Leptospirosis in the Asia Pacific region.

BACKGROUND: Leptospirosis is a worldwide zoonotic infection that has been recognized for decades, but the problem of the disease has not been fully addressed, particularly in resource-poor, developing countries, where the major burden of the disease occurs. This paper presents an overview of the current situation of leptospirosis in the region. It describes the current trends in the epidemiology of leptospirosis, the existing surveillance systems, and presents the existing prevention and control programs in the Asia Pacific region. METHODS: Data on leptospirosis in each member country were sought from official national organizations, international public health organizations, online articles and the scientific literature. Papers were reviewed and relevant data were extracted. RESULTS: Leptospirosis is highly prevalent in the Asia Pacific region. Infections in developed countries arise mainly from occupational exposure, travel to endemic areas, recreational activities, or importation of domestic and wild animals, whereas outbreaks in developing countries are most frequently related to normal daily activities, over-crowding, poor sanitation and climatic conditions. CONCLUSION: In the Asia Pacific region, predominantly in developing countries, leptospirosis is largely a water-borne disease. Unless interventions to minimize exposure are aggressively implemented, the current global climate change will further aggravate the extent of the disease problem. Although trends indicate successful control of leptospirosis in some areas, there is no clear evidence that the disease has decreased in the last decade. The efficiency of surveillance systems and data collection varies significantly among the countries and areas within the region, leading to incomplete information in some instances. Thus, an accurate reflection of the true burden of the disease remains unknown.

Low frequency of infection with avian influenza virus (H5N1) among poultry farmers, Thailand, 2004.

In Thai provinces where avian influenza outbreaks in poultry had been confirmed in the preceding 6 months, serum from 322 poultry farmers was tested for antibodies to avian influenza virus subtype H5N1 by microneutralization assay. No study participant met the World Health Organization serologic criteria for confirmed infection.

Assessing the sensitivity of surveillance for pneumonia in rural Thailand.

We conducted a household survey among Sa Kaeo residents to characterize self-reported health-seeking behavior for pneumonia and the proportion of individuals who seek care at a hospital to determine the coverage of a surveillance system. A 2-stage cluster sample was used to select households. A case of pneumonia was defined as a self-reported history of cough and difficulty breathing for at least 2 days or being given a diagnosis of pneumonia by a healthcare provider in the 12-month period beginning February 1, 2002, and ending January 31, 2003. Interviewers administered a structured questionnaire that asked about clinical illness and utilization of healthcare services. Among 1,600 households, 5,658 persons were surveyed, of whom 62 persons met the case definition. Of the 59 persons with complete data, 53 (90%, 95% CI: 79-96) sought medical care and 47 (80%, 95% CI: 67-89) sought care at a hospital facility in the province. Neither distance nor cost was reported as a barrier to seeking care. Most individuals with self-reported pneumonia sought care at the hospital level. Population-based surveillance can provide reliable estimates of hospitalized, chest radiograph-confirmed pneumonia in Sa Kaeo if adjustments are made to account for the proportion of individuals who access a hospital where radiologic assessment is available.

HIV communication between husbands and wives: effects on husband HIV testing in northern Thailand.

In northern Thailand, where substantial male-to-female transmission of HIV has occurred in stable partnerships, the relationships between counseling, communication, and HIV-preventive behaviors in married couples have not been well studied. In a study of HIV incidence among women in northern Thailand, each participant was advised to learn her husband's HIV-infection status and was asked to bring him for an interview at the final 12-month follow-up visit. Of the 337 men interviewed, 58% reported having ever had an HIV test. More men reported testing following their wives' enrollment: 12% in the year prior to enrollment vs 22% during the 1-year study (p < 0.001). In the univariate analysis, men's HIV testing during the 6 months before being interviewed was associated with communication about HIV testing with their wife and extra marital sex with non-FSW while married. Testing following their wife's request was the most common reason reported. Agreement between husband's and wife's reports was poor for most issues, such as whether HIV-related communication had occurred, but agreement as to whether the husband had ever been tested for HIV was relatively high (kappa = 0.62). However, in the logistic regression analysis, only sex with non-FSW while married remained associated with HIV testing (p = 0.02). The results suggest a relationship between counseling, communication, and husband HIV testing. Better communication by couples may result in more effective use of HIV testing, which is already prevalent in this population, to prevent HIV transmission.

theta-Defensin pseudogenes in HIV-1-exposed, persistently seronegative female sex-workers from Thailand.

