Human papillomavirus genotype distribution in cervical samples among vaccine naïve Barbados women.

PURPOSE: This study was undertaken to provide baseline HPV genotype distribution among women in Barbados before HPV immunization was introduced. This information would then be used as a denominator for post-vaccine surveillance and is expected to aid in understanding the effect of vaccination on cervical disease in Barbados. METHODS: Liquid-based cytology specimens were collected from 413 women (age range 18-65 years) attending three clinics, in a pre-vaccination, population-based study. After consent was obtained, sexual behavior and socio-demographic information were acquired from self-administered questionnaires. HPV types were detected using Luminex-based HPV PCR genotyping methodology. RESULTS: HPV was detected in 33% (135/413) of the subjects overall (95% CI 32.7, 33.37), of which 70% (95/135) were high-risk types, with 35 different types being detected in this population. Single and multiple high-risk HPV types were detected in 14% (13/95) and 31% (29/95) of the subjects, respectively. The most common high-risk HPV types detected were 45(n = 22, 23%), 16 (n = 17, 18%), 52 (n = 16, 17%), and 58 (n = 10, 11%). Persons with the highest level of infection by age were 21-25 (n = 25/135;19%; 95% CI 18.8, 19.3); 26-30 (n = 22/135;16%; 95% CI 15.9, 16.2); 31-35 (n = 19/135;14%; 95% CI 13.9, 14.2); 36-40 (n = 17/135;13%; 95% CI 12.2, 13.2), and 18-21 (n = 15/135;11%; 95% CI 10.9, 11.2). 91/413 (22%) persons had a normal cytology result. CONCLUSION: A high prevalence of HPV type 45 was found in the screening population of women in Barbados. The results of cytological examinations and HPV positivity suggest that both tests should be used for greater reliable diagnosis of HPV infection.

Molecular serovar characterization of Leptospira isolates from animals and water in Colombia / Caracterización molecular de serovariedades de Leptospira spp. aisladas de muestras de animales y agua en Colombia

Introduction: Leptospirosis is a bacterial disease transmitted directly or indirectly from animals to humans that may result in severe hemorrhagic, hepatic/renal and pulmonary disease. There are 20 known Leptospira species and hundreds of serovars, some of which belong to different species. It is essential to identify pathogenic Leptospira serovars and their potential reservoirs to prepare adequate control strategies. Objective: To characterize the Leptospira serovars isolated from rodents, dogs, pigs and water samples in Colombia. Materials and methods: Leptospira organisms were isolated and cultured, and pathogenic strains were identified using a polymerase chain-reaction (PCR). Leptospira DNA and Salmonella Braenderup H9812 (molecular weight standard) DNA were cleaved using NotI and subjected to pulsed-field gel electrophoresis (PFGE). The PFGE patterns were analyzed based on bacterial strain-typing criteria and Dice coefficients (DCs) between these isolates and over 200 Leptospira organisms isolated from other parts of the world. Results: All of the isolates were pathogenic strains, and five were genetically characterized. The P275 (84% DC) and P282 (95% DC) pig isolates were related to the Leptospira interrogans Pomona serovar; the I15 (DC: 100%) rat isolate was identical to the Leptospira interrogans Icterohameorrhagiae or Copenhageni serovars, while the C67 (64% DC) dog and A42 (60% DC) water isolates were not related (< 73.7% DC) to any of the 200 reference serovars; the closest serovars were the Leptospira noguchii Nicaragua and Orleans serovars, respectively. Conclusion: This was the first molecular characterization of Colombian Leptospira spp isolates; these isolates will be used to develop a Colombian diagnostic panel.

