DETERMINANTS OF ARBOVIRUS VECTOR DENSITY AS A MEASURE OF TRANSMISSION RISK IN REGIONS OF RECENT ZIKA VIRUS INTRODUCTION IN THE AMERICAS

SANDER, BEATE; MIRETTI MARCOS; BENOIT TALBOT; CEVALLOS, VARSOVIA E.; GONZALES ROSAS C.; MAURICIO ESPINEL, JIANHONG WU, MARÍA CRISTINA CARRASQUILLA FERRO, MARIO IVÁN ORTIZ YANINE, DENISSE BENÍTEZ, PATRICIO PONCE, NERIS GAUTO, KAREN LÓPEZ, CLAUDIO CARISSIMO, FABIÁN ZELAYA, SERGIO LITWIÑIUK, MANISHA A. KULKARNI

Virtual

Congreso; American Society of Tropical Medicine and Hygiene Meeting; 2020

American Society of Tropical Medicine and Hygiene

Globalization has increased the exposure of world populations to severalvector-borne and zoonotic diseases, including tropical arboviruses. Theglobal impact of Zika virus in Latin America and the Caribbean has drawnrenewed attention to other circulating mosquito-borne viruses in thisregion, such as dengue and chikungunya viruses. Our objective was toassess socioecological factors associated with Aedes vector density asa measure of arboviral transmission risk in three regions of recent Zikavirus introduction: Posadas, Argentina; Ibagué, Colombia; and Manta,Ecuador, in order to inform disease mitigation strategies. We monitoredAedes mosquito populations over 12 months starting in 2018 in a totalof 1152 randomly selected households across four neighborhoods persite using kairomone traps, light traps, resting traps, and aspirators,and tested pooled specimens for Zika, dengue and chikungunya virusesusing standardized qPCR assays. For each sampled household, wecollected socio-economic and microenvironmental data using structuredquestionnaires. We used generalized mixed-effects Poisson regressionanalyses to identify predictors of Aedes density, with month, site andneighborhood as random-effects variables. Mean female Aedes mosquitodensity per household was 2.10. No pools tested positive for Zika, while5-14 pools were positive for dengue and/or chikungunya in each studysite. The lowest sextile of household wealth (Incidence rate ratio, IRR =1.81), the number of household occupants (IRR = 1.08) and presence ofholes in the household structure used by mosquitoes as points of entry(IRR = 1.25) were associated with a higher number of female Aedesmosquitoes per household. Knowledge of how arboviruses are transmitted(IRR = 0.85) and regular emptying of water containers by occupants (IRR= 0.83) were associated with lower female Aedes mosquito density. Ourstudy addresses the complexities of arboviruses of global significanceat the interface between humans, vectors and the environment, andidentifies parameters that can be used to inform future mitigationstrategies.