Seroprevalence of Foot and Mouth Disease virus antibodies in trade cattle ( Bos indicus ) in Kwara state of Nigeria

Aim: A serological survey for the detection of Foot and Mouth Disease virus antibodies in trade cattle was conducted to determine the seroprevalence of Foot and Mouth Disease (FMD) in the Kwara state of Nigeria. Materials and Methods: A cross-sectional study based on convenient sampling for bovine blood was carried out in 5 cattle markets (Offa, Bode Sadu, Ilesha baruba, Ilorin, Ajasse) across five local government areas in Kwara State amongst cattle with unknown history of FMD vaccination over a period of August-September-October, 2011. The sera obtained were screened R using NS-Blocking ELISA kit (PRIOCHECK ). Results: Out of the 450 cattle (268 cows and 182 bulls) screened for FMD antibodies, sero-positivity was highest amongst cows 62.13%. Percentage distribution of sero-positive reactors by location showed Ilesha baruba, Ilorin and Offa had 27.14%, 23.80% and 13.33% respectively, while seropositivity amongst bulls was 37.86%, highest occurrence in Offa 30.46% and least in Ilesha baruba 14.84%. FMD carriers according to breeds showed 77.21% white Fulani (Bunaji) was positive over the other breeds. The sex, location and breed was significant by chi square p<0.05. FMD seropositivity according to age indicated young cattle within 6 months-2years group had the highest occurrence 75.14% over the adult group 24.85%. Conclusion: The occurrence thus confirms FMD endemicity and susceptibility of all sex, ages, and various breed of unvaccinated trade cattle especially amongst white Fulani, young cows within the local markets and those from neighboring West African countries. Thus, circulating FMDV strains responsible for this seropositivity should be established in order to design appropriate control strategy to limit FMD effect.


Introduction
A, O, SAT 1 and SAT 2 have been responsible for disease outbreaks in Northern Nigeria as these Foot and mouth disease (FMD), is a highly serotypes have been in circulation in the last 54 years contagious viral disease of both domestic and wild   [8; 9].The inaccurate reported endemicity cloven hoofed animals characterized by high morbidity of the disease [4] is associated to none reporting of and decreased livestock productivity, with affected disease outbreaks [5] due to inefficient disease countries being excluded from international animal reporting system in the country [10] and this has made trade [1].FMD virus (FMDV) which consists of a planning for prevention and control of the disease very single-stranded, positive-sense RNA genome, difficult [7].Despite the endemicity of Foot and mouth belonging to the family Picornaviridae that encodes a disease, there is paucity of reported information as large polyprotein, which is then cleaved into the regards the dynamics and status of FMD in Kwara state structural proteins and nonstructural proteins [2].The where a high concentration of cattle herds is found.seven distinct serotypes include Type A, O, C This was associated with insufficient control efforts (European types), South African types (SAT SAT 1, 2, which had made the disease endemic with mild course SAT ) and Asiatic Type.Cumulative incidence of FMD 3 and mortality [11].Serological demonstration of serotypes showed that six of the seven serotypes (O, A, specific antibodies to non-structural proteins in non-C, SAT-1, SAT-2, SAT-3) have occurred in Africa [3].
vaccinated animals, where a vesicular condition is In Nigeria, previous reports confirm endemicity of present, is sufficient for a positive diagnosis.This is FMD with serious economic losses due to serotypes A, particularly useful in mild cases or in cases where and SAT 2 [4; 5], serotypes O, SAT1 and SAT2 [6].
epithelial tissue cannot be collected [12].The detection SAT1 and SAT 2 serotypes antibodies were also of antibodies to the NSP 3ABC of FMDV has been demonstrated [7].Reviews of FMD reported serotypes shown to be sensitive and specific method to differentiate between infection and vaccination [13][14][15][16][17]. NSPs, unlike structural proteins, are highly conserved and therefore, are not serotype specific and as a consequence, the detection of these antibodies is not serotype restricted [18].Enzyme-linked of the cattle marketers as earlier conducted [22].The immunosorbent assay (ELISA) test is a more specific, ages were designated in Hausa as Marki (male)/ Marka sensitive, and fast and is independent of cell cultures (female)/Wege (Fulani) as age from 6 months-2years.and usually not affected by anti-complement factors Bijimi (male)/Karsana (female) in Hausa while Nghari present in the cattle serum.The ELISA can be performed (Fulani) as from 3-5years above.Age was grouped into with inactivated antigens, thus requiring less restrictive two categories: 6 months -2 years and 3 years and biocontainment facilities [19].Hence serologic above.quantification of FMD antibody level to 3-ABC non-Sample collection: Five milliliters of blood was structural protein can be used to establish the disease collected from each well restraint animal through the burden [14].This premised the use of PRIOCHECK jugular vein by using 10 ml syringe and 18G needle FMD-3ABC NS protein ELISA to establish the into 5 ml sample vials and kept at room temperature at prevalence of FMD in Kwara State which hosts the o an angle of 45 C for 6-8 hrs to allow for clotting of Ilesha baruba cattle international market in Baruten blood and sera separation.The sera were aspirated into LGA that shares an international border with Benin new set of 5 ml plastic tubes, labeled, stored on ice pack Republic.
and transported to the laboratory, National Veterinary o

