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02/2012; , ISBN: 978-953-307-938-7
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01/2012; , ISBN: 978-953-307-938-7
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ABSTRACT: 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.
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.
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%).
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.
Revista Panamericana de Salud Pública 05/2011; 29(5):350-7. · 0.85 Impact Factor
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ABSTRACT: Tuberculosis (TB) in the Caribbean remains a significant health issue with many countries exceeding the WHO target of 5 cases / 100,000 populations. As a developing nation, many of these Caribbean countries face serious challenges in the diagnosis, treatment, care and management of patients with tuberculosis. In light of the current problems facing the tuberculosis programs in the Caribbean, there is a need for studies to be conducted so as to better understand the epidemiology of this disease in such a heterogeneous setting. This investigation describes a first global molecular epidemiological study on 480 clinical M. tuberculosis isolates from as many patients, collected in 12 territories of the Caribbean: Bahamas, Barbados, Belize, Dominica, Guyana, Jamaica, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Suriname, Trinidad and Tobago, Turks and Caicos. Analysis of “de-identified” patient data showed that TB cases more often concerned males (male to female sex-ratio, 3.1), and persons within age group 25-45 years. The rate of TB/HIV coinfection was unexpectedly high with rates ranging from 44.4% in Guyana, 42.9% in Bahamas, 30.6% in Trinidad and Tobago, 21.4% in Suriname, 14.3% in Barbados and 13.5% in Jamaica. The highest rate of drug-resistant TB was observed in Guyana (27.8%, among which 76% were multidrug-resistant). Spoligotyping generated a total of 104 distinct patterns for the 480 isolates studied; 49 patterns containing 425 isolates (88.5%) corresponded to clustered strains (2-93 isolates per cluster), while the remaining 55 patterns corresponded to unclustered strains (11.5%). A comparison of the spoligotypes with the SITVIT2 global database showed that the isolates belonged to the following predominant genotypic lineages: the ill-defined T lineage (31.0%), East-African Indian (EAI, 19.0%), Latin American and Mediterranean (LAM, 10.4%), the X clade (8.3%), Haarlem (5.8%), and Beijing (3.5%). The diversity of strains circulating in the Caribbean essentially represented their colonial past (clades of European descent such as Haarlem, and X clades) as well as population movements (EAI, Beijing). Lineages characteristic of the Indian subcontinent (East- African-Indian, Central-Asian) were seen in Trinidad and Tobago, Guyana, and Suriname where there is a large population of East Indians brought during the indentureship period, after slavery was abolished. Lastly, a peculiar local evolution of M. tuberculosis strains in Trinidad and Tobago was evidenced with the exclusive local emergence of a specific TB clone (named SIT566, belonging most probably to the X clade), which resulted in 56% of all TB cases.
BMC proceedings 01/2011; 5(Suppl. 1):P81.
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ABSTRACT: To compare the QuantiFERON®-TB Gold (QFT-G) assay and tuberculin skin test (TST) in screening/diagnosis of latent tuberculosis infection (LTBI) among individuals in Trinidad & Tobago at high risk for TB.
A total of 560 individuals (TB patient contacts, HIV patients, health care workers, prison inmates, and TB patients [controls]) were recruited for the study. Blood was drawn and processed using the QFT-G assay, followed by immediate administration of TST solution on subjects' forearm. Data were analyzed with Epi InfoTM 3.5.1 software. Results were compared across the target groups using the chi-square test (P < 0.05).
The QFT-G assay detected LTBI in 51% of the subjects (with most positive results occurring among the control group) whereas the TST detected it in 39.4% (P = 0.001). Overall, the QFT-G assay detected LTBI more frequently than the TST among all subjects except the control group, where detection favored the TST. The QFT-G assay produced indeterminate and nonreactive results in some HIV patients but required less turnaround time than the TST (23.3 h versus 70.2 h; P < 0.0001). The TST cost less per subject than the QFT-G assay (US $3.70 versus US $18.60; P = 0.0008).
The QFT-G assay cost more but had a higher detection rate among most target groups and required less turnaround time than the TST. However, its sensitivity was lower among immunocompromised subjects. Therefore, the QFT-G assay should be used with caution for LBTI screening/diagnosis in resource-poor, high-HIV prevalence settings such as Trinidad & Tobago.
