<p>Locations of cases are indicated by circles, with black circles indicating locations fro... more <p>Locations of cases are indicated by circles, with black circles indicating locations from which RABV sequences were derived for the current study and white circles designating unsampled locations.. For sampled locations, the number of cases from which sequences were derived and their date and species of origin are indicated in blue. The location of co-circulation of Trinidad I and Trinidad IIa lineages is also indicated by an asterisk.</p
¥<p>Sequences obtained from the repository of the Rabies Program, CDC and from the Wildlife... more ¥<p>Sequences obtained from the repository of the Rabies Program, CDC and from the Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal Health and Veterinary Laboratories Agency (Weybridge).</p
<p>The location state probabilities for selected nodes are shown as percentages. The estima... more <p>The location state probabilities for selected nodes are shown as percentages. The estimated dates of divergence from mainland lineages and mean dates of existence for the most recent common ancestor (MRCA) for lineages containing Trinidadian sequences (with 95% HPD in parentheses) are shown in blue and black respectively to the left of relevant nodes. (<b>B</b>) Histogram inserts indicating the location state probabilities for the estimated introductions of RABV that gave rise to Trinidad lineages I (I1), IIa (I2) and IIb (I3).</p
<p>Clade credibilities of 95% and over are indicated in black at the relevant nodes. Termin... more <p>Clade credibilities of 95% and over are indicated in black at the relevant nodes. Terminal branches are coloured according to the sampled location and internal branches are coloured according to the most probable (modal) location of their parental nodes. Major clades and Trinidadian lineages are labeled accordingly. Chiropteran phylogenetic clusters are identified by dotted bar lines to the right and labeled according to group (species) designation which is further described in the inset.</p
Many of the emerging and reemergent infectious diseases experienced by humans in the last century... more Many of the emerging and reemergent infectious diseases experienced by humans in the last century have been caused by pathogenic viruses. Some are deadly pathogens, killing in days to weeks, while yet others, though for the most part not fatal still result in large social and economic burdens. Several have caused epidemics and even pandemics in naive populations, and with the greater connectedness of today’s world, and the changes in environment due to population expansion, urbanization, and global warming, it also means greater exposure to such viral pathogens that were at one time limited in their range. This chapter describes some of the more pertinent of these viral pathogens: their genetic organization, structure, diversity, how these affect their replication and pathogenesis, and finally how we can detect, treat, and/or manage the diseases they cause.
Rabies virus (RABV) is the only lyssavirus known to be present within the Caribbean. The island o... more 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 seroposi...
Abstract: Oryzoborus angolensis (Lesser Seed-Finch), Oryzoborus crassirostris (Large-billed Seed-... more Abstract: Oryzoborus angolensis (Lesser Seed-Finch), Oryzoborus crassirostris (Large-billed Seed-Finch), and Sporophila intermedia (Grey Seedeater) are finch species native to the Caribbean island of Trinidad. These species are locally trapped and kept for their song, but with declining native populations, enthusiasts have turned to illegally importing birds from the South American mainland. The smuggling of wild birds from South America poses significant disease risks to the native bird species of Trinidad. Herein we describe the first case of poxviral infection in these illegally imported birds in Trinidad and partial genome sequence of the causative agent. Phylogenetic analysis of the 4b core protein sequence indicated that the avian poxvirus identified was most closely related to a 2012 avian pox sequence from Brazil, with 96.2% and 98.1% identity at the nucleotide and amino acid level.
Bat-borne zoonotic pathogens belonging to the family Paramxyoviridae, including Nipah and Hendra ... more Bat-borne zoonotic pathogens belonging to the family Paramxyoviridae, including Nipah and Hendra viruses, and the family Filoviridae, including Ebola and Marburg viruses, can cause severe disease and high mortality rates on spillover into human populations. Surveillance efforts for henipaviruses and filoviruses have been largely restricted to the Old World; however, recent studies suggest a potentially broader distribution for henipaviruses and filoviruses than previously recognized. In the current study, we screened for henipaviruses and filoviruses in New World bats collected across 4 locations in Trinidad near the coast of Venezuela. Bat tissue samples were screened using previously established reverse-transcription polymerase chain reaction assays. Serum were screened using a multiplex immunoassay to detect antibodies reactive with the envelope glycoprotein of viruses in the genus Henipavirus and the family Filoviridae. Serum samples were also screened by means of enzyme-linked ...
