Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

Abstract

Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Epidemiologic profile and clinical course of four confirmed rickettsiosis cases in Southern Mexico during 2016

“…Another explanation is related to the health conditions inherent to each patient; for instance, the patient in case study 4 was older, of high socioeconomic status and, therefore, probably a healthier environment than the other two pediatric patients. Thus, despite experiencing a severe infection, the patient was able to reestablish his health .…”

Detección de Rickettsia typhi en Rhipicephalus sanguineus s.l. y Amblyomma mixtum en el sur de México

“…Considerando las especies de garrapatas donde R. typhi se detectó, estos resultados podrían representar una mayor dispersión de esa bacteria en Chiapas, debido a que dichas especies están ampliamente distribuidas en ambientes rurales y urbanos. 19,20 En este sentido, los datos de distribución y preferencia de hábitat señalan que las garrapatas del complejo Rh. sanguineus están adaptadas para habitar ambientes tanto urbanos como rurales, 21 mientras que A. mixtum está entre las especies más comunes en ambientes rurales.…”

Suspected and Confirmed Vector-Borne Rickettsioses of North America Associated with Human Diseases

“…The prevalence of R. typhi in fleas in North America varies greatly: 0–2% of C. felis in California [ 82 , 105 , 106 ], 0–7% of C. felis in Texas [ 99 , 107 , 108 ] and 2% of X. cheopis in Hawaii [ 109 ]. Though X. cheopis and C. felis are the presumed vectors in urban and suburban areas, respectively, R. typhi DNA has been detected in a variety of other arthropods including other flea species, lice and ticks [ 83 , 110 , 111 , 112 ]. However, experimental studies are needed to elucidate the role these other vectors might play in the transmission of this disease.…”