Temporal and spatial limitations in global surveillance for bat filoviruses and henipaviruses

Sampling reservoir hosts over time and space is critical to detect
epizootics, predict spillover and design interventions. However, because
sampling is logistically difficult and expensive, researchers rarely
perform spatio-temporal sampling of many reservoir hosts. Bats are
reservoirs of many virulent zoonotic pathogens such as filoviruses and
henipaviruses, yet the highly mobile nature of these animals has limited
optimal sampling of bat populations. To quantify the frequency of temporal
sampling and to characterize the geographical scope of bat virus research,
we here collated data on filovirus and henipavirus prevalence and
seroprevalence in wild bats. We used a phylogenetically controlled
meta-analysis to next assess temporal and spatial variation in bat virus
detection estimates. Our analysis shows that only one in four bat virus
studies report data longitudinally, that sampling efforts cluster
geographically (e.g. filovirus data are available across much of Africa
and Asia but are absent from Latin America and Oceania), and that sampling
designs and reporting practices may affect some viral detection estimates
(e.g. filovirus seroprevalence). Within the limited number of longitudinal
bat virus studies, we observed high heterogeneity in viral detection
estimates that in turn reflected both spatial and temporal variation. This
suggests that spatio-temporal sampling designs are important to understand
how zoonotic viruses are maintained and spread within and across wild bat
populations, which in turn could help predict and preempt risks of
zoonotic viral spillover.