Peru-15 (Choleragarde(®)), a live attenuated oral cholera vaccine, is safe and immunogenic in human immunodeficiency virus (HIV)-seropositive adults in Thailand.

BACKGROUND: Many areas with endemic and epidemic cholera report significant levels of HIV transmission. According to the World Health Organization (WHO), over 95% of reported cholera cases occur in Africa, which also accounts for nearly 70% of people living with HIV/AIDS globally. Peru-15, a promising single dose live attenuated oral cholera vaccine (LA-OCV), was previously found to be safe and immunogenic in cholera endemic areas. However, no data on the vaccine's safety among HIV-seropositive adults had been collected. METHODS: This study was a double-blinded, individually randomized, placebo-controlled trial enrolling HIV-seropositive adults, 18-45 years of age, conducted in Bangkok, Thailand, to assess the safety of Peru-15 in a HIV-seropositive cohort. RESULTS: 32 HIV infected subjects were randomized to receive either a single oral dose of the Peru-15 vaccine with a buffer or a placebo (buffer only). No serious adverse events were reported during the follow-up period in either group. The geometric mean fold (GMF) rise in V. cholerae O1 El Tor specific antibody titers between baseline and 7 days after dosing was 32.0 (p<0.001) in the vaccine group compared to 1.6 (p<0.14) in the placebo group. Among the 16 vaccinees,14 vaccinees (87.5%) had seroconversion compared to 1 of 16 placebo recipients (6.3%). V. cholerae was isolated from the stool of one vaccinee, and found to be genetically identical to the Peru-15 vaccine strain. There were no significant changes in HIV viral load or CD4 T-cell counts between vaccine and placebo groups. CONCLUSION: Peru-15 was shown to be safe and immunogenic in HIV-seropositive Thai adults.

Oseltamivir and inhaled zanamivir as influenza prophylaxis in Thai health workers: a randomized, double-blind, placebo-controlled safety trial over 16 weeks.

OBJECTIVES: Long-term chemoprophylaxis using neuraminidase inhibitors may be needed during influenza epidemics but safety data are limited to several weeks. We sought to assess the tolerability of oseltamivir and zanamivir as primary prophylaxis over 16 weeks. METHODS: We conducted a parallel group, double blind, 2 (active drug) :1 (placebo) randomized trial of oral oseltamivir/placebo or inhaled zanamivir/placebo over 16 weeks in healthy, Thai hospital professionals at two Bangkok hospitals. The primary endpoint was study withdrawal due to drug-related (possibly, probably, definitely) serious or adverse events (AEs) graded ≥ 2. RESULTS: Recruited subjects numbered 129 oseltamivir/65 placebo and 131 zanamivir/65 placebo. A total of 102 grade ≥ 2 AEs were reported or detected in 69 subjects: 23/129 (17.8%) versus 15/65 (23.1%) (P=0.26), and 23/131 (17.6%) versus 8/65 (12.3%) (P=0.28). Intercurrent infections/fevers [26/102 (25.5%)], abnormal biochemistry [25/102 (24.5%)] and gastrointestinal symptoms [18/102 (17.6%)] were the most frequently reported AEs. There were no drug-related study withdrawals. Eight serious AEs were all due to intercurrent illnesses. Laboratory, lung function and ECG parameters were similar between drugs and placebos. CONCLUSIONS: Oseltamivir and zanamivir were well tolerated in healthy hospital professionals. Both drugs can be recommended for primary influenza prophylaxis for up to 16 weeks.

Quantitation of human immunodeficiency virus type 1 DNA by competitive nested PCR assay.

A quantitative competitive nested PCR assay was developed for quantifying HIV-1 proviral DNA in clinical samples. A competitor DNA was constructed from a conserved region of the HIV-1 gag gene by deleting a sequence of 18 base pairs. We quantitated HIV-1 proviral DNA copy number in clinical samples. Peripheral blood mononuclear cells (PBMCs) from 35 HIV-infected patients with a CD4 count range of 4-728 cell/mm3 were analyzed by this method. The copy numbers of HIV-1 DNA detected ranged between 518 to 67,340 copies per 10(6) CD4+ T-cells. The copy numbers correlated inversely with the CD4 counts.

Target cell populations of human immunodeficiency virus type 1 in peripheral blood lymphocytes with different chemokine receptors at various stages of disease progression.

