TY - JOUR AU - Moraes-Filho, Jonas AU - Costa, Francisco AU - Gerardi, Monize AU - Soares, Herbert AU - Labruna, Marcelo T1 - Rickettsia rickettsii Co-feeding Transmission among Amblyomma aureolatum Ticks T2 - Emerging Infectious Disease journal PY - 2018 VL - 24 IS - 11 SP - 2041 SN - 1080-6059 AB - Amblyomma aureolatum ticks are vectors of Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever in Brazil. Maintenance of R. rickettsii in nature depends on horizontal transmission along tick generations. Although such transmission is known to occur when uninfected and infected ticks feed simultaneously on susceptible animals (co-feeding systemic transmission), we investigated co-feeding nonsystemic transmission, which was based on R. rickettsii–infected and –uninfected A. aureolatum ticks feeding simultaneously on guinea pigs immune to R. rickettsii. Our acquisition and transmission infestations demonstrated that horizontal transmission of R. rickettsii by co-feeding ticks on immune hosts with no systemic infection did not occur when uninfected larvae fed distantly from infected nymphs but did occur in a few cases when uninfected larvae fed side-by-side with infected nymphs, suggesting that they shared the same feeding site. The co-feeding nonsystemic transmission type might have no epidemiologic importance for Rocky Mountain spotted fever. KW - Rickettsia rickettsii KW - Amblyomma aureolatum KW - Rocky Mountain spotted fever KW - cofeeding KW - Brazil KW - vector-borne infections KW - guinea pigs KW - ticks KW - bacteria KW - co-feeding DO - 10.3201/eid2411.180451 UR - https://wwwnc.cdc.gov/eid/article/24/11/18-0451_article ER - End of Reference