The Detection of Spotted Fever Group Rickettsia DNA in Tick Samples From Pastoral Communities in Kenya

Abstract

In this study, ticks from pastoral communities in Kenya were tested for Rickettsia spp. infections in geographical regions where the presence of tick-borne arboviruses had previously been reported. Rickettsial and arbovirus infections have similar clinical features which makes differential diagnosis challenging when both diseases occur. The tick samples were tested for Rickettsia spp. by conventional PCR using three primer sets targeting the gltA, ompA, and ompB genes followed by amplicon sequencing. Of the tick pools screened, 25% (95/380) were positive for Rickettsia spp. DNA using the gltA primer set. Of the tick-positive pools, 60% were ticks collected from camels. Rickettsia aeschlimannii and R. africae were the main Rickettsia spp. detected in the tick pools sequenced. The findings of this study indicate that multiple Rickettsia species are circulating in ticks from pastoral communities in Kenya and could contribute to the etiology of febrile illness in these areas. Diagnosis and treatment of rickettsial infections should be a public health priority in these regions.

Pathogens, endosymbionts, and blood-meal sources of host-seeking ticks in the fast-changing Maasai Mara wildlife ecosystem

“…Analysis of tickborne zoonotic pathogens in this study corroborate findings of previous studies in Kenya, which have demonstrated circulation of zoonotic SFG Rickettsia in ticks from various ecologies [21,33,34). The presence of R. africae, which causes a potentially fatal, but as yet neglected febrile illness, was first reported in this ecosystem in 2003 [29].…”

“…gemma and Am. variegatum ticks, confirming the strong link between ticks of Amblyomma species and the epidemiology of R. africae in sub-Saharan Africa [34,35,41]. Further, R. africae-infected ticks were sampled from Kichwa Tembo area in MMNR, which is a wildlife-human interface dominated by tented camps and resorts.…”

Vector-borne bacteria in blood of camels in Iran: New data and literature review

“…have been detected in camel blood serum with prevalences of up to 83% [21,58] and R. aeschlimannii, R. africae, R. sibirica mongolitimonae and Rickettsia sp. have been identified in several tick species collected from camels [20,[59][60][61][62][63][64][65][66]. Despite this, there are no reports on diseases in camels caused by these organisms.…”

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels ( Camelus dromedarius ) and their infesting ticks from Tunisia

“…In addition , Rickettsia spp. was identified, not only, in other several ixodid tick species as Amblyomma gemma (Koka et al, ), Dermacentor variabilis (3.6%) (Ammerman et al, ), Rhipicephalus sanguineus sensu lato (37.5%) (Khrouf et al, ) and Ixodes ricinus (38%) (Sfar et al, ), but also in the cat flea Ctenocephalides felis (0.3%) (Znazen et al, ), the Trombiculidae mites infesting rodents (32.46%) (Miťková et al, ) and the ovine blood‐sucking fly Melophagus ovinus (12.63%) (Liu et al, ). This may consolidate the major role of arthropod vectors, particularly ticks, in rickettsial spread (Parola et al, ).…”

“…The epidemiological cycle of Rickettsia species is mainly maintained by various animal hosts and wide range of haematophagous arthropods. Regarding ticks, the trans‐stadial and/or transovarial transmission modes were confirmed among the most predominant involved genera (Socolovschi, Bitam, Raoult, & Parola, ) including Ixodes (Katargina et al, ), Rhipicephalus (Pacheco et al, ), Hyalomma (Chisu et al, ), Amblyomma (Koka, Sang, Kutima, & Musila, ; Noda, Rodríguez, Miranda, Mattar, & Cabezas‐Cruz, ), Dermacentor (Ammerman et al, ) and Haemaphysalis (Portillo, Santibáñez, Santibáñez, Pérez‐Martínez, & Oteo, ).…”