Rickettsia parkeri Rickettsiosis in Different Ecological Regions of Argentina and Its Association with Amblyomma tigrinum as a Potential Vector

Abstract

Abstract. Rickettsia parkeri, a newly recognized tick-borne pathogen of humans in the Americas, is a confirmed cause of spotted fever group rickettsiosis in Argentina. Until recently, almost all cases of R. parkeri rickettsiosis in Argentina have originated from the Paraná River Delta, where entomological surveys have identified populations of R. parkeri-infected Amblyomma triste ticks. In this report, we describe confirmed cases of R. parkeri rickettsiosis from Có rdoba and La Rioja provinces, which are located several hundred kilometers inland, and in a more arid ecological region, where A. triste ticks do not occur. Additionally, we identified questing A. tigrinum ticks naturally infected with R. parkeri in Có rdoba province. These data provide evidence that another human-biting tick species serves as a potential vector of R. parkeri in Argentina and possibly, other countries of South America.

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States

“…The (3,(61)(62)(63)(64). Since the discovery in 2010 of a rickettsial disease caused by an SFGR identical or very similar to Rickettsia sp.…”

Genetic identification of Rickettsia sp. strain Atlantic rainforest in an endemic area of a mild spotted fever in Rio Grande do Sul state, Southern Brazil

“…Uruguay (Pacheco et al, 2006), Argentina (Romer et al, 2014), Bolivia (Tomassone et al, 2010) and Brazil, where the strain At#24, infecting an Amblyomma triste specimen, was successfully established in Vero cell culture. This tick species is the most common human-biting tick in Uruguay, however in Brazil there are no reports of this tick biting a human (Silveira et al, 2007).…”

Rickettsia infection in Amblyomma tonelliae, a tick species from the Amblyomma cajennense complex

“…In Argentina, 49 species of ticks have been recorded to date, and Amblyomma is the genus with the highest specific richness (25 species) Nava, 2005, 2006;Nava et al, 2009Nava et al, , 2014a. With the exception of the records of Rickettsia massiliae in Rhipicephalus sanguineus sensu lato , all rickettsiae vectored by ticks in this country were found to be associated to Amblyomma species Pacheco et al, 2007;Nava et al, 2008;Paddock et al, 2008;Tomassone et al, 2010;Cicuttin and Nava, 2013;Romer et al, 2014). Furthermore, most of the ticks recorded on humans in Argentina belong to the genus Amblyomma (Guglielmone et al, 1991Nava et al, 2006).…”