Vector-borne Disease Surveillance in Southeast Asia – Challenges and Opportunities in Vector Collection and Pathogen Detection MAJ Brian Evans, Ph.D.; Jim McAvin; Alongkot Ponlawat, PhD; Ratree Takhampunya, PhD; LTC Jason Richardson, PhD . Mission Intelligence requirements
Challenges and Opportunities in Vector Collection and
MAJ Brian Evans, Ph.D.; Jim McAvin; Alongkot Ponlawat, PhD; Ratree
Takhampunya, PhD; LTC Jason Richardson, PhD
PM detachment capabilities
Detection capabilities (JBAIDS)
Value of pathogen assays
Where is the gap?
To accurately asses the risk of vector-borne disease in an AO and to recommend/ implement measures that reduce the disease threat among soldiers.Mission
Human case data AO and to recommend/ implement measures that reduce the disease threat among soldiers.
Vector data (presence/absence)
Pathogen data (presence/absence)
Environmental dataIntelligence Requirements
Pre-deployment intelligence AO and to recommend/ implement measures that reduce the disease threat among soldiers.
Gather case data (non-specific/specific)
Limited vector surveillance
Limited or no pathogen detection capability.PM Detachment Capabilities
Case data is specific in number and location.
Vector surveillance, pathogen detection tools, and control tools are effective.
Case data AO and to recommend/ implement measures that reduce the disease threat among soldiers.
Adult mosquito/sand fly collection devices minimally effective; taxonomic keys
1 or 2 Ae. aegypti /house (15 mins/house); countless man-hours and houses needed for sufficient sample sizes (1 in 1000 infected); this is an area where there is transmission of dengue year-round.Where is the gap?
BG Sentinel (BG Lure)
Bed net trap - NAMRU-2
Rodent-baited traps as a tool for collecting chigger mites, vectors of scrub typhus.Where is the gap?
Figure 13: Field caught rodent on snap trap
Figure 4: Rodent with chiggers
Low densities; seasonality? vectors of scrub typhus.
How does pathogen/vector data translate into risk?
What does it mean to have 6 in 1000 infected; should I be concerned?
Even when we know the vector locations and where the pathogen is most prevalent in the vector, do we understand the biology?
Not one-size fits all solutions; same species from different locations may have evolved independently; different vector ecologyOther Challenges?
Bottom-line: Pathogen detection has greatest added value for risk determination and control efficacy in instances where there is limited or no case data. If disease is seasonal, a valuable forecasting tool.
Challenge: Relevancy of pathogen detection data is highly-dependent on the vector surveillance tool.
Pathogen surveillance should be a critical part of the PM mission; need more effective surveillance tools to complement this mission; need trained soldiers who can interpret information/data.
Where time/resources/money are limited, should be very selective about when and where to use pathogen detection assays.Conclusion