Tacaribe virus (TCRV) was isolated in the 1950s from artibeus bats captured on the island of Trin... more Tacaribe virus (TCRV) was isolated in the 1950s from artibeus bats captured on the island of Trinidad. The initial characterization of TCRV suggested that artibeus bats were natural reservoir hosts. However, nearly 60 years later experimental infections of Jamaican fruit bats (Artibeus jamaicensis) resulted in fatal disease or clearance, suggesting artibeus bats may not be a reservoir host. To further evaluate the TCRV reservoir host status of artibeus bats, we captured bats of six species in Trinidad for evidence of infection. Bats of all four fruigivorous species captured had antibodies to TCRV nucleocapsid, whereas none of the insectivore or nectarivore species did. Many flat-faced fruit-eating bats (A. planirostris) and great fruit-eating bats (A. literatus) were seropositive by ELISA and western blot to TCRV nucleocapsid antigen, as were two of four Seba's fruit bats (Carollia perspicillata) and two of three yellow-shouldered fruit bats (Sturnira lilium). Serum neutralizati...
Tropical medicine and infectious disease, Jan 20, 2018
Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, L... more Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, Latin America and the Caribbean are often grouped together. Our study aimed to independently analyse the rabies situation in the Caribbean and examine changes in rabies spatiotemporal epidemiology. A questionnaire was administered to the 33 member countries and territories of the Caribbean Animal Health Network (CaribVET) to collect current data, which was collated with a literature review. Rabies was endemic in ten Caribbean localities, with the dog, mongoose, and vampire bat identified as enzootic reservoirs. The majority of animal cases occurred in Puerto Rico, the Dominican Republic, and Haiti, while human cases only consistently occurred in the latter two areas. Rabies vaccination was conducted for high-risk animal populations with variable coverage, and rabies diagnostic capacities varied widely throughout the region. Illegal importation and natural migration of animals may facilita...
Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, L... more Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, Latin America and the Caribbean are often grouped together. Our study aimed to independently analyse the rabies situation in the Caribbean and examine changes in rabies spatiotemporal epidemiology. A questionnaire was administered to the 33 member countries and territories of the Caribbean Animal Health Network (CaribVET) to collect current data, which was collated with a literature review. Rabies was endemic in ten Caribbean localities, with the dog, mongoose, and vampire bat identified as enzootic reservoirs. The majority of animal cases occurred in Puerto Rico, the Dominican Republic, and Haiti, while human cases only consistently occurred in the latter two areas. Rabies vaccination was conducted for high-risk animal populations with variable coverage, and rabies diagnostic capacities varied widely throughout the region. Illegal importation and natural migration of animals may facilitate the introduction of rabies virus variants into virus-naïve areas. Passive surveillance, together with enhanced methods and serological screening techniques, can therefore be of value. The insularity of the Caribbean makes it ideal for conducting pilot studies on reservoir host population management. Best practice guidelines developed for these reservoir hosts can be individually modified to the epidemiological status and available resources within each locality.
Vampire bat-transmitted rabies was first recognized in Trinidad during a major outbreak reported ... more Vampire bat-transmitted rabies was first recognized in Trinidad during a major outbreak reported in 1925. Trinidad is the only Caribbean island with vampire bat-transmitted rabies. We conducted a literature review to describe the changing epidemiology of rabies in Trinidad and give a historical perspective to rabies prevention and control measures on the island. The last human case of rabies occurred in 1937 and although no case of canine-transmitted rabies was reported since 1914, sporadic outbreaks of bat-transmitted rabies still occur in livestock to date. Over the last century, seven notable epidemics were recorded in Trinidad with the loss of over 3000 animals. During the 1950s, several measures were effectively adopted for the prevention and control of the disease which led to a significant reduction in the number of cases. These measures include: vampire bat population control, livestock vaccination, and animal surveillance. However, due to lapses in these measures over the years (e.g., periods of limited vampire control and incomplete herd vaccination), epidemics have occurred. In light of the significant negative impact of rabies on animal production and human health, rabies surveillance in Trinidad should be enhanced and cases evaluated towards the design and implementation of more evidence-based prevention and control programs.
