Epidemiological and laboratory characteristics of multidrug-resistant tuberculosis patients in Bhutan, 2015-2019.

Background: Bhutan is no exception to the rising global threat of drug resistance tuberculosis (TB), particularly multidrug-resistant (MDR) TB. Although drug resistance surveillance has been carried out in Bhutan since 2010, limited analysis reports are available. Therefore, we looked at data from 2015-2019 to understand patient characteristics. Method: To obtain data for MDR-TB from the past 5 years, we looked at manual registers and laboratory worksheets for all samples received at National TB Reference Laboratory. Epidemiological factors and laboratory variables were analyzed using descriptive statistics. Result: Among 304 patients with MDR-TB, 85.20% (n=259) are new cases with no previous history of treatment. Those aged 16-25 years from both genders are affected more (46.05%, n=140) than other age groups. The majority (94.62%, n=264) of rifampicin resistance was found in the MUT 3 rpoB gene. For Isoniazid, 97.13% (n=271) resistance was seen in the MUT1 band of the katG gene. Conclusion: A high number of MDR-TB cases among new patients and little variation in the resistance band pattern over 5 years could indicate uncontrolled ongoing transmission. Whole-genome sequencing for the samples is required to further understand the epidemiology of the resistance pattern.

Scrub Typhus Outbreak in a Remote Primary School, Bhutan, 2014.

Scrub typhus in Bhutan was first reported in 2009. We investigated an outbreak of scrub typhus in a remote primary school during August-October 2014. Delay in recognition and treatment resulted in 2 deaths from meningoencephalitis. Scrub typhus warrants urgent public health interventions in Bhutan.

A Prospective Hospital-based Surveillance to Estimate Rotavirus Disease Burden in Bhutanese Children under 5 Years of Age.

As part of efforts to develop an informed policy for rotavirus vaccination, this prospective study was conducted to estimate the burden of rotavirus diarrhea among children less than 5 years old attended to the Department of Pediatrics, Jigme Dorji Wangchuk National Referral Hospital (JDWNRH), Thimphu, Bhutan. The duration of the study was three years, extending from February 2010 through December 2012. We estimated the frequency of hospitalization in the pediatric ward and dehydration treatment unit (DTU) for diarrhea and the number of events attributable to rotavirus infection among children under 5 years of age. During the study period, a total of 284 children (1 in 45) were hospitalized in the pediatric ward, and 2,220 (1 in 6) in the DTU with diarrhea among children residing in the Thimphu district. Group A rotavirus was detected in 32.5% and 18.8% of the stool samples from children hospitalized in the pediatric ward, respectively. Overall, 22.3% of the stool samples were rotavirus-positive, and the majority (90.8%) of them was detected in children under 2 years of age. From this study, we estimated that the annual incidence of hospitalization in the pediatric ward and DTU due to rotavirus diarrhea was 2.4/1000 (95% CI 1.7-3.4) and 10.8/1000 (95% CI 9.1-12.7) children, respectively. This study revealed that rotavirus is a major cause of diarrhea in Bhutanese children in Thimphu district and since no study has been performed previously, represents an important finding for policy discussions regarding the adoption of a rotavirus vaccine in Bhutan.

Dominance of emerging G9 and G12 genotypes and polymorphism of VP7 and VP4 of rotaviruses from Bhutanese children with severe diarrhea prior to the introduction of vaccine.

A prospective study was performed to determine the molecular characteristics of rotaviruses circulating among children aged <5 years in Bhutan. Stool samples were collected from February 2010 through January 2011 from children who attended two tertiary care hospitals in the capital Thimphu and the eastern regional headquarters, Mongar. The samples positive for rotavirus was mainly comprised genotype G1, followed by G12 and G9. The VP7 and VP4 genes of all genotypes clustered mainly with those of neighboring countries, thereby indicating that they shared common ancestral strains. The VP7 gene of Bhutanese G1 strains belonged to lineage 1c, which differed from the lineages of vaccine strains. Mutations were also identified in the VP7 gene of G1 strains, which may be responsible for neutralization escape strains. Furthermore, we found that lineage 4 of P[8] genotype differed antigenically from the vaccine strains, and mutations were identified in Bhutanese strains of lineage 3. The distribution of rotavirus genotypes varies among years, therefore further research is required to determine the distribution of rotavirus strain genotypes in Bhutan.

Novel human bufavirus genotype 3 in children with severe diarrhea, Bhutan.

We identified a new genotype of bufavirus, BuV3, in fecal samples (0.8%) collected to determine the etiology of diarrhea in children in Bhutan. Norovirus GII.6 was detected in 1 sample; no other viral diarrheal pathogens were detected, suggesting BuV3 as a cause of diarrhea. This study investigates genetic diversity of circulating BuVs.

Complete Genome Sequences of Two Astrovirus MLB1 Strains from Bhutanese Children with Diarrhea.

In addition to the eight genotypes of classic human astroviruses, seven new genotypes have been reported from two novel clades, MLB and VA. However, the epidemiology of these highly diverse astroviruses remains largely unknown. We report here the complete genome sequences of two MLB1 strains from Bhutanese children with diarrhea.