Thinley Yangzom; Cara Smith Gueye; Rinzin Namgay; Gawrie NL Galappaththy; Krongthong Thimasarn; Roly Gosling; Shiva Murugasampillay; Vas Dev

“ In Bhutan, where borders are porous and migrant populations pass daily over the border, other measures may be needed in addition to the border screening centers, which target longer-term migrant workers. Regional or cross-border initiatives may be an important tool to lower importation risk [1] , [7] . Harmonized surveillance, case management and vector control strategies and their synchronized implementation in border regions are generally successful through a multi-country platform. ”

“ The low-lying southern region of Bhutan is at high-risk for malaria transmission [6] and has a highly porous border with India, through which there is significant population movement. In addition, large numbers of migrant workers enter the country to work in large-scale development projects in areas vulnerable to malaria transmission, creating a risk of continual importation and re-introduction of malaria into the area [7] . Given these and other challenges, the recent success in reducing malaria incidence may contain lessons for other countries [8] . ”

“ It is unknown how many migrants pass through unregulated areas of the border, and as these populations have not been studied, there are no certain estimates of cross border movement. A clearer understanding of the migration pathways into and within Bhutan would help in targeting interventions to prevent importation of malaria. ”

“ The evidence-based strategies implemented by the VDCP are likely the root of Bhutan's malaria success, along with the economic and social development seen in the country. The programme benefits from a strong primary health care system and continually expanding access to health care, including malaria diagnosis and treatment, at the district and sub-district levels in rural and remote areas. A well-functioning health supply system allows few stock-outs. ”

“ Progressive malaria elimination in Bhutan will require intensified efforts in case-based surveillance, with rapid notification, case investigation and case containment strategies. The expansion of parasitological and entomological surveillance is a priority, and must include the identification and mapping of local malaria foci, which is dependent upon the creation of district-level case investigation and rapid response teams. ”

“ While the socio-economic development taking place in Bhutan may play a role in reducing the receptivity to malaria transmission, there are major development projects underway that could undermine those advances. ”

“ Bhutan has made significant strides towards elimination and has adopted a goal of national elimination. A major challenge in the future will be prevention and management of imported malaria infections from neighbouring Indian states. Bhutan plans to implement screening at border points to prevent importation of malaria and to targeted prevention and surveillance efforts towards at-risk Bhutanese and migrant workers in construction sites. ”

“ Outside of migrant labor, further population movement results from the national resettlement programme, which relocates Bhutanese from low transmission areas to endemic areas to increase access to arable land. These resettled populations may both lack malaria immunity and knowledge about the disease and its prevention and treatment [35] .
Thirdly, there have been recent short and long-term changes in climate and rainfall, which are thought to have contributed to the increase in incidence in 2009 [12] . ”

“ There are virtually no malaria surveillance or referral services, apart from non-governmental organizations (NGOs) based in the area [23] . As a result, Assam population groups often migrate into Bhutan seeking healthcare services, in particular at Sarpang District Hospital. Other migrant groups include daily contractual workers and casual laborers. There is an estimated daily migration of 1,000 people entering Bhutan through each regulated checkpoint in ten border towns. ”

“ Malaria microscopy training is ordered if there are false positive or negative rates beyond the acceptable limit. A significant challenge is that blood films are sent by post and are sometimes broken and un-readable upon arrival.
Vertical reporting occurs each week wherein reports flow from health facilities to the districts, then to the VDCP [12] . Reports are submitted to the Bhutan information system of the Ministry of Health each quarter. Reporting is supervised by on-site data verification during monitoring and supervision visits to the health centers. ”

“ Although, over the last decade there have been recent improvements in the number of staff available in the national health system, historically there have been shortages of highly trained workers as a result of the limited training institutions located in Bhutan. ”

“ Vector prevalence, vector behavior, and proximity to populations along and across the border were introduced as additional stratification criteria for use of IRS. Focal IRS is carried out in villages that do not meet the IRS stratification criteria. Focal IRS consists of spraying households within a one-kilometer radius of an indigenous case when reported. ”

“ These health workers, whose salary is paid by the Ministry of Health, work only on malaria and provide a wide range of services including reading blood slides for malaria diagnosis, issuing treatment, case reporting, and case follow-up. ”