Introducción. La leptospirosis es una infección bacteriana transmitida directa o indirectamente de animales a humanos, la cual puede resultar en una enfermedad hemorrágica grave, hepática o renal y pulmonar. Hay 20 especies de Leptospira conocidas y cientos de serovariedades, algunas de las cuales pertenecen a diferentes especies. Es esencial identificar las serovariedades patógenas y sus reservorios potenciales para enfocar estrategias de control. Objetivo. Caracterizar las serovariedades de Leptospira aisladas de muestras de roedores, perros, cerdos y agua en Colombia. Materiales y métodos. Las cepas de leptospiras aisladas fueron identificadas como patógenas usando la reacción en cadena de la polimerasa (PRC). Sus ADN y el ADN de Salmonella Braenderup H9812 (marcador de peso molecular) fueron cortados con NotI y corridos en electroforesis de campo pulsado. Los patrones de la ECP se analizaron con base en los criterios de tipificación para cepas bacterianas y el coeficiente de Dice, cuando se compararon con 200 cepas aisladas en otras partes del mundo. Los perfiles de ADN con un coeficiente de Dice entre 73,7 % y 100 % se consideraron pertenecientes a la misma especie. Resultados. Todos los aislamientos fueron cepas patógenas y cinco se caracterizaron genéticamente. El aislamiento P275 (coeficiente de Dice: 84 %) y el P282 (coeficiente de Dice: 95 %) de cerdos, se relacionaron con Leptospira interrogans de serovariedad Pomona; el aislamiento de rata (I15) fue indistinguible de Leptospira interrogans de serovariedades Icterohaemorrhagiae o Copenhageni (coeficiente de Dice: 100 %), mientras que los aislamientos de perro (C67) y agua (A42) no se relacionaron (coeficiente de Dice <73,7 %) con ninguna de las 200 cepas de referencia; las más cercanas fueron Leptospira noguchii de serovariedades Nicaragua (coeficiente de Dice: 63 %) y Orleans (coeficiente de Dice: 60 %). Conclusiones. Esta fue la primera caracterización molecular de serotipos de aislamientos colombianos, los cuales serían los primeros miembros de un panel diagnóstico colombiano.

Molecular serovar characterization of Leptospira isolates from animals and water in Colombia.

INTRODUCTION: Leptospirosis is a bacterial disease transmitted directly or indirectly from animals to humans that may result in severe hemorrhagic, hepatic/renal and pulmonary disease. There are 20 known Leptospira species and hundreds of serovars, some of which belong to different species. It is essential to identify pathogenic Leptospira serovars and their potential reservoirs to prepare adequate control strategies. OBJECTIVE: To characterize the Leptospira serovars isolated from rodents, dogs, pigs and water samples in Colombia. MATERIALS AND METHODS: Leptospira organisms were isolated and cultured, and pathogenic strains were identified using a polymerase chain-reaction (PCR). Leptospira DNA and Salmonella Braenderup H9812 (molecular weight standard) DNA were cleaved using NotI and subjected to pulsed-field gel electrophoresis (PFGE). The PFGE patterns were analyzed based on bacterial strain-typing criteria and Dice coefficients (DCs) between these isolates and over 200 Leptospira organisms isolated from other parts of the world. RESULTS: All of the isolates were pathogenic strains, and five were genetically characterized. The P275 (84% DC) and P282 (95% DC) pig isolates were related to the Leptospira interrogans Pomona serovar; the I15 (DC: 100%) rat isolate was identical to the Leptospira interrogans Icterohameorrhagiae or Copenhageni serovars, while the C67 (64% DC) dog and A42 (60% DC) water isolates were not related (< 73.7% DC) to any of the 200 reference serovars; the closest serovars were the Leptospira noguchii Nicaragua and Orleans serovars, respectively. CONCLUSION: This was the first molecular characterization of Colombian Leptospira spp isolates; these isolates will be used to develop a Colombian diagnostic panel.

Cross-sectional study of Leptospira seroprevalence in humans, rats, mice, and dogs in a main tropical sea-port city.

