RESUMO
Leptospira is a bacterial genus that includes several pathogenic species related to leptospirosis. In Colombia, leptospirosis is a mandatorily reported disease, widely distributed across the country. In the Villeta municipality, leptospirosis has been identified as an important cause of febrile illness; however, to date, no studies have been performed to identify the circulating species. A genus-specific qualitative qPCR was performed on DNA extracted from febrile patients' acute-phase whole-blood samples targeting a fragment of the rrs gene. Positive qPCR samples were further amplified for the adk, icdA, LipL32, LipL41, rrs, and secY genes through conventional PCR for sequencing. All high-quality obtained sequences were further assessed through concatenated phylogenetic analysis. A total of 25% (14/56) of febrile patients' acute blood samples were positive for Leptospira spp. High-quality sequences were obtained for only five genes, and analysis through concatenated phylogeny identified that all sequences clustered within the P1/pathogenic clade; some of them formed a robustly supported clade with Leptospira santarosai, and others were closely related with other Leptospira species but exhibited considerable genetic divergence. We describe the presence of pathogenic Leptospira species among febrile patients from the Villeta municipality and identify L. santarosai and other Leptospira species as causative agents of leptospirosis in the region.
RESUMO
Chikungunya fever is a debilitating disease caused by Chikungunya virus (CHIKV) that can result in long-lasting arthralgias. The early diagnosis of CHIKV relies on PCR during the acute infection phase to allow differential diagnosis with other co-circulating arboviruses such as dengue and Zika. Alternatively, serology can support diagnosis and provide epidemiological information on current and past outbreaks. Many commercial serological ELISA assays are based on the inactivated whole CHIKV, but their sensitivity and specificity show great variability. We produced recombinant CHIKV E2 that is suitable for ELISA assays, which was used for the serodiagnosis of CHIKV infections occurring in an arbovirus endemic Mexican region within Michoacán state. A cross-sectional study was conducted in 2016-2017; sera was obtained from 15 healthy donors and 68 patients presenting undifferentiated febrile illness. Serum samples were screened by RT-PCR and by our in-house ELISA assay. Our results indicate that IgM and IgG anti-CHIKV E2 antibodies were detected with our ELISA assay with higher sensitivity than a commercially available CHIKV ELISA kit. Our simple and sensitive ELISA assay for the serodiagnosis of CHIKV infections can be applied to population-based seroprevalence surveys and has potential for monitoring vaccine immunogenicity in CHIKV vaccine clinical trials.
Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya , Ensaio de Imunoadsorção Enzimática , Proteínas Virais , Febre de Chikungunya/imunologia , Febre de Chikungunya/virologia , Vírus Chikungunya/genética , Vírus Chikungunya/imunologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , México/epidemiologia , Vigilância em Saúde Pública , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Proteínas Virais/imunologiaRESUMO
Resumen Entre las enfermedades infecciosas febriles se encuentran: dengue, leptospirosis, rickettsiosis y salmonelosis, entre otras. El objetivo de este estudio fue detectar la presencia de anticuerpos IgM a dengue y Leptospira en pacientes febriles. La seropositividad para IgM frente al dengue fue 34%; 26,3% en mujeres y 7,6% en varones, sin diferencias significativas (p = 0,181). La seropositividad para los anticuerpos IgM a Leptospira fue 3,2%; encontrándose sólo en mujeres. La serología positiva para leptospirosis y dengue fue 1%. Los serovares detectados fueron Pomona y Canicola por la técnica de microaglutinación. Se pudo identificar la presencia insospechada de leptospirosis y dengue en meses atípicos para este último, hecho importante para considerar el estudio de serología en el diagnóstico diferencial de enfermedades febriles.
Among the infectious diseases characterized by a febrile picture are: dengue, leptospirosis, rickettsiosis and salmonellosis, among others. The objective of this study was to identify IgM antibodies against dengue and Leptospira in febrile patientes. The seropositivity for IgM antibodies to dengue was 34%; 26.3% for women and 7.6% for men, without differences significant (p = 0.181). The seropositivity for IgM antibodies to Leptospira was 3.2%, being found only in women. Positive serology for both dengue and Leptospira was 1%. The serovars detected were Pomona and Canicola by the microagglutination technique. It was possible to identify the unsuspected presence of leptospirosis and dengue in atypical months for the latter, an important fact to consider the study of serology in the differential diagnosis of febrile diseases.
Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Imunoglobulina M/sangue , Dengue/epidemiologia , Leptospirose/epidemiologia , Anticorpos Antibacterianos/sangue , Estudos Soroepidemiológicos , Prevalência , Estudos Transversais , Dengue/diagnóstico , Diagnóstico Diferencial , Hospitais Gerais , Leptospirose/diagnóstico , México/epidemiologiaRESUMO
Objetivo. Analizar la utilización de las unidades de atención primaria a la salud (UAPS) por pacientes febriles en áreas de transmisión de paludismo, en diferentes condiciones de organización de los servicios de salud. Material y métodos. Estudio transversal realizado en septiembre de 1993, en 32 localidades de los estados de Tabasco (con servicios de salud descetralizados) y Campeche ( no descentralizados). Se efectuó un análisis descriptivo y se identificaron variables predictoras de utilización de las UAPS mediante una regresión logística. Resultados. Se entrevistaron 817 febriles, de los cuales 55 por ciento se atendieron en casa; 16.4 por ciento utilizaron UAPS y 17 por ciento fueron atendidos por colaboradores voluntarios, sin diferencias entre ambos estados. Los febriles de localidades con UAPS las utilizaron 11 veces más (IC 95 por ciento 7.0-18.2) que aquéllos sin UAPS; los graves 2.8 veces más (IC 95 por ciento 1.7-4.6) que los leves-moderados y los <13 años (IC 95 por ciento 1.3-2.9) 1.9 veces más que los ò13 años. Sólo 2 por ciento de los febriles fueron casos de paludismo. Conclusiones. No hubo diferencias en la utilización de UAPS entre estado descentralizado y no descentralizado. Debe revalorarse la fiebre como indicador único para detección de paludismo
Objective. To analyze primary health care service (PHCS) utilization by febrile patients in a malarial area of Mexico. Material and Methods. A cross-sectional study was carried out in September, 1993, in 32 communities of Tabasco (decentralized health services) and Campeche (non-decentralized) states. Predictors of utilization were analyzed using descriptive statistics and logistic regression analysis. Results. 817 febrile patients were interviewed, 55% of all febrile patients received care at home (SELF), 16.5% by PHCS and 17% by volunteer collaborators, with no significant differences in health services utilization between states. Febrile patients living in communities where PHCS was available used these facilities 11 times more than those without PHCS (C.I. 95%: 7.0-18.2%). Severely febrile patients used PHCS 2.8 times more than mild-moderate cases (C.I. 95%: 1.7-4.6%). Febrile patients under 13 years of age used PHCS 1.9 times more than older patients. Two per cent of febrile patients consisted of malaria cases. Conclusions. There was no difference between decentralized and non-decentralized health services regarding the utilization of PHCS. Fever symptoms must be evaluated as a single screening indicator of malarial disease.