“ District and sub-district health facilities coordinate movement of supplies to avoid stock-outs.
Bhutan's health services are nearly all provided by the public sector. There are no private medical facilities and only a handful of retail pharmacy shops [12] , [35] . As a result, the government has a high level of control of case management and malaria control measures.
Challenging factors
Rugged terrain and remote, hard-to-access population groups create challenges in access to healthcare facilities. The majority of the population (69.1%) live in rural areas [5] . ”

“ Data triangulation was used to identify trends in epidemiology and key strategies and interventions through analysis of the VDCP surveillance and programme records and the literature review. Enabling and challenging factors were identified through analysis of socio-economic and health indicators, corroborated through a review of national and international reports and peer-review articles.
Findings
Confirmed malaria cases in Bhutan declined by 98.7% from 1994 to 2010. The majority of indigenous cases were due to Plasmodium vivax (59.9%) and adult males are most at-risk of malaria. ”

“ Malaria screening does not occur in antenatal clinics.
Malaria control strategies and interventions Prevention and vector control
The major prevention and vector control interventions in Bhutan are IRS, ITNs, and LLINs. Larviciding and environmental management have been explored only through small-scale projects. Up until 1998, IRS was the main method of vector control, applied in malaria-endemic southern districts every 6 months with a goal of universal coverage. IRS is not conducted in other areas besides these southern districts. ”

“ This case study is based on a retrospective analysis of national surveillance data on confirmed malaria infections. The number of unconfirmed cases is not known, yet the relatively high level of access to public health facilities and lack of private sector facilities translates to a negligible level of unconfirmed infections. The epidemiology data does not allow for a more extensive analysis of the malaria infection of long-term migrant workers in Bhutan. ”

“ In the future it is expected that the role of Malaria Technicians will increasingly become integrated and their main activities may change, posing a risk of diminishing vigilance for malaria as other diseases become a greater priority. ”

“ As a result of these improvements, access to timely diagnosis and treatment through PCD has likely improved, with weekly case reporting linking epidemiological trends to vector control measures. Evidence-based case management policies, including the implementation of ACT for P. falciparumcases, may have also contributed to the declining transmission [24] .
The deployment of IRS, ITN, and LLIN with the use of strong stratification criteria has resulted in high coverage of targeted populations most at-risk, contributing to the downward trend in incidence [6] , [24] . ”

“ In 2006, LLIN distribution began, with support from the Global Fund. LLINs were sent to the health centers which in turn distributed to households. While the majority of LLINs were sent to the endemic southern districts, more than 20,000 LLINs were sent to areas throughout the country considered "hard-to-reach," or more than 3 h walking distance from the nearest health center or BHU.
A total of 228,053 LLIN were distributed from 2006 to 2010. In 2010, coverage of households specifically targeted for LLIN was 96.9%, and a household survey in 2009 found that 82.5% had at least one LLIN [27] . ”

“ While a recent cross sectional survey conducted in two hydroelectric plant construction sites indicated a low level of parasitaemia in worker groups, the overall risk posed by these migrants is not known [36] . ”

“ In addition, the World Health Organization (WHO) and other partners have provided technical assistance and some financial support. Out of ten countries in the South-East Asia region, Bhutan ranks the highest in cumulative per person availability of donor funding, at $10.75 USD per capita [22] .
Epidemiology of malaria Locally contracted or indigenous cases
In 2010, there were 436 microscopy-confirmed indigenous cases. ”

“ Abeyasinghe, RR & Rodriguez, MH, “Operational strategies to achieve and maintain malaria elimination”, Lancet 376: 1592–1603, pmid:21035841, DOI 10.1016/S0140-6736 (10) 61269-X 1 2 3 Tobgay, T; Torres, CE & Na-Bangchang, K, “Malaria prevention and control in Bhutan: Successes and challenges”, Acta Trop 117: 225–228, pmid:21114957, DOI 10.1016/j.actatropica.2010.11.008 ↑ Statistical Yearbook of Bhutan, October 2009, National Statistics Bureau, 1–183 1 2 The World Factbook: Bhutan, 1 2 3 4 Wangdi, K ”