Verónica Contreras

First molecular evidence of Coxiella burnetii infecting ticks in Cuba.

Coxiella burnetii is the causative agent of Q fever. In order to explore the occurrence of C. burnetii in ticks, samples were collected from horses, dogs and humans living in a Cuban occidental community. The species most commonly recovered were Amblyomma mixtum (67%), Rhipicephalus sanguineus s.l. (27%) and Dermacentor nitens (6%). Specific IS1111 PCR and amplicon sequencing allowed the identification of C. burnetii DNA in A. mixtum collected from a domestic horse. These findings, for first time in Cuba, indicate the need for an in-depth assessment of the C. burnetii occurrence in hosts and humans at risk of infection.

Human prevalence of the spotted fever group (SFG) rickettsiae in endemic zones of Northwestern Colombia

In February 2006, an outbreak of human rickettsiosis occurred in the municipality of Necoclí Colombia, with 35% of lethality. This episode was, followed by two more, one in the municipality of Los Cordobas in 2007 with a 54% of lethality and the other one in the municipality of Turbo in 2008 with 27% of lethality. The aim of this study was to perform serological tests in healthy persons to determine the seroprevalence of antibodies against spotted fever group (SFG) rickettsiae and develop a survey to study some infection risk-related factors. A cross-sectional study was performed in 2011 and 2012. A blood sample and survey of associated factors was performed in healthy persons. A prevalence of 32%-41% was found in healthy people. From the multivariate analysis, we found that people living more than 16 years in these sites had a 79% higher risk of being seropositive and a 46% higher risk when they reported having birds in their houses if the variable of having a horse was included in the model. In conclusion, this study shows endemicity of at least one spotted fever group Rickettsia in the study zone.

Fiebre Q: una zoonosis olvidada en Colombia

La fiebre Q es una zoonosis ampliamente distribuida, capaz de provocar innumerables perdidas economicas en rumiantes domesticos (ovinos, caprinos y bovinos). En humanos se presenta con gran versatilidad de manifestaciones clinicas; mas de la mitad de los casos suelen ser asintomaticos, la infeccion aguda generalmente se presenta como una enfermedad febril no especifica, con gran potencial para desarrollar neumonia, hepatitis y endocarditis cronica. En la mayoria de paises latinoamericanos la fiebre Q es una enfermedad olvidada, principalmente por el desconocimiento y falta de asociacion epidemiologica por parte de profesionales de la salud, sumado a la carencia de herramientas de diagnostico preciso y asequible, que como consecuencia, influencian en el subreporte y subdiagnostico de la enfermedad. El objetivo de esta revision fue describir los aspectos clinicos, eco-epidemiologicos, diagnostico y tratamiento de la fiebre Q. Se utilizo una busqueda sistematica de articulos, los cuales fueron revisados y evaluados criticamente de acuerdo a su calidad, basado en el rigor cientifico, credibilidad, relevancia y aplicabilidad de los resultados sobre los temas abordados a fin de proveer una actualizacion y profundizacion en el conocimiento de la enfermedad.

Surveillance of Rickettsia sp. infection in capybaras (Hydrochoerus hydrochaeris) a potential model of epidemiological alert in endemic areas

INTRODUCTION Capybaras (Hydrochoerus hydrochaeris) are considered amplifying hosts of Rickettsia sp. These rodents are usually parasitized by the tick vector, Amblyomma cajennense, the main vector of rickettsioses in humans and animals in South America. Capybaras can be used as sentinels in detection of circulation of rickettsiae. OBJECTIVE Antibodies to rickettsiae of spotted fever group were detected in capybaras in a rural area of Cordoba Province, northern Colombia. MATERIALS AND METHODS Sera were analyzed from 36 capybaras in a rural area of Monteria (village of San Jeronimo) in Córdoba. For the detection of IgG antibodies, indirect immunofluorescence was performed. The antigens were derived from R. rickettsia strain Taiaçu isolated in Brazil. Capybara sera were diluted 1:64 for IFA analysis. Ticks were collected from each capybara (also known as chigüiro) and identified to species. RESULTS The seroprevalence of spotted fever group Rickettsia was 22% (8 capybaras). Four sera had a titer of 1:64, 3 had a titer of 1:128 and one serum had a titer of 1:512. All ticks removed from the capybaras (n=933) were taxonomically identified as Amblyomma cajennense. CONCLUSION Colombia has areas endemic for rickettsioses, as indicated by confirmed annual outbreaks. The current study reports the first evidence of natural rickettsial infection of the spotted fever group in capybaras from Colombia. The findings suggest that capybaras can be used as sentinels for the circulation of rickettsiae and can identify endemic areas for the transmission of rickettsial diseases.