Abstract:
Pathogen circulation among reservoir hosts is a precondition for zoonotic
spillover. Unlike the acute, high morbidity infections typical in spillover
hosts, infected reservoir hosts often exhibit low morbidity and mortality.
Although it has been proposed that reservoir host infections may be
persistent with recurrent episodes of shedding, direct evidence is often lacking.
We construct a generalized SEIR (susceptible, exposed, infectious,
recovered) framework encompassing 46 sub-models representing the full
range of possible transitions among those four states of infection and
immunity. We then use likelihood-based methods to fit these models to
nine years of longitudinal data on henipavirus serology from a captive
colony of Eidolon helvum bats in Ghana. We find that reinfection is necessary
to explain observed dynamics; that acute infectious periods may be very
short (hours to days); that immunity, if present, lasts about 1–2 years; and
that recurring latent infection is likely. Although quantitative inference is
sensitive to assumptions about serology, qualitative predictions are robust.
Our novel approach helps clarify mechanisms of viral persistence and
circulation in wild bats, including estimated ranges for key parameters
such as the basic reproduction number and the duration of the infectious
period. Our results inform how future field-based and experimental work
could differentiate the processes of viral recurrence and reinfection in
reservoir hosts.
