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Jaswant et al. One Health Implement Res 2024;4:15-37 https://dx.doi.org/10.20517/ohir.2023.61 Page 25

exceptions in Africa where victims were scratched or licked [136,137] . The first case involved a 26-month old
child scratched by a puppy in Gauteng Province, South Africa. Genetic analysis linked this case to an
[137]
outbreak that spread in dogs in southern Johannesburg following an introduction from KwaZulu-Natal .
In the second case, a 6-year-old child from KwaZulu-Natal had no history of being bitten. However, a
neighbour’s dog died of unknown causes three days before the child’s death. Although rabies was not
suspected or tested for in the dog at the time, the authors speculate that this dog was the child’s most likely
source of exposure to rabies, possibly through non-bite contact with saliva (e.g., lick or scratch).
Phylogenetic analysis of other cases circulating in the region identified genetic similarity to the child’s
sample, further supporting the hypothesis that the child was infected through local exposure .
[136]

RABV movement
Phylogeographic analysis identified local transmission and long-distance movement of RABVs based on the
geographic association or displacement of clades, subclades and lineages. Some studies revealed situations
characterised by sustained local circulation, with distinct lineages and closely related sequences confined
within specific geographic areas. For instance, in Nigeria, sequences within AF2 (AF2-1 and AF2-2)
[130]
clustered in Northern and Southern Nigeria respectively . Similar clustering was observed in India [81,94]
and major island groups in the Philippines [78,138] . However, local circulation was often not confined by
political borders across contiguous landscapes. For example, samples from the border between Brazil (Mato
Grosso do Sul state) and Bolivia clustered, reflecting frequent movement across this boundary .
[139]

Most publications mentioned human-mediated long-distance viral movement but only about 25%
substantiated their claims through phylogeographic analysis. In Tanzania, discrete phylogeographic analysis
[140]
revealed long-distance movement between regions (> 750 km apart) , and sequences from distant
[9]
ecosystems (Serengeti and Tarangire, > 200 km apart) grouped together , with seasonal migration of
pastoralists (and their dogs) proposed as an explanation. In Asia, long-distance movement was attributed to
waves of human migration from China to Southeast Asia . Indeed, increased trade between and within
[141]
countries , including animal trade [75,104] and the dog meat trade [77,113,143] , were identified as playing a role in
[142]
RABV incursions and expansion.

Three sources of evidence were used to infer transboundary spread: co-circulation of divergent RABVs,
clustering of related sequences from adjacent countries/regions and phylogeographic analyses using location
data associated with sequences. Studies reported co-circulating divergent viruses in 31 countries, likely
caused by introductions that persisted [13,14,96,99,100,144] . For example, AF1a, AF1b and AF2 were found co-
circulating in southern Cameroon, with the AF1b and AF2 sequences most closely related to sequences
from the Central African Republic . RABVs circulating in neighbouring countries were often closely
[96]
[57]
related, particularly across shared land borders, like Azerbaijan with Georgia, Bangladesh with India,
[90]
and Tibet with Nepal. There were also instances of emerging subclades within one country closely
[142]
connected to another. For example, Nepalese isolates identified as a new lineage within the Arctic-like
(AL-1) subclade that circulates in India . Indeed, some studies aimed to quantify transmission between
[21]
countries [74,102] . One study highlighted the importance of China, suggesting the country was a source of
[68]
translocation to 12 Asian countries due to migration and trade . Similarly another study used Bayesian
inference to test the hypothesis that AF2 was introduced to Ghana from other West African countries with
results suggesting spread from Nigeria .
[99]
Several studies used phylogeographic analyses to infer RABV spatiotemporal dynamics [74,79,111,141,145] ,
particularly the direction and speed of dispersal [18,68,146,147] . Faster dispersal was associated with anthropogenic
factors. Dog-associated lineages in Brazil dispersed at 30.5 kilometres per year (km/year) in comparison to a