Location: Mosquito and Fly Research
Project Number: 6036-32000-052-110-I
Project Type: Interagency Reimbursable Agreement
Start Date: May 1, 2024
End Date: Aug 6, 2024
Objective:
Vector-borne diseases have historically been among the leading causes of Disease and Non-Battle Injury (DNBI) among U.S. service members deployed in support of military operations. Vector-borne diseases remain one of the top force health protection (FHP) threats and can rapidly degrade mission readiness. There are no vaccines or chemoprophylaxis for many vector-borne pathogens; therefore, it is essential to understand the potentials risk to service members operating in vector-borne disease endemic areas. Within the U.S. Southern Command (USSOUTHCOM) Area of Responsibility (AOR), numerous pathogens which cause disease in humans, are transmitted by mosquitoes (malaria, dengue, chikungunya, Zika, and Mayaro virus disease), sand flies (leishmaniasis and Bartonellosis), ticks (rickettsiosis), and triatomine bugs (Chagas). In the absence of vaccines, vector control programs throughout Latin America have relied heavily on pyrethroid insecticides for the control of medically important arthropods; consequentially, pyrethroid resistance is widespread throughout the region. There is limited information on the distribution of vector and vector-borne pathogens in relevant areas across the SOUTHCOM AOR. Vector surveillance, pathogen detection, and the characterization of insecticide resistance profiles are essential for 1) implementing appropriate countermeasures against vector-borne disease threats to service members operating within the USSOUTHCOM AOR and 2) the early detection of vectors and vector-borne pathogens prior to spread to the U.S. mainland.
NAMRU-S’s mission is to ensure readiness and health of U.S. service members, Peruvian national partners, and global stakeholders through biomedical research, infectious disease surveillance, medical countermeasure testing, and evaluation, and global health engagement. NAMRU-6 has received funding via the Armed Forces Health Surveillance Division (AFHSD)-Global Emerging Infections Surveillance (GEIS), Military Infectious Diseases Research Program (MIDRP), and Deployed Warfighter Protection Program (DWFP) for vector surveillance, pathogen testing, insecticide resistance monitoring, and evaluating products that reduce the risks of vector-borne disease. The focus of the USDA ARS Center for Medical, Agricultural and Veterinary Entomology (CMAVE) in Gainesville, FL, is the study of arthropods of medical and veterinary importance, the development of improved methods of arthropod control, and the dissemination of this information to benefit the American Public and collaborators.
A support agreement (N44852-GTC-23-11559) identifies the interactions among parties in the execution of mutually beneficial collaborative research efforts. This broad agreement allows for the sharing of entomological samples collected and associated data (“Material”).
Approach:
Study site: Surveillance sites in Peru, Colombia, Panama and Honduras
Sample collection: Adult and larval mosquitoes will be collected from surveillance sites by USDA, NAMRU-S personnel and contracted personnel using a variety of trapping and sampling methods during FY2024. Sample metadata will be frecorded and the samples will be frozen or saturated in preservation reagent before shipping to CMAVE under APHIS permit #: 610-23-66-80928.
Molecular analysis of vector samples: For the molecular work, we will use a combination of traditional PCR and existing protocols as well as nanopore sequencing for more in depth analysis of detected pathogens. Nanopore sequencing allows use of a field deployable device that can allow for rapid sequencing and molecular identification of pathogens identification, vector species, bloodmeal and insecticide resistance status.
Virus detection: The pre-identified and sorted mosquitos will be pooled by collection site and tested for MAYV, DENV and
other arboviruses . Mosquito tissue will be pulverized in lysis buffer and total RNA extracted using the Qiagen RNA extraction kit following the protocol provided by the manufacturer. A one-step RTPCR will be conducted using Qiagen QuantiTect Probe RT-PCR kit to detect viral RNA.
Insecticide resistance: For insecticide resistance analysis, we will use molecular genetic markers targeting single nucleotide polymorphisms (SNPs) in Ae. aegypti. We will target insecticide resistance genetic markers in the voltage gated sodium
channel (VGSC) including F1534C andV1016I. We will also assess the presence of traditionally Indopacific kdr mutations
(S989P and V1016G) which have recently been collected in the Caribbean and are becoming a priority target for surveillance.
