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

Clinical study concerning the relationship between community-acquired pneumonia and viral infection in northern Thailand

OBJECTIVE

The etiological agents associated with community-acquired pneumonia (CAP) in Thailand have been studied extensively in bacterial pathogens, but not in viral pathogens. To clarify the association of viral pathogens with CAP, we conducted a comprehensive study of viral and bacterial pathogens in patients with CAP.

METHODS

We enrolled 119 hospitalized patients with CAP in Nakornping Hospital, Chiang Mai, Thailand between 2006 and 2008. The severity of pneumonia was classified and the risk factors for death were estimated. Bacterial and fungal pathogens were determined from specimens taken from blood and sputum, and viral pathogens were identified from nasopharyngeal specimens by RT-PCR using primers specific for 7 respiratory viruses.

RESULTS

Overall, 29 patients were HIV-infected and 90 patients were non-HIV-infected. The microbial pathogens most commonly isolated among HIV-infected patients were: 4 Klebsiella pneumoniae, 4 Mycobacterium tuberculosis and 3 Haemophilus influenzae. Among non-HIV infected patients, predominant microbial pathogens were: 6 Pseudomonas aeruginosa, 5 Haemophilus influenzae and 4 Klebsiella pneumoniae. As for viral pathogens for CAP, influenza virus was identified from 2 HIV-infected patients and 5 non-HIV infected patients. In addition, human rhinovirus (HRV) and respiratory syncytial virus (RSV) were identified from 2 patients each among non-HIV-infected patients.

CONCLUSION

Our study demonstrates that the most common viral agent was influenza virus (5%), followed by HRV (2%) and RSV (2%) among CAP patients in northern Thailand. The underlying chronic obstructive pulmonary disease (COPD) seems to be correlated with the severity of illness.

Clinical and microbiological characteristics of community-acquired pneumonia among human immunodeficiency virus-infected patients in northern Thailand

Human immunodeficiency virus (HIV) infections are prevalent in Thailand. However, the clinical and microbiological characteristics of community-acquired pneumonia (CAP) in such patients are not completely clear at present. In the present study, we analyzed the characteristics of CAP in 191 HIV-infected patients (192 episodes, 130 males and 61 females, mean age 32.9 years, range: 20-62) who had been admitted to Nakornping Hospital in northern Thailand between December 1996 and January 2002. The mean peripheral blood CD4 lymphocyte count was 68.5/mm3 (range: 0-791). The most common organisms detected in the blood of the subjects were as follows: Penicillium marneffei, 13, Salmonella spp., 5, Cryptococcus neoformans, 4, Staphylococcus aureus, 3, and Rhodococcus equi, 3, and the most common organisms detected in sputum included Haemophilus influenzae, 38, P. marneffei, 10, Streptococcus pneumoniae, 10, R. equi, 9, and S. aureus, 9. Life-threatening meningitis in 5 (cryptococcal in 3 and tuberculous in 2), pneumothorax in 2, and tuberculous lymphadenitis in 1 were also noted, resulting in 21 fatalities (10.9%). The mean peripheral blood CD4 lymphocyte count for cases in which the subject died was 74.8/mm3 (range: 0-340). Logistic regression analysis demonstrated that high age (odds ratio of over 40 years: 15.62) and R. equi infection (odds ratio: 8.14) are related to death of HIV-infected patients with CAP. The above findings indicate that various types of organisms, including mixed organisms, cause CAP in HIV-infected patients in northern Thailand, and high age and R. equi infection seem to be risk factors for death.

HIV drug resistance transmission threshold survey in Bangkok, Thailand

Background

Antiretroviral therapy (ART) began in Thailand in the Bangkok Metropolitan Area (BMA) in 1988 and scale-up began in 2001. The national first-line regimen is stavudine, lamivudine and nevirapine in fixed-dose combination, which is a regimen with a low genetic barrier for resistance. Because viral load and resistance testing are not widely available, unidentified HIV drug resistance (HIVDR) may occur during treatment and could be transmitted.

Methods

We undertook a threshold survey to assess HIVDR transmission in two subsets of recently infected individuals in the BMA. The first group consisted of returning blood donors tested at the Thai Red Cross National Blood Centre who seroconverted within the past 12 months. The second group comprised recently infected (as defined by BED assay) clients of the Thai Red Cross voluntary counselling and testing centre (VCT).

