Demographic risk factors for extra-pulmonary tuberculosis: a rising public health threat in Bhutan.

BACKGROUND: Recently, extra-pulmonary tuberculosis (EPTB) has been increasingly reported in Bhutan, rising from 26% in 2001 to 39% in 2010. In 2016, almost half (49%) of all reported TB cases were classified as EPTB. Thus, this study was conducted to understand the epidemiology and identify risk factors contributing to increasing notification of EPTB in Bhutan. METHODS: A case-control study was conducted by recruiting all 110 cases of nationally notified EPTB (Extrapulmonary bacteriologically confirmed/EPBC) as cases and 235 Pulmonary TB (Pulmonary bacteriologically confirmed/PBC) as controls. Data were collected on socio-demography, clinical and diagnostic, behavioral and lifestyle and environmental exposures using a structured questionnaire between April and September, 2018. RESULTS: The median age of the cases was 25 years, ranged 9-79 years. Lymphatic TB was predominant (n = 78; 70.91%) followed by genitourinary TB (n = 4 (3.64%). The likelihood of EPTB decreased with increase in age (p = 0.023). The odds of EPTB in females was 1.65 times higher than the males (p = 0.038). Increase in Body Mass Index (adjusted odds ratio (AOR): 1.1; 95% confidence interval (CI): 1.052-1.200) and urban residency were (AOR 1.6; 95% CI 1.016-2.805) were found to have higher odds of developing EPTB. CONCLUSION: Females, urban residents, and those with higher BMI are at increased risk of developing EPTB. These at-risk groups can be used to target limited public health resources to control EPTB in Bhutan.

Environmental, Occupational, and Demographic Risk Factors for Clinical Scrub Typhus, Bhutan.

Underdiagnosis and underreporting of scrub typhus has increasingly affected public health in Bhutan since its initial detection in 2008. Identifying scrub typhus risk factors would support early diagnosis and treatment for this nonspecific febrile disease, reducing the incidence of potentially fatal complications. We conducted a hospital-based, case‒control study during October‒December 2015 in 11 scrub typhus‒prone districts. We identified harvesting cardamom as the major risk factor (odds ratio 1,519; p<0.001); other factors were traditional housing, largely caused by an outside toilet location, as well as owning a goat and frequently sitting on grass. Harvesting vegetables, herding cattle in the forest, and female sex were protective. Age had a nonlinear effect; children and the elderly were more likely to seek treatment for clinical scrub typhus. This study has informed public health policies and awareness programs for healthcare workers through development of National Guidelines for Prevention, Treatment and Control of Scrub Typhus in Bhutan.

Has COVID19 derailed Bhutan's national malaria elimination goal? A commentary.

The COVID-19 pandemic has resulted in massive global disruptions with considerable impact on the delivery of health services and national health programmes. Since the detection of the first COVID-19 case on 5th March 2020, the Royal Government of Bhutan implemented a number of containment measures including border closure and national lockdowns. Against the backdrop of this global COVID-19 pandemic response, there was a sudden surge of locally-transmitted malaria cases between June to August 2020. There were 20 indigenous cases (zero Plasmodium falciparum and 20 Plasmodium vivax) from a total of 49 cases (seven P. falciparum and 42 P. vivax) in 2020 compared to just two from a total of 42 in 2019. Over 80% of the cases were clustered in malaria endemic district of Sarpang. This spike of malaria cases was attributed to the delay in the delivery of routine malaria preventive interventions due to the COVID-19 pandemic. As a result, Bhutan is unlikely to achieve the national goal of malaria elimination by 2020.

Clinical and Epidemiological Patterns of Scrub Typhus, an Emerging Disease in Bhutan.

Scrub typhus (ST) is a vector-borne rickettsial infection causing acute febrile illness. The re-emergence of ST in the Asia-Pacific region represents a serious public health threat. ST was first detected in Bhutan in 2008. However, the disease is likely to be under-diagnosed and under-reported, and the true impact is difficult to estimate. At the end of 2014, the SD Bioline Tsutsugamushi TestTM rapid diagnostic test (RDT) kits became available in all hospitals to assist clinicians in diagnosing ST. We conducted a retrospective descriptive study, reviewing records from all hospitals of Bhutan to identify all RDT-positive clinical cases of ST in Bhutan in 2015. The aim was to evaluate the burden of ST in Bhutan, describe the demographic, spatial and temporal patterns of disease, and identify the typical clinical presentations. The annual incidence of RDT-positive cases of ST reporting to Bhutanese hospitals in 2015 was estimated to be 62 per 100,000 population at risk. The incidence of disease was highest in the southern districts with a subtropical climate and a high level of agricultural production. The highest proportion of cases (87%) was rural residents, with farmers being the main occupational category. The disease was strongly seasonal, with 97% of cases occurring between June and November, coinciding with the monsoon and agricultural production seasons. Common ST symptoms were not specific, and an eschar was noted by clinicians in only 7.4% of cases, which is likely to contribute to an under-diagnosis of ST. ST represents an important and neglected burden, especially in rural communities in Bhutan. The outcomes of this study will inform public health measures such as timely-awareness programmes for clinicians and the public in high-risk areas, to improve the diagnosis, treatment and clinical outcomes of this disease.

Survey and Phylogenetic Analysis of Rodents and Important Rodent-Borne Zoonotic Pathogens in Gedu, Bhutan.

Rodents are well-known reservoirs and vectors of many emerging and re-emerging infectious diseases, but little is known about their role in zoonotic disease transmission in Bhutan. In this study, a cross-sectional investigation of zoonotic disease pathogens in rodents was performed in Chukha district, Bhutan, where a high incidence of scrub typhus and cases of acute undifferentiated febrile illness had been reported in people during the preceding 4-6 months. Twelve rodents were trapped alive using wire-mesh traps. Following euthanasia, liver and kidney tissues were removed and tested using PCR for Orientia tsutsugamushi and other bacterial and rickettsial pathogens causing bartonellosis, borreliosis, human monocytic ehrlichiosis, human granulocytic anaplasmosis, leptospirosis, and rickettsiosis. A phylogenetic analysis was performed on all rodent species captured and pathogens detected. Four out of the 12 rodents (33.3%) tested positive by PCR for zoonotic pathogens. Anaplasma phagocytophilum, Bartonella grahamii, and B. queenslandensis were identified for the first time in Bhutan. Leptospira interrogans was also detected for the first time from rodents in Bhutan. The findings demonstrate the presence of these zoonotic pathogens in rodents in Bhutan, which may pose a risk of disease transmission to humans.