News

From 3 – 5 September 2018, the APMEN Vector Control Working Group (VCWG)/Mekong Outdoor Malaria Transmission Network (MOMTN) was held in Bangkok, Thailand. The meeting was attended by 16 country members and 19 institutional partners from across the region, with the purpose of “Moving towards vector surveillance and response system for malaria elimination”.

The aims of the meeting were to:

• Review and share information and experience of progress, good practice and studies for outdoor malaria transmission.
• Discuss implications of outdoor transmission and country efforts for malaria elimination.

During the session on Residual Malaria, Dr Jeffrey Hii delivered a presentation titled, “How much residual transmission in GMS: Thailand and Viet Nam”. Dr Hii presented results from his mixed methods study which investigated the magnitude and factors contributing to low (<1% prevalence) but sustained malaria transmission in rural communities.

The study findings suggest that primary drivers of residual malaria transmission in the study sites were due to:

• Higher mosquito abundance in forested areas where LLINs were used less frequently or could not be used;
• Human-mosquito interaction in sites without LLIN/IRS and/or where LLIN could not be used;
• Late sleeping and waking times coinciding with peak biting hours;
• Feeding preferences of Anopheles mosquitos (e.g. feeding outdoors or on animals) taking them away from LLINs and IRS;
• Non-use of LLIN or using torn/damaged LLINs;
• High population movement across the border and into forested areas; and
• Plasmodium vivax predominance resulting in relapse of previous infection.

Photo of participants at the APMEN VCWG meeting (credit: https://www.apmen.org)

One of his recommendations was to explore personal protection methods that are appropriate within these local areas. He also suggested investigating the durability and ease of use of protection products, as well as those that require minimal behaviour change and communication. The study also highlighted the need for a more holistic definition of RMT, as net use is often overestimated and does not consider people outside of the household, or lower LLIN coverage in farm huts and forest areas.

The meeting led to several important and shared decisions, including an agreement among APMEN members to initiate a multi-country proof of concept study on vector control tools to address outdoor transmission. View more details about the objectives, expected outputs and the agenda of the meeting here.