Dengue virus serotypes in Jamaica, 2003-2007.

BACKGROUND: Dengue virus (DENV) infection is increasing in prevalence and severity globally. The severity of dengue is influenced by several factors including the immune response, viral and host genetic factors. METHOD: The DENV serotypes were determined in 770 serum samples from dengue immunoglobulin (Ig) M antibody positive (n = 469), dengue IgM negative (n = 185) and dengue antibody negative (n = 116) patients with suspected dengue who presented during (n = 150) or after (n = 620) the acute phase of illness during 2003-2007. Dengue antibodies were detected by enzyme-linked immunosorbent assays and DENV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on serum and cell culture supernatants of C6/36 mosquito cells inoculated with acute phase serum (n = 150). RESULTS: Based on serological profiles, 41% of acute phase sera and 66% of post acute sera were from patients with current primary or secondary dengue, while 41% and 35% of acute and post-acute phase sera, respectively, were from patients with secondary dengue or past exposure only. Dengue virus RNA was found in 20/770 samples (2.6%). Only 1.5% (9/620) of sera collected after the acute phase of illness tested positive for DENV RNA compared with 2.6% (4/150) of sera collected during the acute phase and 7.3% of cell culture supernatants inoculated with acute phase serum (11/150, p = 0.001). All four serotypes including DENV-1 (3/20, 15%), DENV-2 (7/20, 35%), DENV-3 (3/20, 15%) and DENV-4 (7/20, 35%) were identified over the five-year period. These results also showed that DENV-1, 2 and 4 were present during 2007 and that DENV-2 and DENV- 4 were the likely causative viruses of the 2007-2008 dengue outbreak in Jamaica. The three strains of DENV-3 were isolated from infants less than three years of age with primary infection during 2006. CONCLUSION: This study highlights the increasing threat of dengue and severe dengue disease to the Jamaican population. Preventative measures including laboratory surveillance and vector control should be strictly maintained at the highest level.

Molecular epidemiology of dengue in Jamaica dengue virus genotypes in Jamaica, 2007.

The genotypes of dengue viruses (DENV) isolated from patients with dengue in Jamaica during 2007 were determined using DNA sequencing and phylogenetic analysis of the C-prM gene junction. The 17 DENV analysed included strains of DENVserotypes 1 (DENV-1, n = 3), DENV-2 (n = 7) and DENV-4 (n = 7). All strains ofDENV-1 were classified as genotype III, while 1 of 7 strains of DENV-2 belonged to the Asian American/Asian genotype, genotype I/III (Jamaica genotype), 2 were genotype V, the American genotype and 4 strains clustered with reference strains belonging to genotype IV. The 6 DENV-4 strains from Jamaica and the control strain clustered together in a separate clade from Caribbean/American reference strains, which belong to genotype II and Asian strains, classified as genotypes I and III. There has been little evolution in the DENV-1 strains circulating in Jamaica over the years and this might reduce the risk of outbreaks due to this serotype. In contrast, the high genetic diversity in strains of DENV-2 viruses in circulation, the presence of more recently introduced genotypes and a new clade of DENV-4 might contribute to the epidemic potential of these DENV serotypes. These preliminary data clearly indicate the need to maintain laboratory surveillance, and other control measures against hyperendemicity of dengue in Jamaica.

Dengue HLA associations in Jamaicans.

BACKGROUND: Polymorphisms in the human leukocyte antigen (HLA) genes might predispose certain individuals to dengue fever (DF) and the severe forms of the disease: dengue haemorrhagic fever/ dengue shock syndrome (DHF/DSS). SUBJECTS AND METHOD: A DNA-based HLA typing method was used to determine the HLA class I and II alleles in 50 patients with dengue, including 45 cases of DF 5 cases of DHF and 177 healthy individuals in Jamaica. RESULTS: HLA-A*24 and - DRbeta5*01/02 were significantly associated with dengue infection while possession of HLA-A*23, -CW*04, -DQbeta*02, -DQbeta*03 and DQbeta*06 were protective. No other significant associations were found after correction for the number of alleles tested at each HLA-locus. CONCLUSION: This is the first study to report a significant association with HLA-A*24 and DF although this allele is associated with DHF and DSS in Vietnamese patients. The other HLA associations observed in the Jamaican cohort also are different from those reported in other ethnic groups. Further studies which involve larger numbers of patients with DHF and explore functional aspects of HLA allelic associations with dengue in Jamaicans are necessary.

