Shirematee Baboolal

Evaluation of Methods for Rapid Detection of Resistance to Isoniazid and Rifampin in Mycobacterium tuberculosis Isolates Collected in the Caribbean

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.

First Insight into Mycobacterium tuberculosis Epidemiology and Genetic Diversity in Trinidad and Tobago

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.

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.

A First Assessment of Mycobacterium tuberculosis Genetic Diversity and Drug-Resistance Patterns in Twelve Caribbean Territories

With the exception of some French-speaking islands, data on tuberculosis (TB) in the Caribbean are scarce. In this study, we report a first assessment of genetic diversity of a convenience sample of Mycobacterium tuberculosis strains received from twelve Caribbean territories by spoligotyping and describe their drug-resistance patterns. Of the 480 isolates, 40 (8.3%) isolates showed resistance to at least one anti-TB drug. The proportion of drug-resistant strains was significantly higher in The Bahamas (21.4%; P = 0.02), and Guyana (27.5%; P < 0.0001), while it was significantly lower in Jamaica (2.4%; P = 0.03) than in other countries of the present study. Regarding genetic diversity, 104 distinct spoligotype patterns were observed: 49 corresponded to clustered strains (2 to 93 strains per cluster), while 55 remained unclustered among which 16 patterns were not reported previously. Combining the study results with regional data retrieved from the international SITVIT2 database underlined a connection between frequency of certain M. tuberculosis phylogenetic lineages and the language spoken, suggesting historical (colonial) and ongoing links (trade, tourism, and migratory flows) with European countries with which they shared a common past.

Highlighting the genetic and epidemiologic disparities of Mycobacterium tuberculosis epidemic in 12 Caribbean territories in a first global study

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.

Laboratory Diagnosis of Latent and Active Tuberculosis Infections in Trinidad & Tobago and Determination of Drug Susceptibility Profile of Tuberculosis Isolates in the Caribbean

Tuberculosis (TB) is a life-threatening, infectious disease caused by the bacteria Mycobacterium tuberculosis. The disease has plagued human beings for many centuries as signs of tubercular damage have been found in Egyptian mummies and bones dating back at least 5,000 years ago [1]. Today, despite advances in diagnosis and treatment, TB is still a global pandemic, fueled by the spread of the Human Immunodeficiency Virus (HIV), the Acquired Immunodeficiency Syndrome (AIDS), poverty and a lack of proper health services in many developing countries [2]. As a developing nation, many of the Caribbean countries face serious challenges in the diagnosis, treatment, care and management of patients with TB. Some of these challenges include TB/HIV co-infection, drug resistance, inadequate laboratory services, growth of inequity stemming from rising poverty and the presence of weak health systems in many countries [3]. A major challenge that affects the Caribbean is the lack of proper facilities for laboratory diagnosis of TB; and there is a dire shortage of laboratory facilities and capability for culture and drug susceptibility testing. Because of this, many cases of TB with low bacillary load may be missed by smear microscopy if culture is not routinely performed. This is even more so in HIV/AIDS patients where smear microscopy may be negative due to the small numbers of bacilli being produced as a result of reduced pulmonary cavity formation [4].