The leukocytes of rhesus monkeys contain cyclic octadecapeptides (theta;-defensins) that can protect cells from infection by HIV-1 in vitro. Although humans express mRNA from one or more theta;-defensin pseudogenes, these transcripts contain a premature stop codon that prevents formation of theta;-defensin peptides. We hypothesized that some highly exposed persistently seronegative (HEPS) individuals might have intact theta;-defensin (DEFT) genes and produce functional theta;-defensins that might account for their resistance to HIV-1 infection. We sequenced DEFT genes from 30 women in Chiang Rai, northern Thailand: 11 HEPS female sex-workers and 19 control women (10 HIV-1 infected and 9 HIV-1 uninfected). We found that theta;-defensin genes from all 11 HEPS women contained the crucial signal sequence stop codon, as did the 19 control women. Synthetic theta;-defensins based on the cDNA sequences to generate a human theta;-defensin (termed retrocyclin-1 and -2) were capable of inhibiting replication of Thai HIV-1 subtype B and CRF01_AE isolates regardless of the coreceptor utilization of the isolates. Although our study indicates that synthetic theta;-defensin peptides are effective in vitro against Thai subtype B and CRF01_AE isolates of HIV-1, the presence of premature stop codons in the DEFT genes of these HEPS women makes it unlikely that endogenous theta;-defensin production accounts for their resistance to HIV-1.

Polymorphisms in the CCR5 coding and noncoding regions among HIV type 1-exposed, persistently seronegative female sex-workers from Thailand.

Resistance to HIV-1 infection despite repeated exposures has been associated with one or more HIV-specific responses, enhanced nonspecific immune modifications, and/or host genetic polymorphisms in certain individuals (highly exposed, persistently seronegative, HEPS). In the present investigation, we focused on the CCR5 gene polymorphisms and the association of such mutations to resistance to HIV-1 infection among 12 HEPS women in Chiang Rai, northern Thailand, and compared our findings with data from 10 HIV-1-infected and 9 HIV-1-uninfected unexposed women from the same geographic area. Although we have previously shown that none of the Thai women carried the Delta32 mutation, further analysis of the CCR5 coding gene region revealed that none of the women had other mutations that affect coreceptor activity (C101X or FS299) or chemokine responses (C20S, A29S, L55Q, C178R). Analysis of the CCR5 promoter region revealed that the CCR5 haplogroup C (HHC; 60%) was the predominant haplogroup among these women. Comparative analysis of the frequencies of different haplogroups among the three groups did not reveal any statistically significant differences (p > 0.05). However, we did find that two individuals from the HEPS group were homozygous for HHF*2 (the CCR2b- 64I bearing haplogroup) compared to none from the HIV-1-infected and -uninfected groups. There was no detectable difference in specific CCR5 haplogroups and their ability to mediate env fusion or to mediate HIV-1 infection in vitro. These data suggest that homozygosity of the HHF*2 haplogroup may be one of the factors that mediate resistance to HIV-1 infection in this cohort of HEPS women.

Human immunodeficiency virus type 1 subtype and other factors associated with extrapulmonary Cryptococcosis among patients in Thailand with AIDS.