Samples were collected from 128 symptomatic humans, 83 dogs, 49 mice, and 20 rats (Rattus rattus: 16; Rattus norvegicus: 4) in neighborhoods where human leptospirosis have been reported within the principal sea-port city of Colombia. Seroprevalences were assessed against 19 pathogenic, 1 intermediate pathogenic, and 1 saprophytic Leptospira serogroups. Pathogenic Leptospira were confirmed using conventional Leptospira-specific polymerase chain-reaction and pulsed-field gel electrophoresis analysis was used for serovar identification. Seroprevalences of 20.4%, 12.5%, 25.0%, 22.9%, and 12.4% were obtained against one to seven different serogroups in mice, R. rattus, R. norvegicus, dogs, and humans, respectively. The DNA was confirmed to be from pathogenic Leptospira by detecting the lipL32 gene in 12.5%, 3.7%, and 0.03% of the R. rattus, dog, and human samples, respectively. The first genetically typed Colombian isolate was obtained from a rat and identified as Leptospira interrogans serovar Icterohaemorrhagiae/Copenhageni.

Methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin toxin in Trinidad & Tobago: a case report.

INTRODUCTION: Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. CASE PRESENTATION: A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. CONCLUSION: Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.

Methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin toxin in Trinidad & Tobago: a case report

INTRODUCTION: Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. CASE PRESENTATION: A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. CONCLUSION: Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.

Human leptospirosis caused by a new, antigenically unique Leptospira associated with a Rattus species reservoir in the Peruvian Amazon.

As part of a prospective study of leptospirosis and biodiversity of Leptospira in the Peruvian Amazon, a new Leptospira species was isolated from humans with acute febrile illness. Field trapping identified this leptospire in peridomestic rats (Rattus norvegicus, six isolates; R. rattus, two isolates) obtained in urban, peri-urban, and rural areas of the Iquitos region. Novelty of this species was proven by serological typing, 16S ribosomal RNA gene sequencing, pulsed-field gel electrophoresis, and DNA-DNA hybridization analysis. We have named this species "Leptospira licerasiae" serovar Varillal, and have determined that it is phylogenetically related to, but genetically distinct from, other intermediate Leptospira such as L. fainei and L. inadai. The type strain is serovar Varillal strain VAR 010(T), which has been deposited into internationally accessible culture collections. By microscopic agglutination test, "Leptospira licerasiae" serovar Varillal was antigenically distinct from all known serogroups of Leptospira except for low level cross-reaction with rabbit anti-L. fainei serovar Hurstbridge at a titer of 1:100. LipL32, although not detectable by PCR, was detectable in "Leptospira licerasiae" serovar Varillal by both Southern blot hybridization and Western immunoblot, although on immunoblot, the predicted protein was significantly smaller (27 kDa) than that of L. interrogans and L. kirschneri (32 kDa). Isolation was rare from humans (2/45 Leptospira isolates from 881 febrile patients sampled), but high titers of MAT antibodies against "Leptospira licerasiae" serovar Varillal were common (30%) among patients fulfilling serological criteria for acute leptospirosis in the Iquitos region, and uncommon (7%) elsewhere in Peru. This new leptospiral species reflects Amazonian biodiversity and has evolved to become an important cause of leptospirosis in the Peruvian Amazon.

Reclassification of Roseomonas fauriae Rihs et al. 1998 as a later heterotypic synonym of Azospirillum brasilense Tarrand et al. 1979.

The relatedness of Roseomonas fauriae and Azospirillum brasilense was investigated using phenotypic methods and DNA-DNA hybridization. Conventional biochemical tests did not differentiate between the two taxa. DNA-DNA hybridization experiments revealed high values for relatedness between the type strains of these species and suggest that these two taxa constitute a single species. Strains previously identified as R. fauriae should be reclassified as A. brasilense, with the name Roseomonas fauriae as a later heterotypic synonym of Azospirillum brasilense.

Identification of Streptococcus iniae by commercial bacterial identification systems.

The fish pathogen Streptococcus iniae cannot be identified by most commercial bacterial identification systems. The results presented here indicate that over 70% of our S. iniae isolates have been identified using the Biolog(R) GP microplate panels and Microlog(R) database. The isolates were confirmed as S. iniae by specific PCR methods and have been found to conform to the result obtained with the type strain S. iniae ATCC 29178.

Evaluation of the CD14/-260 polymorphism and house dust endotoxin exposure in the Barbados Asthma Genetics Study.

