Virus surveillance in Trinidad - January 1970 - January 1973

A continuing surveillance programme is being carried out at the Trinidad Regional Virus Laboratory, and the report summarises information obtained during period 1970 to 1973. Specimens were collected regularly from cases of suspected viral illness at health clinics in North and South Trinidad and at the Port of Spain and San Fernando General Hospitals. Two primary cell cultures, RhMK and HEK and one continuous line, HEp-2, were used for virus isolation from all specimens. Acute sera and rectal swabs were inoculated into baby mice. Virus identification was done by neutralization tests in Tissue Culture or mice, or by haemagglutination and haemadsorption inhibition. A total of 3780 cases were investigated from which 758 viruses were isolated. The viruses most frequently isolated from respiratory cases were influenza A Hong Kong. Parainfluenza, Herpesvirus and Adenoviruses, while isolates from gastroenteritis cases were mainly Echoviruses, Adenoviruses and Coxsackie viruses. Several outbreaks of respiratory illness occurred during this period. The first in April 1970 yield a mixture of Influenza a Hong Kong *(11) and Parainfluenza 1, 2, 3, *(11). Influenza A Hong Kong was the predominant virus isolated from outbreaks in October - December, 1970 (23), August - December, 1971 (47). The December 1972 - January 1973 (38) outbreak yielded isolates which appears to be closely related to Influenza A Hong Kong, but have not yet been completely identified. In February - May 1971 there was an increase in respiratory cases from which Adenovirus type 2 and Parainfluenza 1 and 3 (14) were recovered. Poliovirus surveillance yield only one isolate of Poliovirus type two in 1970, but several isolates, Jan.- Sept 1971 (3 type 1, 7 type 2 and 3 type 3) gave wrarning of the epidemic which started in December 1971 and ended in February 1972. One hundred and one stains of Poliovirus type 1 were isolated during this outbreak. Following this a serological survey was undertaken to determine the response to the polio immunization campaingn which was started during the epidemic. Of 60 paired sera tested, 90 percent showed a fourfould or greater increase in antibody level to Poliovirus 1. Sera of infants aged 6 to 48 months were also tested and 129 of 162 had titers of 1/8 or greater to poliovirus type 1. Echo virus and Coxsackie virus isolations remained at a low level during 1970 (20) and 1971 (41) but in the second half of 1972 there was an unusually long outbreak of gastroenteritis in children from which 168 Echo viruses, mainly types 12, 13, 14, and 22 were recovered. * number of isolates (AU)

A new group of viruses in Jamaica: 1. Initial studies

Sixteen isolates were uncovered from bird sera and mosquitoes collected at Caymanas Estates, Jamaica. One of these isolates was St. Louis encephalitis virus, two isolates were not fully characterised and 13 belonged to a group that was, before now, not described in Jamaica. This group had similarities to the Coxsackie A viruses but showed no serological relationship to the Coxsackie viruses to which they were most similiar. These viruses were capable of infecting man, causing at least in some cases clinical illness and possibly may be responsible for some of the fevers of unknown origin in Jamaica. (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)

Arbovirus studies in Bush Bush Forest, Trinidad, W.I., September 1959-December 1964. VI. Rodent-associated viruses (VEE and agents of groups C and Guama): isolations and further studies

Details are given on isolations of seven virus types from material collected in Bush Bush Forest during the study period: 262 of Venezuelan equine encephalitis (VEE), 71 of Caraparu-like, three of Oriboca, two of Restan, 63 of Bimiti, 56 of Catu, and 87 of Guama. Data from experimental-infection studies are presented, as well as results of serologic studies with hemagglutinating antigens of VEE and Caraparu-like viruses and some 1,200 sera of Bush Bush rodents. It was found that the natural transmission cycles of five of these virus types in Bush Bush are similar and include a period of multiplication and viremia in forest-floor rodents and a period of multiplication in mosquitoes among which Culex (Melanoconion) protesi, at least, is capable of subsequent transmission. Similar cycles are inferred for the remaining two virus types, Oriboca and Restan. In 1964 a severe reduction of the rodent population took place, Culex portesi continued abundant, and only Bimiti of the seven virus types was isolated. It is concluded that an alternate host population of sufficient size was not then available to these viruses in Bush Bush. Very little evidence was found to implicate mosquito species other than C.portesi as essential vectors during epizootic or inter-epizootic periods. (AU)

Arbovirus studies in Bush Bush Forest, Trinidad, W.I., September 1959-December 1964. V. Virus isolations