Delineating factors associated with extrapulmonary cryptococcosis (EPC), a major disease burden among Thailand's AIDS patients, can clarify its pathogenesis and guide preventive interventions. From November 1993 through June 1996, enhanced surveillance of 2261 human immunodeficiency virus (HIV)-seropositive patients in a hospital near Bangkok showed EPC among 561 of 1553 AIDS patients (36.1%). Univariate analysis results were confirmed by multivariate analyses of data on 1259 patients. Logistic regression models identified factors significantly associated with EPC to be male sex (adjusted odds ratio [aOR], 2.0; 95% confidence interval [CI], 1.3-2.9), age <33 years (aOR, 1.5; 95% CI, 1.2-1.9), severe immunosuppression (aOR, 1.8; 95% CI, 1.3-2.6), not injecting drugs (aOR, 3.0; 95% CI, 1.7-5.5), and infection with HIV-1 circulating from CRF01_AE (formerly subtype E) versus subtype B (aOR, 2.3; 95% CI, 1.2-4.5). The association with CRF01_AE may result from undetermined markers of exposure or viral subtype effects on host immune responses. Better understanding of the epidemiology of EPC may reduce EPC incidence through targeted primary prevention and treatment.

Infection control practices for SARS in Lao People's Democratic Republic, Taiwan, and Thailand: experience from mobile SARS containment teams, 2003.

BACKGROUND: Despite available recommendations on infection control for severe acute respiratory syndrome (SARS), information is limited on actual practices in Asian hospitals during the epidemic. We describe practices observed by mobile SARS containment teams (mobile teams) during outbreak investigations. METHODS: We retrospectively summarized infection control practices observed in hospitals visited by mobile teams in the Lao People's Democratic Republic (PDR), Taiwan, and Thailand, during March and April 2003. RESULTS: Mobile teams investigated 22 reports of SARS in 20 hospitals (1, 5, and 14 hospitals in Lao PDR, Taiwan, and Thailand, respectively). Facilities ranged from urban hospitals with negative-pressure isolation rooms and high-efficiency particulate air filtration to rural hospitals with patient rooms open to outside air circulation and intermittent running water. At the time of mobile team visits, 5 (25%) hospitals implemented infection control practices consistent with World Health Organization recommendations on visitor policies, private negative-pressure rooms, and personal protective equipment. CONCLUSIONS: Early in the SARS epidemic, mobile teams found wide variations in infection control practices and resources among Asian hospitals evaluating patients for SARS, indicating the importance of ongoing assessment during SARS preparedness. Mobile teams are one mechanism to assess practices and promote implementation of recommended infection control measures.

Knowledge and perceptions of HIV among peripartum women and among men whose wives are of reproductive age, northern Thailand.

To investigate knowledge and perceptions of HIV transmission risk and interest in vaginal microbicides in northern Thailand, we conducted 14 focus group discussions and 80 interviews with men and women in Chiang Rai province. Women were recruited from antenatal or postpartum clinics, and men from various work sites. Participants evinced substantial knowledge about HIV, with two exceptions important for prevention campaigns: (a) confusion about the window period between a new infection and positive HIV-test result and (b) overestimation of the safety of extramarital sex with partners who are not sex workers. Most participants reported no personal HIV risk. Participants described Thai women as generally vulnerable to HIV infection because of the unlikelihood of condom use with their husbands and because women cannot control their husbands' extramarital behavior. Women apparently face particular risk after childbearing; peripartum abstinence averages 6-9 months, during which time some Thai men may have alternative sex partners. Women, and to a lesser degree, men were interested in potential microbicides, although they voiced many thoughtful questions about the products and about efficacy trials.

Sexual coercion among adolescents in northern Thailand: prevalence and associated factors.

Sexual coercion was assessed in a cross-sectional survey of drug use and sexual behavior in vocational school students from Chiang Rai, Thailand (n = 1725; ages 15-21), using audio-computer assisted self-interview. Sexual coercion was reported by 6.5% of males and 21% of females. Mean age at first occurrence was 16 years (range 8-20) among males and 17 years (range 5-21) among females. Most perpetrators were male (52% among males; 98% among females) and known by the participants. Among females, associated factors were history of pregnancy, selling sex, marijuana use, perceived risk of STD, two or more lifetime sexual partners, and living away from family. Among males, associated factors were homo- or bisexual self-identification, parents living together, and ulcerative STD history.