Revista Panamericana de Salud Pública 07/2010; 28(1):36-42. · 0.85 Impact Factor
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ABSTRACT: We report on a fine molecular and phylogenetical characterization of circulating Mycobacterium tuberculosis strains isolated from patients during a 1-year period in Trinidad and Tobago (T&T). The spoligotyping data coupled to minisatellite typing and available epidemiological data showed that a single major clone of "evolutionary modern" tubercle bacilli (SIT566) was responsible for more than half of the tuberculosis (TB) cases. It preferentially infected younger age groups (mean 39.1 years versus 47.7 years for other genotypes, p<0.0005), and was overrepresented in Port-of-Spain (1 out of 3 patients). A comparison of genotyping results to data gathered for 6 Caribbean countries (n=2653 clinical isolates) showed that the overall lineage distribution in T&T was completely different from its neighbors, e.g., T&T was the only country harboring a unique sublineage of the Latin American & Mediterranean (LAM) family, designated LAM-10CAM with phylogeographical specificity for Cameroon and neighboring countries in West Africa; interestingly 3/4 of the patients within this group in T&T were African descendants. Similarly, strains belonging to East African Indian (EAI) lineage with phylogeographical specificity for the Indian subcontinent, were found in T&T (13% of all strains), but were absent among the neighboring countries. Although the predominant SIT566 was not yet detected elsewhere in the Caribbean, available information underlined that this genotype was already present in the United States as imported cases of disease among T&T-born patients. Characterization of SIT566 strains using 12-, 15- and 24-loci MIRU typing, and comparison of results to international databases showed that these isolates were characterized by a common 12-loci MIRU pattern 224315153324 corresponding to MIRU International Type-MIT633 in 21/25 strains tested, as well as its 4 variants; an orphan pattern , MIT27-, MIT117-, and MIT1158-. Extended 24-loci MIRU typing led to a predominant pattern 224315153324323483334323 in a total of 16/21 MIT633 isolates, as well as identification of 3 supplemental patterns. Comparison of 24-loci MIRU data with the international database MIRU-VNTRplus showed the unique nature of the patterns obtained in T&T. Further analysis using the Levenshtein algorithm showed that the first 2 closest matches with the SIT566/MIT633 clone belonged to the X lineage strains in MIRU-VNTRplus. This observation corroborates our preliminary spoligotyping-based analysis using minimum spanning and neighbor-joining trees, which suggested a phylogenetical relatedness of the SIT566 clone with SIT119, which represents X1 lineage prototype in SpolDB4 database. We hypothesize that the predominant SIT566 clone might have evolved from a pool of X lineage M. tuberculosis strains with phylogeographical affinity for Anglo-Saxon descendants.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 09/2009; 9(6):1336-44. · 3.22 Impact Factor
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ABSTRACT: This report is based on a 1-year recruitment of all of the culture-positive Mycobacterium tuberculosis cases in Trinidad and Tobago (n = 132). The study population was characterized by a high male-to-female sex ratio of 4 and a human immunodeficiency virus-tuberculosis (TB) coinfection rate of 30%. It mainly occurred among African descendants, who represent 37.5% of the total population but 69.7% of all TB cases (P < 0.001). Spoligotyping resulted in 25 different patterns and 12 clusters (2 to 74 strains per cluster), with the predominance of a highly conserved spoligotype international type clone, SIT566.
Journal of clinical microbiology 04/2009; 47(6):1911-4. · 4.16 Impact Factor
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ABSTRACT: Tuberculosis Mycobacterium, Spoligotyping, Minisatellites
MIRU-VNTR, Epidemiology, Phylogeny,Trinidad and Tobago
Infection Genetics and Evolution 01/2009; 9:1336 - 1344. · 3.13 Impact Factor
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ABSTRACT: The rapid identification of drug-resistant strains of Mycobacterium tuberculosis is crucial for the timely initiation of appropriate antituberculosis therapy. The performance of the Genotype MTBDRplus assay was compared with that of the Bactec 460 TB system, a "gold standard" culture-based method. The Genotype MTBDRplus assay was quicker and more cost-effective for the detection of rifampin resistance, but it was not as good for the detection of isoniazid-resistant strains in our setting.
Journal of clinical microbiology 09/2008; 46(10):3426-8. · 4.16 Impact Factor
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ABSTRACT: This study was carried out to provide some evidence for the interruption of transmission of lymphatic filariasis (LF) among schoolchildren in Trinidad and Tobago. A cross-sectional survey for LF antigenaemia was performed among 63 (13.2%) of the 479 primary schools located in eight administrative (and geographical) regions of Trinidad and Tobago. From these communities, 2597 schoolchildren aged 6-12 years were sequentially selected for a survey of bancroftian antigenaemia. From each child, 100 microl (finger-prick) whole blood sample was applied to a Binax immunochromatographic card test (ICT), and read for the presence of antigenaemia. The ICT results showed a negative finding for LF antigenaemia and suggest that LF transmission has been interrupted in the survey areas.
Transactions of the Royal Society of Tropical Medicine and Hygiene 09/2004; 98(8):473-7. · 2.16 Impact Factor
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ABSTRACT: The seroprevalence of toxocariasis was investigated in 1997/98 in 1009 schoolchildren (aged 5-12 years) throughout Trinidad. Infection, as measured by titre, was found to be high compared to values obtained from children in other countries. Using an excretory-secretory antigen and performing an ELISA test, it was found that 62.3% of children had an IgG antibody titre of > or = 1:100, indicating exposure to the parasite, while 27.2% had a titre of > or = 1:800, indicating a current or recent infection. Relationships were explored between seroprevalence and host factors including age, sex, school location, and other risk factors including geophagia, thumb-sucking, presence of other gastrointestinal-tract parasitism and pet ownership. There was no significant relationship between age and the presence of current or recent infection (P = 0.746). Boys were significantly more commonly infected than girls as were the attendees of rural schools versus urban schools (P < 0.001). The percentage of seropositivity among children varied widely from school to school. Pet ownership and the absence of pipe-borne water in the household were found to be significantly associated with positive serology (P < 0.05). Clinical symptoms mostly associated with positive serology were eczema, seizures and chronic cough. Recommendations derived from this study include health education in order to increase the public awareness on the transmission of the disease, de-worming all dogs and cats periodically and the curbing of stray dogs and cats. Environmental sanitation measures should include keeping children away from contaminated areas and practising proper hygiene after play.
Transactions of the Royal Society of Tropical Medicine and Hygiene 96(2):139-43. · 2.16 Impact Factor
