Longitudinal follow-up of Zika virus RNA in semen of a traveller returning from Barbados to the Netherlands with Zika virus disease, March 2016

We report the longitudinal follow-up of Zika virus (ZIKV) RNA in semen of a traveller who developed ZIKV disease after return to the Netherlands from Barbados, March 2016. Persistence of ZIKV RNA in blood, urine, saliva and semen was followed until the loads reached undetectable levels. RNA levels were higher in semen than in other sample types and declined to undetectable level at day 62 post onset of symptoms...(AU)

Doxycycline treatment of asymptomatic dogs seropositive for Ehrlichia canis

In Grenada, West Indies dogs are at frequent exposure to the rickettsial pathogen, Ehrlichia canis, as demonstrated by high seroprevalence rates. However, many of these seropositive dogs are clinically normal. In this study we identified clinically normal, E. canis seropositive dogs and assigned half to an antibiotic treatment group and half to a no treatment group. All dogs were evaluated for the presence of E. canis DNA by PCR on whole blood before, during and after treatment. Only one seropositive dog was also PCR+ before treatment. Our results suggest that most clinically normal, E. canis seropositive dogs in a highly endemic geographic area are not concurrently infected and thus routine treatment of clinically normal, seropositive dogs is not warranted.

Seroprevalence of Porcine Circovirus type 2 in swine herds in Trinidad and Tobago.

The seroprevalence of porcine circovirus type 2 (PCV2) in the swine population of Trinidad and Tobago was studied, focusing on the association between the seroprevalence of the virus and each of four variables: gender, age, group, farm size, and geographic location. Farms were classified as large (>1000 sows) or small (2 pigs to 250 sows); three age groups-nursery pigs (3 to 10 weeks, n=82), grower (11 to 22 weeks, n=107), and breeding animals(n=85) were studied. A multistage sampling design with non-proportional sampling between strata (farm sizes) was employed. A total of 274 serum samples were tested, collected from three large farms (n=109) and 109 randomly chosen small farms (n=165). Samples were tested using the PCV type 2 indirect fluorescent antibody test kit by VMRD (USA). Sixty-one percent of the farms tested were positive (2 large farms, 66 small farms). The overall seroprevalence of PCV2 was 62.0% (170/274) and after adjusting for non-proportional sampling between strata, was 70.3% ...

Seroprevalence of Hantavirus in Rattus norvegicus in Grenada, West Indies.

Hantavirus is an emerging zoonotic virus with potential for significant human disease and mortality. Rodents are the natural reservoir for the virus. This study reports the seroprevalence of hantavirus in brown rats (Rattus norvigicus) in Grenada. Serum samples from 198 brown rats were tested for the immunoglobulin G (IgG) antibody to hantavirus using an enzyme-linked immunosorbant assay (ELISA). A seroprevalence rate of 29.3% was found. This is the first report of hantavirus exposure in any species on the island of Grenada and documents the brown rat as a reservoir host on the island.

Seroprevalence of Porcine Circovirus type 2 in swine herds in Trinidad and Tobago.

The seroprevalence of porcine circovirus type 2 (PCV2) in the swine population of Trinidad and Tobago was studied, focusing on the association between the seroprevalence of the virus and each of four variables: gender, age, group, farm size, and geographic location. Farms were classified as large (>1000 sows) or small (2 pigs to 250 sows); three age groups-nursery pigs (3 to 10 weeks, n=82), grower (11 to 22 weeks, n=107), and breeding animals(n=85) were studied. A multistage sampling design with non-proportional sampling between strata (farm sizes) was employed. A total of 274 serum samples were tested, collected from three large farms (n=109) and 109 randomly chosen small farms (n=165). Samples were tested using the PCV type 2 indirect fluorescent antibody test kit by VMRD (USA). Sixty-one percent of the farms tested were positive (2 large farms, 66 small farms). The overall seroprevalence of PCV2 was 62.0% (170/274) and after adjusting for non-proportional sampling between strata, was 70.3% ...

Seroprevalence of Hantavirus in Rattus norvegicus in Grenada, West Indies.