Early containment of severe acute respiratory syndrome (SARS); experience from Bamrasnaradura Institute, Thailand.

BACKGROUND: On March 11, 2003, a World Health Organization (WHO) physician was admitted to Bamrasnaradura Institute, after alerting the world to the dangers of severe acute respiratory syndrome (SARS) in Vietnam and developing a fever himself. Specimens from the first day of his admission were among the first to demonstrate the novel coronavirus, by culture, reverse transcription-polymerase chain reaction (RT-PCR), and rising of specific antibody, but proper protective measures remained unknown. The authors instituted airborne, droplet and contact precautions from the time of admission, and reviewed the efficacy of these measures. MATERIAL AND METHOD: A specific unit was set up to care for the physician, beginning by roping off an isolated room and using a window fan to create negative pressure, and later by constructing a glass-walled antechamber, designated changing and decontamination areas, and adding high-efficiency particulate air (HEPA) filters. The use of personal protective equipment (PPE) was consistently enforced by nurse managers for all the staff and visitors, including a minimum of N95 respirators, goggles or face shields, double gowns, double gloves, full head and shoe covering, and full Powered Air Purifying Respirator (PAPR) for intubation. To assess the adherence to PPE and the possibility of transmission to exposed staff a structured questionnaire was administered and serum samples tested for SARS coronavirus by enzyme-linked immunosorbent assay (ELISA). Exposure was defined as presence on the SARS ward or contact with laboratory specimens, and close contact was presence in the patient's room. RESULTS: The WHO physician died from respiratory failure on day 19. 112 of 129 exposed staff completed questionnaires, and the 70 who entered the patient's room reported a mean of 42 minutes of exposure (range 6 minutes-23.5 hours). 100% reported consistent handwashing after exposure, 95% consistently used a fit-tested N95 or greater respirator, and 80% were fully compliant with strict institutional PPE protocol. No staff developed an illness consistent with SARS. Serum samples from 35 close contacts obtained after day 28 had a negative result for SARS coronavirus antibody. CONCLUSIONS: Hospitalization of one of the earliest SARS patients with documented coronavirus shedding provided multiple opportunities for spread to the hospital staff, but strict enforcement of conservative infection control recommendations throughout the hospitalization was associated with no transmission.

Safety and acceptability of the candidate microbicide Carraguard in Thai Women: findings from a Phase II Clinical Trial.

OBJECTIVE: To determine the safety and acceptability of vaginal application of Carraguard, a carrageenan-derived candidate microbicide gel. DESIGN: A randomized, placebo-controlled, triple-blinded clinical trial was conducted in Chiang Rai, northern Thailand. METHODS: Women were asked to insert one applicator of study gel vaginally at least three times per week (with or without sex) and to use gel with condoms every time they had sex. Safety was assessed by visual inspection of the vagina and cervix, changes in vaginal flora and self-reported symptoms at day 14, month 1 and then monthly for up to 1 year. Acceptability was assessed through reported use of the gel, return of used and unused applicators, and quarterly interviews. RESULTS: One hundred sixty-five women were randomized: 83 to Carraguard and 82 to the placebo (methylcellulose gel) group. Study gel use was similarly high in both groups throughout the trial with an average of four applicators per week. Carraguard use was not associated with abnormal genital clinical findings, abnormal vaginal flora, Pap smear abnormalities or other abnormal clinical signs or symptoms. Adverse events were mostly mild, not attributed to gel use, and similarly distributed between groups. Participants in both groups reported high acceptability. CONCLUSIONS: Carraguard can safely be used an average of four times per week with or without sex and is acceptable to Thai women. A Phase III efficacy trial of Carraguard is warranted and is currently ongoing in South Africa.

High rates of pregnancy among vocational school students: results of audio computer-assisted self-interview survey in Chiang Rai, Thailand.