Virus isolates totaling 593 and representing 19 different virus types were recovered from sentinel animals, small mammals, and arthropods during studies carried out in Bush Bush Forest, Trinidad, over a 5-year period. The laboratory techniques used are described, and details are given regarding 49 isolates belonging to 12 virus types: Una, St. Louis encephalitis, Ilheus, Bush-bush, TRVL 57896 (Moriche), Wyeomyia, Cache Valley, Cocal, Oropouche, Aruac, Nariva, and TVRL 39316-1-5 type (Pacui). The remaining 544 isolates were identified as Venezuelan equine encephalitis virus or members of serologic groups C and Guama, and are discussed elsewhere (AU)

The role of respiratory viruses in Jamaica

This thesis describes a survey for respiratory viruses and their antibodies carried out at the Department of Microbiology, U. W. I., Mona from January, 1964 to June, 1966. The thesis is designed to show that representatives of the newer groups of viruses known to be associated with respiratory infections in humans are present in Jamaica, and to give indication of the prevalence of these viruses and their epidemiological behaviour in a tropical area. Two different approaches were made to the problem. Specimens from over 500 patients of ll ages and both sexes, suffering from both mild and severe respiratory infections were examined for the presence of respiratory viruses and their antibodies. Virus infection was detected in 67 (12.14 percent ) of these patients. Members of all the major groups of respiratory viruses, except rhinoviruses, were cultivated and serological conversions to many of them were also observed. Infections in children were found to be fairly common. Secondly, a series of surveys for antibodies to respiratory viruses in the general population were undertaken. Particular attention was paid to group A influenza viruses and their epidemic behaviour. Antibodies to type A2/Jamaica/2/63 influenza virus were widespread in the population, and there was a definite age-distribution of haemagglutination-inhibiting antibodies to certain other influenza strains. Antibodies to type C influenza virus were very common in the population of Jamaica. Antibodies to the parainfluenza viruses were also not infrequent in the sera of Jamaicans and evidence was obtained to show that these viruses and also respiratory syncytial virus caused frequent infections in infants and young children. Similarly, adenovirus antibodies were found to be acquired by the population at an early age (AU)

Nepuyo virus, a new group C agent isolated in Trinidad and Brazil. II. Serological studies

Nepuyo virus, represented by one strain from Trinidad and five from Brazil, reacts by hemagglution-inhibition (HI), neutralization and complement-fixation (CF) testing with previously described group C types but is distinct from them. By HI and neutralization testing Nepuyo is most closely related to Murutucu virus, and by CF testing to Apeu and Marituba viruses. (AU)

Studies on the ecology of V E E virus in Bush Bush Forest, Trinidad

This agent depended on a rodent-mosquito cycle which, in Bush Bush, was interrupted when the rodent population disappeared. The possible mechanisms for the escape of V E E virus from Bush Bush were discussed (AU)

Vesiculo-bullous eruptions due to virus infection as seen in Jamaica

The object of this project was to present cases of vesiculo-bullous eruptions due to virus infection as seen in Jamaica, and to outline laboratory procedures in diagnosis especially in relation to isolation in human thyroid tissue culture and differential diagnosis based on egg and animal inoculations and serological techniques. Previously, diagnoses were mainly based on clinical and epidemiological observations due to a lack of virus diagnostic facilities. This paper presented the nature of the aetiological agents as proven by isolation and identification: unusual manifestations of such viral agents, and the utilisation of a common system for isolation and relatively simple procedures for identification. Cases studied included Eczema vaccinatum due to vaccinia and to herpes simplex, vesiculo bullous eruptions on the lips, buccal mucosa, tongue and anterior fauces due to herpes simplex, herpes genitalis in adult males, uveitis and conjunctivitis as sequelae of severe herpes stomatitis, epidemic and sporadic cases of varicella, fatal case of varicella in an adult male, herpes zoster involving the opthalmic branch of trigeminal nerve, T4 and T5 on chest and dorsum and sacral plexus, auto-inoculation of arm and vulva with vaccinia in infant (AU)

Virus transmission studies with Trinidadian mosquitoes part IV. Kairi virus

This reports infectability of several Trinidadian mosquitoes with Kairi virus. Mosquitoes were inoculated and salivary gland virus was passaged weekly: for 5 weeks in Aedes scapularis, 4 weeks in A. taeniorhynchus, 1 week in Mansonia titillans and 3 weeks in Culex pipens quinquefasciatus. All 4 species transmitted Kairi virus by the bite of single mosquitoes after extrinsic incubation for 14-19 days. An attempt to infect A. Scapularis by feeding on an infected mouse failed. C. pipiens quinquefasciatus does not appear to be a suitable host for Kairi virus. (AU)

