Hematology and biochemical values in equines naturally infected with Theileria equi in Nigeria.

Equine piroplasmosis (EP) is a tick-borne disease of equines with resultant economic consequences. To date, little information is available regarding the effects of EP on the health of equids in Nigeria. Therefore, this study was carried out to ascertain the effects of natural sub-clinical infection with T. equi on the hematology and biochemical profiles of horses and donkeys. Blood and serum samples were subjected to hematology and serum biochemistry analyses, respectively. Data corresponding to PCR-positive (infected) and PCR-negative (uninfected) was computed to ascertain changes in any of the parameters. Hematological significant findings (P<0.001) in both horses and donkeys include decreased packed cell volume (PCV), red blood cell (RBC) count, hemoglobin (Hb) concentration, and white blood cell (WBC) counts in the infected group compared to the uninfected group. In horses, the PCV (%) and Hb (g/dL) values were 40.6±1.0 and 13.4±1.7 in the uninfected group compared with 30.8±0.6 and 10.1±0.3 in the infected group respectively and differs significantly (P<0.001). Similarly, in the donkeys, the PCV (%) and Hb (g/dL) values were 32.2 ± 0.5 and 10.5 ± 0.2 in the uninfected group compared with 28.5±0.7 and 9.5±0.2 in the infected group respectively with significant difference (P<0.001). Additionally, we observed a slight decrease in WBC counts (×103/µL) in the infected group in horses (9.9±0.4) and donkeys (10.2±4.3) compared with 10.5±2.0 and 13.0±0.8 from the uninfected respectively. Serum biochemical profiles revealed slight increase in the levels of total proteins principally the globulin fractions in the infected group in both equids. The findings from this study will be helpful in the diagnosis, prognosis, and treatment evaluation of equines in Nigeria.

Serosurvey for equine piroplasms in horses and donkeys from North-Western Nigeria using IFAT and ELISA.

Equine piroplasmosis is caused by apicomplexan parasites, namely, Babesia caballi and Theileria equi, which are transmitted to equids principally through ticks. To ascertain the exposure of equines to agents of equine piroplasms, we tested serum samples collected from horses (n = 272) and donkeys (n = 170) in North-Western Nigeria for the presence of antibodies against B. caballi and T. equi using IFAT and ELISA. The seroprevalence of T. equi in the horses determined using IFAT and ELISA was 48.89% and 45.96%, respectively, while for B. caballi, it was 6.3% and 0.4%, respectively. For T. equi, the seroprevalence based on IFAT and ELISA results in donkeys was 14.1% and 2.9%, respectively, while for B. caballi, the seroprevalence was 2.4% and 0.6%, respectively, for ELISA and IFAT. Mixed infection detected in the horses using IFAT and ELISA was 5.5% and 0.4%, respectively, while no mixed infection was observed in the donkeys. The seroprevalence of T. equi was significantly (P < .0001) higher than that of B. caballi in both horses and donkeys. Comparatively, the IFAT detected a greater number of piroplasm seropositive animals than ELISA, indicating a difference in their diagnostic accuracy. Findings from this study confirm the existence of equine piroplasms in both horses and donkeys in North-Western Nigeria and highlights the need for robust and effective control measures against the disease.

Equine piroplasmosis: an insight into global exposure of equids from 1990 to 2019 by systematic review and meta-analysis.

Equine piroplasmosis (EP) is a tick-borne disease of economic importance, relevant in the international movement of equids. The causative agents are at least two apicomplexan protozoan parasites Babesia caballi and Theileria equi. To date, there is no study that estimates global and regional exposure of equids to EP. We therefore conducted a systematic review and meta-analysis to estimate the pooled prevalence and heterogeneity of EP using random-effects model. Six electronic databases were searched for publications on EP and assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A total of 66 eligible studies published between 1990 and 2019 and representing 24 041 equids were included. The overall pooled prevalence estimates (PPEs) of B. caballi was 22.3% (95% CI 21.7-22.8), while the overall PPE for T. equi was 29.4% (95% CI 28.7-30.0). The overall pooled prevalence due to co-infection with both parasites was 11.8% (95% CI 11.32-12.32). Also, subgroup analysis according to sex, age, diagnostic technique, equid species, region and publication years showed a substantial degree of heterogeneity across studies computed for both B. caballi and T. equi infections in equids. Awareness of the current status of EP globally will alert the relevant authorities and stakeholders where necessary on the need for better preventive and control strategies against the disease.

Molecular evidence of Babesia caballi and Theileria equi in equines and ticks in Nigeria: prevalence and risk factors analysis.

