Natural exposure of bats in Grenada to rabies virus

Abstract

Introduction: Grenada is a rabies endemic country, where terrestrial rabies is maintained in the small Indian mongoose (Herpestes auropunctatus). The role of bats in the epidemiology of rabies in Grenada is unknown. A 1974 report described one rabies virus positive Jamaican fruit bat (Artibeus jamaicensis), and a high seroprevalence in this species. In the current study, the natural exposure to rabies virus in Grenadian bats was re-evaluated. It is postulated that bats serve as a natural rabies reservoir, probably circulating a bat-specific rabies virus variant.Material and methods: Bats were trapped in 2015 in all six parishes of Grenada using mist- and hand nets. For the detection of rabies virus in brain tissue, the direct fluorescent antibody test (dFAT) and the reverse transcription polymerase chain reaction (RT-PCR) were used. Serum neutralizing antibodies were determined using the fluorescent antibody virus neutralization test (FAVN).Results and discussion: Brain tissue and sera from 111 insectivorous and frugivorous bats belonging to four species were tested (52 Artibeus jamaicensis, two Artibeus lituratus, 33 Glossophaga longirostris, 24 Molossus molossus). Rabies virus antigen and genomic RNA were not detected in brain tissues. Rabies virus neutralizing antibodies were detected in the sera of eight A. jamaicensis in four of the six parishes. Bats in Grenada continue to show natural exposure to rabies virus. As rabies virus was not isolated in this study, serology alone is not sufficient to determine the strain of rabies virus circulating in A. jamaicensis bats in Grenada.Conclusion: Artibeus jamaicensis appears to play a role as a reservoir bat species, which is of public health concern in Grenada. Dispersion of bats to neighboring islands is possible and serological bat surveys should be initiated in these neighboring states, especially in those areas that are free of rabies in terrestrial mammals.

Phylogenetic relationships and diversity of bat-associated Leptospira and the histopathological evaluation of these infections in bats from Grenada, West Indies

“…All processing was conducted with appropriate personal protective equipment (latex gloves, surgical masks and eyewear). Rabies virus has not been detected in bats in Grenada using viral detection by RT-PCR or direct immunofluorescence, but neutralizing antibodies to rabies virus have been observed previously [36]. Thus, all personnel handling the bats had completed the rabies vaccination series and demonstrated protective titers.…”

The Serological Prevalence of Rabies Virus-Neutralizing Antibodies in the Bat Population on the Caribbean Island of Trinidad

“…In comparison to viral investigative studies for RABV in bats, there have been limited investigations into the serological prevalence of rabies antibodies in bat populations. In Latin America and the Caribbean, the previous serological studies revealed significantly variable rates for the prevalence of rabies antibodies in bats [29][30][31][39][40][41][42][43][44] which may be attributed to differences in viral population dynamics influenced by spatio-temporal and bat demographic factors as discussed below.…”

“…In light of the apparently low prevalence of virus among bats, rabies antibody levels may be used as an indicator of virus exposure to gauge the risk of virus transmission. Few studies on rabies antibody prevalence have been conducted within the Caribbean [29][30][31][32] and the only report from Trinidad (conducted in 1974 during a small epizootic event) demonstrated a seropositive proportion of 12.8% [29]. We therefore sought to determine the current seroprevalence of rabies virus neutralizing antibodies (RVNA) in the Trinidadian bat population over a period of five years in order to infer the extent of natural exposure to RABVs and the spatio-temporal dynamics of RABV infection in the bat population.…”

Risk Modeling of Bat Rabies in the Caribbean Islands

“…The validation model ( Figure 3) determined Cuba (6.17) and the island shared by the Dominican Republic and Haiti (6.08) as the highest risk, followed by Trinidad and Tobago (5.24), and Grenada (5.31). All these islands have documented occurrences of laboratory confirmed rabid bats [4,[12][13][14][15]. Risk values attained from the validation model for each of the Caribbean countries where bat rabies has been detected are displayed in Table 3 .…”

“…Elsewhere, in a serosurvey conducted between 2005 and 2010 [62], researchers found serological evidence of widespread lyssaviruses in frugivorous and insectivorous bats on islands in the southwest Indian Ocean, including those self-declaring as rabies free. Additional examples of island countries discovering the presence of UBAT-RV or Lyssavirus only after active surveillance can be seen in the Philippines and Grenada [14,63,64].…”