Results

Genotyping of 50 consecutive specimens each from blood donors and VCT clients during 2005–2006 showed no mutations associated with HIVDR in the reverse transcriptase or protease regions of the HIV pol gene. These results are categorized by the WHO HIV drug resistance threshold survey method as representing a low prevalence (<5%) of transmitted HIV drug resistance.

Conclusions

Every effort should be made to minimize the emergence of resistance in treated individuals and to prevent primary and secondary HIV transmission. To continue to monitor HIVDR transmission, Thailand has planned additional surveys – including longitudinal surveys – in these and additional groups of individuals.

Thailand's response to the HIV epidemic: yesterday, today, and tomorrow

Thailand's comprehensive national response to the HIV/AIDS epidemic has been extensively documented since the beginning of epidemic. Substantial progress in the fight against HIV/AIDS has been made because awareness of the problem was raised. Top-level political commitment and multisectoral strategies mobilized funds and human resources to implement the control program at all levels. Behavioral change resulting in increased condom use in brothels on a national scale rose from virtually nil to more than 95%. This was accompanied by a 90% reduction of the sexually transmitted disease rate. In parallel, the rate of new HIV infections dropped by 80%. Despite these achievements, there remains an urgent need to continue efforts to ensure universal and unfailing condom use. Further, Thailand needs to establish pragmatic innovative approaches to reduce transmission, especially among injection drug users, women, and youth, as well as to develop effective strategies for implementation of antiretroviral treatment. Further strategies also need to consider the changing cultural, social, and economic characteristics of the Thai populations.

Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae and molecular characterization of multidrug-resistant serotype 19F, 6B, and 23F Pneumococci in northern Thailand

Penicillin-resistant Streptococcus pneumoniae is widely spread worldwide. Our study was undertaken to examine the susceptibility and serotypes of S. pneumoniae in northern Thailand. Ninety-three S. pneumoniae strains were isolated from 93 patients at Chiang Mai University Hospital, Chiang Mai, Thailand, from September 1999 to June 2000. The strains were isolated from sputum (n = 51), blood (n = 15), nasopharynges (n = 14), and other sources (e.g., pus, ears, ascites, and cerebrospinal fluid) (n = 13). Of the 93 isolates, 29 (31.2%) were susceptible, 24 (25.8%) showed intermediate resistance (MIC, 0.12 to 1.0 micro g/ml), and 40 (43.0%) were fully resistant (MIC, >/=2.0 micro g/ml) to penicillin G. Seven (46.7%) from blood, 5 (35.7%) from nasopharynges, 15 (29.4%) from sputum, and 2 (15.4%) from other sources were susceptible isolates. Serotyping with the use of antiserum revealed differences in the predominant types that were susceptible (6A, 11A, and 19A), intermediately resistant (6B and 23F), and fully resistant (6B, 19F, and 23F). Molecular typing by pulsed-field gel electrophoresis of multidrug-resistant pneumococci showed four patterns (A, B, C, and D) for 16 isolates of serotype 19F, with pattern B being predominant (12 isolates). This finding was different from that with the Taiwan multidrug-resistant serotype 19F clone. Eleven isolates of serotype 6B all showed pattern E, and nine isolates of serotype 23F showed two patterns (F and G), with pattern F being predominant (seven isolates). This finding was similar to that with the Spanish multidrug-resistant serotype 23F clone. Our results indicated that the resistance of pneumococci to antibiotics in northern Thailand is progressing rapidly and that effort should be intensified to prevent any spread of pandemic multidrug-resistant serotypes 19F, 6B, and 23F.

Survey of reverse transcriptase from the heterosexual epidemic of human immunodeficiency virus type 1 CRF01_AE in Thailand from 1990 to 2000

Genetic diversity of the HIV-1 envelope gene has shown a steady increase over time in the Thai and other regional epidemics. A serial survey of subtype CRF01_AE polymerase gene (RT) diversity in Thailand was performed, using 48 novel and 15 reported sequences covering the period 1990--2000. These sequences were gathered from individuals whose sole risk factor for infection was heterosexual contact. By contrast to envelope, diversity was low and, despite a 40% increase early in the epidemic, has remained static since 1996. These results indicate that epidemic HIV-1 may be constrained within defined limits of genetic diversity at least in some genomic regions.