Molecular detection of spotted fever group rickettsiae in ticks from Ethiopia and Chad

Abstract

DNA extracted from 363 ticks collected in Ethiopia and 9 ticks collected in Chad, Africa were screened by PCR to detect DNA from spotted fever group rickettsiae. Fifteen ticks (4.1%) collected in Ethiopia and one tick (11%) collected in Chad tested positive when PCR targeting the gltA and ompA rickettsial genes was performed. PCR-positive products of the gltA and ompA genes were used for DNA sequencing. Rickettsia africae was detected in 12/118 Amblyomma lepidum and in 1/2 A. variegatum. Also, 2/12 Hyalomma marginatum rufipes collected in Ethiopia and one H. marginatum rufipes collected in Chad were positive for R. aeschlimannii. Our results confirm the previously reported presence of R. africae in Ethiopia and also show the first evidence of R. aeschlimannii in ticks collected in Ethiopia and Chad.

Pathogen Prevalence in Ticks Collected from the Vegetation and Livestock in Nigeria

“…This is the first comprehensive study on the diversity of bacte- rial and protozoan tick-borne pathogens in both questing and feeding ticks not only in Nigeria but also in sub-Saharan Africa. All of the investigated pathogens are widespread throughout Africa and represent a threat to both human and animal health (4,(19)(20)(21)(22)(23)(24)(25)27). As expected, the infection rate for most of the pathogens was significantly higher in feeding than in questing ticks ( Table 2), suggesting that a number of these pathogens originated from the cow blood ingested before tick collection rather than from transstadially maintained infections acquired during earlier blood meals.…”

“…Tick-borne human ehrlichiosis of varying severity is caused by Ehrlichia chaffeensis and Ehrlichia ewingii (24). Several human-pathogenic tick-borne Rickettsia species have been found in Africa, including Rickettsia conorii conorii, R. conorii caspia, R. africae, R. aeschlimannii, R. massiliae, R. akari, and R. sibirica mongolotimonae (8,19,27). Humans are frequently infected with Rickettsia species in Senegal, Burkina Faso, Cameroon, Mali, and the Ivory Coast, where seroprevalence rates from 17 to 36% have been reported (16).…”

Spotted fever group rickettsiae in ixodid ticks in Oromia, Ethiopia

“…R. aeschlimannii, the agent of SFG rickettsiosis, had been detected in Hyalomma marginatum rufipes and R. africae, the agent of African tick bite fever (ATBF), has been detected in Amblyomma lepidum and Am. variegatum ticks from eastern Ethiopia (Mura et al, 2008), and also R. africae had been detected in pools of Amblyomma and Rhipicephalus ticks (Pader et al, 2012) (summarized in Fig. 1).…”

Spotted Fever Group Rickettsiae in Ticks Collected from Wild Animals in Israel

“…marginatum ticks tested ranges from 1.8% to 64% in different studies. 23,[27][28][29] Rickettsia aeschlimannii has also been detected in Hyalomma aegyptum (L.) in Algeria, 30 Haemaphysalis inermis Birula in Spain, 27 Hyalomma marginatum rufipes Koch in Egypt, Ethiopia, and Chad, 28,31 Hyalomma anatolicum excavatum Koch from the Greek Island of Cephalonia, 32 and Hyalomma dromedarii Koch and Hyalomma impeltatum Schulze and Schlottke from Egypt. 31 Furthermore, five other human biting tick species including Haemaphysalis punctata Canestrini and Fanzago, Ixodes ricinus (L.), Rh.…”

“…turanicus . 23,28,[35][36][37] Rickettsia massiliae has been detected in Rhipicephalus ticks in Europe, Africa, and in South and North America. [37][38][39] There are several confirmed clinical cases caused by R. massiliae reported in the peer-reviewed literature.…”