High genetic diversity in human immunodeficiency virus-type 1 in Jamaica.

The subtypes of the human immunodeficiency virus - type 1 (HIV-1) strains from 54 HIV-1 - infected persons including 44 strains which were typed previously by heteroduplex mobility assay (HMA) were determined by DNA sequencing and phylogenetic analysis. Of 54 HIV- infected persons, 92.5% were infected with HIV-1 subtype B and 7.5% with other HIV-1 subtypes including subtypes D (3.7%), A (1.9%) and J (1.9%). In the phylogenetic analysis, the subtype A virus found in the sample clustered with subtype A reference strains and a circulating recombinant form (CRF) reference strain which originates in Central Africa and is circulating in Cuba indicating a close relationship between these viruses. There was 86% concordance between HMA and DNA sequencing in assigning subtype B viruses. For the non-B subtype viruses, there was less concordance between the two methods (67%). The results confirm the predominance of HIV-1 subtype B strains and the high genetic diversity of HIV-1 strains in circulation in Jamaica. The efficacies and some limitations of the HMA as a method of HIV-1 subtyping also were noted. It is important that the HIV/AIDS epidemic in Jamaica be monitored meticulously for possible expansions in non-B subtypes and the emergence of inter-subtype recombinant forms. We recommend that the more expensive DNA sequencing and phylogenetic analysis, including HIV-1 genotyping for antiretroviral drug resistance testing, be used as an adjunct to the more cost-effective HMA to track the HIV/AIDS epidemic in Jamaica.

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation.

Some antibiotics have been shown to modify the host immune response. Infection with Stenotrophomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors examined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF alpha) production by human peripheral blood mononuclear cells (PBMC) stimulated with heat-killed S maltophilia. Cotrimoxazole was the only antibiotic that suppressed TNFa secretion at clinically achievable concentrations. This may explain its use with good effect in the treatment of S maltophilia infections. However at supratherapeutic concentrations, ceftazidime and ciprofloxacin, but not piperacillin-tazobactam, also inhibited significantly the production of TNF alpha. Cotrimoxazole, in addition to its antimicrobial effect against S maltophilia, has an immunomodulatory effect on peripheral blood mononuclear cells stimulated by S maltophilia.

Seroprevalence of sexually transmitted infections among accepted and deferred blood donors in Jamaica.

Critical donor selection and testing increases the safety of blood transfusion by excluding donors at risk of transmitting infections. This study investigated the seroprevalence of and risk factors for sexually transmitted infections (STIs) among accepted and deferred blood donors in Jamaica. A total of 1015 blood donors consisting of 794 (78%) accepted donors and 221 (22%) deferred donors presenting at the Central Blood Bank, Jamaica, over a six-month period, were recruited for this study. A standardized questionnaire was administered to each participant and a sample of blood obtained for detection of hepatitis B surface antigen, antibodies to Treponema pallidum, human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus type-1 (HTLV-1). Deferred donors were three times more likely to be seropositive for STI than accepted donors (16.3% vs 5.2%, OR 3.57, 95% CI 2.16 - 5.90, p < 0.0001). Males had significant association between STI seropositivity and having fathered children with two or more women (p = 0.0085), unprotected sexual intercourse with several persons (p = 0.0326), and history of genital herpes (p = 0.0121). Significant risk factors identified among females were unprotected sex with several partners (p = 0.0385); having more than ten lifetime partners (p = 0.0105); and use of depoprovera (p = 0.0028). This study confirms higher rates of STI among deferred blood donors and supports the donor deferral system in Jamaica.

Clinical and epidemiological characteristics of adult and adolescent patients newly diagnosed with the human immunodeficiency virus at a Jamaican clinic for sexually transmitted infections.

