Rickettsia africae and Rickettsia massiliae in ixodid ticks infesting small ruminants in agro-pastoral settlements in Plateau State, Nigeria.

Arthropods, especially ixodid ticks, have been incriminated in the epidemiology of Spotted Fever Group rickettsioses globally leading to an increasing spectrum of emerging and re-emerging zoonoses with attendant consequences on trade and tourism. The objective of this study was to determine the role of ixodid ticks infesting small ruminants in Plateau State, Nigeria, in the epidemiology of Spotted Fever Group Rickettsiae (SFGR) in the study area. DNA from 130 out of 323 ixodid ticks collected from 179 goats and 121 sheep owned by agro-pastoralists in Plateau State were screened for the evidence of SFGR by molecular methods. Six tick species from four genera were identified: Amblyomma, Hyalomma, Rhipicephalus (Boophilus) and Rhipicephalus. Rhipicephalus sanguineus sensu lato (s.l.) was the predominant (54.5%) species among collected ticks. Tick infestation was significantly associated with the species of small ruminants, the sex of the animals and the sampling locations except for Jos South. Conventional PCR targeting the 381 bp of the citrate synthase (gltA) and 820 bp of the outer membrane protein B (ompB) genes detected DNA of SFGR in nine and eight samples, respectively. Sequence analysis revealed that five sequences obtained from Amblyomma variegatum were 99-100% identical to Rickettsia africae and three sequences from Rh. sanguineus (s.l.) were 100% identical to Rickettsia massiliae reported from Spain. To our knowledge, this is the first report of the detection of R. africae DNA in Am. variegatum collected from small ruminants in Plateau State. Ixodid ticks infesting small ruminants in Plateau state harbor DNA of SFGR with potential veterinary and public health implications.

Absence of DNA and anti-leishmanial antibodies in dogs (Canis familiaris) in Plateau state, Nigeria.

Dogs are important sentinels for the surveillance of some zoonotic diseases including human leishmaniasis. To obtain information on the role of dogs in the epidemiology of leishmaniasis in Nigeria, 98 sera and 204 DNA samples obtained from dogs were screened for anti-leishmania antibodies and DNA of Leishmania spp. using the enzyme linked immunosorbent assay (ELISA) and PCR, respectively. Initially, three out of the 98 sera samples had ELISA borderline optical density (OD) values and were retested. Two out of the three samples turned out to be negative while one sample gave yet a borderline OD value on a retest. A real time polymerase chain reaction (RT-PCR) targeting the 120-bp fragment of the minicircle kDNA of Leishmania spp. run on DNA extracted from EDTA preserved blood of the borderline positive serum failed to amplify the 120-bp sequence of Leishmania spp. In the second phase of the study, 204 DNA from dog blood samples were subjected to conventional PCR targeting the 300-350 bp of the internal transcribe spacer region 1 (ITS1) of Leishmania spp. None of the samples could be amplified (n = 204, 0%). Our study suggests that L. infantum is not prevalence in Jos, Plateau State, Nigeria and this should be confirmed using a larger sample of local dogs tested using PCR methods in lymphoid tissue samples.

Serosurvey for Toxoplasma gondii in dogs in Maiduguri, Borno State, Nigeria.

The seroprevalence of Toxoplasma gondii (T. gondii) antibodies in dogs in Maiduguri, the capital of Borno State, Nigeria, was determined using the Latex Aagglutination Test (LAT). Antibodies (LAT titer > 1:64) to T. gondii were found in 42 (25%) of the animals examined. Antibody titers in positive dogs ranged from 1:64 (15 dogs) to 1:2048 (3 dogs). There was a significant statistical difference (P < 0.05) between age groups of dogs, the prevalence being higher in dogs > or = 3 years (chi2 = 13.73 P = 0.0002, OR 2.80 CI95% 1.28-6.13 P = 0.008). Pure Alsatians and their crosses were less likely to be seropositive (OR cross breed 0.28 CI95% 0.13-0.61 P = 0.001, OR Alsatian 0.16 CI95% 0.04-0.58 P = 0.002). The high prevalence of T. gondii infection that we found in dogs suggests a need for a larger survey to determine the national prevalence and identify possible risk factors in different agro-climatic zones. Such a study will help in formulating nation-wide control measures for toxoplasmosis.