Malaria elimination in Bhutan: asymptomatic malaria cases in the Bhutanese population living in malaria-risk areas and in migrant workers from India

In 2018, Bhutan reported 54 cases of malaria, of which six were indigenous, 14 introduced and 34 imported. Considering the continuous reduction in the number of indigenous cases, Bhutan plans to eliminate malaria by 2025 under the Bhutan Malaria Elimination Strategy. The study was conducted to assess the presence of asymptomatic plasmodial infection in both, Bhutanese population living in malaria-risk areas and in migrant workers to guide the elimination strategies. A cross-sectional study was conducted from April to May 2016 in 750 Bhutanese people and 473 migrant workers. Plasmodium falciparum and Plasmodium vivax infections were investigated by using a rapid diagnostic test (RDT) and the polymerase chain reaction (PCR). Prevalence of asymptomatic plasmodial infection based on PCR was 0.27% (95% CI: 0.05–1.07%) among Bhutanese people with a mean age of 43 years old. The proportions of males and females were 45% and 55%, respectively. Among migrant workers, the prevalence of asymptomatic plasmodial infection was 0.42% (95% CI: 0.07– 1.69%) with a mean age of 30 years old. The majority of migrant workers were from the neighboring Indian State of West Bengal (57.51%), followed by Assam (12.26%). RDT in both study groups did not detect any plasmodial infection. The presence of a low prevalence of asymptomatic plasmodial infection indicates that the current elimination strategies and interventions are effective

One Health research and training and government support for One Health in South Asia

Introduction: Considerable advocacy, funding, training, and technical support have been provided to South Asian countries to strengthen One Health (OH) collaborative approaches for controlling diseases with global human pandemic potential since the early 2000s. It is essential that the OH approach continues to be strengthened given South Asia is a hot spot for emerging and endemic zoonotic diseases. The objectives of this article are to describe OH research and training and capacity building activities and the important developments in government support for OH in these countries to identify current achievements and gaps. Materials and methods: A landscape analysis of OH research, training, and government support in South Asia was generated by searching peer-reviewed and grey literature for OH research publications and reports, a questionnaire survey of people potentially engaged in OH research in South Asia and the authors’ professional networks. Results: Only a small proportion of zoonotic disease research conducted in South Asia can be described as truly OH, with a significant lack of OH policy-relevant research. A small number of multisectoral OH research and OH capacity building programmes were conducted in the region. The governments of Bangladesh and Bhutan have established operational OH strategies, with variable progress institutionalising OH in other countries. Identified gaps were a lack of useful scientific information and of a collaborative culture for formulating and implementing integrated zoonotic disease control policies and the need for ongoing support for transdisciplinary OH research and policy-relevant capacity building programmes. Discussion: Overall we found a very small number of truly OH research and capacity building programmes in South Asia. Even though significant progress has been made in institutionalising OH in some South Asian countries, further behavioural, attitudinal, and institutional changes are required to strengthen OH research and training and implementation of sustainably effective integrated zoonotic disease control policies

Occupational exposure to pathogenic Leptospira from sheep carcasses in a New Zealand abattoir : a dissertation presented in partial fulfilment of the requirements for the degree of Masters in Veterinary Studies at Massey University, Palmerston North, New Zealand