Persons infected with the human immunodeficiency virus (HIV) may have protean clinical manifestations. These characteristics have not been described for adult patients in Jamaica. This study was conducted to determine the clinical and epidemiological characteristics of adult and adolescent persons newly diagnosed with HIV presenting at a specialized clinic for sexually transmitted infections (STI). A retrospective analysis of the medical records of adult and adolescent patients newly diagnosed with HIV was undertaken over a 12-month period. The results showed that most patients (64%) were between 20 and 39 years old (age range 14-68 years, M:F ratio 1.4:1). Heterosexual practice was admitted to by 77% of patients. At the time of presentation most patients (53%) were asymptomatic while 24% had some symptoms and 21% had acquired immunodeficiency syndrome (AIDS). The most common presentation was generalized lymphadenopathy (67%) which was significantly higher than skin rash (27%), oral candidiasis (24%), cough (24%), weight loss (24%) and pallor of mucous membranes (19%, p < 0.001). This study affirms that young people account for the majority of new cases of HIV infection. The heterosexual route was the predominant mode of transmission. Generalized lymphadenopathy was the commonest presenting feature of persons newly diagnosed with HIV infection.

Human immunodeficiency virus type-1 (HIV-1) subtypes in Jamaica.

The subtypes of 141 isolates of human immunodeficiency virus type-1 (HIV-1) from Jamaica were determined by a combination of env and gag heteroduplex mobility analysis (HMA) genotyping. The majority of HIV-1 isolates were subtype B (131/141, 93.0%); one (0.8%) isolate each of subtypes C, D and E was found and 7 (4.9%) were indeterminate. These results and the failure of the sets of primers used to amplify some of the HIV-1 isolates provide strong evidence of genetic diversity of the HIV/AIDS epidemic in Jamaica. Surveillance of the circulating HIV-1 genetic subtypes is a pre-requisite for developing regional vaccine strategies and understanding the transmission patterns of the virus. This is the first study of its kind in Jamaica and the findings complement data from other Caribbean countries. This work supports the view of colleagues from the French and Spanish-speaking Caribbean that an epidemiological network supported by regional laboratories will help track this epidemic accurately with positive outcomes for the public.

Prevalence of chronic renal failure in the diabetic population at the University Hospital of the West Indies.

The prevalence of chronic renal failure (CRF) in 460 patients with diabetes mellitus attending the diabetic outpatient clinic at the University Hospital of the West Indies in Jamaica was determined from a review of medical records. The prevalence of CRF was 10% (39/386) in the diabetic clinic population. Significant positive associations with CRF were found with male gender (20/98, 20% vs 19/287, 7%; odds ratio (OR), 3.24; p = 0.001); age 60 years and older (22/162; 14% vs 17/221, 8%; OR, 2.01; p = 0.04); fasting blood glucose concentrations exceeding 8.0 mmol/L (22/162, 13% vs 12/182, 7%; OR, 2.08; p = 0.05); the presence of significant proteinuria as a marker for outcome (13/39, 33% vs 48/346, 14%; OR, 3.60; p = 0.02) and peripheral vascular disease (6/20, 30% vs 139/386, 10%; OR, 4.75; p = 0.005). The prevalence of CRF did not differ significantly between patients with Type 1 and Type 2 diabetes mellitus. Also, the presence of CRF was not significantly associated with duration of diabetes mellitus, type of hypoglycaemic agents used, or history of hypertension. However, the presence of persistent proteinuria was significantly associated with duration of diabetes mellitus exceeding five years (46/255, 17% vs 11/149, 7%; OR, 2.52; p = 0.005) and a history of hypertension (41/235, 17% vs 20/198, 10%; OR, 1.88; p = 0.03) but not with age or gender. This study emphasizes the need to evaluate patients with diabetes mellitus for renal impairment so that intervention strategies may be adopted early to delay progression to endstage renal disease.

