Patterns of rabies cases in South Africa between 1993-2019, including
the role of wildlife
Abstract
Rabies is a global viral zoonosis endemic to South Africa, resulting in
fatal encephalitis in warm blooded animals, including humans. The loss
of human lives and economic losses in rural areas through loss of
livestock are substantial. A review was conducted of all confirmed
rabies cases in South Africa from 1993 to 2019, with a total of 11 701
cases identified to species level to assess the wildlife plays in the
epidemiology of rabies. A spatiotemporal cluster analysis using a
discrete Poisson space-time probability model, accounting for underlying
estimated dog and livestock densities, identified 13 significant
clusters (p<0.05). These included four long-term clusters
lasting more than 8 years in duration and seven short term clusters
lasting less than 2 years, with the remaining two clusters being of
intermediate length. Outside of these endemic clusters, wildlife
outbreaks in the remainder of South Africa were often less than one and
a half years in duration most likely due to the rapid decline of
wildlife vectors, especially jackals associated with rabies infection.
Domestic dogs accounted for 59.8% of cases, with domestic cats (3.2%),
livestock (21.1%) and wildlife (15.8%) making up the remainder of the
cases. Yellow mongoose (Cynictis penicillate) was the most frequently
affected wildlife species, followed by bat-eared fox (Otocyon
megalotis), black-backed jackal (Canis mesomelas), meerkat (Suricata
suricatta) and aardwolf (Proteles cristatus). Rabies in wildlife species
followed different spatial distributions: black-backed jackal cases were
more common in the north-western parts of South Africa, yellow mongoose
cases more frequent in central South Africa, and bat-eared fox and
aardwolf cases were more frequent in southern and western South Africa.
Clusters often spanned several provinces, showing the importance of
coordinated rabies control campaigns across administrative boundaries,
and high-risk areas were highlighted for rabies in South Africa.