Babesia caballi and Theileria equi are biological agents responsible for equine piroplasmosis (EP). We conducted a robust and extensive epidemiological study in Nigeria on the prevalence and risk factors of EP. Blood (468, both horses and donkeys) and ticks (201 pools) were screened using polymerase chain reaction (PCR). DNA of equine piroplasms was observed in tick pools with B. caballi amplified in Rhipicephalus evertsi evertsi only [minimum infection rate (MIR) of 7.6%] while T. equi was observed in R. e. evertsi (MIR, 61.6%), Hyalomma dromedarii (MIR, 23.7%) and H. truncatum (MIR, 50.0%). Overall results showed that 196/468 (41.9%) animals were positive for equine piroplasms (both B. caballi and T. equi). The prevalence for T. equi was 189/468 (40.4%) compared to 7/468 (1.5%) for B. caballi. In the horses and donkeys, respectively, the prevalence for T. equi was (39.9%; 112/281) and (41.2%; 77/187) compared with (1.4%; 4/281) and (1.6%; 3/187) due to B. caballi. Our analysis showed that location (Jigawa state), Talon breed, horses used for work and reproduction, unsatisfactory husbandry practices, contact with other mammals are risk factors that associated positivity to T. equi infection in horses, whilst horses kept on intensive management appeared to be less prone to infection. On the other hand, Jangora breed of donkeys and location (Jigawa state) are risk factors to infection with T. equi in donkeys. Findings suggest the persistence of EP in equids and ticks in Nigeria.

Prevalence and molecular characterization of ticks and tick-borne pathogens of one-humped camels (Camelus dromedarius) in Nigeria.

BACKGROUND: Ticks are hematophagous arthropods responsible for maintenance and transmission of several pathogens of veterinary and medical importance. Current knowledge on species diversity and pathogens transmitted by ticks infesting camels in Nigeria is limited. Therefore, the aim of this study was to unravel the status of ticks and tick-borne pathogens of camels in Nigeria. METHODS: Blood samples (n = 176) and adult ticks (n = 593) were collected from one-humped camels (Camelus dromedarius) of both sexes in three locations (Kano, Jigawa and Sokoto states) in north-western Nigeria and screened for the presence of Rickettsia spp., Babesia spp., Anaplasma marginale, Anaplasma spp. and Coxiella-like organisms using molecular techniques. All ticks were identified to species level using a combination of morphological and molecular methods. RESULTS: Ticks comprised the three genera Hyalomma, Amblyomma and Rhipicephalus. Hyalomma dromedarii was the most frequently detected tick species (n = 465; 78.4%) while Amblyomma variegatum (n = 1; 0.2%) and Rhipicephalus evertsi evertsi (n = 1; 0.2%) were less frequent. Other tick species included H. truncatum (n = 87; 14.7%), H. rufipes (n = 19; 3.2%), H. impeltatum (n = 18; 3.0%) and H. impressum (n = 2; 0.3%). The minimum infection rates of tick-borne pathogens in 231 tick pools included Rickettsia aeschlimannii (n = 51; 8.6%); Babesia species, (n = 4; 0.7%) comprising of B. occultans (n = 2), B. caballi (n = 1) and Babesia sp. (n = 1); Coxiella burnetii (n = 17; 2.9%); and endosymbionts in ticks (n = 62; 10.5%). We detected DNA of "Candidatus Anaplasma camelli" in 40.3% of the blood samples of camels. Other tick-borne pathogens including Anaplasma marginale were not detected. Analysis of risk factors associated with both tick infestation and infection with Anaplasma spp. in the blood indicated that age and body condition scores of the camels were significant (P < 0.05) risk factors while gender was not. CONCLUSIONS: This study reports low to moderate prevalence rates of selected tick-borne pathogens associated with camels and their ticks in north-western Nigeria. The presence of zoonotic R. aeschlimannii emphasizes the need for a concerted tick control programme in Nigeria.

Parasitic and zoonotic meningoencephalitis in humans and equids: Current knowledge and the role of Halicephalobus gingivalis.

Halicephalobus gingivalis is a saprophytic nematode parasite that causes a rare form of fatal meningoencephalomyelitis in equids, humans, and ruminants. This nematode has neurotropic activity, but has also been found in the kidney, liver, lungs, optic nerves and even heart of its host. Despite the zoonotic potential and severity of the disease, the epidemiology, pathogenesis, life cycle, and risk factors are poorly understood. Cases have been reported from several countries in Europe countries and North America but none is recorded in Africa except Egypt. This review looks at the historical overview, morphology, diagnosis, treatment and summary of reported cases in humans and equids. We recommend the parasitic helminthic infection in the differential list of meningoencephalitis involving humans and animals worldwide despite its rareness.