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation / Efecto inmunomodulatorio de los antibióticos sobre la secreción del factor de necrosis tumoral alfa por células sanguíneas mononucleares periféricas en respuesta a la estimulación de stenotrophomonas maltophilia

Some antibiotics have been shown to modify the host immune response. Infection with Stenotrophomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors examined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF alpha) production by human peripheral blood mononuclear cells (PBMC) stimulated with heat-killed S maltophilia. Cotrimoxazole was the only antibiotic that suppressed TNFa secretion at clinically achievable concentrations. This may explain its use with good effect in the treatment of S maltophilia infections. However at supratherapeutic concentrations, ceftazidime and ciprofloxacin, but not piperacillin-tazobactam, also inhibited significantly the production of TNF alpha. Cotrimoxazole, in addition to its antimicrobial effect against S maltophilia, has an immunomodulatory effect on peripheral blood mononuclear cells stimulated by S maltophilia.

Algunos antibióticos han mostrado ser capaces de modificar la respuesta inmune del huésped. Las infecciones con Stenotrophomonas maltophilia – un patógeno emergente – son difíciles de tratar debido a su multiresistencia a los antibióticos. Examinamos el efecto de cuatro agentes antimicrobianos comúnmente usados (ciprofloxacina, ceftazidima, cotrimoxazol, y piperacilina-tazobactam) sobre la producción del factor de necrosis tumoral alfa (FNTa) por las células sanguíneas mononucleares periféricas humanas (PBMC) estimuladas con S maltophilia inactivadas mediante calor. El cotrimoxazol – en concentraciones clínicamente posibles – fue el único antibiótico que eliminó la secreción FNTa. Esto puede explicar su uso efectivo en el tratamiento de las infecciones por S maltophilia. Sin embargo, en concentraciones supraterapéuticas, la ceftazidima y la cipro-floxacina – pero no la piperacilina-tazobactam – también inhibieron significativamente la producción de FNTa. El cotrimoxazol, además de su efecto antimicrobiano contra S maltophilia, tiene un efecto inmuno-modulatorio sobre las células sanguíneas mononucleares periféricas estimuladas por S maltophilia.

Seroprevalence of sexually transmitted infections among accepted and deferred blood donors in Jamaica / Seroprevalencia de las infecciones transmitidas sexualmente entre los donantes de sangre aceptados y diferidos en Jamaica

Critical donor selection and testing increases the safety of blood transfusion by excluding donors at risk of transmitting infections. This study investigated the seroprevalence of and risk factors for sexually transmitted infections (STIs) among accepted and deferred blood donors in Jamaica. A total of 1015 blood donors consisting of 794 (78) accepted donors and 221 (22) deferred donors presenting at the Central Blood Bank, Jamaica, over a six-month period, were recruited for this study. A standardized questionnaire was administered to each participant and a sample of blood obtained for detection of hepatitis B surface antigen, antibodies to Treponema pallidum, human immunodeficiency virus (HIV) and human T-cell lymphotrophic virus type-1 (HTLV-1). Deferred donors were three times more likely to be seropositive for STI than accepted donors (16.3vs 5.2, OR 3.57, 95CI 2.16 - 5.90, p < 0.0001). Males had significant association between STI seropositivity and having fathered children with two or more women (p = 0.0085), unprotected sexual intercourse with several persons (p = 0.0326), and history of genital herpes (p = 0.0121). Significant risk factors identified among females were unprotected sex with several partners (p = 0.0385); having more than ten lifetime partners (p = 0.0105); and use of depoprovera (p = 0.0028). This study confirms higher rates of STI among deferred blood donors and supports the donor deferral system in Jamaica.

