Arbovirus titer variation in field-collected mosquitoes

Area of Science:

• * Arbovirology and Vector-Borne Diseases
• * Epidemiology and Public Health Surveillance
• * Entomology and Mosquito Vector Capacity

Background:

• * Arboviruses are a significant public health concern, transmitted primarily by mosquitoes.
• * Current surveillance relies on metrics like the minimum infection rate (MIR).
• * Understanding virus concentration (titer) within vectors offers additional insights.

Purpose of the Study:

• * To examine patterns in arbovirus titers within field-collected mosquito pools.
• * To assess the influence of virus type, location, year, and mosquito species on virus titers.
• * To evaluate the utility of virus titer data in arbovirus surveillance.

Main Methods:

• * Analysis of virus isolation records from 1974-1993 from the Centers for Disease Control and Prevention.
• * Classification of mosquito pools into low titer (<= 3.0 log10 PFU/ml) and high titer (> 3.0 log10 PFU/ml).
• * Comparison of high titer proportions across different arboviruses, geographic sites, years, and mosquito species.

Main Results:

• * The proportion of high-titer mosquito pools varied significantly across arboviruses, sites, years, and mosquito species.
• * Alphaviruses showed a higher proportion of high-titer pools compared to flaviviruses.
• * Variations suggest differences in mosquito/virus strains and species-specific vectorial capacity.

Conclusions:

• * Virus titer in mosquito pools provides valuable data beyond traditional surveillance metrics.
• * High virus titers indicate potentially more efficient transmission dynamics.
• * Incorporating titer data can improve the sensitivity and specificity of arbovirus surveillance programs.