We studied the distribution of human immunodeficiency virus type 1 (HIV-1) DNA in CCR5-positive and -negative peripheral blood lymphocyte populations in HIV-1-infected individuals. While HIV-1 DNA in the CCR5-positive population showed no correlation with CD4 count, the increase of total HIV-1 DNA with lower CD4 count was mainly contributed by the increase of HIV-1 DNA in the CCR5-negative population. This might indicate the change in coreceptor usage from CCR5 to CXCR4 in later stages of disease progression. However, some of the samples with a high viral DNA load in the CCR5-negative population did not have any characteristic of the V3 loop sequence that is compatible with CXCR4 usage or the syncytium-inducing (SI) phenotype. We also did not find any known characteristic change predictive of the SI phenotype in V1 and V2 sequences. Our findings showed that there might be a shift in target cell populations during disease progression, and this shift was not necessarily associated with the genetic changes characteristic of CXCR4 usage.

A randomized, open-label, comparative trial of zidovudine plus lamivudine versus zidovudine plus lamivudine plus didanosine in antiretroviral-naive HIV-1-infected Thai patients.

OBJECTIVE: To assess the efficacy and tolerability of a triple nucleoside reverse transcriptase inhibitor combination of zidovudine, lamivudine, and didanosine therapy. DESIGN: A randomized open-label trial. PATIENTS: Antiretroviral-naive HIV-infected patients with CD4+ cell counts of 100 to 500 cells/microl. METHODS: A total of 106 patients were randomly assigned to 300 mg of zidovudine (200 mg for body weight <60 kg) twice daily plus 150 mg of lamivudine twice daily plus 200 mg of didanosine (125 mg for body weight <60 kg) twice daily (n = 53) or to zidovudine plus lamivudine (n = 53) for 48 weeks. MAIN OUTCOME MEASURES: Degree and duration of reduction of HIV-1 RNA load and increase in CD4+ cell counts from baseline and development of drug-related toxicities. RESULTS: At 48 weeks, triple drug therapy showed greater declines in plasma HIV-RNA levels from the beginning of treatment than double drug therapy (1.86 vs. 1.15 log10 copies/ml, respectively; p <.001). The proportions of patients with HIV-RNA <50 copies/ml in an intention-to-treat analysis were 54.7% (29 of 53 patients) and 11.3% (6 of 53 patients) in the triple and double drug therapy, respectively (p =.001). There was no significant difference in increase of CD4 count. CONCLUSION: Triple drug therapy with zidovudine, lamivudine, and didanosine was significantly more effective in inducing sustained immunologic and virologic responses than the double combination of zidovudine and lamivudine.

Protozoan enteric infection in AIDS related diarrhea in Thailand.

The aim of this study was to determine the prevalence of enteric protozoa and other pathogens in AIDS patients with diarrhea in Bangkok, Thailand. Of 288 consecutive patients screened in the 10 month period between November 1999-August 2000 inclusive, 55 (19.2%) had Cryptosporidium spp, 13 (4.5%) had Isospora oocyst, 11 (3.8%) had Giardia lamblia, 3 (0.9%) had Entamoeba histolytica, and 1 (0.3%) had Iodamoeba butschlii infection. The prevalence of microsporidia was 11% in this study. Of 251 patients for whom stool culture for bacteria was performed, enteric bacterial pathogens isolated were Campylobacter spp in 18 (7.1%), Salmonella spp in 11 (4.3%), and Shigella spp in 1 (0.5%). Other pathogens found in these patients were Clostridium difficile in 16/102 (15.6%). Mycobacterium spp in 18/287 (6.2%), and Strongyloides stercoralis in 23/288 (8.0%). Overall, parasitic and bacterial pathogens were identified in 140 (48.6%) patients. These pathogens were identified by the routine simple wet smear technique in 32, formalin-ether concentration method in 46, culture for S. stercoralis in 5, and culture for bacteria in 30. Additional test, using modified Ziehl-Neelsen staining, identified cryptosporidial oocyst, isospora oocyst, and Mycobacterium spp in 72. The microsporidia, initially identified by modified trichrome blue staining, all were then determined to be Enterocytozoon bieneusi by thin sectioning electron microscopy. Protozoan and bacterial pathogens were confirmed to be important etiologic agents in diarrhea in AIDS in Thailand. They were all associated with increased mortality. Routine stool examination by simple wet smear detected only one-fourth of these pathogens. Therefore all diagnostic techniques for these organisms should be made more widely available in Thailand.