This research was undertaken in response to a rising trend in the incidence of notified human leptospirosis cases, particularly in meat workers, between 2000 and 2005 in New Zealand. Meat workers constituted the highest proportion (65% during 2004) of notified leptospirosis cases. Sheep either alone or in combination with other animals constituted the second most important animal contact source of human infection (after cattle). Further justification of this research was due to the fact that a number of cases were reported from meat workers employed in sheep-only abattoirs and concerns were raised that sheep may be a significant source of human infection. A longitudinal study was undertaken to determine the serological and cultural prevalence of two of the most commonly diagnosed serovars, Leptospira borgpetersenii serovar Hardjobovis and Leptospira interrogans serovar Pomona. Lines of sheep and individual sheep were systematically randomly sampled at a sheep-only abattoir in Feilding from May 2004 to June 2005. In addition, an assessment of the risk of occupational exposure of meat workers to carcasses shedding live leptospires was carried out using a stochastic model. The association between white-spotted kidney lesions and the serological and cultural prevalence of leptospirosis in sheep was determined along with the diagnostic value of these lesions to predict serological and culture status at the line and individual carcass levels. The study showed that the prevalence of lines with sheep seropositive to one or both serovars was 44% (95% CI 35–54), corresponding to 45% (95% CI 35–55) of farms. This indicates that nearly half the sampled farms had been exposed to infection previously. The overall individual serological prevalence in the sample of 15,855 sheep processed was 6% (95% CI 5–7). Lambs born in the 2003–2004 season had a significantly higher serological prevalence to one or both serovars at the line and individual animal levels compared with lambs born in the 2004–2005 season, suggesting a strong seasonal effect. The serological prevalence of Hardjobovis was significantly higher than Pomona at the line and individual animal levels. The overall isolation rates of live leptospires from seropositive kidneys of Hardjobovis and Pomona were 22% and 17% respectively, and 1% from seronegative carcasses. From a purposively selected line (suspected of being from a farm with active leptospirosis) all 13 kidneys of seropositive carcasses were culture positive indicating a high risk of exposure of meat workers to leptospires in such a situation. Kidneys from seropositive carcasses were significantly more likely to return culture positive compared with kidneys from seronegative carcasses. The assessment of daily risk of exposure of meat workers indicated moderate risk for eviscerators and meat inspectors ranging from 3–11 (95% CI 0–22) and 6–18 (95% CI 1–34) carcasses potentially shedding live leptospires respectively, and a high risk for offal-handlers that ranged from 18–54 (95% CI 7–91) shedding carcasses. The results from the third study showed that the prevalence of white spotted kidneys was 16% and 91% at the individual sheep and line levels, respectively. Carcasses with white spotted kidneys were 5.2 times (95% CI 3.9–7.1) more likely to test seropositive to one or both serovars, but lesions were poor predictors of serological status as judged by test sensitivity and positive predictive values. Furthermore, a positive linear association between white-spot kidney lesion scores and seropositivity to either or both serovars was evident. Consideration of lesion status of lines rather than for individual animals resulted in higher test sensitivity but still suffered from a low positive predictive value. Leptospires were isolated from 5% (95% CI 4–8) kidneys that were cultured. There was no statistically significant association between white spotted kidney lesion scores and culture test results in the survey data; however, a significant linear positive association was evident when culture data from a purposively sampled farm was merged with the survey data. We conclude that the processing of sheep in sheep-only abattoirs constitutes a definite exposure risk of meat workers to leptospirosis and that exposure risks ranged from moderate to high degrees depending on type of duties performed on the slaughter room floor. Furthermore, since grossly visible white-spotted kidney lesions were positively associated with serological and cultural prevalence of disease it would be advisable for meat workers to take extra care when processing lines with a high prevalence of carcasses with these lesions to reduce the risk of infection. This recommendation is made despite the poor predictability of serological and cultural status of these lesions

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

Human rabies encephalomyelitis in the background of rabies outbreak in animals in Gelephu, Bhutan, 2023: a case report

Abstract Background Rabies continues to pose significant public health challenges in many developing countries including Bhutan. A probable case of rabies was admitted to our hospital and its reporting led to the uncovering of an outbreak in domestic and wild animals. We discuss the challenges in the diagnosis and management of rabies in a resource-limited setting. Case presentation A 35-year-old male presented with intermittent fever, bilateral lower limb weakness that was rapidly progressive, urinary incontinence with episodes of palpitations and sweating. He had sustained a Category III bite on the right lower thigh with four bite marks, inflicted by a stray dog. He had received post-exposure prophylaxis with intra-dermal anti-rabies vaccine. On initial examination, the patient was in distress but cooperative for the interview. He had pulse rate ranging from 60 to 100/min with episodes of diaphoresis and palpitations, but with normal capillary blood glucose. In the lower limb, the muscle power was zero with absent tendon reflexes in the lower limb and impaired abdominal reflex below T10 level. He had hyperaesthesia below T8, hydrophobia, aerophobia and photophobia. He had multiple spontaneous fasciculations in both the thighs and right deltoid and these later involved the intercostal muscles, neck and face muscles. He had altered sensorium and desaturation for which he required mechanical ventilation. Polymerase chain reaction for rabies virus was negative in cerebrospinal fluid and saliva. Rabies virus neutralizing antibody was negative in cerebrospinal fluid but had high titres in the serum. He received Human Rabies Immunoglobulin after admission. He was managed in the intensive care unit and died 23 days later. After this case was notified, a rapid response team was deployed in the field, and uncovered rabies outbreak in animals in the locality. Conclusions This case called for a serious evaluation of the country’s efforts in achieving zero rabies deaths by 2030. The management of this case identified several critical areas of context-specific interventions in Bhutan. There is also an urgent need to improve diagnostic capabilities at the national reference laboratory and enhance the technical competencies of healthcare workers in the management of dog bite cases. Graphical Abstrac

