DBS was amplified by nested PCR, and a 389-nucleotide segment of the C2-V3 env gene region was sequenced, from which 287 base pairs were aligned and subtyped by phylogenetic analysis with neighbor-joining and other methods. From southern India, there were 25 infections with subtype C and 2 with subtype A. From Myanmar (Burma), we identified the first subtype E infection, as well as six subtype BB, a distinct cluster within subtype B that was first discovered in Thailand and that has now appeared in China, Malaysia, and Japan. From southwest China, one BB was identified, while a "classical" B typical of North American and European strains was found in Indonesia. From Thailand, five DBS of ambiguous serotype were identified as three B, one BB, and one E. A blinded control serotype E specimen was correctly identified, but a serotype BB control was not tested. Most HIV-1 in southern India appears to be env subtype C, with rare A, as others have reported in western and northern India. The subtypes BB and E in Myanmar, and the BB in China, suggest epidemiological linkage with these subtypes in neighboring Thailand. DBS are a practical, economical technique for conducting large-scale molecular epidemiological surveillance to track the global distribution and spread of HIV-1 variants.