Tuberculosis at a university hospital, Thailand: A surprising incidence of TB among a new generation of highly exposed health care workers who may be asymptomatic.

OBJECTIVES: There are a few reports of TB disease among healthcare workers (HCWs) in Thailand. The authors assessed the demographic data and incidence of overall TB disease including specific profession among HCWs in order to reduce the incidence rate. METHODS: This was a descriptive, cross-sectional study of 195 HCWs at King Chulalongkorn Memorial Hospital (KCMH), Bangkok, Thailand, who had TB disease from 2003-2020. RESULTS: The average incidence of TB disease in HCWs at KCMH was 164 per 100,000 HCWs with 95% confidential interval [CI], 107 to 220; (94.4% had pulmonary TB). Most of the HCWs were from a young age group (43.08% were 20-29 years old) and the duration of work was short (58.82% had worked at KCMH for less than 5 years). Radiological technicians had the highest incidence of TB, followed by supportive teams, scientists, and physicians (429, 241, 205, and 193 per 100,000 HCWs according to their profession, respectively). Seventy five percent of TB disease was found in physicians who worked at KCMH within 2 years. TB incidence was highest among residents (688 per 100,000 residents) in a subgroup of physicians. CONCLUSIONS: The incidence of TB disease in HCWs was close to the general population of Thailand (153 per 100,000 population with 95% CI, 116 to 195). A higher incidence was observed in the profession that had contact with TB patients and their specimens. A high proportion of asymptomatic HCWs also had TB disease and TB incidence was found in a new generation of HCWs who have worked for less than 5 years. More rigorous epidemiology investigations are needed to establish a definitive relation to subsequently developing TB after working in a hospital. The authors suggest active surveillance in all new incoming HCWs and TB preventive therapy should also be provided to recent converters.

Wolbachia supergroups A and B in natural populations of medically important filth flies (diptera: muscidae, calliphoridae, and sarcophagidae) in Thailand.

Filth flies, belonging to suborder Brachycera (Family; Muscidae, Calliphoridae and Sarcophagidae), are a major cause of nuisance and able to transmit pathogens to humans and animals. These insects are distributed worldwide and their populations are increasing especially in sub-tropical and tropical areas. One strategy for controlling insects employs Wolbachia, which is a group of maternally inherited intracellular bacteria, found in many insect species. The bacteria can cause reproductive abnormalities in their hosts, such as cytoplasmic incompatibility, feminization, parthenogenesis, and male lethality. In this study we determined Wolbachia endosymbionts in natural population of medically important flies (42 females and 9 males) from several geographic regions of Thailand. Wolbachia supergroups A or B were detected in 7 of female flies using PCR specific for wsp. Sequence analysis of wsp showed variations between and within the Wolbachia supergroup. Phylogenetics demonstrated that wsp is able to diverge between Wolbachia supergroups A and B. These data should be useful in future Wolbachia-based programs of fly control.