Serological Evidence of Antibodies to Rift Valley Fever Virus in Wild and Domestic Animals in Bauchi State, Nigeria.

Rift Valley fever (RVF) is an arthropod-borne zoonotic disease responsible for severe outbreaks in livestock and humans with concomitant economic losses in many countries in sub-Saharan Africa. The study, therefore, investigated the seroprevalence of the Rift Valley fever virus (RVFV) among wild and domestic animals. Blood samples were collected between 2013 and 2015 from 106 wild animals, 300 cattle (Bos indicus), and 200 horses (Equus caballus), respectively, in Yankari Game Reserve (YGR) and Sumu Wildlife Park (SWP) in Bauchi state, Nigeria. Harvested sera from blood were evaluated for the presence of anti-RVFV IgM/IgG antibodies. The overall seroprevalence in cattle was 11.3% (p = 0.677; 95% CI: 0.624-0.730) and in wildlife was 8.5% (p = 0.006; 95% CI: 0.00-0.60). The diversity of wildlife species sampled indicated seropositivity of 36.0% in waterbuck (Kobus ellipsiprymus), 25.0% in elephant (Loxodonta africana), 12.5% in eland (Taurotragus oryx), and 8.3% in wildebeest (Connochaetes taurinus). Whereas, samples from zebra (Equus quagga crawshayi), kudu (Tragelaphus strepsiceros), and hartebeest (Alcelaphus buselaphus caama) did not show detectable antibodies to RVFV, and seroprevalence in female (15.0%) wildlife species was higher than in males (4.5%) (p = 0.061). Classification of cattle into breed and sex showed no significant difference in seropositivity. Seropositivity of 12.0% was observed in White Fulani, 12.1% in Red Bororo, and 7.8% in Sokoto Gudali breeds of cattle (p = 0.677). Whereas, seropositivity of 13.6% was observed in females and 6.4% observed in males (p = 0.068). This study indicated the presence of antibodies to RVFV among some wild animals and cattle in the absence of a reported outbreak in the study area. The circulation of RVFV in the study area may pose a significant health risk to livestock, wildlife, and humans. Therefore, surveillance for RVFV should be intensified targeting mosquito vectors and humans in Bauchi state, Nigeria.

Seroprevalence of Foot and Mouth Disease Virus Infection in Some Wildlife and Cattle in Bauchi State, Nigeria.

Foot and mouth disease (FMD) is an important transboundary viral disease of both domestic and wild cloven-hoofed animals characterized by high morbidity with devastating consequence on the livestock worldwide. Despite the endemic nature of FMD in Nigeria, little is known about the epidemiology of the disease at the wildlife-livestock interface level. To address this gap, blood samples were collected between 2013 and 2015 from some wildlife and cattle, respectively, within and around the Yankari Game Reserve and Sumu Wildlife Park in Bauchi State, Nigeria. Wild animals were immobilized using a combination of etorphine hydrochloride (M99® Krüger-Med South Africa) at 0.5-2 mg/kg and azaperone (Stresnil®, Janssen Pharmaceuticals (Pty.) Ltd., South Africa) at 0.1 mg/kg using a Dan-Inject® rifle (Dan-Inject APS, Sellerup Skovvej, Denmark) fitted with a 3 ml dart syringe and for reversal, naltrexone (Trexonil® Kruger-Med South Africa) at 1.5 mg IM was used, and cattle were restrained by the owners for blood collection. Harvested sera from blood were screened for presence of antibodies against the foot and mouth disease virus (FMDV) using the PrioCHECK® 3ABC NSP ELISA kit, and positive samples were serotyped using solid-phase competitive ELISA, (IZSLER Brescia, Italy). Out of the 353 sera collected from cattle and wildlife 197 (65.7%) and 13 (24.5%) (P < 0.05), respectively, tested positive for antibodies to the highly conserved nonstructural 3ABC protein of FMDV by the FMDV-NS blocking ELISA. Classification of cattle into breed and sex showed that detectable antibodies to FMDV were higher (P < 0.05) in White Fulani 157 (72.8%) than in Red Bororo 23 (39.7%) and Sokoto Gudali 17 (33.3%) breeds of cattle, whereas in females, detectable FMDV antibodies were higher (P < 0.05) 150 (72.8%) than in males 47 (50.0%). In the wildlife species, antibodies to FMDV were detected in the waterbucks 2 (28.6%), elephant 1 (25.0%), wildebeests 4 (33.3%), and elands 6 (25.0%). Four serotypes of FMDV: O, A, SAT 1, and SAT 2 were detected from the 3ABC positive reactors in waterbucks, elephants, wildebeests, and elands. The results showed presence of antibodies to FMDV in some wildlife and cattle and suggested that wildlife could equally play an important role in the overall epidemiology of FMD in Nigeria. FMD surveillance system, control, and prevention program should be intensified in the study area.

Phenotypic resistance of indigenous goat breeds to infection with Haemonchus contortus in northwestern Nigeria.

Two studies at the National Animal Production Research Institute (NAPRI), Zaria, Nigeria, compared Red Sokoto (RS), Sahelian (SG), and West African Dwarf (WAD) goats after experimental or natural infection with Haemonchus contortus. In the first study, 20 RS, 17 SG, and 14 WAD kids were challenged at 6 months of age with 5000 L3 larvae of H. contortus. Fecal egg counts (FEC), packed cell volumes (PCV), and body weights (BW) were recorded 0, 28, 35, and 42 days after infection. The FEC and PCV were affected only by time of measurement. In the second study, 322 RS and 97 SG kids were produced at NAPRI over 3 years, weaned at 4 to 6 months of age, dewormed, returned to contaminated pastures, and evaluated 28 and 35 days later. Effects of breed, year, breed × time interaction, and breed × year interaction were observed for PCV and BW; FEC was only affected by time of measurement, year and breed × year interaction. The FEC were larger and PCV were smaller on day 35 compared to day 28 and in year 2 compared to years 1 and 3. The SG kids were notably smaller than RS kids in year 2, with higher FEC and lower PCV, but FEC were larger for RS kids in years 1 and 3. Differences in parasite resistance among these Nigerian goat breeds were therefore small and likely reflected underlying differences in growth, development, and disease history.

Seroprevalence of Brucella antibodies in camels in Katsina State, Nigeria.

A cross-sectional study was carried out to determine the status of Brucella infection in one-humped (Dromedary) camels in the North and Central senatorial districts of Katsina State, Nigeria. Nine hundred and eighty serum samples from live and slaughtered camels were tested. Modified Rose Bengal plate test (RBPT) and serum agglutination test (SAT) with ethylenediaminetetraacetic acid, (EDTA) were used as screening and standard tests, respectively. The prevalence of Brucella antibodies were 110 (11.2%) and 103 (10.5%) for RBPT and SAT, respectively. Of the 472 and 508 serum samples tested from the herds and abattoirs, respectively, 63 (13.3%) and 47 (9.3%) were positive by RBPT while 62 (13.1%) and 41 (8.1%) were positive by SAT, respectively. Based on the results, it was concluded that Brucella antibodies were present in camels in the study area. Poor management practices and mixing of camels with other species of livestock as well as unrestricted movement of camels were proposed to be the reasons for the prevalence of the disease in the study area. In view of the public health importance of the disease, it is recommended that there is the need to develop a strategic plan to decrease spread of brucellosis in the study area.