BACKGROUND: Both a functional promoter polymorphism in the gene encoding CD14 (C-260T) and exposure to endotoxin are believed to play key roles in modulating the immune response and expression of atopic disease. OBJECTIVE: We aimed to evaluate the role of the CD14 C-260T polymorphism in a population of African descent and to test for interaction between this genotype and house dust endotoxin (HDE) exposure on atopic phenotypes. METHODS: Asthmatic probands and their families were recruited as part of the Barbados Asthma Genetics Study. The C-260T polymorphism and two additional CD14 promoter markers (G-1461T, C-1721T) were genotyped. Endotoxin was measured in house dust samples. RESULTS: Using a Family-Based Association Test, the C-260T allele appeared to be protective against asthma ( z = -2.444; P = .015) and asthma severity ( z = -2.615; P = .009) under a recessive model. No significant associations were observed for the G-1461T and C-1721T markers both individually and in haplotypes. In a case-control analysis, the CD14 TT genotype was found to reduce risk of asthma compared with the CD14 CC/CT genotypes (odds ratio [OR], 0.26; 95% CI, 0.14-0.49) and was associated with lower asthma severity scores ( P < .002). The TT genotype might protect against asthma for individuals with low HDE (OR, 0.09; 95% CI, 0.03-0.24), but may be a risk factor for individuals with high HDE (OR, 11.66; 95% CI, 1.03-131.7), suggesting a gene-environment interaction. CONCLUSION: These data suggest that the CD14-260 polymorphism may play a role in controlling risk to atopic disease and underscore the importance of incorporating key environmental exposures into studies of genetic risk factors.

Evaluation of the CD14/-260 polymorphism and house dust entotoxin exposure in the Barbados Asthma Genetics Study

BACKGROUND: Both a functional promoter polymorphism in the gene encoding CD14 (C-260T) and exposure to endotoxin are believed to play key roles in modulating the immune response and expression of atopic disease. OBJECTIVE: We aimed to evaluate the role of the CD14 C-260T polymorphism in a population of African descent and to test for interaction between this genotype and house dust endotoxin (HDE) exposure on atopic phenotypes. METHODS: Asthmatic probands and their families were recruited as part of the Barbados Asthma Genetics Study. The C-260T polymorphism and two additional CD14 promoter markers (G-1461T, C-1721T) were genotyped. Endotoxin was measured in house dust samples. RESULTS: Using a Family-Based Association Test, the C-260T allele appeared to be protective against asthma (z=−2.444; P=.015) and asthma severity (z=−2.615; P=.009) under a recessive model. No significant associations were observed for the G-1461T and C-1721T markers both individually and in haplotypes. In a case-control analysis, the CD14 TT genotype was found to reduce risk of asthma compared with the CD14 CC/CT genotypes (odds ratio [OR], 0.26; 95% CI, 0.14-0.49) and was associated with lower asthma severity scores (P < .002). The TT genotype might protect against asthma for individuals with low HDE (OR, 0.09; 95% CI, 0.03-0.24), but may be a risk factor for individuals with high HDE (OR, 11.66; 95% CI, 1.03-131.7), suggesting a gene-environment interaction. CONCLUSION: These data suggest that the CD14-260 polymorphism may play a role in controlling risk to atopic disease and underscore the importance of incorporating key environmental exposures into studies of genetic risk factors.

Direct detection of leptospiral material in human postmortem samples.

Leptospiral culture, direct immunofluorescence, and the polymerase chain reaction (PCR) were used to detect leptospiral material in postmortem specimens collected from eight patients who died of leptospirosis. Diagnosis of leptospiral infection was based on clinical summary (premortem) and confirmed by serological analysis and/or culture of leptospires. Leptospiral culture was the least sensitive technique, yielding two isolates (3%) from 65 samples. Both isolates were from the aqueous humour and cerebrospinal fluid of the same patient. Direct immunofluorescence was of intermediate sensitivity for detection of leptospires, confirming the presence of leptospires in 11% (2 of 18) of tissue samples from three patients. PCR analysis was the most sensitive technique for detection of leptospiral material in tissue samples, being positive in 20% (11 of 56) of samples from eight patients. Both samples (cerebellum and liver) positive by immunofluorescence were also positive by PCR. The sensitivity of the PCR assay was 1-10 leptospires ml(-1) sample, and the assay was specific for Leptospira pathogenic species. Multi-system involvement was indicated based on successful amplification of leptospiral DNA from more than one tissue sample, which corroborated with the clinical and pathologic findings. The results suggest that in acute and/or fatal leptospirosis, the pathogenesis of the pathologic features are related to the presence of the organisms in the tissues. In conclusion, PCR combined with serology appears to be a useful tool for diagnosis of leptospirosis and may be invaluable in epidemiological studies.

