Rickettsioses in Latin America, Caribbean, Spain and Portugal

Data on genus and infectious by Rickettsia were retrospectively compiled from the critical review literature regarding all countries in Latin America, Caribbean islands, Portugal and Spain. We considered all Rickettsia records reported for human and/or animal hosts, and/or invertebrate hosts considered being the vector. In a few cases, when no direct detection of a given Rickettsia group or species was available for a given country, the serologic method was considered. A total of 13 Rickettsia species have been recorded in Latin America and the Caribbean. The species with the largest number of country confirmed records were Rickettsia felis (9 countries), R. prowazekii (7 countries), R. typhi (6 countries), R. rickettsii (6 countries), R. amblyommii (5 countries), and R. parkeri (4 countries). The rickettsial records for the Caribbean islands (West Indies) were grouped in only one geographical area. Both R. bellii, R. akari, and Candidatus ‘R. andeane’ have been recorded in only 2 countries each, whereas R. massiliae, R. rhipicephali, R.monteiroi, and R. africae have each been recorded in a single country (in this case, R. africae has been recorded in nine Caribbean Islands). For El Salvador, Honduras, and Nicaragua, no specific Rickettsia has been reported so far, but there have been serological evidence of human or/and animal infection. The following countries remain without any rickettsial records: Belize, Venezuela, Guyana, Surinam, and Paraguay. In addition, except for a few islands, many Caribbean islands remain without records. A total of 12 Rickettsia species have been reported in Spain and Portugal: R. conorii, R. helvetica, R. monacensis, R. felis, R. slovaca, R. raoultii, R. sibirica, R. aeschlimannii, R. rioja, R. massiliae, R. typhi, and R. prowazekii. Amongst these Rickettsia species reported in Spain and Portugal, only R. prowazekii, R. typhi, R. felis, and R. massiliae have also been reported in Latin America. This study summarizes the current state of art on the rickettsial distribution in Latin America, Caribbean, Spain and Portugal. The data obtained allow a better understanding on rickettsial epidemiology and distribution of vector ecology. Key words: Acari, epidemiology, rocky mountain spotted fever, vector control. (Source: DeCS

Coxiella burnetii in Ticks, Argentina

The Gammaproteobacterium Coxiella burnetii is the causative agent of acute Q fever and chronic endocarditis in humans worldwide. It is transmitted primarily by aerosol route or by ingestion of fomites from infected animals, mostly from domestic ruminants.Fil: Pacheco, Richard C.. Universidade Federal de Mato Grosso Do Sul; Brasil;Fil: Echaide, Ignacio Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria, Rafaela; ArgentinaFil: Alves, Rosiane N.. Universidad Federal de Uberlândia; BrasilFil: Beletti, Marcelo E.. Universidad Federal de Uberlândia; BrasilFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria, Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Labruna, Marcelo B.. Universidade Do Sao Paulo; Brasil

Reinstatement of rhipicephalus (Boophilus) australis (Acari: Ixodidae) with redescription of the adult and larval stages

Rhipicephalus australis Fuller, the Australian cattle tick, is reinstated and the adults and larvae redescribed from material collected in Australia. This long ignored boophilid was previously known as R. microplus Canestrini for specimens reported in Australia and New Caledonia. The adults of R. australis are easily recognized by a combination of characters, such as the ventro-medial spurs in the palpal segments of the male, and the abundant, plumose, pale white setae on the dorsum of the female. Other details, such as coxal and adanal shields are more variable among different populations and may lead to incorrect determinations. Larvae of R. australis are clearly smaller than those of R. microplus. The use of principal components analysis on body measurements leads to a clear separation of larvae of both taxa. A phylogenetic analysis based on 12S- and 16S-rDNA gene sequences supports the conspecificity of the neotype material on which the reinstatement of the species is proposed, and of the specimens used for previous interspecific crosses. R. australis is now known to be present in Australia, New Caledonia, the island of Borneo, Philippines, Sumatra, Java, New Guinea, Cambodia, and Tahiti. Both R. microplus and R. australis coexist in some countries in southeastern Asia. Given the extreme importance of these ticks for the cattle industry, field data on their distribution in the region are required to know the actual range of these species and to understand the evolution of the group.Fil: Estrada Peña, Agustín. Universidad de Zaragoza; EspañaFil: Venzal, José M.. Universidad de la República; UruguayFil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Guglielmone, Alberto Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Labruna, Marcelo B.. Universidade de Sao Paulo; BrasilFil: de la Fuente, José. Instituto de Investigación en Recursos Cinegéticos; Españ

Rocky Mountain Spotted Fever in Dogs, Brazil

Clinical illness caused by Rickettsia rickettsii in dogs has been reported solely in the United States. We report 2 natural clinical cases of Rocky Mountain spotted fever in dogs in Brazil. Each case was confirmed by seroconversion and molecular analysis and resolved after doxycycline therapy

Rickettsia parkeri in Brazil

We report finding Rickettsia parkeri in Brazil in 9.7% of Amblyomma triste ticks examined. An R. parkeri isolate was successfully established in Vero cell culture. Molecular characterization of the agent was performed by DNA sequencing of portions of the rickettsial genes gltA, htrA, ompA, and ompB

Exploring the ecological and evolutionary relationships between Rickettsia and hard ticks in the Neotropical region