Identification, Distribution, and Habitat Suitability Models of Ixodid Tick Species in Cattle in Eastern Bhutan

Tick infestation is the most reported parasitological problem in cattle in Bhutan. In May and June 2019, we collected ticks from 240 cattle in two districts of Eastern Bhutan. Tick presence, diversity, and infestation prevalence were examined by morphological identification of 3600 live adult ticks. The relationships between cattle, geographic factors, and infestation prevalence were assessed using logistic regression analyses. Habitat suitability for the tick species identified was determined using MaxEnt. Four genera and six species of ticks were found. These were Rhipicephalus microplus (Canestrini) (70.2% (95% confidence interval (CI): 68.7–71.7)), Rhipicephalus haemaphysaloides Supino (18.8% (95% CI: 17.5–20.1)), Haemaphysalis bispinosa Neumann (8.2% (95% CI: 7.3–9.1)), Haemaphysalis spinigera Neumann (2.5% (95% CI: 2–3)), Amblyomma testudinarium Koch (0.19% (95% CI: 0.07–0.4)), and a single unidentified Ixodes sp. Logistic regression indicated that the variables associated with infestation were: longitude and cattle age for R. microplus; latitude for R. haemaphysaloides; and altitude and cattle breed for H. bispinosa and H. spinigera. MaxEnt models showed land cover to be an important predictor for the occurrence of all tick species examined. These findings provide information that can be used to initiate and plan enhanced tick surveillance and subsequent prevention and control programs for ticks and tick-borne diseases in cattle in Bhutan

A knowledge, attitudes, and practices study on ticks and tick-borne diseases in cattle among farmers in a selected area of eastern Bhutan.

Livestock farming plays an important role in supporting the livelihood of resource-poor subsistence farmers in Bhutan. However, ticks and tick-borne diseases (TBDs) are one of the major constraints to livestock farming due to their negative effect on health and production. To date, no study has been conducted in Bhutan to assess farmers' knowledge, attitude, and practices (KAP) about ticks and TBDs in cattle, although such information is essential in ensuring the development and adoption of effective prevention and control measures. Therefore, a KAP survey was conducted among 246 cattle owners in the Samkhar sub-district of eastern Bhutan in June 2019, using a structured questionnaire. Based on our scoring criteria, 52% [95%CI: 45.5-58.4] had adequate knowledge about ticks as potential vectors of diseases. Logistic regression analysis showed that the individuals who practiced a stall-feeding system of cattle rearing were 2.8 times [OR = 2.8 (95%CI: 1.66-4.78)] more likely to have adequate knowledge than others. Sixty-eight percent [95%CI: 62.5-74.4] had a favorable attitude toward tick prevention and control programs. Men were 1.95 times [OR = 1.95 (95%CI: 1.09-3.55)] more likely to have a favorable attitude than women, and the individuals who practiced a stall-feeding system were 2.59 times [OR = 2.59 95%CI: 1.45-4.78)] more likely to have a favorable attitude than others, after adjusting for the effect of other variables in the model. Overall, only 38% [95%CI 32.5-45] of the respondents reported tick infestation as one of the most important animal health problems, but 100% reported using acaricides to control ticks in cattle. Despite a high level of acaricide usage, the level of knowledge was low among the farmers interviewed. Findings from this study underline the importance of considering identified knowledge gaps and initiating education efforts to improve the adoption of effective tick prevention and control measures among farmers

High quality social environment buffers infants’ cognitive development from poor maternal mental health: Evidence from a study in Bhutan

Poor maternal mental health negatively impacts cognitive development from infancy to childhood, affecting both behavior and brain architecture. In a non-western context (Thimphu, Bhutan), we demonstrate that culturally-moderated factors such as family, community social support, and enrichment may buffer and scaffold the development of infant cognition when maternal mental health is poor. We used eye-tracking to measure early building blocks of cognition: attention regulation and social perception, in 9-month-old Bhutanese infants (N = 121). The cognitive development of Bhutanese infants in richer social environments was buffered from poor maternal mental health, while for infants in environments with lower rates of protective social environment factors, worse maternal mental health significantly predicted greater costs for infant attention, a fundamental building block cognition. International policies and interventions geared to improve maternal mental health and child health outcomes should incorporate each regions’ unique family, cultural, and community support structures