<p>Locations of cases are indicated by circles, with black circles indicating locations fro... more <p>Locations of cases are indicated by circles, with black circles indicating locations from which RABV sequences were derived for the current study and white circles designating unsampled locations.. For sampled locations, the number of cases from which sequences were derived and their date and species of origin are indicated in blue. The location of co-circulation of Trinidad I and Trinidad IIa lineages is also indicated by an asterisk.</p
¥<p>Sequences obtained from the repository of the Rabies Program, CDC and from the Wildlife... more ¥<p>Sequences obtained from the repository of the Rabies Program, CDC and from the Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal Health and Veterinary Laboratories Agency (Weybridge).</p
<p>The location state probabilities for selected nodes are shown as percentages. The estima... more <p>The location state probabilities for selected nodes are shown as percentages. The estimated dates of divergence from mainland lineages and mean dates of existence for the most recent common ancestor (MRCA) for lineages containing Trinidadian sequences (with 95% HPD in parentheses) are shown in blue and black respectively to the left of relevant nodes. (<b>B</b>) Histogram inserts indicating the location state probabilities for the estimated introductions of RABV that gave rise to Trinidad lineages I (I1), IIa (I2) and IIb (I3).</p
<p>Clade credibilities of 95% and over are indicated in black at the relevant nodes. Termin... more <p>Clade credibilities of 95% and over are indicated in black at the relevant nodes. Terminal branches are coloured according to the sampled location and internal branches are coloured according to the most probable (modal) location of their parental nodes. Major clades and Trinidadian lineages are labeled accordingly. Chiropteran phylogenetic clusters are identified by dotted bar lines to the right and labeled according to group (species) designation which is further described in the inset.</p
Many of the emerging and reemergent infectious diseases experienced by humans in the last century... more Many of the emerging and reemergent infectious diseases experienced by humans in the last century have been caused by pathogenic viruses. Some are deadly pathogens, killing in days to weeks, while yet others, though for the most part not fatal still result in large social and economic burdens. Several have caused epidemics and even pandemics in naive populations, and with the greater connectedness of today’s world, and the changes in environment due to population expansion, urbanization, and global warming, it also means greater exposure to such viral pathogens that were at one time limited in their range. This chapter describes some of the more pertinent of these viral pathogens: their genetic organization, structure, diversity, how these affect their replication and pathogenesis, and finally how we can detect, treat, and/or manage the diseases they cause.
Rabies virus (RABV) is the only lyssavirus known to be present within the Caribbean. The island o... more 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 seroposi...
Abstract: Oryzoborus angolensis (Lesser Seed-Finch), Oryzoborus crassirostris (Large-billed Seed-... more Abstract: Oryzoborus angolensis (Lesser Seed-Finch), Oryzoborus crassirostris (Large-billed Seed-Finch), and Sporophila intermedia (Grey Seedeater) are finch species native to the Caribbean island of Trinidad. These species are locally trapped and kept for their song, but with declining native populations, enthusiasts have turned to illegally importing birds from the South American mainland. The smuggling of wild birds from South America poses significant disease risks to the native bird species of Trinidad. Herein we describe the first case of poxviral infection in these illegally imported birds in Trinidad and partial genome sequence of the causative agent. Phylogenetic analysis of the 4b core protein sequence indicated that the avian poxvirus identified was most closely related to a 2012 avian pox sequence from Brazil, with 96.2% and 98.1% identity at the nucleotide and amino acid level.
Bat-borne zoonotic pathogens belonging to the family Paramxyoviridae, including Nipah and Hendra ... more Bat-borne zoonotic pathogens belonging to the family Paramxyoviridae, including Nipah and Hendra viruses, and the family Filoviridae, including Ebola and Marburg viruses, can cause severe disease and high mortality rates on spillover into human populations. Surveillance efforts for henipaviruses and filoviruses have been largely restricted to the Old World; however, recent studies suggest a potentially broader distribution for henipaviruses and filoviruses than previously recognized. In the current study, we screened for henipaviruses and filoviruses in New World bats collected across 4 locations in Trinidad near the coast of Venezuela. Bat tissue samples were screened using previously established reverse-transcription polymerase chain reaction assays. Serum were screened using a multiplex immunoassay to detect antibodies reactive with the envelope glycoprotein of viruses in the genus Henipavirus and the family Filoviridae. Serum samples were also screened by means of enzyme-linked ...