Sex differences in heritability of sensitization to Blomia tropicalis in asthma using regression of offspring on midparent (ROMP) methods.

A genetic basis for asthma- and atopy-related quantitative traits, such as allergen-specific immunoglobulin E (IgE) levels, has been suggested by the observed familial aggregation of these traits in temperate climates. Less information is available for tropical climates, where different allergens may predominate. Sensitivity to the mite Blomia tropicalis is related to asthma in tropical climates, but heritability of B. tropicalis sensitivity and the impact of age, sex, and other environmental covariates on heritability have not been widely explored. Total and specific IgE levels were measured by immunochemiluminescent assay in 481 members of 29 Barbadian families (comprised of 340 parent-offspring trios or pairs) ascertained through two asthmatic siblings. Trait heritability was estimated using regression of offspring on mid-parent (ROMP) and pairwise correlation analysis of unadjusted IgE levels and on residual values after adjustment for covariates. Heritability of IgE levels to the major antigen of B. tropicalis (Blo t M) estimated by ROMP in 180 complete parent-offspring trios was 0.56. Heritability was consistently greater for male offspring than for female offspring. Similar sex-specific patterns were observed for specific IgE to Dermatophagoides pteronyssinus and total IgE levels and were relatively unaffected by adjustment for covariates. Pairwise correlational analyses of specific and total IgE levels showed similar results. Moderate heritability of Blo t M IgE levels was detected in these Barbadian families and was greater for sons than daughters. Adjustment for covariates had minimal impact. This suggests that future investigations of genetic determinants of IgE levels should include approaches that allow for potential sex differences in their expression.

Correlates of sensitization to Blomia tropicalis and Dermatophagoides pteronyssinus in asthma in Barbados.

BACKGROUND: Sensitivity to the mite Blomia tropicalis is related to asthma in tropical climates, but correlates of sensitivity to B. tropicalis and its relationship to Dermatophagoides pteronyssinus sensitivity have not been widely examined in families with asthma. The main objective of this study was to determine prevalence and correlates of sensitivity to these mites in families with asthma and characteristics of persons sensitized to both. METHODS: Antibodies to major antigens (Blo t 5 and Der p 1) of these mites were measured by immunochemiluminescent assay in 481 members of 29 families from Barbados ascertained through two asthmatic siblings. RESULTS: Blo t 5 sensitivity was present in 261 subjects (46%) and was associated with younger age, higher total serum IgE level, and more than a three-fold increased prevalence of asthma (42 vs. 13%). Der p 1 sensitivity was less common (27%) and showed similar associations with age, IgE, and asthma. Of the 261 subjects sensitized to Blo t 5, 116 were also sensitized to Der p 1; they were younger, had higher total and Blo t 5 specific IgE levels, and had more than twice the asthma prevalence as those sensitized to Blo t 5 alone (59 vs. 29%). Der p 1 sensitivity without Blo t 5 sensitivity was uncommon; 90% of those sensitized to Der p 1 were also sensitized to Blo t 5. Geometric mean total IgE levels were lowest in the 207 participants without any mite sensitization (102 U/ml), intermediate in 158 sensitized to either Blo t 5 OR Der p 1 (609 U/ml), and highest in 116 sensitized to both (1,869 U/ml). CONCLUSIONS: Blo t 5 is the predominant sensitizing mite allergen in these Barbadian families with correlates similar to Der p 1. Concomitant sensitization to Der p 1 appears to identify a more reactive subgroup of individuals at a higher risk of asthma.

