Significant progress has been made towards LF elimination in the Pacific Island countries. Following the extensive and statistically sound surveys conducted in 2007 the Pacific Programme to Eliminate Lymphatic Filariasis (PacELF) was re-established on scientific evidence. The achievement of <1% antigenemia prevalence at national levels in four countries and the significant reduction in Mf prevalence observed in most countries clearly indicate the success of the strategy used in this part of the world. As countries move closer towards the elimination goal it became obvious that the initial “one size fits all strategy” was no longer appropriate and strategies had to be tailored to provincial or divisional levels. Similarly in 2007 a “post MDA active surveillance strategy for the Pacific Island Countries” was developed addressing the specific situation of the region. This strategy has been implemented since then by several countries.
The 2017 WHO Weekly Epidemiological Report reported two additional countries, Marshall Islands and Tonga, were acknowledged for achieving elimination of LF as a public health problem bringing the total number meeting validation criteria in the region to 6. In preparation for validation, Vietnam evaluated the availability of MMDP and reassessed endemicity in some non- endemic IUs to strengthen evidence in the elimination dossier. Wallis and Futuna implemented and passed TAS3 in all endemic districts. Kiribati implemented TAS2 in the Line Islands and passed. Palau initiated a surveillance study among migrant workers which is still in progress. Philippines continues to make progress with TAS implementation and has now stopped MDA in 36 of 46 endemic districts. Malaysia has passed TAS and stopped MDA in 96% of endemic IUs. The remaining 4% of IUs in Eastern Malaysia are more rural areas with persistent transmission of B. malayi.
MDA was still required among a total population of 8.5 million in the Philippines and 6.2 million persons in 6 other countries. 74% of endemic IUs have stopped MDA after TAS resulting in 36.8 million persons no longer requiring MDA. With the exception of New Caledonia and Papua New Guinea, all countries in the region have been implementing MDA in all endemic IUs.
American Samoa failed TAS3 indicating resurgence in transmission. Samoa postponed a second round of MDA in an IU that previously failed TAS. Follow-up sentinel and spot-check sites were conducted in Fiji in 2016 during which at least one survey site was found to have greater than 2% antigenemia in 5 of 6 IUs and therefore ineligible to proceed to TAS. French Polynesia imple- mented MDA in 6 IUs and followed with sentinel and spot-check surveys. In 2 of the 6 IUs, antigenemia exceeded 1% and the programme chose to continue MDA. The 4 IUs implementing TAS passed. Aedes mosquitoes are the primary vector of W. bancrofti in these Pacific Islands where unsuccessful results were observed in 2016.
The most important challenges of the region are identifying innovative strategies to scale up MDA in Papua New Guinea and overcome these new occurrences of persistent transmission. Additionally, identifying sustainable methods for surveillance post-validation in the region is an emerging operational research priority.
The treatment regime in all SEARO endemic countries is albendazole plus DEC (diethylcarbamazine).
The Western Pacific Regional Programme Review Group (RPRG), the body which reviews national programmes, applications for drug donations, provides technical guidance and identifies operational research issues is chaired by:
National Institute of Parasitic Diseases
Chinese Center for Disease Control and Prevention
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