A SYSTEMATIC REVIEW AND META-ANALYSIS TO ASSESS THE SIGNIFICANCE OF
MICROBIAL INFECTIONS IN ZEBRA
Abstract
Wild equids can harvest multiple-host infectious agents that are able to
affect other wildlife species, but also domestic animals and humans. The
contact between wild and domestic equids is constantly increasing due to
the depletion of natural areas, climate and land-usage changes, which
could result in burdensome epidemics. Nevertheless, currently there is a
lack of adequate epidemiological data from zebra. Three electronic
databases were searched from 10 to 20 March 2021 for publications
reporting bacterial, viral and protozoan infections in zebra. Data for a
total of 12 nominal variables were extracted from reviewed papers to
undergo a qualitative analysis on microbial infections in zebra.
Prevalence-reporting studies were subjected to meta-analysis for
estimating the pooled prevalence and seroprevalence of infectious agents
in wild zebra populations. We identified 29 pathogen species and the
most represented were Equine Herpesvirus 1 and 9, Bacillus
anthracis, African Horse Sickness virus and Theileria equi. They
were reported from all the three zebra species, both in captivity and
wilderness. Pooled seroprevalences were estimated for the equine
Orbiviruses AHSV (70%; 95%CI: 35-96%) and EEV (21%; 95%CI: 8-38%)
and for the equine α -Herpesviruses EHV-1 (72%; 95%CI: 43-93%), EHV-4
(40%; 95%CI: 0-100%) and EHV-9 (58%; 95%CI: 9-98%), and pooled
prevalences for the equine piroplasms T. equi (100%; 95%CI:
94-100%) and B. caballi (8%; 95%CI: 0-28%). Zebra is most
probably a reservoir from which AHSV, EHV-1 and T. equi can be
transmitted to horse populations, potentially causing disastrous
epidemics. Zebra can also harvest zoonotic pathogens like B.
anthracis, A. phagocytophylum, CCHFV and T. brucei. Other agents
like EHV-9, BPV-1 and BPV-2 have the potential to spread from zebra to
other wild endangered animal species. We conclude that zebra is an
important host for multiple and dangerous pathogens. Alert and
epidemiological research should be increased on infectious agents of
zebra.