Hantavirus is an emerging zoonotic virus with potential for significant human disease and mortality. Rodents are the natural reservoir for the virus. This study reports the seroprevalence of hantavirus in brown rats (Rattus norvigicus) in Grenada. Serum samples from 198 brown rats were tested for the immunoglobulin G (IgG) antibody to hantavirus using an enzyme-linked immunosorbant assay (ELISA). A seroprevalence rate of 29.3% was found. This is the first report of hantavirus exposure in any species on the island of Grenada and documents the brown rat as a reservoir host on the island.

Serological tests for lyme disease in patients with tropical spastic paraparesis and healthy Jamaicans

The significance of reactive serlogical tests for lyme disease in patients with tropical spastic paraparesis (TSP) was assessed by examining serum samples from 128 of these patients and 200 healthy Jamaicans by lyme indirect immunofluorescent antibody (IFA), enzyme immuno-assay (EIA) and western blot analyses. Sera were also examined in serological tests for syphilis (STS), an unabsorbed fluorescent treponemal antibody test and leptospira microagglutination test. The prevalence of positive Lyme IFA and EIA results did not differ significantly between sera from TSP patients (12.5 percent and healthy controls (10.0 percent). Western blot analyses showed that the positive lyme IFA and EIA results observed in this study were due to false positive reactions. Seventy-five per cent of lyme IFA/EIS positive sera from TSP patients had treponemal antibodies. Eighty per cent of those from healthy controls were negative in standard STS but 85 percent were positive when tested in an unabsorbed fluorescent treponemal antibody (FTA). These data indicate that reactive serological tests for lyme disease in Jamaican TSP patients and healthy Jamaicans are false positive reactions due to cross-reactivity with other spirochaetes, notably treponema pallidum and non pathogenic treponemes (AU)

Dengue activity in Puerto Rico

The laboratory-based dengue surveillance program in Puerto Rico aims to provide early and precise information to public health officials on four aspects of increased dengue activity: time, location, virus stereotype, and disease severity. The Dengue Branch, San Juan Laboratories (SJL) of the National Center for Infectious Diseases, Centers for Disease Control, receives blood specimens from government clinics, public and private hospitals, and physicians' offices throughout Puerto Rico. These specimens are sent directly or collected locally and transported to SJL by personnel of the Community Hygiene Division (HAFI, for its initials in Spanish) of the Puerto Rico Health Department (PRHD). All serum specimens are tested for anti-dengue IgM to a mixture of four dengue virus antigens, by IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA). All specimens that test positive by MAC-ELISA are further evaluated with an IgG-ELISA to determine whether the infection is primary or secondary. Up to 125 early acute-phase samples per week are processed in C636 mosquito cell cultures for attempted virus isolation. In addition, sera from all patients with haemorrhagic manifestations and all patients from outside Puerto Rico and the U.S. Virgin Islands, if collected fewer than 6 days after onset of illness, are injected into Toxorhynchites mosquitoes. Dengue virus-infected cell cultures or tissues from inoculated mosquitoes (AU)

The epidemiology of infantile gastroenteritis in the Eastern Caribbean with special reference to the role of rotavirus infection

The objectives of this work were (1) to determine the relative importance of rotavirus, cytopathic viruses, selected bacteria and faecal parasites in infantile gastroenteritis in Guyana, Trinidad and St. Vincent; (2) to study the occurrence and distribution of rotavirus gastroenteritis and the clinical course of the disease; (3) to investigate transmission of faecal micro-organisms in families; (4) to assess the influence of malnutrition and respiratory disease on the course of illness; (5) to explore the role played by maternal characteristics, environment and economic status in this continuing problem; (6) to seek for rotavirus in calves in Trinidad. Human study subjects were 397 hospitalized gastroenteritis cases under three years of age. Healthy controls, registered at district health offices, were matched by age, sex and approximate home address. Data were collected from hospital records and by questionnaire. Weights were taken during hospitalization and follow-up. Stool samples were tested for viruses, bacteria and parasites. Rotavirus was detected by counterimmuno electrophoresis and ELISA with confirmation by electron microscopy. Forty-seven random family pairs were used for transmission data and samples of five-year old children were screened for rotavirus antibody. Rotavirus, the most prevalent pathogen, occurred in 21 percent of cases and one percent of controls. It was found more frequently in children 6-35 months old and not in premature newborn infants. Eighty-four percent of five-year olds had antibody. The illness was generally mild, but 5 of 30 fatal cases excreted rotavirus. Significantly increased morbidity and mortality were associated with age (<6 months), low birth weight (<2.5 kg), malnutrition (Gomez 11 or 111) and little or no breast-feeding (<1 month). Gastroenteritis cases had mothers with less education and interest in health services and fathers with more unskilled jobs and lower incomes. Case families were similar in size and structure to controls but had more diarrhoeal illness, more gastrointestinal infections and less pipe-borne water at home. Rotavirus was detected in calves with and without diarrhoea. Persistence in the environment was suspected (AU)

