STUDIES OF BOVINE FOOT AND MOUTH DISEASE IN KWARA STATE-NIGERIA

STUDIES OF BOVINE FOOT AND MOUTH DISEASE IN KWARA STATE-NIGERIA

Abstract:

Studies of Bovine Foot and Mouth Disease in Kwara state-Nigeria were conducted to establish Foot and Mouth Disease Virus (FMDV) serotypes, occurrence, dynamics, associated hematological variations as well as knowledge, attitude and practice (KAP) of Fulani herdsmen. A purposive study was conducted in twelve (12) cattle herds from 15 outbreaks over a period of 4 months (December, 2010 – March, 2011) in Ilesha Baruba. In the second phase, serological survey of FMD antibodies was carried out on sampled cattle with unknown FMD vaccination history in cattle markets and slaughter slabs in five local government areas (Offa, Bode Sadu, Ilesha Baruba, Ilorin, Ajasse) over a period of 3 months (August-September-October, 2011). Outbreak blood, epithelial tissues, and sera samples obtained randomly were stored and processed in accordance with standard methods. FMD Participatory appraisal was conducted during sampling and all outbreak locations were geo-referenced in accordance with standard methods. Sera were subjected to NS-ELISA and SPC-ELISA tests, while epithelial tissues were subjected to RNA extraction, Real-Time Polymerase Chain Reaction (rRT-PCR) and sequencing of positive amplicons in accordance with standard protocols. Geo-spatial and participatory appraisal analysis was conducted on obtained data. The blood was subjected to standard hematological analysis. Out of 450 cattle screened 75.11% (338) were positive for FMD antibodies. Overall sero-positivity was highest amongst cows (78.4%), White Fulani (Bunaji) breed (85.3%), young cattle (85.2%) and Ilesha Baruba district (84.4%) which showed FMD association p<0.05 by Chi square analysis. FMD serotypes amongst trade cattle were A, O, SAT1, and SAT2. However, multiple serotype of O and A, A and SAT2 as well as O and SAT2 were also observed. Vaccination evidence was observed in some sero-positive trade cattle. NS-ELISA sero-diagnosis in outbreak herd representatives ix showed FMD evidence in 71.11% (64) cattle with overall incidence of 19.8% amongst cows (75.5%), White Fulani (Bunaji) breed (73.2%), young cattle (74.4%). The occurrence rates of serotype O, A and multiple serotype of O and A and O and SAT 2 in FMD outbreaks were 83% (53), 7.8% (5), 4.7% (3) and 1.6% (1) respectively, while vaccine strains O and SAT 2 occurred at the rates of 1.6% (1) each. No FMD virus RNA extract was obtained from blood samples. The blood beta-actin ranged from Ct=30 to 34. Real-time RT-PCR assay showed six (6) positives (Ct values =15.28 to 26.42) and one negative. Direct product sequencing confirmed SAT2 serotype was closely related to SAT2 isolate of LIB/7/2003 sequence. RT-PCR product cloned in pGEM-T easy vector for sequencing confirmed serotype A isolate closely related with A/NIG/21/2009 isolate, though multiple NIG/2009 sequences were also identified. Obtained sequence isolates were named A/NIG/1/2011 and SAT2/NIG/3/2011. Geo-spatial distribution of FMD outbreaks and serotypes indicated inter-connectivity of towns, road network, rivers and forest as possible features that enhanced virus spread. Cattle outbreak locations in 500m-1km buffer zones further confirmed road network, rivers and clustered (NNI Ratio=0.095054) herds and outbreaks in Ilesha Baruba district as potential facilitators of virus spread. Appraisal responses were independent and statistically significant by chi square (P<0.05) except responses on source of water, season of occurrence and type of medication. Hematological picture observed outbreak sero-positive cattle showed anemia characterized by anisocytosis and poikilocytosis, leucopenia and leucocytosis with no association (P>0.05) with FMD. The disease serotype endemicity and susceptibility in all sex, ages and breeds of both unvaccinated and vaccinated trade cattle especially amongst white Fulani, young cows within Nigerian local markets and Fulani herds were highlighted. In conclusion, findings of this study confirmed FMD predicament amongst Fulani livestock pastoralists which x requires proactive intervention plan while hematological variations also provided preliminary information on some diagnostic parameters associated with natural FMD outbreak. Thus, established circulating FMDV serotypes responsible for this sero-positivity should be used to design control strategy to limit FMD economic losses in livestock industry. In addition, continuous geo-spatial surveillance and quarantine of cattle within herds and inter-state and national borders should be encouraged

STUDIES OF BOVINE FOOT AND MOUTH DISEASE IN KWARA STATE-NIGERIA