Human Rickettsiosis Caused by Rickettsia parkeri Strain Atlantic Rainforest, Urabá, Colombia

Abstract

A mong the numerous causes of acute undifferentiated nonmalarial febrile illness, rickettsiae are amenable to treatment that can prevent death or, in the case of non-life-threatening diseases, shorten and ameliorate the course of illness (1). Awareness and knowledge of these infectious diseases are crucial and necessary. In Colombia, Rocky Mountain spotted fever was recognized in the 1930s and then rediscovered in the 21st century (2). Clusters of cases were documented in the departments of Cundinamarca, Córdoba, and Antioquia (2-4). Five fatal cases of Rocky Mountain spotted fever occurred in the village of Las Changas in the district of Necoclí in 2006, and 4 fatal cases occurred in a village in the district of Turbo in 2008 (4). Prevalence of antibodies to spotted fever group (SFG) rickettsiae of 25.6% among healthy residents of several areas in Colombia suggests contact of persons with less-virulent SFG rickettsiae, such as Rickettsia parkeri, which has previously been reported in Colombia in ticks of the species Amblyomma ovale, and R. amblyommatis, previously reported in A. cajennense ticks (5-7).

Phylogenetic Differentiation of Rickettsia parkeri Reveals Broad Dispersal and Distinct Clustering within North American Strains

“…In South America, the Atlantic rainforest strains of R. parkeri sensu lato (s. l.) have caused four confirmed cases of human rickettsiosis in Brazil, with Amblyomma ovale Koch implicated as the responsible vector ( 27 – 30 ). A recent report further confirmed a case of human rickettsiosis caused by R. parkeri s. l. strain Atlantic rainforest from Colombia ( 31 ) in a region where an isolate of this pathogen was previously obtained from a questing A. ovale tick ( 32 ). An additional strain of R. parkeri s. l. Atlantic rainforest was isolated from Amblyomma aureolatum (Pallas) in southern Brazil in the state of Santa Catarina, where R. parkeri s. l. strain Atlantic rainforest had previously been detected in A. ovale , A. aureolatum , and Rhipicephalus sanguineus (Latreille) ( 33 , 34 ).…”

Rickettsiosis Caused by Rickettsia parkeri, Mexico

“…Rickettsiosis caused by R. parkeri ( R. parketri ) is a recently discovered disease. The first human case was reported in United States in 2004, and the bacterium was subsequently found in South America ( 2 – 5 ). R. parkeri infection is less virulent than infection with R. rickettsii , the agent of Rocky Mountain spotted fever .…”

“…Signs and symptoms of R. parkeri infection are fever, rash, myalgia, and headache. Presence of eschar lesions at the inoculation site are common ( 5 ). In Mexico, R. parkeri strain Atlantic Rainforest has been identified in Amblyomma ovale ticks in Veracruz, R. parkeri sensu stricto in A. maculatum ticks collected from dogs in Sonora, and R. parkeri strain Black Gap in Dermacentor parumapertus ticks in Sonora and Chihuahua ( 6 ).…”

“…For conventional PCR diagnosis, we obtained a 3-mL whole blood sample and sent it to our laboratory. In regions where rickettsiosis caused by R. parkeri are common, medics usually take samples from eschar lesions ( 5 , 8 , 9 ). We obtained a skin biopsy from the eschar lesion 2 days after treatment was initiated.…”

“…MN027564.1) ( 8 ) and Colombia (GenBank accession no. MK860201.1) ( 5 ), as well as to a recently identified R. parkeri isolate (GenBank accession no. MK814825.1) from A. ovale in Veracruz, Mexico.…”