Serological and ecological study of the genus Leptospira in Jamaica

In a serological and ecological study of the genus Leptospira in Jamaica, 535 sera from three species of livestock animals, bovine, porcine and caprine were serologically tested by the microscopic agglutination technique using live leptospiral antigens. Of the number tested, 316 (59.06 percent) were reactive with titers equalling or greater than 1:100. A total of six serotypes were identified and representative serovars were as follows:- jules (serogroup Hebdomadis) 257 (51.92 percent); icterohemorrhagiae (serogroup Ictero-hemorrhagiae) 140 (28.07 percent); autumnalis (serogroup Autumnalis) 41 (8.3 percent); canicola (serogroup Canicola) 30 (6.06 percent); pomona (serogroup Pomona) 25 (5.19 percent) and abramis (serogroup Pyrogenes) 2 (0.4 percent). The porcine species recorded the highest percentage of reactive sera (65.5 percent) and the caprine the lowest (38.9 percent). The widest distribution of serotypes occurred in pigs. A comparison of the parishes showed that the positive sera from Portland (80.9 percent) and Westmoreland (71.6 percent) topped others and St. Andrew had the lowest 11.0 percent. For the ecological study, 22 soil and 25 water samples collected from five selected livestock farms in the island were cultured initially in enrichment artificial medium (Ellinghausen and McCullough semi-solid), ESS, incorporating 5-fluorouracil, for the isolation of leptospires. A total of 23 (48.9 percent) isolates were obtained:- 16 (72.7 percent) from the soil samples and 7 (28 percent) from the water samples. One water isolate was lost and the 22 parent isolates were subsequently inoculated into weanling hamsters. The kidney tissues and heartblood of the inoculated hamsters on culture yielded 8 leptospiral isolates and the microscopic agglutination test of the sera of inoculated hamsters gave 9 reactive results. There was no positive results either from culture or serological test of the control (uninoculated) hamsters. The investigations revealed that the constituents of Jamaican soil, the heavy rainfall and the various environmental factors are ideal for the survival and distribution of leptospires in the island. Flooding helps to spark off epizootic outbreaks and the leptospiral serotypes mentioned earlier are enzootic and endemic in Jamaica. The predominant serotypes are jules and icterohemorrhagiae. People at high risk are the livestock attendants and milkers. The epidemiological importance of the serotypes identified and suggested means of dealing with their adverse effects are discussed (AU)

Comparison of two human pathogenic strains with a commensal strain of Herpes Simplex virus isolated at the University Hospital of the West Indies

Comparision has been made between two human "neuropathogenic" and one "commensal" strains of herpes simplex virus. These terms are assigned to these viruses on the basis of their origin. The first two were related from patients with encephalitis and the third from a benign recurrent lesion. A number of physiochemical characteristics of these three strains were studied. The major differences observed between the "pathogens" and the "commensal" virus are: 1. The ability of the commensal herpes virus to infect adult mice while the pathogenic herpes could not. 2. The commensal herpes virus could not be neutralized by the hyperimmune sera of the pathogenic herpes and vice versa, although all crossreacted in complement fixation tests. 3. The commensal virus was significantly inactivated by chloroform, while the pathogens were not significantly affected under the same conditions. 4. Freezing and thawing followed by differential centrifugation rendered the commensal herpes vulnerable to inactivation of DNAse. Inactivation of the pathogens by this enzyme could only be acheived after chromatography on the anion exchanger, Diethyl aminoethyl. 5. The absorbtion spectrum gave a maximum peak at wave lenghts between 260-270 mu for the pathogenic virus. The peak absorption of the commensal herpes was at 280 mu. The peak at 260-270 mu by the pathogens is most likely due to the presence of nucleic acid. The peak absorption of the commensal virus is similar to that given by a typical protein. The relatively high concentration of protein which accompanies the commensal virus might account for the behaviour of this virus. 6. The "pathogenic" and "commensal" strains could be distinguished with respect to susceptibility to interferon. The commensal strain being more susceptible and also more effective in inducing interferon synthesis. 7. The method of comparision used in this investigation, and the results which reflect the marked difference between the strains of herpes simplex studied here produce some methods which may be used for differentiating between pathogenic and commensal strains of herpes simplex virus. It would appear that the methods used here are valuable to the study of viral genetics and the physiochemical study of herpes viruses. Evidence has been presented to show that there is molecular structural difference between the pathogenic and the commensal strains of herpes simplex virus. Such a difference or such differences may provide tools to probe into the pathogenic physiology of infected cells, or help to elucidate the factors responsible for neurotropicity and commensalism in herpes virus. The author is convinced that the differences cited above are genetically based. However, until further investigations are carried out, it is a subjective choice whether to consider the differences as sufficient basis for the subgrouping of herpes simplex virus. No claim is made that the distinction cited are attributes of other strains associated with encephalitis or limited lesions of recurrent herpes (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)

