Ben Dickson was a Euan Crone Asian Awareness Scholarship 2014 recipient. Applications for 2015 are now open until Friday 4 September.
Lymphatic filariasis (LF), the disease responsible for elephantiasis, is endemic across South-East Asia. Within the region, Myanmar is one of the hardest hit. The World Health Organisation (WHO) aims to eliminate the disease worldwide by 2020, however a lack of accurate epidemiological data and an under-resourced public health system are straining Myanmar’s efforts to eradicate the disease.
With all of its neighbours making strong progress toward elimination, why does Myanmar continue to lag behind? Myanmar’s decades of political and economic turmoil under military rule since 1962 have no doubt played their part. However, diagnosing and treating the direct causes of Myanmar’s persistent LF problem is difficult, especially without reliable data.
Because of the country’s political isolation, no formal filariasis studies have been undertaken since the 1960s. Recent figures only come from studies of Myanmar migrants on the Thai border and from government surveys. Whilst the WHO provides general guidelines, the methodology of these government surveys varies substantially, and may be suboptimal, because of poorly resourced programmes and frequent personnel changes.
Myanmar’s government surveys suggest that most regions in northern, central and southern parts of the country are endemic for W. bancrofti. In 2001, the National Elimination Programme commenced its MDA rounds in two districts and has since expanded the program to cover all but the northern endemic areas of the country. The Ministry of Health reports that since 2002, the national infection prevalence has declined from 15.1 percent to 2.7 percent. Foci of moderate to high rates of infection however are reported to persist in Mandalay Region and the western states of Sagaing, Magway, Rakhine and Chin.
In an effort to bolster current data and help identify the causes of persistent LF in Myanmar, we recently conducted the country’s first formal LF prevalence study since the 1960s. In collaboration with the Myanmar National Elimination Programme and the WHO, we surveyed over 1000 individuals across 24 villages in Mandalay Region in central Myanmar.
The study results show higher levels of LF infection than previous data, and much greater than expected for an area that has completed six MDA rounds. Those identified in the study as infected would have not received treatment, or have become re-infected. Those without treatment have either had no access to medication (i.e poor MDA distribution) or refused to take the medication when offered. Re-infection is caused by high-exposure to infected mosquitos (i.e ongoing LF transmission). In Myanmar, the night-feeding Culex mosquitoes transmit LF.
Whilst data analysis is still ongoing, the results shed light on some of the potential causes of persistent LF in the region. MDA coverage was incomplete and in those who were offered medication, many refused because of fears about side effects. Many individuals had little awareness of filariasis or the reason for taking the medication. As a result, the average individual only took de-worming medication 2.5 times out of a possible six. Despite the low MDA participation, mosquito-net use was high, suggesting re-infection rates were low, or occurred in the early evening.
Distribution and participation issues have been compounded by gaps in annual MDA rounds. Although the WHO recommends annual treatment, the National Programme reports that there have been gaps of up to two years between rounds as a result of financial and logistical problems. Whilst the required de-worming medications for MDA are provided for free by pharmaceutical manufacturers, the government is responsible for other program costs (such as distribution, and staff training). Insufficient funding to meet these costs has resulted in substantial gaps in MDA rounds, which reduce drug pressures and allows for continued parasite transmission.
To combat these issues, financial and logistical barriers need to be overcome to allow continuous MDA rounds until elimination is reached in the region. During the implementation of MDA, funding should be allocated to LF-related education to ensure participants are aware of the reason they are taking medication and the minimal risk of side effects. Increased attention should also be given to ensuring complete distribution, particularly in remote areas.
Our study results also found a high prevalence of hydrocoeles of over six percent amongst men, but low levels of lymphoedema. Whilst the risk factors associated with the development of LF-related morbidity are still poorly understood, high-infection density and genetic factors probably play a significant part. Targeted surgical programs should be initiated alongside further studies to elucidate the morbidity burden in the remainder of the country.
Despite persistently high levels of LF infection and morbidity in some States, the Myanmar National Elimination Programme has made considerable progress. With increased funding, education programs and a more evidence-based focus, Myanmar may be able to eliminate LF by 2020 and prevent thousands from a life of permanent disability.
Benjamin Dickson is a final year medical student at James Cook University, and a recipient of the AIIA’s Euan Crone Asian Awareness Scholarship. He was been working on lymphatic filariasis in both Myanmar and PNG. This article can be republished with attribution under a Creative Commons Licence.