Spatio-temporal patterns of malaria infection in Bhutan: a country embarking on malaria elimination

Abstract

BackgroundAt the verge of elimination of malaria in Bhutan, this study was carried out to analyse the trend of malaria in the endemic districts of Bhutan and to identify malaria clusters at the sub-districts. The findings would aid in implementing the control activities. Poisson regression was performed to study the trend of malaria incidences at district level from 1994 to 2008. Spatial Empirical Bayesian smoothing was deployed to identify clusters of malaria at the sub-district level from 2004 to 2008.ResultsTrend of the overall districts and most of the endemic districts have decreased except Pemagatshel, which has an increase in the trend. Spatial cluster-outlier analysis showed that malaria clusters were mostly concentrated in the central and eastern Bhutan in three districts of Dagana, Samdrup Jongkhar and Sarpang. The disease clusters were reported throughout the year. Clusters extended to the non-transmission areas in the eastern Bhutan.ConclusionsThere is significant decrease in the trend of malaria with the elimination at the sight. The decrease in the trend can be attributed to the success of the control and preventive measures. In order to realize the target of elimination of malaria, the control measure needs to be prioritized in these high-risk clusters of malaria.

Cross-Border Malaria: A Major Obstacle for Malaria Elimination

“…Economic migrants are the world's fastest growing group of migrants. Economic motivations are the main reasons for people to migrate from countries with high levels of malaria to malaria-eliminating countries, impeding malaria elimination efforts in those countries (Carme, 2005;Davin and Majidi, 2009;Kitvatanachai et al, 2003;Wangdi et al, 2011). Economic migration is exacerbated when there are substantial differences in the economic development and job opportunities in neighbouring countries.…”

Epidemiological and Molecular Characterization of Dengue Virus Circulating in Bhutan, 2013-2014

“…WHO has at least partially attributed outbreaks in Nepal and Bhutan to increasing global temperatures [ 10 ]. Although Bhutan is mostly situated at elevations of greater than a thousand meters above sea level, some areas of Chukha and Samtse districts are located as low as 100 meters above sea level, bearing climates that favor transmission of DENV and other tropical pathogens [ 39 ]. More importantly, these two districts share an unrestricted border with India which regularly reports dengue outbreaks of all serotypes [ 11 ], contributing to the DENV presence in Bhutan.…”

Ending Malaria Transmission in the Asia Pacific Malaria Elimination Network (APMEN) Countries: Challenges and the Way Forward

“…Malaria control in border areas is often difficult for being heavily forested, mountainous and inaccessible terrain, and unregulated population movements across the borders [103,104]. Open porous international borders allow unchecked movement of people [105][106][107][108][109][110][111]. Such cross-border migration is likely to derail the malaria control activities of the neighbouring countries and risk introduction of drugresistant parasites [112].…”

“…Malaria has a focal spatial distribution in pre-elimination and elimination phases, with hotspots of transmission in which the risk of malaria (including asymptomatic parasitaemias) and number of cases are higher than in surrounding areas [141,142]. The scale at which spatial Towards Malaria Elimination -A Leap Forward heterogeneity occurs ranges from micro-geographical setting beginning with household or village level [143][144][145][146][147][148][149] to municipalities [150], sub-districts [111], district [151][152][153], subnational [105,[154][155][156], national [40], regional [157], and global scales [70]. These spatial clusters of malaria have the potential to be sources of spread into neighbouring regions and countries if there is no focused intervention in the hotspot areas.…”

“…Passive case detection (PCD) could capture imported cases and allow interventions that would prevent resurgence in the presence of robust health system [175]. However, in areas with high transmission intensities in APMEN countries [70,176], and unchecked migration across borders [103][104][105][106][107][108][109][110][111], there is likely to be significant transmission even in low transmission settings. Therefore, imported infections must be prevented through border screening, regional and cross-border initiatives and dialogue, proactive case detection, and treatment in high-risk population groups and travellers preventing resurgence of the disease [177].…”