Search

Between 2006 and 2008, three outbreaks of human rickettsiosis occurred in Northwestern Colombia (municipalities of Necoclí, Los Córdobas and Turbo), with case fatality rates between 27% and 54%. The aim of this study was to determine previous exposure of wild and domestic animals to spotted fever group (SFG) rickettsiae through serological tests, to detect rickettsial evidence in their ectoparasites, and to analyze their possible role in the epidemiology of rickettsial diseases in this zone of the country. A cross-sectional association study was performed from 2010 to 2011. Blood and ectoparasite samples were collected from domestic animals and small mammals. A statistically significant association (p<0.05) between seropositive animals and the study zones was observed. A total of 2937 ticks, 672 fleas and 74 lice were collected and tested in pools by PCR. The minimum infection rate (MIR) of the positive pools was 5% in ticks, 4% in fleas, and 0% in lice. Phylogenetic analyses showed circulation of three 4.Rickettsiaspecies: R. felisin fleas, and R. belliiand Rickettsiasp. strain Atlantic rainforest, both in Amblyomma ovaleticks. In conclusion, this study demonstrated the occurrence of SFG rickettsiae in domestic, synanthropic and wild animals, and suggests the use of equines and canines as good sentinels of infection, in the study zone. We speculate that a transmission cycle exist involving rodents in the areas where these outbreaks have occurred. Tomes' spiny rats (Proechimys semispinosus) and common opossums (Didelphis marsupialis) could be good candidates as amplifier hosts for SFG rickettsiae in enzootic/endemic zones.

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 Rickettsiain the study zone.

Our goal was to understand rickettsial spotted fevers’ circulation in areas of previous outbreaks reported from 2006 to 2008 in Colombia. We herein present molecular identification and isolation of Rickettsiasp. Atlantic rainforest strain from Amblyomma ovaleticks, a strain shown to be pathogenic to humans. Infected ticks were found on dogs and a rodent in Antioquia and Córdoba Provinces. This is the first report of this rickettsia outside Brazil, which expands its known range considerably.

The study of the profiles of velocity and fluid flow rate in porous media with cylindrical geometries were made, using Maple, and the results were obtained in terms of the Bessel Functions. Some of them were the generalized forms of the Haugen-Poiseuille Law. The results could be applied to synthetic media such as zeolites. Only newtonian fluids were considered, but it’s possible to consider non newtonian fluids in the future investigations.

Coxiella burnetiiis the causative agent of Q fever. In order to explore the occurrence of C. burnetiiin 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 sanguineuss.l. (27%) and Dermacentor nitens(6%). Specific IS1111 PCR and amplicon sequencing allowed the identification of C. burnetiiDNA in A. mixtumcollected from a domestic horse. These findings, for first time in Cuba, indicate the need for an in-depth assessment of the C. burnetiioccurrence in hosts and humans at risk of infection.