Unplanned pregnancy among young people can lead to adverse social, psychological, and health outcomes, particularly when it results in abortion. In 1999, we examined the prevalence of and factors associated with pregnancy and abortion among 1725 consenting vocational school students in northern Thailand. Results from an audio computer-assisted self-interview showed that 48% of the male and 43% of the female students reported ever having had sexual intercourse. Among those who had had intercourse, 27% of the women and 17% of the men said they or their partner had ever been pregnant. Among the last reported pregnancies that resulted in delivery or abortion, 95% were aborted. Age, current contraceptive use, early initiation of sexual intercourse (

Rapid whole-blood finger-stick test for HIV antibody: performance and acceptability among women in northern Thailand.

Although use of rapid HIV antibody tests of finger-stick blood specimens could expand voluntary counseling and testing in areas where fear of venipuncture and delays in learning test results are barriers, there is little information on performance and acceptability of these tests in Asia. We used the Hema. Strip HIV-1/2 test (Saliva Diagnostic Systems, Vancouver, WA) in a prospective cohort study of HIV seroincidence among women in northern Thailand from 1998 to 1999. Nurses obtained whole-blood specimens by finger-stick testing and provided test results and counseling at each visit. Acceptability of the rapid test was assessed at the first 6-month follow-up visit. HIV-1 seroprevalence among the 804 women screened at enrollment was 3.1%. Positive rapid test results from 25 women were confirmed by enzyme immunoassay and Western blot analysis using serum obtained by venipuncture. Of the 741 women who returned for follow-up, 56% preferred specimen collection by finger-stick testing to venipuncture, 80% preferred immediate rather than delayed test results, 79% preferred the rapid test method to typical testing methods, and 97% were satisfied with the test method used. Results from this study demonstrate the utility and acceptability of the rapid finger-stick test for HIV antibody among women in northern Thailand.

The prevalence of bisexual and homosexual orientation and related health risks among adolescents in northern Thailand.

Homo- or bisexual (HB) adolescents may have greater and different health risks than the population of heterosexual adolescents. We assessed sexual orientation and health risk behaviors in 1,725 consenting 15- to 21-year-old vocational school students in northern Thailand. Data were collected using audio-computer-assisted self-interviewing. Nine percent of males and 11.2% of females identified themselves as homo- or bisexual. HB males had an earlier mean age at sexual debut (14.7 years) and a higher mean number of lifetime sexual partners (7.9) than did heterosexual males (16.8 years and 5.8 partners, respectively). HB males (25.9%) and females (32.2%) were sexually coerced more often than were heterosexual males (4.6%) and females (19.6%). Drug use was reported significantly more frequently by HB females and significantly less frequently by HB males than by their heterosexual counterparts. HB males showed more signs of social isolation and depression than did heterosexual males. We conclude that HB adolescents in northern Thailand are at greater and different health risks than are their heterosexual counterparts. Differential health education messages for HB and heterosexual youth are warranted.

Incidence of HIV-1 infection and effects of clinic-based counseling on HIV preventive behaviors among married women in northern Thailand.

To determine the incidence of and risk factors for HIV-1 infection among married women in northern Thailand, we enrolled 779 seronegative women from family planning clinics and a postpartum ward in Chiang Rai, Thailand, from 1998 through 1999. Women were tested for HIV antibodies at 6 and 12 months after enrollment. They received HIV prevention counseling at enrollment and at each follow-up visit. Counseling covered partner communication, partner HIV testing, and condom use by steady partners. Effects of counseling were measured using standardized questionnaires. Follow-up rates were 94% at 6 months and 92% at 12 months. Only 1 woman seroconverted during the follow-up period, yielding an overall HIV incidence of 0.14 per 100 person-years. After receiving counseling, women reported significantly increased communication with husbands concerning HIV risk, HIV testing, and condom use during the first 6 months after enrollment; communication remained high for 6 to 12 months. Women reported a modest increase in HIV testing and consistent condom use by husbands. The risk for HIV transmission to women in steady relationships is low in northern Thailand. Although HIV prevention counseling promoted partner communication, its effects on HIV preventive behaviors were limited.