A comparison of two dosing regimens of zidovudine in Thai adults with early symptomatic HIV infection. Conducting clinical HIV trials in South-East Asia.

AIM: To compare the clinical and immunological efficacy, and tolerance of two dosage regimens of zidovudine (ZDV) in an adult Thai population with early symptomatic human immunodeficiency virus (HIV) disease and to identify important clinical issues associated with conducting HIV trials in South-East Asia. METHODS: HIV-infected Thai adults, with early symptomatic HIV disease and CD4 lymphocyte counts less than 400/mm3, who were managed in the infectious diseases clinics at two university teaching hospitals in Bangkok, Thailand, were enrolled in a randomised, open-label, dose-regimen comparison trial of ZDV. Two oral ZDV dosing regimens: regimen A, 100 mg tid+200 mg nocte (ZDV-A) vs regimen B, 250 mg bid (ZDV-B) were compared. The main outcome measures were: 1. Clinical efficacy: rate of progression to acquired immunodeficiency syndrome (AIDS) or death. 2. Immunologic efficacy: changes in CD4 lymphocyte numbers compared to baseline; rate of decline of CD4 lymphocyte numbers to less than 100/mm3. 3. Toxicity, as defined by clinical symptomatology and laboratory parameters. RESULTS: Two hundred and four patients were enrolled (103 ZDV-A; 101 ZDV-B) of whom 195 were followed beyond baseline. Patients were typical of those encountered with HIV in Thailand: mean age 33 years; 89% male; 88% heterosexual HIV acquisition; mean baseline CD4 lymphocyte count 241/mm3. Follow-up while on therapy was comparable for the two groups (mean+/-SD): 533+/-236 days (ZDV-A) vs 592+/-210 days (ZDV-B). One hundred and eleven patients (57%; 51 ZDV-A; 60 ZDV-B) were treated for at least 22 months (669+/-30 days). Clinical and immunological outcomes for ZDV-A and ZDV-B, including rate of progression to AIDS or death, development of non-AIDS-defining opportunistic infections, mean changes in CD4 lymphocyte numbers/mm3, difference in area under the CD4:time distribution curve and difference in the rate of decline of CD4 lymphocyte numbers to less than 100/mm3, were not significantly different. The presence of oral hairy leukoplakia or unintentional weight loss of 10-20% at enrollment were significantly associated with the later development of AIDS (p=0.03 and 0.04, respectively). ZDV-associated toxicity was similar for both regimens. Maintaining protocol adherence and appropriate clinical follow-up emerged as important practical issues. CONCLUSION: In Thai adults, ZDV 100 mg tid+200 mg nocte and ZDV 250 mg bid have similar clinical and immunological efficacy. Rates of ZDV toxicity are comparable to those reported in non-Asian populations. Despite limitations in medical care access and maintaining long-term follow-up, successful trials of antiretroviral agents are feasible in South-East Asia and multi-drug treatment trials should be pursued in appropriate institutions.

A randomized, controlled 24-week study of intermittent subcutaneous interleukin-2 in HIV-1 infected patients in Thailand.

OBJECTIVES: To assess the immunological and virological effects, safety profile and feasibility of subcutaneous interleukin-2 (scIL-2) therapy in an HIV-infected Thai population. DESIGN: Seventy-two patients with baseline CD4 cell count of > or = 350 x 10(6)/l and no history of opportunistic infection were randomized to receive antiretroviral therapy plus scIL-2 (scIL-2 group) or antiretroviral therapy alone (control group). scIL-2 was administered at one of three doses for at least 24 weeks. The main measure of treatment efficacy was change in CD4 cell count. RESULTS: The time-weighted mean change in CD4 cell count from baseline to week 24 was + 252 x 10(6)/l for the scIL-2 group compared with + 42 x 10(6)/l for the control group (P< 0.0001). Changes in plasma HIV RNA were not significantly different between the groups over the same time period: there was a 0.83 log10 copies/ml decrease for the scIL-2 group and a 0.70 log copies/ml decrease for the control group (P= 0.362). CONCLUSIONS: This study provides the most extensive experience of scIL-2 therapy in HIV-1 infected women and Asians, and demonstrates the immunological efficacy, tolerability and feasability of scIL-2 therapy in this population. Data from this study were instrumental in guiding the selection of the scIL-2 dosing regimen for ongoing phase III trials.