This study addresses a meta-analysis of the distribution of Rickettsia spp. in the Neotropical region, as well as their associations with ticks and vertebrates. A total of 219 published reports on Rickettsia in ticks in the target region were compiled, providing 599 records of 31 species of Rickettsia recorded in 50 species of Ixodidae. The aim is to capture the phylogenetic relationships between rickettsiae and the ticks carrying them in the target region, with a focus on the co-speciation ticks-rickettsiae. We compared the phylogeny of ticks, the records of rickettsiae, the environmental gradients colonized by ticks and the effect of the phylogenetic composition of vertebrates feeding ticks on the detection of Rickettsia in ticks. Results show that differences in rickettsial composition in ticks do not depend on the vertebrate's blood-source. This is the first time this result is demonstrated. This study pinpoints that some Neotropical rickettsial organisms are associated with well-defined phylogenetical clusters of ticks. Secondarily, and probably only in a few cases, rickettsiae share species of phylogenetically distant ticks distributed along a gradient of environmental traits in which the ticks overlap (i.e., the different strains of Rickettsia parkeri sensu lato). We outline the importance of some ticks that share hosts and habitat: these ticks may act as “bridges” for the circulation of rickettsial species. There are also many species of Rickettsia that have been detected so far in only one tick species, pointing to a tight relationship or to the lack of data preventing conclusions about the detection of these bacteria in other ticks. Two species, namely Rickettsia amblyommatis and Rickettsia bellii have been recorded in the majority of ticks in the region (mainly Amblyomma spp.) and seem to be not associated with definite tick species because they may be an essential symbiont of the ticks. We conclude that an adequate analysis of rickettsiae-ticks-habitat is necessary to address the human health issues derived from the infections by rickettsiae.Fil: Estrada Peña, Agustín. Universidad de Zaragoza. Instituto Agroalimentario de Aragon; EspañaFil: Binder, Lina C.. Universidade de Sao Paulo; BrasilFil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; ArgentinaFil: Szabó, Matias P. J.. Universidade Federal de Uberlandia; BrasilFil: Labruna, Marcelo B.. Universidade de Sao Paulo; Brasi

Rickettsia felis infection in cat fleas Ctenocephalides felis felis

The present study evaluated the rickettsial infection in a laboratory colony of cat fleas, Ctenocephalides felis felis (Bouche) in Brazil. All flea samples (30 eggs, 30 larvae, 30 cocoons, 30 males, and 30 females) tested by polymerase chain reaction (PCR) were shown to contain rickettsial DNA. PCR products, corresponding to the rickettsial gltA, htrA, ompA and ompB gene partial sequences were sequenced and showed to correspond to Rickettsia felis, indicating that the flea colony was 100% infected by R. felis. The immunofluorescence assay (IFA) showed the presence of R. felis-reactive antibodies in blood sera of 7 (87.5%) out of 8 cats that were regularly used to feed the flea colony. From 15 humans that used to work with the flea colony in the laboratory, 6 (40.0%) reacted positively to R. felis by IFA. Reactive feline and human sera showed low endpoint titers against R. felis, varying from 64 to 256. With the exception of one human serum, all R. felis-reactive sera were also reactive to Rickettsia rickettsii and/or Rickettsia parkeri antigens at similar titers to R. felis. The single human serum that was reactive solely to R. felis had an endpoint titer of 256, indicating that this person was infected by R. felisFAPESPCNP

Vigilancia de la infección por Rickettsia sp. en capibaras (Hydrochoerus hydrochaeris) un modelo potencial de alerta epidemiológica en zonas endémicas

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.Introducción. Los capibaras o chigüiros (Hydrochoerus hydrochaeris) son huéspedes amplificadores de Rickettsia sp. Usualmente se encuentran parasitados por la garrapata Amblyomma cajennense, principal vector de rickettsiosis en Suramérica. Los capibaras pueden ser usados como potenciales centinelas de la circulación de rickettsias.Objetivo. Detectar anticuerpos contra Rickettsia sp. del grupo de las fiebres manchadas en capibaras de una zona rural del municipio de Montería, departamento de Córdoba.Material y métodos. Se analizaron 36 sueros de capibaras de una zona rural de Montería (vereda San Jerónimo) en Córdoba. Para la detección de anticuerpos IgG se practicó inmunofluorescencia indirecta, que utilizó antígenos de la cepa Taiaçu de Rickettsia rickettsii de Brasil. Los sueros de los capibaras fueron diluidos 1:64. Se capturaron las garrapatas que se encontraban parasitando los capibaras y se clasificaron hasta su especie.Resultados. La seroprevalencia contra Rickettsia sp. del grupo de la fiebres manchadas encontrada fue de 22 % (8 capibaras); se encontraron cuatro sueros con título de 1:64, tres sueros con título 1:128 y un suero presentó titulación de 1:512. Todas las garrapatas (n=933) fueron identificadas taxonómicamente como A. cajennense.Conclusión. En Colombia existen zonas endémicas de rickettsiosis y la aparición de brotes anuales lo confirma (Necoclí, 2006; Los Córdobas, 2007, y Altos de Mulatos, 2008). El presente estudio reporta por primera vez la presencia de infección natural por rickettsia del grupo de las fiebres manchadas en capibaras de Colombia. Los hallazgos sugieren que los capibaras pueden ser usados como potenciales centinelas de la circulación de rickettsias y marcadores de las áreas de riesgo para la transmisión de rickettsiosis