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

Abstract

Rabies virus (RABV) is the only lyssavirus known to be present within the Caribbean. The island of Trinidad, is richly diverse in chiropteran fauna and endemic for bat-transmitted rabies with low RABV isolation rates observed in this population. We aimed to determine the seroprevalence of rabies virus neutralizing antibodies (RVNA) in light of spatio-temporal and bat demographic factors to infer the extent of natural exposure to RABV in the Trinidadian bat population. RVNA titers were determined by the RABV micro-neutralization test on 383 bat samples representing 21 species, comprising 30.9% of local bat diversity, from 31 locations across the island over 5 years. RVNA was positively detected in 33 samples (8.6%) representing 6 bat species (mainly frugivorous) with titers ranging from 0.1 to 19 IU/mL (mean 1.66 IU/mL). The analyses based on a multivariable binomial generalised linear mixed-effects model showed that bat age and year of capture were significant predictors of seropositivity. Thus, juvenile bats were more likely to be seropositive when compared to adults (estimate 1.13; p = 0.04) which may suggest early exposure to the RABV with possible implications for viral amplification in this population. Temporal variation in rabies seropositivity, 2012–2014 versus 2015–2017 (estimate 1.07; p = 0.03) may have been related to the prevailing rabies epizootic situation. Regarding other factors investigated, RVNA was found in bats from both rural and non-rural areas, as well as in both hematophagous and non-hematophagous bat species. The most common seropositive species, Artibeus jamaicensis planirostris is ubiquitous throughout the island which may potentially facilitate human exposure. The findings of this study should be factored into public health assessments on the potential for rabies transmission by non-hematophagous bats in Trinidad.

Different but Not Unique: Deciphering the Immunity of the Jamaican Fruit Bat by Studying Its Viriome

“…Urban areas were also more likely to contain seropositive bats than more rural regions. Moreover, despite the presence of neutralizing antibodies (titers ranging from 10 to 1900), these bats did not display signs of disease [15], indicating that unlike the experimental infection experiments using the murine CVS-24-N2c strain, the infection was not lethal to these wild bats. Studies have shown, notably, that RABV strains of bat origin tend to be less pathogenic in mice than strains from other reservoirs, indicating an adaptation of the virus to its host [29].…”

“…Consistent with its ability to infect a wide range of animals, the virus circulates in many other Artibeus species, including the flat-faced fruit bat and great fruit-eating bat. Artibeus bat colonies in Grenada are therefore believed to be reservoirs of RABV [13][14][15][16].…”

“…Recent serological examinations that aimed to identify exposure of bats to RABV in Trinidad revealed flat-faced fruit bats, at the time misidentified as Jamaican fruit bats, to be most seropositive of the species tested [15]. Interestingly, it appeared that juvenile bats were more likely to be seropositive than adult bats.…”

“…They were found to be infected with multiple viruses in nature, including dengue virus (DENV) [5][6][7], West Nile virus (WNV) [8], Zika virus Viruses 2022, 14, 238 2 of 11 (ZIKV) [8], alphacoronaviruses (α-CoV) [9], chikungunya virus (CHIKV) [10], Tacaribe virus (TCRV) [11,12], and rabies virus (RABV) [13][14][15][16], many of which are pathogenic to humans. Although infections with DENV, WNV, and ZIKV are due to epizootic events, it could be shown that Jamaican fruit bats may represent a reservoir for RABV [15]. TCRV, which has been isolated from bats of two Artibeus species, did not transmit to other bats under experimental conditions [17].…”

Risk Modeling of Bat Rabies in the Caribbean Islands

“…These are of particular concern, as they both are heavily populated, large islands that currently conduct limited active or passive rabies surveillance in bats. These are also the most densely human-populated islands, and studies elsewhere in the Caribbean have shown that urbanization level may be positively associated with rabies seroprevalence in bats [11]. The two lowest ranking island nations are the Bahamas (RV = 1.57) and Turks and Caicos Islands (RV = 1.57).…”