The role of parainfluenza viruses in respiratory diseases in Trinidad

Studies in other countries have shown that the parainfluenza viruses play an important role in respiratory disease especially among infants and children. Serologic evidence of infection with parainfluenza three was found to be widespread reaching up to 90 percent in children and 100 percent in adults. This study, conducted in Trinidad, W.I. shows that the parainfluenza viruses are not the major cause of respiratory disease in that country. Serological tests, hemagglutination inhibition, neutralization tests and complement fixation tests show that the incidence of antibody in Trinidad is much lower than that in other countries of temperate climate. Parainfluenza 1, 2, and 3 viruses were isolated from cases of respiratory disease during the course of the study but no epidemics caused by these viruses were seen. That is, no real increase of respiratory disease reflected in increased admissions to hospital or attendance at clinics was seen that could be traced to parainfluenza virus infections. These viruses seem to be the sporadic cause of respiratory disease in Trinidad. The incidence seems to be spaced over a period of months in a given year (AU)

Serological evaluation services: Eastern Caribbean

In 1960, a serological evaluation service was established primarily for the Eastern Caribbean Laboratories, and the V.D. Laboratory at the Caribbean Medical Centre in Trinidad serve as the evaluating centre for the Group. The first series of the Caribbean Study was completed in 1962. Steps were taken to correct errors and improve techniques occuring in the laboratories showing an unsatisfactory performance. The series is to be continued and extended to other laboratories (AU)

Isolation of St. Louis encephalitis virus from the blood of a child in Trinidad, W.I

St. Louis encephalitis virus was isolated from the blood of an 11-year-old boy, resident of Trinidad, W.I., in September, 1958, in the absence of sufficient symptoms or signs to support a clinical diagnosis of encephalitis. (Summary)

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. (Summary).

Neutralizing antibodies against certain viruses in the sera of residents of Trinidad, B.W.I

Blood samples taken from 1,055 indigenous residents of Trinidad, B.W.I., were tested for neutralizing antibody against 17 different viral agents known or believed to be arthropod-borne, in 4,555 protection tests. Yellow fever, Ilheus and dengue are, or have, on the basis of protection tests, presumably present, widespread, and common in Trinidad. A yellow fever outbreak occurred during the course of investigations in 1954. There is no evidence that Venezuelan equine encephalitis has been present on the island since the last reported outbreak in 1943. A small number of sera were found which neutralized St. louis encephalitis virus. No interpretation of this result is attempted. Although no human sera netralized Eastern equine encephalitis virus, two different specimens of serum from one donkey neutralized the virus in two tests. Interpretation of tests against Uganda S, West Nile, Semliki, Ntaya, and Japanese B is complicated by the possibility of interfering cross-immune reactions. All tests with Bwamba, Zika, Anopheles A, Western equine encephalitis, and Bunyamwera viruses were negative. A provisional ecological zoning of the island is presented, based upon distribution of immunity against several Virus agents. (Summary).

Arthropod borne encephalitis viruses in the West Indies area. Part I. A serological survey of Grenada, W.I

Serological studies of blood specimens collected in Grenada in 1956 indicate that dengue infections have been prevalent in certain regions of the island. Ilheus virus infections, if they occur, are relatively uncommon. Similarly St. Louis virus infections,if they occur, are relatively uncommon. The only yellow fever immune individuals were over 50 years old. No evidence of existence of Mayaro infection was found. (Summary)