Evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of Jujuy, Argentina.

Abstract

Abstract. Between November 1993 and March 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in Jujuy Province, Argentina. Immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (IFA) demonstrated antibodies reactive with spotted fever group rickettsiae. A serosurvey was conducted among 16 households in proximity to the index case. Of 105 healthy subjects evaluated by IFA, 19 (18%) Between November 1993 and March 1994, 6 children presented to medical practitioners in Jujuy Province in northwestern Argentina with illnesses characterized by fever, headache, purpuric rash, and a history of tick bite 1-2 weeks preceding the illness. This cluster included two fatal cases occurring in a family residing in Saladillo in the Santa Barbara Department of Jujuy Province (Figure 1). The clinical and epidemiologic findings common to each case suggested a rickettsial etiology. In this report, we describe evidence for spotted fever group rickettsial infections in northern Argentina, including laboratory-confirmed infections in patients with acute disease, and serologic evidence of past rickettsial and ehrlichial infections among healthy persons residing in Jujuy Province. METHODSDescription of the area. Jujuy Province is situated in northwestern Argentina (Figure 1) and is a relatively warm (20-22ЊC) subtropical region located at 2,200 feet (670 meters) elevation. The average annual rainfall is 32 in (80 cm), and most precipitation occurs between December and March. The province has a stable population of approximately 560,000 inhabitants. The study area of Palma Sola and surroundings (which includes the town of Saladillo) has a population of approximately 2,000 persons. It is located in the Department of Santa Barbara, with a population of 15,540 persons. The terrain consists of partially forested rolling hills that support a diverse collection of birds, small, medium, and large mammals, as well as many domesticated animals including dogs, cattle, pigs, and horses. Adult A. cajennense have been collected from dogs and horses in the region.Serosurvey. Healthy persons from 16 households in Saladillo were interviewed and a peripheral blood specimen was collected from each person. The interview included questions on prior tick bites and on illnesses at any time, specifically illnesses with signs and symptoms compatible with rickettsial spotted fever. Informed consent was obtained for the survey following guidelines of the U.S. Department of Health and Human Services and those of the Jujuy Provincial Ministry of Social Welfare for clinical studies.Immunohistochemistry. Sections of formalin-fixed, paraffin-embedded tissues obtained at autopsy from a patient with fatal disease were evaluated for spotted fever group rickettsial infection using an indirect immunoalkaline phosphatase staining technique. 9 ...

Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil

“…The rate found here sounds high but was similar to the rate found among 726 febrile patients without acute rickettsial infection from the city of Juiz de Fora (Costa 2004), and also to others reported elsewhere (Paddock & Childs 2003). In one of the few serologic surveys in South America, Ripoll et al (1999) found 14% of positivity in Argentina but rates have ranged from 2 to 20% throughout the world (Paddock & Childs 2003). Ehrlichia species particularly E. canis have been recently isolated from Brazilian dogs (Machado 2004) indicating the presence of bacteria belonging to this genus in Brazil.…”

“…The used method for antibody testing in this study (IFA) has the same limitations of other serologic methods added to the subjectivity of the viewer but even though it has been considered the standard for serosurveys of rickettsial infections (Anstey et al 1997, Ripoll et al 1999. The concomitant testing with another method, especially Western blotting (Carpenter et al 1999, Unver et al 2001 could overcome some consequent pitfalls of studies like this but from the practical standpoint the majority of published studies have not been testing more than one method simultaneously (Lemos et al 1994, Galvão 2004).…”

Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens from Northern Peru

“…Brazilian spotted fever, which is transmitted by the tick Amblyomma cajennense (12), was initially reported in Brazil more than 60 years ago (14), and cases have increasingly been documented over the last 20 years (10,11,13,43,46). Rickettsiae and rickettsioses have also been recorded in Mexico (52), Costa Rica (19), and Argentina (27,39). The SFG rickettsia agent, R. felis, has been identified in domestic animals and is thought to infect humans in Peru, although these data remain unpublished (C. Moron, unpublished data).…”

Aproximación clínica y principales rickettsiosis transmitidas por garrapatas presentes en Latinoamérica

“…El exantema puede ser maculo-papular y a menudo petequial (Figura 1). Suele iniciarse en extremidades con afectación de palmas y plantas y progresar posteriormente al tronco; en ocasiones se presentan equimosis múlti-ples con signos de vasculitis grave (Figura 2) 8,12,16,21,27 . La frecuencia de exantema es variable en las distintas series, habiéndose descrito entre 18 y 100% 8,12,13,20,23,25 .…”