La prueba y selección crítica del donante aumenta la seguridad de la transfusión de sangre, excluyendo a los donantes con riesgo de transmitir infecciones. Este estudio investigó la seroprevalencia de las infecciones transmitidas sexualmente (ITS) entre los donantes de sangre aceptados y diferidos en Jamaica. Un total de 1015 donantes de sangre consistente en 794 (78%) donantes aceptados, y 221 (22%) donantes diferidos que acudieron al Banco de Sangre Central en Jamaica por un periodo de seis meses, fueron reclutados para este estudio. A cada uno de los participantes se le aplicó una encuesta estandarizada, y se obtuvo una muestra de sangre para la detección del antígeno de superficie de la hepatitis B, los anticuerpos del Treponema pallidum, el virus de la inmunodeficiencia humana (VIH), y el virus linfotrópico humano de células T tipo 1 (HTLV-1). Los donantes diferidos presentaron una probabilidad tres veces mayor de ser seropositivos que los donantes aceptados (16.3% frente a 5.2%, OR 3.57, 95% CI 2.16 - 5.90, p <0.0001). En los varones se dio una asociación significativa entre la seropositividad de ITS y el haber engendrado hijos con dos o más mujeres (p = 0.0085), el intercambio sexual desprotegido con distintas personas (p = 0.0326), y una historia de herpes genitales (p = 0.0121). Los factores de riesgo significativos identificados entre las hembras fueron el sexo desprotegido con diferentes parejas (p = 0.0385), el haber tenido más de diez parejas a lo largo de su vida (p = 0.0105), y el uso de depoprovera (p = 0.0028). Este estudio confirma que las tasas de ITS entre los dotantes de sangre diferidos son más altas, y respalda el sistema de aplazamiento de donantes en Jamaica.

Clinical and epidemiological characteristics of adult and adolescent patients newly diagnosed with the human immunodeficiency virus at a Jamaican clinic for sexually transmitted infections / Características clínicas y epidemiológicas de los pacientes adultos y adolescentes diagnosticados recientemente con el virus de la inmunodeficiencia humana en una clínica jamaicana para infecciones de transmisión sexual

Persons infected with the human immunodeficiency virus (HIV) may have protean clinical manifestations. These characteristics have not been described for adult patients in Jamaica. This study was conducted to determine the clinical and epidemiological characteristics of adult and adolescent persons newly diagnosed with HIV presenting at a specialized clinic for sexually transmitted infections (STI). A retrospective analysis of the medical records of adult and adolescent patients newly diagnosed with HIV was undertaken over a 12-month period. The results showed that most patients (64) were between 20 and 39 years old (age range 14-68 years, M:F ratio 1.4:1). Heterosexual practice was admitted to by 77of patients. At the time of presentation most patients (53) were asymptomatic while 24had some symptoms and 21had acquired immunodeficiency syndrome (AIDS). The most common presentation was generalized lymphadenopathy (67) which was significantly higher than skin rash (27), oral candidiasis (24), cough (24), weight loss (24) and pallor of mucous membranes (19, p < 0.001). This study affirms that young people account for the majority of new cases of HIV infection. The heterosexual route was the predominant mode of transmission. Generalized lymphadenopathy was the commonest presenting feature of persons newly diagnosed with HIV infection.

Las personas infectadas con el virus de la inmunodeficiencia humana (VIH) pueden presentar manifestaciones clínicas proteicas. Estas características no han sido descritas en relación con pacientes adultos en Jamaica. Este estudio se llevó a cabo con el propósito de determinar las características clínicas y epidemiológicas de personas adultas y adolescentes diagnosticadas recientemente con VIH, quienes acudieron a una clínica especializada en infecciones de transmisión sexual (ITS). Por espacio de 12 meses, se llevó a cabo un análisis retrospectivo de los archivos médicos de pacientes adultos y adolescentes recientemente diagnosticados con VIH. Los resultados mostraron que la mayoría de los pacientes (64%) tenían entre 20 y 39 años de edad (rango de edad 14-68, ratio M:F igual a 1.4: 1). El 77% de los pacientes dijo ser heterosexual. En el momento de manifestación, la mayoría de los pacientes (53%) eran asintomáticos, mientras que el 24% tenía algunos síntomas, y el 21% había adquirido el síndrome de la inmunodeficiencia (SIDA). La manifestación más común fue la linfadenopatía generalizada (67%), que fue significativamente más alta que la erupción cutánea (27%), la candidiasis oral (24%), la tos (24%), la pérdida de peso (24%) y la palidez de las membranas mucosas (19%) (p < 0.001). Este estudio afirma que la mayoría de los nuevos casos de infección de VIH esta constituida por personas jóvenes. La ruta heterosexual era el modo predominante de transmisión. La linfadenopatía generalizada fue el rasgo más común presente en las personas recientemente diagnosticadas con la infección del VIH.

