Rickettsia rickettsii in Amblyomma patinoi Ticks, Colombia

To the Editor: Rickettsia rickettsii is the etiologic agent of Rocky Mountain spotted fever (RMSF), a highly lethal tick-borne rickettsioses restricted to the Western Hemisphere (1,2). In Colombia, R. rickettsii was first reported during the 1930s, when 62 (95%) of 65 affected persons died of RMSF in Tobia town (Cundinamarca Department) (3), from where highly virulent strains of R. rickettsii were isolated through the inoculation of patient blood or of Amblyomma cajennense sensu lato (s.l.) extracts into guinea pigs (4). Thereafter, RMSF remained unnoticed in Colombia until the 21st century, when new outbreaks with high case-fatality rates were reported in different regions, including Villeta, a nearby locality of Tobia (1).