Use of drug-susceptibility testing for management of drug-resistant tuberculosis, Thailand, 2004-2008.

In 2004, routine use of culture and drug-susceptibility testing (DST) was implemented for persons in 5 Thailand provinces with a diagnosis of tuberculosis (TB). To determine if DST results were being used to guide treatment, we conducted a retrospective chart review for patients with rifampin-resistant or multidrug-resistant (MDR) TB during 2004-2008. A total of 208 patients were identified. Median time from clinical sample collection to physician review of DST results was 114 days. Only 5.8% of patients with MDR TB were empirically prescribed an appropriate regimen; an additional 31.3% received an appropriate regimen after DST results were reviewed. Most patients with rifampin -resistant or MDR TB had successful treatment outcomes. Patients with HIV co-infection and patients who were unmarried or had received category II treatment before DST results were reviewed had less successful outcomes. Overall, review of available DST results was delayed, and results were rarely used to improve treatment.

PERSONAL AND ENVIRONMENTAL RISK FACTORS SIGNIFICANTLY ASSOCIATED WITH ELEVATED BLOOD LEAD LEVELS IN RURAL THAI CHILDREN.

A community-based study was conducted to determine personal risk factors and environmental sources of lead exposure for elevated blood lead levels (≥ 10 µg/dl, EBLLs) among rural children living at the Thailand-Myanmar border in Tak Province, northwestern Thailand. Six hundred ninety-five children aged 1-14 years old were screened for BLLs. Environmental specimens for lead measurements included samples of water from the streams, taps, and household containers, house floor dust, and foods. Possible lead release from the cooking ware was determined using the leaching method with acetic acid. The overall prevalence of EBLLs was 47.1% and the geometric mean level of blood lead was 9.16 µg/dl. Personal risk factors significantly associated with EBLLs included being male, younger age, anemia, and low weight-for-age. Significant environmental risk factors were exposure to a lead-acid battery of solar energy system and use of a non-certified metal cooking pot. Some families whose children had high BLLs reported production of lead bullets from the used batteries at home. About one-third of the house dust samples taken near batteries contained lead content above the recommended value, compared with none of those taken from other areas and from the houses with no batteries. The metal pots were safe for cooking rice but might be unsafe for acidic food preparation. Both nutritional intervention and lead exposure prevention programs are essential to reduce EBLLs in this population.

Effect of mycobacterial drug resistance patterns on patients' survival: a cohort study in Thailand.

BACKGROUND: Drug resistance substantially increases tuberculosis (TB) mortality. This study aimed to describe the prevalence of mycobacterial drug resistance pattern and association of common resistance patterns with TB mortality in Thailand. METHOD: A retrospective cohort study was conducted using TB surveillance data. A total of 9,518 culture-confirmed, pulmonary TB patients registered from 1 October 2004 to 31 December 2008 from the Thailand TB Active Surveillance Network were included in this study. Patients were followed up until TB treatment completion or death. Mycobacterial drug resistance patterns were categorized as pan-susceptible, rifampicin resistance, isoniazid monoresistance, and ethambutol/streptomycin resistance. Drug susceptibility testing (DST) was determined by Mycobacterial Growth Indicator Tube (MGIT) liquid culture systems. Survival analysis was applied. RESULT: Isoniazid monoresistance was the most common pattern, while rifampicin resistance had the largest impact on mortality. Cox regression analysis showed a significantly higher risk of death among patients with rifampicin resistance (adjusted hazard ratio (aHR) 1.9, 95% confident interval (CI), 1.5-2.5) and isoniazid monoresistance (aHR 1.4, 95% CI 1.1-1.7) than those with pan-susceptible group after adjustment for age, nationality, human immunodeficiency virus (HIV) and antiretroviral therapy (ART) status, diabetes mellitus, cavitary disease on chest x-ray, treatment observation, and province. HIV co-infection was associated with higher mortality in patients both on ART (aHR 1.9, 95% CI 1.5-2.5) and not on ART (aHR 8.1, 95% CI 6.8-9.8). CONCLUSION: Rifampicin resistance and isoniazid monoresistance were associated with increased TB mortality. HIV-coinfection was associated with a higher risk of death including among those taking antiretroviral therapy.