Failures of 1 week on, 1 week off antiretroviral therapies in a randomized trial.

BACKGROUND: Scheduled treatment interruptions are being evaluated in an effort to decrease costs and side effects of highly active antiretroviral therapy (HAART). A schedule of 1 week on and 1 week off therapy offers the promise of 50% less drug exposure with continuously undetectable HIV RNA concentration. METHODS: In the Staccato study 600 patients on successful HAART were to be randomized to either continued therapy, CD4-guided therapy, or one week on, one week off therapy. A scheduled preliminary analysis evaluated effectiveness in the 1-week-on-1-week-off arm. RESULTS: Of 36 evaluable patients, 19 (53%) had two successive HIV RNA concentrations > 500 copies/ml at the end of the week off therapy, and were classified as virological failure. Most of those who failed took didanosine, stavudine, saquinavir, and ritonavir (11 patients). In these patients, there was no evidence of mutations suggestive of drug resistance, and plasma saquinavir levels were within the expected range. Two of three patients failing on triple nucleotides had drug resistance mutations, but nonetheless responded to reintroduction of triple nucleotide therapy. One of two patients taking nevirapine, and one of eight taking efavirenz, also failed. Both had resistance mutations at the time of failure, but not at baseline. CONCLUSIONS: The 1-week-on-1-week-off schedule, as tested in the Staccato study, showed an unacceptably high failure rate and was therefore terminated.

Widely varying HIV prevalence and risk behaviours among the ethnic minority peoples of northern Thailand.

We compared HIV prevalence, risk behaviours, and social and sexual norms among nine ethnic minority (Hilltribe) groups in northern Thailand. Communities were selected on the basis of size, ethnicity, development level and geography. Subjects (15-45 years) were stratified by gender and selected by household using two-stage randomization. Forty volunteers were identified in each of 27 villages. Participation was voluntary and informed consent was obtained. HIV infection status was determined using ELISA and Western Blot on saliva samples. Risks for HIV were measured with structured interviews using local languages. Overall HIV prevalence was 23/1080 (2.13%) with an equal male-female ratio. HIV prevalence rates were: Shan 8.75%, Akha 5.0%, Yao 5.0%, Thin 1.25%, Hmong 0.63%, Lahu 0.63%, Lisu 0.63%, Karen 0, and Pa-Long 0. Sex worker use was an HIV risk for men (p = 0.0001), but injecting drug use was not; for women, having been a sex worker was a significant HIV risk (p < 0.0001). HIV rates, social norms and sexual behaviour varied considerably among ethnic groups, as did attitudes toward commercial sex work and use. HIV prevention needs to target the Shan, Akha, and Yao communities, and to focus on reduction of brothel work and use.

PIP: In Thailand, public sector responses to acquired immunodeficiency syndrome (AIDS) have focused almost exclusively on the majority low-lander population. A comparative study of human immunodeficiency virus (HIV) prevalence, risk behaviors, and sexual norms among 9 ethnic minorities in the 6 northernmost Thai provinces revealed substantial variation in these hilltribe communities. 540 men and 540 women 15-45 years old from 27 villages were interviewed and tested for HIV. Each ethnic group included (Shan, Karen, Hmong, Akha, Lahu, Lisu, Pa-Long, and Thin) has its own language, culture, and history. Overall, there were 23 cases (2.13%) of HIV; HIV prevalence was 2.04% among men and 2.22% among women. This rate ranged from a high of 8.75% among the Shan to 0 among the Karen and Pa-Long. HIV-positive women were found in 7 of the 9 ethnic groups, while infected men were found in only 3 groups. In women, HIV prevalence was highest (3.9%) in the 20-24 year age group; in men, it was highest (4.7%) in the 25-29 year age group. 10 of 12 HIV-positive women, compared to only 3 of 11 HIV-positive men, were aware of their serostatus before the survey. Among men, ever having had sex with a commercial sex worker was the only behavioral factor associated with HIV infection; among women, being a commercial sex worker was a significant risk factor. Only 7.8% of women and 15.0% of men had ever used condoms with their spouse. The discordant rates of HIV among men and women in this sample suggest that infection is occurring outside the indigenous areas, primarily as a result of commercial sex encounters.

Lymphocyte immunophenotype reference ranges in healthy Thai adults: implications for management of HIV/AIDS in Thailand.

Lymphocyte immunophenotype reference ranges for T, B, and NK subsets were determined for healthy adult Thais in a multi-center study in Bangkok. Immunophenotyping was by flow cytometry using lysed whole blood. A standard protocol for flow cytometry instrumentation, reagents and quality control was used to minimize site differences and to facilitate comparison of the Thai reference values to those found for Caucasians in previous studies. Major differences were determined for CD3(T), CD4 (T helper/inducer) and CD16+56 (NK) lymphocyte percentages and CD4 lymphocyte absolute counts. Age trends and sex differences were also observed. Compared to Caucasians, Thais, particularly Thai males, had lower CD3 and CD4 T lymphocyte percentages and absolute numbers whereas the percentage of NK lymphocytes was higher. Heterogeneity attributed to biological variation of CD4 T lymphocyte but not other immunophenotype subset distributions was also observed in a well defined geographic population. This study demonstrates the importance of ethnicity, age, sex and possibly environment as factors that influence distribution characteristics of normal lymphocyte immunophenotype reference values. These observations have important implications for the use of lymphocyte subsets-particularly CD3+ CD4+ T lymphocyte measurements as applied to HIV disease staging, AIDS definition and the overall clinical management of HIV/AIDS in Thailand.

Purified equine rabies immune globulin: a safe and affordable alternative to human rabies immune globulin.

Reported are the results of a retrospective study of 3156 patients who were treated at the Queen Saovabha Memorial Institute, Bangkok, with equine rabies immune globulin (ERIG). Only 51 patients (1.6%) exhibited serum-sickness-like reactions, none of which persisted for more than a week, and only 8 of these patients (15%) were treated with a short course of steroids. One patient, whose skin test was negative, had an immediate anaphylactic reaction to ERIG that responded to parenteral therapy with epinephrine and hydrocortisone sodium succinate. Serum-sickness-like reactions were more frequent among females and over 21-year-olds but were exceedingly rare (0.086%) among children under 10 years of age.

Purified equine rabies immune globulin: a safe and affordable alterntaive to human rabies immune globulin

Reported are the results of a retrospective study of 3,156 patients who were treated at the Queen Saovabha Memorial Institute, Bangkok, with equine rabies immune globulin (ERIG). Only 51 patients (1.6 percent) exhibited serum-sickness-like reactions, none of which persisted for more than a week, and only 8 of these patients (15 percent) were treated with a short course of steroids. One patient, whose skin test was negative, had an immediate anaphylactic reaction to ERIG that responded to parenteral therapy with epinephrine and hydrocortisone sodium succinate

Serum-sickness-like reactions were more frequent among females and over 21-year-olds but were exceedingly rare (0.086 percent) among children under 10 years of age(AU)