Rickettsia species in Dermacentor reticulatus ticks feeding on human skin and clinical manifestations of tick-borne infections after tick bite

Abstract

Dermacentor reticulatus ticks are sporadically removed from human skin and therefore the medical consequences of their feeding are neglected compared to Ixodes ricinus. We investigated the prevalence of pathogens in D. reticulatus removed from human skin and possible clinical manifestations suggestive of tick-borne diseases after a tick bite. A total of 2153 ticks were studied and of these only 34 were D. reticulatus. The mean prevalence of Rickettsia in D. reticulatus was 50.0% and R. raoultii was identified in 82.4% of infected D. reticulatus ticks. We confirmed the first case of R. aeschlimannii infection in D. reticulatus ticks. Among participants bitten by D. reticulatus, 13.3% reported reddening around the tick bite site and flu-like symptoms, including lymphadenopathy and 3.3% reported eschar on the tick site bite. All of the participants with flu-like symptoms after tick removal were bitten by ticks infected with R. raoultii. The results of this study indicate that even though D. reticulatus ticks bite humans sporadically, pathogenic Rickettsia have a remarkably high prevalence in this tick species. We can expect that the incidence of tick-borne lymphadenopathy might increase with the reported expansion of the D. reticulatus into new areas and its growing abundance in Central Europe.

Tick-borne pathogens in questing adults Dermacentor reticulatus from the Eastern European population (north-eastern Poland)

“…From a medical point of view, D. reticulatus is of undeniable importance in the transmission of bacteria representing the genus Rickettsia 12 . Although D. reticulatus ticks attack humans sporadically 52 – 54 , it is a main vector of R. raoultii and R. slovaca . Tick-borne lymphadenopathy (TIBOLA)/Dermacentor-borne necrosis erythema-lymphadenopathy (DEBONEL) or scalp eschar and neck lymphadenopathy after a tick bite (SENLAT) are recently described infection syndromes in humans caused by R. raoultii and R. slovaca belonging to spotted fever group (SFG) rickettsiae 55 , 56 .…”

Rickettsial Infection in the COVID-19 Era: The Correlation between the Detection of Rickettsia aeschlimannii in Ticks and Storytelling Photography of a Presumable Human Rickettsiosis Case

“…This is supplemented with the fact that the diagnosis of R. aeschlimannii infection may be extremely challenging; in fact, in addition to the MSF manifestations, characterized by eschar, rash, edema and partial necrosis surrounding the tick bite site, episodes may present with nonspecific clinical symptoms (fever, headache, myalgia, vomiting, hepatitis, meningitis, etc. ), without cutaneous signs, such as observed in the case of an infection acquired in Southern Italy [3], or may be totally asymptomatic [29]. R. aeschlimannii Due to the lack of available serological tests in the medical laboratory and the severe restrictions associated with the SARS-CoV-2 infection, therapy was prescribed for suspected rickettsiosis.…”