The identification and characterization of high impact avian viruses circulating in wild and domestic birds in Trinidad and Tobago

Objective: To identify the extent of circulation and specific characteristics of various high priority avian viruses in wild and domestic birds in Trinidad and Tobago (T&T). Viruses included Avian Influenza virus (AIV), Infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Infectious laryngotracheitis virus (ILTV) Avian metapneumovirus (aMPV), Infectious bursal disease virus (IBDV), Chicken infectious anaemia virus (CIAV), Fowl adenovirus Gp1 (FADV) and Egg drop syndrome virus (EDSV). Design and Methodology: A combination of active and passive surveillance of wild and domestic birds was carried out. Samples were tested for antibodies by enzymelinked immunosorbent assay (ELISA) and for virus by polymerase chain reaction (PCR) / sequencing to identify and characterise the circulating viruses and to determine their serotype and genotype. Results: Antibodies were detected against IBV, NDV, ILTV, APV, IBDV, FADV and EDSV and viral nucleic acid was detected for IBV, APV, CIAV and FADV in domestic poultry in T&T. Further characterisation of FADV revealed that serotypes 8a, 8b, 9, and 11 were circulating in diseased birds, along with CIAV. Phylogenetic analysis of circulating IBV strains identified two lineages, one with high similarity to the vaccine strains and the second being identified as a unique lineage to T&T. AIV antibodies with high neutralising titres against a low pathogenic H5N3 strain were detected in sera from three wild birds, and AIV RNA was detected by PCR in a swab sample taken from another wild bird. Conclusions: This research identified for the first time the presence of various high-impact avian viruses in domestic poultry and wild birds in T&T.

Psittacosis and Pacheco's Disease in Psittacine Birds in Guyana

Psittacosis (also known as chlamydiosis or ornithosis) is caused by Chlamydia psittaci, an obligate intracellular parasite that infects epithelial cells of the host, multiplies and enters new cells either by contact or through the blood stream. The infective form of the organism (elementary body) is shed into the environment via faeces, ocular and nasal discharges. Signs of psittacosis in psittacines include discharges from the eyes and nose, lethargy and a greenish yellow diarrhoea. Infected birds may also be asymptomatic, and will shed organisms intermittently, for extended periods to the environment. Clinically affected birds respond to tetracycline or doxycycline therapy, and the former is often administered orally to birds in Guyana some 30-40 days before export, in accordance with import health requirements. Other birds such as turkeys, pigeons and doves are also susceptible to psittacosis. Psittacosis is transmissable to humans where flu-like symptoms accompany infection.

Absence of Escherichia coli 0157 in a survey of wildlife from Trinidad and Tobago

Fecal, cloacal, or rectal swabs of free-ranging and captive mammalian and avian wildlife in Trinidad and Tobago were cultured for non-sorbitol fermenting Escherichia coli and tested for 0157: H7 strains. Ability of E. coli strains to produce hemolysin and mucoid colonies also was investigated. Of 271 free-ranging mammals tested, 158 (58 percent) yielded E. coli; only one (< 1 percent) bacterial isolate was a non-sorbitol fermenter which was not agglutinated by 0157 antiserum. All isolates were negative for hemolysin production and mucoid colonial growth. Two hundred and sixty-three (90 percent) of 293 free-flying birds were positive for E. coli and all isolates were sorbitol fermenters and negative for production of hemolysin and mucoid growth. Of 175 captive wild animals from individual backyard farms and a government demonstration farm, 145 (83 percent) yielded E. coli with four (2 percent) non-sorbitol fermenters; all were negative for 0157 strains, hemolysin production, and mucoid colonial growth. Of 373 animals in a zoo, 250 (67 percent) were positive for E. coli with only two (0.5 percent) non-sorbitol fermenters. All strains were non-hemolytic and non-mucoid farms. It appears that free-ranging and captive avian and mammalian wildlife are not important reservoirs of 0157: H7 stains of E. coli in Trinidad and Tobago.(AU)

Some bacterial enteropathogens in wildlife and racing pigeons from Trinidad

Fecal and cloacal swabs or feces of wild mammalian, avian and reptilian species, either farmed or free-ranging, and of racing pigeons (Columba livia) kept in lofts were cultured for Salmonella spp., Campylobacter spp., and Yersinia spp. Of 291 free-ranging mammals tested 6 (2 percent) and 1 (< 1 percent) and 1 (< 1 percent) yielded positive culture of Salmonella spp. and Campylobacter spp., respectively. Salmonella newport was the predominant serotype isolated and the opossum (Didelphis marsupialis insularis) had the significantly highest prevalence (29 percent) of Salmonella spp. infection compared to other species such as deer (Mazama americana trinitatis), lappe (Agouti paca), tattoo (Dasypus novemcinctus), agouti (Dasyprocta leporina), and wild hog (Tayassu tajacu). Among 14 species of farmed wildlife studied, 13 (7 percent) and 10 (5 percent) of 184 fecal or cloacal samples tested were positive for Salmonella spp. and Campylobacter spp., respectively. Salmonella javians accounted for 50 percent of the Salmonella spp. isolates and C. jejuni represented 90 percent of the Campylobacter spp. cultured. Only 1 (1 percent) of 124 cloacal swabs of free-flying avian species yielded Salmonella spp. compared to 21 (17 percent) samples positive for Campylobacter spp. Of 171 racing pigeons which originated from 8 fanciers, 8 (5 percent) yielded Salmonella spp. all of which were serotype typhimurium while only 1 (1 percent) were positive for Campylobacter spp. Seven (88 percent) of 8 Salmonella spp. isolates were recovered from one fancier. Yersina spp. was not cultured from any of the above samples. Although the prevalences of Salmonella spp. and Campylobacter spp. in wildlife in Trinidad are low, the practice of wildlife farming and the increased consumption of meat from wildlife may increase the health risk to human consumers(AU)

Salmonella in wildlife from Trinidad and Grenada, W.I

Forty-four of 219 animals from Trinidad and Grenada, W.I., yielded 20 serotypes of Salmonella, 16 of which are known to have been associated with human infection in the United States in recent years. Toads (Bufo marinus) provided the greatest number of isolates. Other carriers were mammals, vultures, lizards, a treefrog and a cave cockroach.(AU)

Virological investigations in Guyana, 1956-1966

During the course of virological investigations in Guyana over a ten-year period, 1956-1966, several viruses were isolated. Eastern equine encephalitis, western equine encephalitis, Cache Valley, and rabies viruses were recovered from equines; poliovirus types 1 and 3, Coxsackie Group B type 3, Coxsackie Group A type 4, and rabies were recovered from humans. In addition, serlological evidence was obtained for the past occurrence of infection with Mayaro, Ilheus, and yellow fever viruses in the Amerindians of the Rupununi, and with Ilheus, St. Louis encephalitis, and dengue in residents of the coastal area. Outbreaks of illness in equines due to viruses occurred on the coast in 1953, 1958, 1962, and 1966 and on the Rupununi Savannahs in 1959. An outbreak of poliomyelitis due to poliovirus type 1 occurred on the coast in 1962. Three members of one family from the north-west district died from rabies, presumably bat transmitted, in 1960 (AU)