The molecular epidemiology and drug resistance determination of HIV type 1 subtype B infection in Barbados.

To better understand the emergence of HIV-1 variants in Barbados and the association with transmission modes, we analyzed phylogenetic relationships and genetic variability among HIV-1 strains collected in 1996 from 36 antiretroviral therapy-naive patients. Only subtype B variants were present in this sampling, based on analysis of HIV-1 envelope (env) C2V3, protease (PR), and reverse transcriptase (RT) sequences. The genetic diversity of env sequences was broad (13.9%; range, 5.9-24.9%), suggesting multiple introductions of distinct HIV-1 strains to the island. The frequency of subtype B HIV-1 variants with similar env V3 features, including the tetrameric tips, GPGR and GPGK, the threonine deletion at position 23, and the substitution of threonine to arginine at position 22, was comparable in heterosexual, bisexual, and homosexual patients. Analyses of amino acid variations in PR sequences revealed a lack of major drug resistance-conferring mutations and a high (90%) prevalence of secondary mutations at positions 36, 63, 71, and 77. While the occurrence of 361, 63P, and 71T mutations in Barbadian strains was similar to the global prevalence for subtype B variants, the frequency (64%) of the V77I mutation was more than three times that seen worldwide. Only two RT antiretroviral resistance mutations (M41L and T215Y) were observed, both from a single patient. This comprehensive genetic analysis documents a broad diversity within HIV-1 subtype B in Barbados and suggests a lack of association between particular subtype B variants and transmission modes.

Usefulness of serologic analysis as a predictor of the infecting serovar in patients with severe leptospirosis.

The diagnosis of leptospirosis is often made using the microscopic agglutination test (MAT), in which live antigens representing >20 serogroups undergo reaction with patient serum samples to detect agglutinating antibodies. Data derived from this assay are often used to infer the identity of the infecting leptospiral serovar or serogroup; however, paradoxical reactions and cross-reactions between serogroups are common. To evaluate the usefulness of this approach, data on culture-proven cases of leptospirosis that occurred in Barbados from January 1980 through December 1998 were reviewed. A total of 151 isolates of 4 serovars were identified. The sensitivity of MAT for the prediction of the infecting serovar was determined. Overall, the predominant serogroup at a titer of >or=100 correctly predicted 46.4% of all serovars isolated. If a titer of >or=800 was used as the cutoff, sensitivity decreased slightly to 44.4%. The overall specificity for all serogroups was 64.8%. Serologic analysis appeared to be of little value for the identification of the infecting serovar in individual cases of leptospirosis in humans. Presumptive serogroup reactivity data should be used only to gain a broad idea of the serogroups present at the population level.

Evaluation of two enzyme-linked immunosorbent assay methods for detection of immunoglobulin M antibodies in acute leptospirosis.

Leptospirosis is a common zoonosis of worldwide distribution. Diagnosis of leptospirosis is usually accomplished by serology, but the microscopic agglutination test (MAT) generally requires paired sera for detection of seroconversion and is considered too complex for routine use. A number of rapid assays have been developed in recent years. In the present study, 2 immunoglobulin (Ig) M enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the early diagnosis of acute leptospirosis in Barbados. A total of 103 patients admitted to the Queen Elizabeth Hospital for diagnosis of suspected leptospirosis were investigated. A case of leptospirosis was confirmed by a 4-fold rise in titer between 2 sera tested by MAT, an initial titer of > or = 800 in the MAT, or by isolation of leptospires from blood or urine. A total of 48 cases of leptospirosis were confirmed. In 33 cases, both commercial assays were positive in the first sample, taken at admission, a mean of 6.7 days after onset of symptoms, whereas seroconversion was detected in a further 9 cases. Both assays were negative in 5 cases, and the remaining case gave discordant results in the 2 assays. False-positive IgM results were detected in 4 patients without leptospirosis. The sensitivity of the 2 assays was 89.6 and 97.5%, respectively, and specificities were 92.7 and 96.4%, respectively. The positive predictive values were 87.8 and 95.5%, and the negative predictive values were 90.7 and 89.5%, respectively. Either of these assays can be used for early diagnosis of leptospirosis, particularly in laboratories that cannot perform more specialized leptospiral serology.

