Serological evidence of hantavirus infection in farm and abattoir workers in Trinidad--a preliminary study.

Hantaviruses are established causative agents of hemorrhagic fevers and renal diseases amongst other clinical manifestations in humans, with most diagnosis based on serological assays. The disease, which is rodent-borne, has been reported in numerous countries worldwide but information about the disease is scanty in the Caribbean. The objective of this investigation is to determine the frequency of exposure to hantaviruses in a selected apparently healthy human population associated with abattoirs and livestock farms in Trinidad using a hantavirus immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). Of a total of 236 individuals tested, 27 (11.4%) were seropositive for hantavirus infection. Amongst abattoir workers the frequency of infection was 9.4% (6 of 64) compared with seropositivity rate of 12.4% (18 of 145) and 11.1% (3 of 27) amongst livestock farm workers and office workers and other individuals with minimal animal contact respectively. The differences were, however, not statistically significant (p > .05; χ(2) test). Age, gender, and race did not significantly affect the infection rate by hantavirus in the workers studied. This is considered the first documented evidence of hantavirus infection in Trinidad and Tobago. It is imperative for local physicians to consider hantavirus as a differential diagnosis in patients with hemorrhagic fever and renal diseases, since there may be a number of undiagnosed cases of hantavirus disease in the human population in the country.

Frequency of detection of immunoglobulins of Toxoplasma gondii, Leptospira spp., and Brucella abortus in livestock/farm and abattoir workers in Trinidad.

Toxoplasma gondi, Leptospira spp., and Brucella abortus are all established parasitic and bacterial zoonoses that manifest themselves in several forms of human diseases. They have been associated with occupational exposures, particularly amongst workers associated with livestock farms. The primary objectives of this study were to determine the seroprevalence of T. gondii immunoglobulin M (IgM) immunoglobulins (serum antibodies), Leptospira IgM immunoglobulins, and B. abortus IgG immunoglobulins, suggestive of acute or chronic infections, in livestock/farm and abattoir workers in Trinidad, and to relate to risk factors. Blood samples were collected from 394 consenting livestock/farm workers and 99 abattoir workers across the island of Trinidad. Serological status was determined by enzyme immunoassay (EIA) for T. gondii IgM, enzyme-linked immunosorbent assay (ELISA) for Leptospira IgM immunoglobulins, and buffered plate agglutination test (BPAT) and competitive ELISA for B. abortus IgG immunoglobulins. Of 394 apparently healthy livestock/farm workers sampled, 150 (38.1%) were seropositive for T. gondii IgM immunoglobulins, compared with 44 (44.4%) of 99 abattoir workers (p > .05; χ(2) test). Five (1.3%) of 371 and 1 (1.0%) of 99 livestock/farm and abattoir workers respectively were positive for Leptospira IgM immunoglobulins. All samples from livestock/farm workers and abattoir workers were negative for B. abortus immunoglobulins. None of the risk factors investigated was statistically significantly (p > .05; χ(2) test) associated with T. gondii and Leptospira spp. infections.

Human leptospirosis in the Caribbean, 1997-2005: characteristics and serotyping of clinical samples from 14 countries.

OBJECTIVE: To determine the frequency of human leptospirosis in the sera of suspected clinical cases sent by 14 Caribbean countries for diagnosis to a regional laboratory in 1997-2005. METHODS: All serum samples were initially tested using the immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) for leptospirosis. Demographic data (such as age and sex), month of the year and clinical manifestations that had been observed by the attending physician were related to seropositivity. The microscopic agglutination test (MAT) was used to serotype sera using a panel of 23 international serovars. RESULTS: Of 3 455 samples tested, 452 (13.1%) were seropositive for IgM antibodies to leptospirosis by the ELISA, with frequencies significantly (P < 0.05; χ2) different across countries and years. Among seropositive patients, the frequency of detection of leptospirosis (23.1%) was significantly higher in the age groups 1-20 years and 31-40 years combined compared with other age groups; and in male patients (72.1%) compared with female patients (19.7%) (P < 0.05; χ2). Chills, jaundice, vomiting, weakness, diarrhea, and kidney failure/problems were significantly (P < 0.05; χ2) exhibited at a higher frequency in seropositive, rather than seronegative patients. Using the MAT on 100 sera tested, 98 (98%) were seropositive, of which the serogroup Icterohaemorrhagiae was most prevalent with the detection of serovars Copenhageni (70%), Icterohaemorrhagiae (67%), and Mankarso (29%). CONCLUSIONS: Since only 13.1% of the suspected cases of leptospirosis were seropositive for IgM ELISA antibodies, other clinical conditions may have been responsible for the clinical manifestations observed, or the patient may have had chronic leptospirosis (IgG). In the Caribbean, serovars of the serogroup Icterohaemorrhagiae were responsible for most infections in the cases tested.

Frequency of seropositivity for Coxiella burnetii immunoglobulins in livestock and abattoir workers in Trinidad.

Coxiella burnetii is a zoonotic, rickettsial pathogen which causes mild and severe diseases often referred to as Q-fever in humans, particularly those occupationally exposed. This study determined the seropositivity for Coxiella burnetii IgM immunoglobulins using the enzyme immunoassay (EIA) in livestock and abattoir workers in Trinidad and related to selected personal characteristics to seroprevalence. Overall, of the 455 humans whose serum samples were tested, 20 (4.4%) were seropositive for C. burnetii IgM immunoglobulin, comprising 13 (4.6%) out of 283 livestock workers, 4 (4.7%) out of 85 abattoir workers and 3 (3.4%) out of 87 office workers (P>0.05; Chi 2). The age, sex and race of workers were not significantly associated with the occurrence of acute Q-fever (P>0.05; Chi 2). This is considered the first documentation of Q-fever in the human population in Trinidad. It is difficult to assess the impact of the disease in the country since the disease is not routinely tested for in the local hospitals or diagnostic laboratories.