Prevalence of disseminated Mycobacterium avium complex infection in Thai AIDS patients.

Infections caused by nontuberculous mycobacteria (NTM), although rare in immuno-competent individuals, can potentially produce problems in immunocompromised patients such as those with acquired immunodeficiency syndrome (AIDS). In this study, hemocultures for mycobacteria using radiometric BACTEC 13A media were taken from 334 patients with known human immunodeficiency virus infection admitted to four referral hospitals with fever of unknown site of infection and negative blood cultures for pathogenic bacteria. The mycobacterial hemocultures were positive for Mycobacterium avium complex (MAC) in 58 patients (17.4%) and positive for Mycobacterium tuberculosis in 34 patients (10.2%). The results of this study have proved that MAC infection, indeed, exists among Thai AIDS patients. The prevalence of MAC infection in Thailand is very high and comparable to that in the western countries. Physicians taking care of AIDS patients in Thailand should be aware of potential MAC infection, particularly in advanced cases. Considering the high prevalence of infection, primary prophylaxis against MAC infection in advanced AIDS patients is recommended.

Prolonged fever due to Mycobacterium avium complex (MAC) disease in advanced HIV infection: a public health concern.

From March 1997 to June 1998, infectious etiologies of prolonged fever was prospectively investigated in 104 advanced human immunodeficiency virus (HIV) infected patients admitted to Siriraj Hospital. The etiology could be identified in 91 cases (87.5%). Of these, blood cultures from 68 patients yielded mycobacteria and fungi. Mycobacterium avium complex was the most common blood isolate in 24 per cent of the patients; followed by Mycobacterium tuberculosis in 20.2 per cent, Cryptococcus neoformans in 5.8 per cent, Penicillium marneffei in 5.8 per cent. During the course of febrile illness, 79 of the 91 patients (86.8%) exhibited focal lesions. Weight loss, elevated serum alkaline phosphatase were often found to be significantly more associated with MAC bacteremia (P < 0.05). Pulmonary involvement significantly correlated more with M. tuberculosis bacteremia than MAC bacteremia (P < 0.05). No cause could be identified in 13 cases. Mycobacterium blood culture alone established the etiologies in 68 cases (65.4%). Of the 25 patients with disseminated MAC (DMAC) infection, nine patients died during hospitalization. Another three cases died within a few months of appropriate anti-MAC chemotherapy. We concluded that the risk of DMAC infection in advanced AIDS patients in Thailand is high when low CD4 lymphocyte count is established. The prolonged fever resulted from DMAC in advanced HIV infection is warrant to be public health concern. Mycobacterium blood culture is a most valuable tool contributing to the diagnosis of infectious agents in this condition. The guidelines of 1997 USPHS/IDSA should be followed to give chemoprophylaxis against DMAC disease in patients with advanced HIV infection and a CD4 count less than 50 cells/mm3.

Primary cryptococcal infection of the larynx in a patient with AIDS: a case report.

Primary laryngeal cryptococcosis was reported in a 42-year-old man with AIDS. The patient also had pulmonary tuberculosis and hydropneumothorax as a complication. Serological tests and/or cultures from blood, CSF, urine and pleural fluid were all negative for cryptococcus. He was successfully treated with oral fluconazole for 8 weeks to clear the infection and remained clear in the follow-up period 9 months after treatment.

The mounting medical care cost for adult AIDS patients at the Faculty of Medicine, Siriraj Hospital: consideration for management.