Tacaribe virus (TCRV) was isolated in the 1950s from artibeus bats captured on the island of Trin... more Tacaribe virus (TCRV) was isolated in the 1950s from artibeus bats captured on the island of Trinidad. The initial characterization of TCRV suggested that artibeus bats were natural reservoir hosts. However, nearly 60 years later experimental infections of Jamaican fruit bats (Artibeus jamaicensis) resulted in fatal disease or clearance, suggesting artibeus bats may not be a reservoir host. To further evaluate the TCRV reservoir host status of artibeus bats, we captured bats of six species in Trinidad for evidence of infection. Bats of all four fruigivorous species captured had antibodies to TCRV nucleocapsid, whereas none of the insectivore or nectarivore species did. Many flat-faced fruit-eating bats (A. planirostris) and great fruit-eating bats (A. literatus) were seropositive by ELISA and western blot to TCRV nucleocapsid antigen, as were two of four Seba's fruit bats (Carollia perspicillata) and two of three yellow-shouldered fruit bats (Sturnira lilium). Serum neutralizati...
Tropical medicine and infectious disease, Jan 20, 2018
Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, L... more Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, Latin America and the Caribbean are often grouped together. Our study aimed to independently analyse the rabies situation in the Caribbean and examine changes in rabies spatiotemporal epidemiology. A questionnaire was administered to the 33 member countries and territories of the Caribbean Animal Health Network (CaribVET) to collect current data, which was collated with a literature review. Rabies was endemic in ten Caribbean localities, with the dog, mongoose, and vampire bat identified as enzootic reservoirs. The majority of animal cases occurred in Puerto Rico, the Dominican Republic, and Haiti, while human cases only consistently occurred in the latter two areas. Rabies vaccination was conducted for high-risk animal populations with variable coverage, and rabies diagnostic capacities varied widely throughout the region. Illegal importation and natural migration of animals may facilita...
Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, L... more Rabies virus is the only Lyssavirus species found in the Americas. In discussions about rabies, Latin America and the Caribbean are often grouped together. Our study aimed to independently analyse the rabies situation in the Caribbean and examine changes in rabies spatiotemporal epidemiology. A questionnaire was administered to the 33 member countries and territories of the Caribbean Animal Health Network (CaribVET) to collect current data, which was collated with a literature review. Rabies was endemic in ten Caribbean localities, with the dog, mongoose, and vampire bat identified as enzootic reservoirs. The majority of animal cases occurred in Puerto Rico, the Dominican Republic, and Haiti, while human cases only consistently occurred in the latter two areas. Rabies vaccination was conducted for high-risk animal populations with variable coverage, and rabies diagnostic capacities varied widely throughout the region. Illegal importation and natural migration of animals may facilitate the introduction of rabies virus variants into virus-naïve areas. Passive surveillance, together with enhanced methods and serological screening techniques, can therefore be of value. The insularity of the Caribbean makes it ideal for conducting pilot studies on reservoir host population management. Best practice guidelines developed for these reservoir hosts can be individually modified to the epidemiological status and available resources within each locality.
Vampire bat-transmitted rabies was first recognized in Trinidad during a major outbreak reported ... more Vampire bat-transmitted rabies was first recognized in Trinidad during a major outbreak reported in 1925. Trinidad is the only Caribbean island with vampire bat-transmitted rabies. We conducted a literature review to describe the changing epidemiology of rabies in Trinidad and give a historical perspective to rabies prevention and control measures on the island. The last human case of rabies occurred in 1937 and although no case of canine-transmitted rabies was reported since 1914, sporadic outbreaks of bat-transmitted rabies still occur in livestock to date. Over the last century, seven notable epidemics were recorded in Trinidad with the loss of over 3000 animals. During the 1950s, several measures were effectively adopted for the prevention and control of the disease which led to a significant reduction in the number of cases. These measures include: vampire bat population control, livestock vaccination, and animal surveillance. However, due to lapses in these measures over the years (e.g., periods of limited vampire control and incomplete herd vaccination), epidemics have occurred. In light of the significant negative impact of rabies on animal production and human health, rabies surveillance in Trinidad should be enhanced and cases evaluated towards the design and implementation of more evidence-based prevention and control programs.
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