Triniti virus, a new agent isolated from Trinidadian mosquitoes

A previously undescribed agent has been isolated from Trichoprosopon mosquitoes captured in the Arena Forest in central Trinidad. The name Triniti virus is proposed for this agent neutralizing antibody to the virus has been demonstrated in human serum. Some of the physical and biological properties of the virus are described.(AU)

Laboratory studies with wild rodents and viruses native to Trinidad. Studies on the behavior of cocal virus

The response of the laboratory-reared Oryzomys laticeps velutinus and Zygodontomys b. brevicauda to inoculation with cocal virus was studied. Zygodontomys appears to be the more susceptible. Low-level viremia of short duration was detected in some animals of this species. Regular virus isolations were made from the crust of superficial skin wounds in Zygodontomys inoculated subcutaneously. Of 22 Zygodontomys inoculated subcutaneously or intradermally with 8th and 1st mouse brain passage virus, respectively, eight became paralyzed in the hind limbs. Death followed in 1 or 2 days in the four paralyzed animals that were not killed. In all eight animals, the virus content of the spinal cord exceeded that of the brain. No illness was observed in Oryzomys. Virus could be isolated with some regularity from the crusts of superficial skin wounds in this species only when the virus had been inoculated in the edge of the wound. Both rodent species appeared to become infected after intradermal inoculation by the multiple pressure method. Nasal instillation of virus infected both species and produced high mortality in Zygodontomys. Virus was recovered from the lungs of two dead Zygodontomys. Both species were refractory to infection by the oral route. The implications of the results for a further understanding of the epozootiology of cocal virus infection are discussed. (SUMMARY)

Tacaribe virus, a new agent isolated from Artibeus bats and mosquitoes in Trinidad, West Indies

Isolation of a new entity, Tacaribe virus, from Artibeus bats and from mosquitoes, in Trinidad, is described. The agent is pathogenic for baby and adult mice and is inactivated by incubation with sodium desoxycholate. It is proposed for inclusion in the group of arthropod-borne viruses (Summary)

Melao virus, a new agent isolated from Trinidadian mosquitoes

A new arthropod-borne agent, Melao virus, was isolated from Aedes scapularis collected in a Trinidadian forest in 1955. The virus was shown to be related immunologically to California encephalitis virus. Some of the physical and biological properties of the virus are reported. Limited studies have not shown evidence of immunity to Melao in human beings or monkeys from Trinidad.(AU)

Bimiti virus: a new agent isolated from Trinidadian mosquitoes

Bimiti virus is a new agent isolated from Culex mosquitoes collected in the Melajo Forest of Trinidad. Its isolation, identification and behavior in various animals and tissue culture are reported. Limited studies disclose a very low incidence of immunity to this virus in the human population of Trinidad.(AU)

Isolation of Ilheus virus from human beings in Trinidad, West Indies

Three strains of Ilheus virus were isolated from human beings in Trinidad. One of these isolations was made from a female resident of Port-of Spain who suffered a severe febrile illness. The other two strains were isolated from mosquito catchers who worked in the forests of eastern Trinidad. One of these men had a mild febrile illness at the time of the isolation, and the other was in good health. The serological reactions in these three cases of Ilheus infection are reported.(AU)

Oropouche virus: a new human disease agent from Trinidad, West Indies

The isolation and laboratory studies of a new virus isolated from a human fever case in Trinidad, West Indies, are described. The virus has been named Oropouche virus after the region from which it was obtained. Oropouche virus has been found to be related to Simbu virus, an agent isolated in South Africa. Neutralising antibodies were found in the blood of a few forest workers, 8 of 26 native cebus monkeys in the Nariva Swamp and 9 of 26 howler monkeys widely distributed over the island (Summary)

Manzanilia virus: a new virus isolated from the blood of a howler monkey in Trinidad, W. I.

The isolation and laboratory studies of an unidentified virus isolated from a howler monkey in Trinidad, W. I., have been described. The virus has been named "Manzanilla virus" after the region from which it was obtained. The absence of virus-neutralizing antibodies from the sera of a number of forest workers would seem indicate that this virus probably is not a frequent cause of infection in man (Summary)