From January 1993 to December 1995, case records of adult AIDS and HIV symptomatic patients admitted in the Department of Medicine, observation room and HIV Counseling Clinic were reviewed for the medical care cost of the patients based on the 1995 value of the Thai baht. In the three years, a total of 196, 227 and 182 adult AIDS case were admitted as in-patients respectively. The median duration of admission was 14 days. The leading causes of admission were tuberculosis, cryptococcal meningitis, Pneumocystis carinii pneumonia, diarrhea, salmonellosis and toxoplasmosis. An increase in the number of AIDS patients in the observation room was observed: from 572 cases in 1993 to 1,205 cases in 1995. In addition, approximately 600 AIDS cases were followed up at four to eight week intervals. The analysis of the data found an average medical care cost for hospitalized patients to be 1,452 baht per day while in the observation room it was 1,509 baht per day and 1,132 baht per month for the patients attending the HIV and Counseling Clinic. Because of the higher number of cases and the limited number of admission beds, only 15 per cent of AIDS patients in the observation room could be admitted as hospitalized patients. At present, it is urgent that a referral network be established among all university hospitals, all government hospitals and health centers. In this way, the more advanced medical facilities can serve as a primary diagnostic center which can refer patients for care and follow-up based on an established referral system. In addition, the development of a hospice service and community care is needed for cases in the terminal stage of the illness.

PIP: This study examines case records of adult AIDS and HIV symptomatic patients admitted to the Siriraj Hospital's Department of Medicine during January 1993 and December 1995. The study aims to determine the medical care cost of adult AIDS patients admitted to the observation room, hospital, and HIV and Counseling Clinic and to determine which factors are the most costly. An AIDS diagnosis is determined according to the Thailand Ministry of Health protocols. Costs include medication cost, facility cost, and testing in 1995 baht prices. Government-supplied medicines are not included in the cost. AIDS cases numbered 196, 227, and 182 adult persons in the respective years 1993, 1994, and 1995. The median CD4 lymphocyte count was 59 cells/mm. The median duration of visit was 14 days. AIDS patients occupied 5.4-7% of inpatient admission beds. 17.6-18.8% of patients were readmitted during the year. 26.4% to 33.7% died before discharge. The leading cause of admission was tuberculosis cryptococcal meningitis, pneumocystis carinii pneumonia, diarrhea, salmonellosis, and toxoplasmosis. The number of AIDS cases admitted to the observation room for 2-5 days increased from 572 cases in 1993 to 1205 cases in 1995. However, due to space limitations, only 15% of AIDS patients under observation were admitted to the hospital in 1995. About 600 cases each year were followed up for complications. Medical care costs were 1452 baht/day/patient for admissions; 1509 baht/day/patient in an observation room; and 1132 baht/month/patient for HIV counseling care. The average cost for all adult AIDS patients/year rose from 18,726,176 baht to 26,812,204 baht during 1993-95. Medicine costs almost tripled for treating cryptococcoses. Treatment costs are lower in provincial hospitals. There is a need for the establishment of a referral network, hospice care, and low costs for treatment.

Evaluation of the MycoDot test for the diagnosis of tuberculosis in HIV seropositive and seronegative patients.

SETTING: Patients were recruited from Siriraj, Bamrasnaradura, and Central Chest Hospitals, the three major hospitals responsible for tuberculosis patients in Bangkok, Thailand, and vicinity. OBJECTIVE: To evaluate a new rapid serologic test, the MycoDot test, for diagnosis of tuberculosis (TB). DESIGN: The study was conducted as a cross-sectional survey. A total of 594 patients were tested with the MycoDot test. This included 142 human immunodeficiency virus (HIV) seropositive patients with active TB, 144 HIV seronegative patients with active TB, 153 HIV seropositive controls, and 155 HIV seronegative controls. RESULTS: The sensitivity of the MycoDot test for detection of TB was 40.1% in HIV seropositive patients, compared with 63.2% in HIV seronegative patients (P < 0.001). If only patients with laboratory proven TB were evaluated, the sensitivity was 40.6% in seropositive and in 70.8% seronegative patients. The sensitivity of the MycoDot test was similar in TB patients with pulmonary and extra-pulmonary disease. The sensitivity of the test in patients with CD4 counts > or = 200 cells/mm3 was significantly higher than in those with CD4 counts < 200 cells/mm3. The specificity of the test was 97.4%, and was identical in HIV seropositive and seronegative individuals. CONCLUSION: The MycoDot test had a higher sensitivity for the diagnosis of TB among HIV seronegative than HIV seropositive patients. Although the MycoDot test has a less than optimal sensitivity, the test specificity approaches 100%. It may be useful in patients with suspected TB and negative smears and in extra-pulmonary TB.

Urinary tract infection in the elderly: a clinical study.