Randomized, placebo-controlled trial of product R, a peptide-nucleic acid immunomodulator, in the treatment of adults infected with HIV.

OBJECTIVE: The efficacy of Product R, a nontoxic peptide-nucleic acid, was tested in 43 HIV-infected adults naïve to antiretroviral therapy. METHOD: Patients were randomized to receive Product R (21 patients) or placebo (22 patients). Dosage was two 1 mL subcutaneous injections daily on days 1-14, followed by 1 mL daily on days 22-28, 36-42, and 50-56. The follow-up period lasted until day 120. RESULTS: Mean root CD4 count increased in the Product R group during treatment and was significantly higher (p =.013) by the end of follow-up. Four Product R-treated patients, but none of the control patients, experienced declines in viral load of >0.5 log. At the end of follow-up, the Product R group experienced a mean weight increase (p =.003), whereas the placebo group experienced a mean weight loss. The number of deaths and opportunistic infections were lower in the Product R group than in the placebo group (p =.076). No toxic effects were observed in any of the patients administered Product R. CONCLUSION: These findings suggest that Product R may have efficacy in the treatment of HIV-infected individuals.

Leptospiral carriage by Mice and Mongooses on the island of Barbados

Leptospirosis is a zoonotic disease, maintained by chronic infection of the kidneys of reservoir animals, usually small mammals. Infection in humans is acquired from direct or indirect exposure to the urine of infected animals. Leptospirosis has a high incidence in tropical regions, and has been studied extensively in several Caribbean countries. We studied the carriage of Leptospira serovars by two small mammals which are potential maintenance host of the disease in Barbados. A total of 136 mongooses (Herpestes auropunctatus) and 97 mice (Mus musculus) were caught in live traps. Leptospiral antibodies were detected by microscopic aggutination test (MAT) using antigens representing 12 serogrouops, and kidney tissues were inoculated into polysorbate medium for isolation of leptospires. The seroprevalence (at a titre of o 100) in mice was 28.2 percent (24/85, 95 percent CI 19.0, 39.1) and in mongooses 40.7 percent (48/118, 95 percent CI 20.1, 39.0) and from 4 mongooses ( 2.9 percent, 95 percent, CI 0.8, 7.4). Mouse isolates were identified as serovars arborea (17) and bim (7). As in other parts of the world, common house mice (Mus musculus) represent a significant reservoir of leptospirosis. Although carriage of the Ballum serovar, arborea, was not unexpected, this represents the first time that an animal reservoir of serovar bim has been identified. This is significant because bim causes about 63 percent of human leptospirosis in Barbados, and control efforts and education for prevention can now be targeted at a specific reservoir. (AU)

Antimicrobial sensitivity of Haemophilus influenzae isolates from bacterial conjunctivitis

Haemophilus influenzae is one of the common bacterial pathogens which affect children. Resistance to frequently use antibiotics is becoming a significant problem in community isolates of common pathogens. A retrospective review was conducted of the serotypes and antimicrobial sensitivity of H influenzae isolates from bacterial conjunctivitis, over an 18-month period. Data on antimicrobial sensitivity (obtained by the National Committee for Clinical Laboratory Standards disk diffusion method) and B-lactamase production, and typing results, were analysed. Ninety-nine islolates were recovered, of which 87 were typed. Most isolates were recovered from children under one year of age. Ninety-three percent were unencapsulated and biotypes I and IV were most common. H influenzae type b was recovered only twice. B-lactamase was produced by 41 percent isolates while four isolates were ampicillin-resistant but did not produce B-lactamase. All isolates were sensitive to chloramphenicol and 45 percent were co-trimoxazole sensitive. H influenzae is commonly isolated from bacterial conjunctivitis in Barbados and, as elsewhere, the majority of isolates are from small children and are non-encapsulated. However, there is a high prevalence of B-lactamase production, which may serve as a reservoir for transfer to more invasive encapsulated strains of H influenzae within the oropharyngeal flora.(Au)