Where chloroquine still works: the genetic make-up and susceptibility of Plasmodium vivax to chloroquine plus primaquine in Bhutan.

BACKGROUND: Bhutan has made substantial progress in reducing malaria incidence. The national guidelines recommend chloroquine (CQ) and primaquine (PQ) for radical cure of uncomplicated Plasmodium vivax, but the local efficacy has not been assessed. The impact of cases imported from India on the genetic make-up of the local vivax populations is currently unknown. METHODS: Patients over 4 years of age with uncomplicated P. vivax mono-infection were enrolled into a clinical efficacy study and molecular survey. Study participants received a standard dose of CQ (25 mg/kg over 3 days) followed by weekly review until day 28. On day 28 a 14-day regimen of PQ (0.25 mg/kg/day) was commenced under direct observation. After day 42, patients were followed up monthly for a year. The primary and secondary endpoints were risk of treatment failure at day 28 and at 1 year. Parasite genotyping was undertaken at nine tandem repeat markers, and standard population genetic metrics were applied to examine population diversity and structure in infections thought to be acquired inside or outside of Bhutan. RESULTS: A total of 24 patients were enrolled in the clinical study between April 2013 and October 2015. Eight patients (33.3 %) were lost to follow-up in the first 6 months and another eight patients lost between 6 and 12 months. No (0/24) treatment failures occurred by day 28 and no (0/8) parasitaemia was detected following PQ treatment. Some 95.8 % (23/24) of patients were aparasitaemic by day 2. There were no haemolytic or serious events. Genotyping was undertaken on parasites from 12 autochthonous cases and 16 suspected imported cases. Diversity was high (H E 0.87 and 0.90) in both populations. There was no notable differentiation between the autochthonous and imported populations. CONCLUSIONS: CQ and PQ remains effective for radical cure of P. vivax in Bhutan. The genetic analyses indicate that imported infections are sustaining the local vivax population, with concomitant risk of introducing drug-resistant strains.

The occurrence and human health risk assessment of total and aflatoxin B1 in selected food commodities in Bhutan.

Aflatoxins are mycotoxins that contaminate staple foods globally and pose a significant health risk. To the best of our knowledge, information on the occurrence of aflatoxins in Bhutanese diets is scarce. This study aimed to estimate the aflatoxin levels in selected foodstuffs in Bhutan and determine the health risk associated with aflatoxin exposure. Ten different types of food commodities were randomly collected from farmers' markets, shelves of supermarkets, and wholesale and retail shops from 20 districts of the country. The samples were subjected to analysis by an enzyme-linked immunosorbent assay for both total aflatoxins (B1, B2, G1 and G2) and aflatoxin B1. Among the 315 samples included, 48.81% and 79.35% were positive for total aflatoxins and aflatoxin B1, respectively. The overall mean total aflatoxin concentration was 11.49 ± 12.83 µg/kg, and that for B1 was 17.62 ± 23.99 µg/kg. The most prevalent food commodity with the highest aflatoxin contamination was chili products. In addition, the estimated daily intake and margin of exposure to aflatoxin B1 via the consumption of chili products ranged from 0.98 to 5.34 ng kg-1 bw day-1 and from 74.90 to 408.10, indicating a risk for public health. The liver cancer risk was estimated to be 0.01 and 0.007 cancers per year per 100,000 population resulting from the consumption of chili products. The present findings revealed the presence of total aflatoxins and aflatoxin B1 in the selected samples. The margin of exposure values was exorbitant, demanding a stringent public health measure. Notably, these results suggest the need for routine monitoring of aflatoxin contamination in the region and stress rigorous safety management strategies to reduce exposure.

Vitamin D Status among the Population Visiting Jigme Dorji Wangchuck National Referral Hospital, Bhutan.

Objective: To study the vitamin D status among the Bhutanese population visiting the Jigme Dorji Wangchuck National Referral Hospital in Thimphu, Bhutan. Materials and Methods: This is a retrospective descriptive study involving the extraction of data from a hospital database. Records of Bhutanese patients who had taken vitamin D tests in the last two years (2020-2021) were included in the study. Result: A total of 1175 individuals took the vitamin D test during the study period, and the age ranged between 1 day and 94 years. Over 60% of the participants were females. The study found that over 83% of our study population had serum vitamin D levels lower than the normal range/deficient. Around 18% of the participants had severe deficiency. Conclusion: The study found that most participants, including children, had vitamin D deficiency, and the finding was homogenous across gender and age groups. Further studies are required to validate these findings and identify the factors associated with vitamin D deficiency in the population for targeted public health interventions.

A review on foodborne disease outbreaks in Bhutan.

Foodborne diseases (FBDs) are a public health threat that can result in loss of lives and are a hurdle to socioeconomic development. The Foodborne Disease Burden Epidemiology Reference Group estimated that the annual burden of FBDs in the South-East Asia Region was more than 150 million illnesses, causing about 175,000 deaths. This review paper aims to compile evidence from the published articles and gray literatures on food-related disease outbreaks in Bhutan. Information was generated from the annual health bulletin published by the Ministry of Health and data from the National Early Warning Alert Response Surveillance and Information System hosted by Royal Centre for Disease Control. The laboratory confirmation rate of FBD investigation outbreaks increased from 25.5% (2012-2018) to 91.7% in 2020, as per the National Food Safety Indicator (FSI). At least 0.15% of the total population had suffered FBD from 2015 to 2020, and the baseline report shows that most of the FBD events occurred during hot and wet seasons (June and August). The common pathogen causing FBD was Salmonella species accounting for 42.9% of cases, followed by Shigella species (21.4%). Most of the FBD events were reported in schools (46.5%). The frequency of the reported FBD outbreaks had increased from 8 events in 2015 to 15 events in 2017 and 10 events in 2018. The study confirms the improved surveillance for FBDs in Bhutan and highlights the need to raise public awareness on food safety.