Urinary tract infection is one of the most common causes of infection in the elderly living in the community as well as in institutions. While the preventive measures involve the enhancement of immunological status, perineal hygiene and avoiding unnecessary instrumentation, the clinical manifestation predicting the outcome, the main objective of the study, is also no less important after the infection takes place. Cross-sectional study was designed recruiting 107 cases from the general medical wards to compare various relevant clinical parameters in terms of the final outcome. The result showed that the aged group 75 years old or more, the catheter-related cases, prior bedbound status, confusion, anorexia with nasogastric tube feeding, respiratory failure requiring mechanical ventilation, septic shock, the presence of candida in urine, the extreme temperature either less than 37 degrees C or more than 40 degrees C and finally the mistake in interpreting the gram stain of the urine were found more common in the dead group with statistical significance. Multiple logistic regression analysis revealed anorexia with nasogastric tube feeding, prior bedbound status, the need for mechanical ventilation, septic shock and extreme body temperature response independently predicted the outcome of the elderly with urinary tract infection.

A comparative study of tuberculin skin test reactivity between asymptomatic HIV-1 seropositive subjects and healthy volunteers.

During November 1993-October 1994 tuberculin skin test reactivity (PPD-Thai Red Cross: 0.1 ml of 10 IU) was determined among 399 asymptomatic HIV-1 positive subjects and 405 healthy volunteers, 10% (40/399) had PPD-TRC induration 0-2 mm compared with 4.2% (17/405) (p = 0.001) and 43.4% (173/399) had induration > or = 10 mm compared with 53.8% (218/405) (p = 0.003) of healthy volunteers. However, the percentage of the PPD-TRC induration 5-9 mm was similar among HIV-1 seropositive subjects and healthy volunteers as 37.6% (150/399) vs 34.8% (141/405) (p = 0.4). The mean PPD-TRC reaction of HIV-seropositive subjects were 6.4 +/- 0.9 mm vs. 11.0 +/- 0.5 mm among those with CD4 lymphocyte counts 200-299 cells/mm3 compared with those > or = 300 cells/mm3 (p < 0.001). We provide support for use of induration of > or = 5 mm of PPD-TRC skin reaction for evidence of latent infection with Mycobacterium tuberculosis as the CDC recommendation in asymptomatic HIV-seropositive subjects. Consideration of tuberculosis chemoprophylaxis should have benefit, particularly in areas where M.tuberculosis is highly prevalent such as Thailand. However, among HIV-1 seropositive carriers with negative tuberculin (PPD-TRC) skin tests, there needs to be a careful evaluation and follow-up for evidence of tuberculous infection.

Seroprevalence of anti-HCV among HIV-infected persons and general population.

From November 1993 to December 1994, the seroprevalence of anti-HCV, HBsAg was studied among 346 HIV-infected persons (asymptomatic HIV-infected persons and AIDS patients) and 1,023 subjects from the general population (including 119 cord blood samples). The prevalence of anti-HCV, HBsAg among HIV-infected patients aged 15-45+ years was 11.0 and 11.6 per cent respectively which is significantly higher than the comparable levels for the general population (1.9% and 4.7%) in the age group 15-44 years. There was no statistically significant association of anti-HCV and HBsAg prevalence among 200 asymptomatic HIV-infected carriers and 146 AIDS patients. Assays for anti-HCV among blood donors are highly recommended to reduce the development of liver disease or cirrhosis in the immediate future.

HIV-1 infection among low income women attending a Siriraj sexually transmitted disease clinic: sociodemographic differentials.

From August 1993 to October 1994, 322 women attended or were referred to a female sexually transmitted disease clinic, were studied for the prevalence of HIV infection. No subject had a history of commercial sex work, injection drugs use or blood transfusion within the past 8 years. The majority of women belonged to the low socioeconomic stratum. HIV-1 antibody was found in the sera of 38 women (11.8%). HIV-1 seropositivity was not associated with any type of current sexually transmitted disease such as genital ulcers, serologic markers of syphilis or other sexually transmitted disease as well as history of past sexually transmitted disease within the past 2 years. Significant differential factors were found between the HIV-1 seropositive and seronegative women for self risk assessment and ability to communicate concerns with the husband or partner regarding HIV infection/AIDS. Programs are urgently needed for HIV/AIDS prevention and control to low-income communities and to determine what factors enable the HIV-1 seronegative women to be more assertive in their relationship and whether these skills can be enhanced to eliminate future episodes of STD and transfer these skills to the more vulnerable low-income women. Early diagnosis and prevention of HIV infection among women is a priority for public health interventions both in industrialized and in developing countries.