Human leptospirosis in the Caribbean, 1997-2005: characteristics and serotyping of clinical samples from 14 countries / Leptospirosis humana en el Caribe entre 1997 y 2005: características y serotipificación de muestras clínicas de 14 países

OBJECTIVE: To determine the frequency of human leptospirosis in the sera of suspected clinical cases sent by 14 Caribbean countries for diagnosis to a regional laboratory in 1997-2005. METHODS: All serum samples were initially tested using the immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) for leptospirosis. Demographic data (such as age and sex), month of the year and clinical manifestations that had been observed by the attending physician were related to seropositivity. The microscopic agglutination test (MAT) was used to serotype sera using a panel of 23 international serovars. RESULTS: Of 3 455 samples tested, 452 (13.1 percent) were seropositive for IgM antibodies to leptospirosis by the ELISA, with frequencies significantly (P < 0.05; χ2) different across countries and years. Among seropositive patients, the frequency of detection of leptospirosis (23.1 percent) was significantly higher in the age groups 1-20 years and 31-40 years combined compared with other age groups; and in male patients (72.1 percent) compared with female patients (19.7 percent) (P < 0.05; χ2). Chills, jaundice, vomiting, weakness, diarrhea, and kidney failure/problems were significantly (P < 0.05; χ2) exhibited at a higher frequency in seropositive, rather than seronegative patients. Using the MAT on 100 sera tested, 98 (98 percent) were seropositive, of which the serogroup Icterohaemorrhagiae was most prevalent with the detection of serovars Copenhageni (70 percent), Icterohaemorrhagiae (67 percent), and Mankarso (29 percent). CONCLUSIONS: Since only 13.1 percent of the suspected cases of leptospirosis were seropositive for IgM ELISA antibodies, other clinical conditions may have been responsible for the clinical manifestations observed, or the patient may have had chronic leptospirosis (IgG). In the Caribbean, serovars of the serogroup Icterohaemorrhagiae were responsible for most infections in the cases tested.

OBJETIVO: Determinar la frecuencia de leptospirosis humana en el suero de presuntos casos clínicos enviados por 14 países del Caribe a un laboratorio regional para la confirmación del diagnóstico entre 1997 y 2005. MÉTODOS: Todas las muestras de suero se analizaron inicialmente mediante el ensayo inmunoenzimático de adsorción (ELISA) para detectar inmunoglobulina M (IgM) contra Leptospira. Se relacionó la seropositividad con datos demográficos (como la edad y el sexo), el mes del año y las manifestaciones clínicas observadas por el médico a cargo. Se usó la prueba de aglutinación microscópica para serotipificar los sueros con un grupo de 23 serovariedades internacionales. RESULTADOS: De las 3 455 muestras analizadas por ELISA, 452 (13,1 por ciento) fueron seropositivas para anticuerpos IgM contra Leptospira, con frecuencias significativamente diferentes (P < 0,05; χ2) según el país y el año. En los pacientes seropositivos, la frecuencia de detección de leptospirosis (23,1 por ciento) fue significativamente mayor en los grupos etarios de 1 a 20 años y de 31 a 40 años combinados, en comparación con otros grupos de edad; y mayor en los varones (72,1 por ciento) en comparación con las mujeres (19,7 por ciento) (P < 0,05; χ2). Los escalofríos, la ictericia, los vómitos, la debilidad, la diarrea y la insuficiencia o los trastornos renales fueron significativamente más frecuentes (P < 0,05; χ2) en los pacientes seropositivos que en los seronegativos. De los 100 sueros que se analizaron con la prueba de aglutinación microscópica, 98 (98 por ciento) fueron seropositivos, y entre estos el serogrupo Icterohaemorrhagiae fue el más frecuente, con detección de las serovariedades Copenhageni (70 por ciento), Icterohaemorrhagiae (67 por ciento) y Mankarso (29 por ciento). CONCLUSIONES: Ya que solo 13,1 por ciento de los presuntos casos de leptospirosis fueron seropositivos por ELISA para anticuerpos IgM, las manifestaciones clínicas observadas pueden haberse debido a otras enfermedades, o el paciente puede haber tenido leptospirosis crónica (con anticuerpos IgG). En los casos analizados en el Caribe, las serovariedades del serogrupo Icterohaemorrhagiae causaron la mayoría de las infecciones.

Frequency of seropositivity for Coxiella burnetii immunoglobulins in livestock and abattoir workers in Trinidad

Coxiella burnetii is a zoonotic, rickettsial pathogen which causes mild and severe diseases often referred to as Q-fever in humans, particularly those occupationally exposed. This study determined the seropositivity for Coxiella burnetii IgM immunoglobulins using the enzyme immunoassay (EIA) in livestock and abattoir workers in Trinidad and related to selected personal characteristics to seroprevalence. Overall, of the 455 humans whose serum samples were tested, 20 (4.4%) were seropositive for C. burnetii IgM immunoglobulin, comprising 13 (4.6%) out of 283 livestock workers, 4 (4.7%) out of 85 abattoir workers and 3 (3.4%) out of 87 office workers (P>0.05; ö2).The age, sex and race of workers were not significantly associated with the occurrence of acute Q-fever (P>0.05; ö2). This is considered the first documentation of Q-fever in the human population in Trinidad. It is difficult to assess the impact of the disease in the country since the disease is not routinely tested for in the local hospitals or diagnostic laboratories.