Canine and ovine tick-borne pathogens in camels, Nigeria.

In April 2008, whole blood samples were collected from 36 dromedary camels in Sokoto, North-western Nigeria. Following PCR and reverse line blotting, twenty-two samples (61%) resulted positive for Ehrlichia/Anaplasma spp. and three (8%) for Theileria/Babesia spp., with three (8%) cases of co-infections being found. Both sequence and BLAST analyses identified Ehrlichia/Anaplasma spp. and Theileria/Babesia spp. positive cases as Anaplasma platys and Theileria ovis, respectively. This is the first report of the detection of A. platys and T. ovis in camels from sub-Saharan Africa. The epidemiological relevance of this finding is enhanced by the close living of these animals with both dogs and small ruminants. The high prevalence detected for A. platys suggests a possible role of camels as carriers of this infection.

Tick-borne pathogens of zoonotic and veterinary importance in Nigerian cattle.

BACKGROUND: Ticks and tick-borne diseases undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. In this West African country, cattle are challenged by numerous tick species, especially during the wet season. Consequently, several TBDs are known to be endemic in Nigerian cattle, including anaplasmosis, babesiosis, cowdriosis and theilerioris (by Theileria mutans and Theileria velifera). To date, all investigations on cattle TBDs in Nigeria have been based on cytological examinations and/or on serological methods. This study aimed to ascertain the occurrence of tick-borne pathogens of veterinary and zoonotic importance in cattle in Nigeria using molecular approaches. METHODS: In October 2008, 704 whole blood samples were collected from indigenous cattle in the Plateau State, Nigeria. Analysis for tick-borne pathogens was conducted by means of PCR-based reverse line blotting (RLB) and sequencing targeting a panel of five genera of microorganisms (i.e. Babesia, Theileria, Anaplasma, Ehrlichia and Rickettsia spp.). RESULTS: In total, 561/704 (82.6%) animals were found infected, with 465 (69.6%) of them being infected by two or more microorganisms, with up to 77 possible combinations of pathogens detected. Theileria mutans was the most prevalent microorganism (66.3%), followed by Theileria velifera (52.4%), Theileria taurotragi (39.5%), Anaplasma marginale (39.1%), Anaplasma sp. (Omatjenne) (34.7%), Babesia bigemina (7.9%), Anaplasma centrale (6.3%), Anaplasma platys (3.9%), Rickettsia massiliae (3.5%), Babesia bovis (2.0%) and Ehrlichia ruminantium (1.1%). Calves were found significantly less infected than juvenile and adult cattle. CONCLUSIONS: This study provides updated, molecular-based information on cattle TBDs in Nigeria. The molecular approach employed allowed the diagnosis of numerous positive cases including carrier statuses, multiple infections and novel pathogen detections within the indigenous cattle population. Moreover, the RLB method here described enabled the detection of veterinary agents not only pertaining to bovine health, including also those of zoonotic importance. The high prevalence recorded for T. mutans, T. velifera, A. marginale, T. taurotragi and Anaplasma sp. (Omatjenne), suggests they may be endemically established in Nigeria, whereas the lower prevalence recorded for other microorganisms (i.e. A. centrale and B. bovis) highlights a less stable epidemiological scenario, requiring further investigations.