Flow cytometric three-color determination of CD4 T-lymphocytes on blood specimens from AIDS patients who have a large number of contaminating non-lymphocytes.

A three-color flow cytometric determination of CD4 T-lymphocytes on whole blood specimens from AIDS patients which contain a high proportion of non-lymphocyte elements is described. Peripheral blood cells were stained by a three-color method using monoclonal antibodies conjugated respectively with fluorescein isothiocyanate (FITC)-CD3, phycoerythrin (PE)-CD4 and peridinin chlorophyll protein (PerCP)-CD45. CD45 stains all leukocytes with the highest fluorescence expression of CD45 antigen in lymphocytes. By combining light scatter with CD45 in the fluorescence 3 (FL3) channel, a light scattering window can be drawn to include almost all bright CD45 lymphocytes. This live gate of lymphocytes was then acquired and analysed simultaneously using other irrelevant two-color (FITC/PE) antibodies of CD3 and CD4 in the FITC and PE channels, respectively. This method is easy and straightforward, and gives successful analysis of CD4 T-lymphocytes in AIDS blood specimens contaminated with an unusually large number of non-lymphocytic cells.

Risk factors for HIV infection among Thai laborers during 1992-1993.

From June 1992 to May 1993, 39,939 Thai men attended the clinic for laborers going abroad at Siriraj Hospital in Bangkok for a pre-assignment physical exam and mandatory blood screen for HIV and syphylis. Of this total, 438 tested positive for HIV antibody (1.1%). Of these, 215 men returned for post test interview and physical exam and were compared with 1,348 men randomly selected HIV-1 seronegative men. None of the HIV-1 seropositive had a history of injecting drug use or had received blood transfusion in the past seven years. HIV-1 seropositivity was associated with the TPHA serological marker for syphylis > 1.160 (p = 0.015, odd ratio 1.8), history of urethritis (p = 0.009, odd ratio 1.92) (Table 4). This study found that HIV-1 seropositive men were mostly single, were likely to be from the rural northern provinces of Thailand or Bangkok. History of purchase of low-fee commercial sex and less condom use were significantly associated with HIV-1 seropositivity as was a history of STD in the year prior to interview. Information on HIV disease and pre-test/post test counselling is needed for Thai laborers who are applying for work abroad to countries which require HIV and syphylis screening. In this effort, the Ministry of Labor and Social Welfare, the Ministry of Public Health and the clinic for laborers going abroad should join forces to provide this service. This will serve to increase awareness and self-determination among an increasingly vulnerable segment of the population who also have the potential to spread HIV infection to their spouse and other sex partners.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: According to data from the Siriraj Hospital Medical School, where mandatory human immunodeficiency virus (HIV) screening is provided for Thais who travel abroad as contract laborers, the incidence of HIV infection in this population group increased from 0.25% in 1989 to 1.16% in 1992. To assess the risk factors associated with this trend, interviews were conducted with every 25th laborer out of the 39,939 men who presented to the clinic from June 1992 to May 1993. This yielded a sample of 1786 men, 438 of whom were HIV-positive. However, only 215 HIV-positive men returned to the clinic, resulting in a sample of 1563 men (average age, 31.4 years). None of the seropositive subjects had a history of intravenous drug use or blood transfusion. HIV-infected laborers were significantly more likely than their noninfected counterparts to be single, from the Northern and Central provinces, and to be less educated and unskilled. 75.3% of HIV-positive men, compared to 19.5% of seronegative men, had engaged in commercial sex in the past year and were more likely than their counterparts to have visited a low fee (under 100 baht) brothel-based prostitute. The rate of condom use during commercial sex encounters was 59.3% among seropositive men compared to 68.9% among seronegative men. 53.7% of seropositive men, compared to 33.1% of their seronegative counterparts, reported having a sexually transmitted disease (especially urethritis) in the preceding year. Given the threat that HIV-infected itinerant laborers will transmit the virus to others in their home provinces, it is recommended that HIV prevention education become a part of labor recruitment; also urged are continued efforts to promote the goal of 100% condom use in Thailand's commercial sex industry.