Spread of Antimicrobial-Resistant Salmonella from Poultry to Humans in Thailand.

Food animal production is important for every country. Several antibiotic agents are used in poultry farming to reduce the economic losses arising from mostly untested infectious diseases. This continued study was performed to determine the prevalence of antibiotic-resistant Salmonella in broiler chickens, poultry farmers, and Salmonella bacteremia patients. A total of 121 Salmonella isolates were collected from the Thai provinces of Khon Kaen (65 isolates), Ratchaburi (43 isolates), and Phayao (13 isolates). Salmonella from chicken showed a high rate of resistance to nalidixic acid and tetracycline. Sixty-four percent of Salmonella isolates carried class 1 integrons (intI1 gene-positive). Among the 121 Salmonella isolates, there were 15 serotypes, with S. Enteritidis being the most common. A clonal relationship between the chicken and human isolates was demonstrated by 3 molecular typing methods: enterobacterial repetitive intergenic consensus polymerase chain reaction; pulsed-field gel electrophoresis; and high-throughput multilocus sequence typing. A spread of the sequence type 11 clone was found between chickens and humans. This study revealed a large-scale Salmonella outbreak in Thailand, a link between resistant bacteria from poultry farms and vertical transmission through the food chain, and horizontal transmission of resistance genes. These results can be used for future surveillance and monitoring.

Association Between the Phenotype and Genotype of Isoniazid Resistance Among Mycobacterium tuberculosis Isolates in Thailand.

PURPOSE: The emergence of isoniazid-resistant tuberculosis (HR-TB) is a global public health problem, causing treatment failure and high mortality rates. This study aimed to determine the minimal inhibitory concentration (MIC) of isoniazid and detect the gene mutation in HR-TB and any association between the level of isoniazid resistance and gene mutation. METHODS: We collected 74 clinical HR-TB isolates from two tertiary-care centers in Thailand. MICs were established using broth macrodilution. A line probe assay (LPA) was used to detect gene mutations that confer resistance to isoniazid, rifampicin, aminoglycosides, and fluoroquinolones. RESULTS: Sixty-one (82.4%) isolates were monoresistant to isoniazid and 44 (72.1%) were highly resistant to isoniazid. From the clinical isolates, the range of isoniazid MICs was 0.4-16 µg/mL. The katG S315T gene mutation was the prominent mutation in both isoniazid-monoresistant TB (70.5%) and multidrug-resistant TB (72.7%) isolates. The positive predictive value (PPV) of katG was 100% in detecting high levels of isoniazid resistance. The PPV of the inhA mutation was 93.8% in detecting low levels of isoniazid resistance. Five isolates (6.8%) exhibited low-level phenotypic resistance, whereas an LPA failed to detect an isoniazid gene mutation. Our study found one HR-TB isolate with a gyrA fluoroquinolone-resistant gene mutation. CONCLUSION: Most HR-TB isolates had high isoniazid-resistance levels associated with the katG gene mutation. High-dose isoniazid should be used with caution in patients with HR-TB. Early detection of drug resistance by genotypic assay can help determine an appropriate regimen.

Characteristics of HIV-infected tuberculosis patients in Thailand.

To improve understanding about the epidemiology and clinical features of HIV-associated tuberculosis (TB) infection we conducted a prospective, multi-center observational study of HIV-infected TB patients in Thailand. We enrolled HIV-infected patients diagnosed with TB at public health facilities from three provinces and the national infectious diseases referral hospital in Thailand. Patients underwent standardized interviews, evaluations, and laboratory testing at the beginning of TB treatment. We analyzed demographic and clinical characteristics of patients and stratified our findings by level of immune-suppression and whether antiretroviral therapy (ART) was used before TB diagnosis. Of 769 patients analyzed, pulmonary TB was diagnosed in 461 (60%). The median CD4+ T-lymphocyte (CD4) count was 63 cells/microl [interquartile range (IQR), 23-163.5] and the median HIV RNA viral load was 308,000 copies/ml (IQR, 51,900-759,000) at the time of TB diagnosis. Methamphetamine use was reported by 304 patients (40%), marijuana by 267 patients (35%), and injection drug use by 199 patients (26%). Three hundred three patients (40%) reported having been previously incarcerated. Among sexually active patients, 142 (42%) reported never using condoms at all. Patients with CD4 counts <200 cells/microl were significantly more likely than patients with CD4 counts > or =200 cells/microl to have extra-pulmonary TB, fever, fatigue, muscle weakness, no hemoptysis, tachycardia, low body mass index, jaundice, or no pleural effusion. Of the 94 patients that received ART before TB diagnosis, the median time from ART initiation to TB diagnosis was 105 days (IQR, 31-468). HIV-infected patients who developed TB after ART initiation were more likely than other HIV-infected TB patients to have extra-pulmonary TB, a normal chest radiograph, low HIV RNA viral load, or a history of previous TB treatment.

Lack of transmission among healthcare workers in contact with a case of Middle East respiratory syndrome coronavirus infection in Thailand.

INTRODUCTION: A hospital-associated outbreak of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was reported. We aimed to assess the effectiveness of infection control measures among healthcare workers (HCWs) who were exposed to a MERS patient and/or his body fluids in our institute. METHODS: A descriptive study was conducted among HCWs who worked with a MERS patient in Bamrasnaradura Infectious Diseases Institute, Thailand, between 18 June and 3 July 2015. Contacts were defined as HCWs who worked in the patient's room or with the patient's body fluids. Serum samples from all contacts were collected within 14 days of last contact and one month later. Paired sera were tested for detection of MERS-CoV antibodies by using an indirect ELISA. RESULTS: Thirty-eight (88.4 %) of 43 identified contacts consented to enroll. The mean (SD) age was 38.1 (11.1) years, and 79 % were females. The median (IQR) cumulative duration of work of HCWs in the patient's room was 35 (20-165) minutes. The median (IQR) cumulative duration of work of HCWs with the patient's blood or body fluids in laboratory was 67.5 (43.7-117.5) minutes. All contacts reported 100 % compliance with hand hygiene, using N95 respirator, performing respirator fit test, wearing gown, gloves, eye protection, and cap during their entire working period. All serum specimens of contacts tested for MERS-CoV antibodies were negative. CONCLUSIONS: We provide evidence of effective infection control practices against MERS-CoV transmission in a healthcare facility. Strict infection control precautions can protect HCWs. The optimal infection control measures for MERS-CoV should be further evaluated.