Human immunodeficiency virus type-1 (HIV-1) subtypes in Jamaica / Subtipos del virus tipo-1 de la inmunodeficiencia humano (VIH-1) en Jamaica

The subtypes of 141 isolates of human immunodeficiency virus type-1 (HIV-1) from Jamaica were determined by a combination of env and gag heteroduplex mobility analysis (HMA) genotyping. The majority of HIV-1 isolates were subtype B (131/141, 93.0); one (0.8) isolate each of subtypes C, D and E was found and 7 (4.9) were indeterminate. These results and the failure of the sets of primers used to amplify some of the HIV-1 isolates provide strong evidence of genetic diversity of the HIV/AIDS epidemic in Jamaica. Surveillance of the circulating HIV-1 genetic subtypes is a pre-requisite for developing regional vaccine strategies and understanding the transmission patterns of the virus. This is the first study of its kind in Jamaica and the findings complement data from other Caribbean countries. This work supports the view of colleagues from the French and Spanish-speaking Caribbean that an epidemiological network supported by regional laboratories will help track this epidemic accurately with positive outcomes for the public.

Los subtipos de 141 aislados del virus tipo 1 de la inmunodeficiencia humno (VIH-1) en Jamaica, fueron determinados combinando la genotipificación por análisis de heterodúplex (HMA) en los genes env y gag. La mayor parte de los aislados HIV-1 fueron del subtipo B (131/141, 93.0%), se halló uno (0.8%) aislado para cada uno de los subtipos C, D y E, en tanto que 7 (4.9%) fueron indeterminados. Estos resultados y el fallo de los conjuntos de primers usados para amplificar algunos de los aislados de VIH-1, ofrecen fuerte evidencia de la diversidad epidémica del VIH/SIDA en Jamaica. La vigilancia de los subtipos genéticos de VIH-1 en circulación, constituye un pre-requisito, tanto para desarrollar estrategias de vacunas a nivel regional, como para entender los patrones de transmisión del virus. Este es el primer estudio de este tipo en Jamaica, y nuestros hallazgos complementan los datos obtenidos en otros países del Caribe. Coincidimos con nuestros colegas del Caribe francófono e hispano-parlante en cuanto a que una red epidemiológica apoyada por los laboratorios regionales, nos ayudaría a continuar rastreando esta epidemia con exactitud, y con resultados positivos para el público.

Prevalence of chronic renal failure in the diabetic population at the University Hospital of the West Indies

The prevalence of chronic renal failure (CRF) in 460 patients with diabetes mellitus attending the diabetic outpatient clinic at the University Hospital of the West Indies in Jamaica was determined from a review of medical records. The prevalence of CRF was 10 (39/386) in the diabetic clinic population. Significant positive associations with CRF were found with male gender (20/98, 20 vs 19/287, 7; odds ratio (OR), 3.24; p = 0.001); age 60 years and older (22/162; 14 vs 17/221, 8; OR, 2.01; p = 0.04); fasting blood glucose concentrations exceeding 8.0 mmol/L (22/162, 13 vs 12/182, 7; OR, 2.08; p = 0.05); the presence of significant proteinuria as a marker for outcome (13/39, 33 vs 48/346, 14; OR, 3.60; p = 0.02) and peripheral vascular disease (6/20, 30 vs 139/386, 10; OR, 4.75; p = 0.005). The prevalence of CRF did not differ significantly between patients with Type 1 and Type 2 diabetes mellitus. Also, the presence of CRF was not significantly associated with duration of diabetes mellitus, type of hypoglycaemic agents used, or history of hypertension. However, the presence of persistent proteinuria was significantly associated with duration of diabetes mellitus exceeding five years (46/255, 17 vs 11/149, 7; OR, 2.52; p = 0.005) and a history of hypertension (41/235, 17 vs 20/198, 10; OR, 1.88; p = 0.03) but not with age or gender. This study emphasizes the need to evaluate patients with diabetes mellitus for renal impairment so that intervention strategies may be adopted early to delay progression to endstage renal disease