Materials and Methods
Research Institute, Vom where it was kept at -20 C until used.this confirmed that such cattle had been recently [26].This variation maybe attributed to high number of exposed to FMD within the minimum of <40> days as female sampled at various locations as more cows are previously documented [16].Thus considered as FMD seemly found in markets following culling probably carriers showing no clinical signs but have evidence of due to failing reproductive performance.detectable antibodies giving an overall prevalence of The distribution of sero-positive FMD carriers 75.11% using ELISA kit (PRIOCHECK).This kit according to breeds in this study (Table II) showed that detects antibodies directed against the non-structural 77.21% white Fulani [Bunaji] was positive which 3ABC protein of FMDV, confirming FMDV infected indicated the highest occurrence over the other breeds animals independent of animal vaccination status as of cattle such as Red bororo [Rahaji] and Sokoto vaccines consist of (partly) purified structural proteins Gudali [Bokoloji].This finding could be associated of FMD virus and therefore vaccinated animals only with the predominance of white Fulani breed within elicits antibodies directed against the structural cattle markets and ultimately their availability at time proteins of the virus, which is the basis of this of sampling.Hence, this observation would require discrimination between infected and vaccinated further elucidation to establish the possibility of any animals.
breed predisposition with FMD.Overall prevalence of 75.11% in this survey is Seropositivity of FMD according to age (Table -3) higher than National surveillance of FMD in which showed that young cattle within 6 months-2 years seroprevalence of 55.5% was reported [23], and also group had the highest occurrence 75.14% over the 64.30% documented [24] in nomadic herds from adult group.These young cattle were most poised for Plateau state as well as 56.3% in Jos south LGA in trade as their heavy availability in the markets could be Plateau state [11] .The increased prevalence found in associated with affordability and high turnover.This this study compared to previous studies may be may also have fast tracked migration and contact with associated with extensive movement of livestock,high other FMD exposed cattle that suffered infection from rate of contact between animals at livestock markets, multiple serotypes thus producing antibodies against common grazing places as well as at watering point all serotypes of FMD.This seroprevalence of FMD along cattle routes as earlier suggested [23] especially association with age was similar to previous report [11] as this study area host the cattle internal market at that cattle within the age of 1-2yrs are more prone to Ilesha baruba, a Nigerian border town to Benin FMD.republic where these cattle are off loaded at Paraku and The ELISA employed in this study showed that trek through cattle routes over a three day journey to the 112 sera was negative [PI% <50%], 69 sera as weak market for on ward distribution to other part of Nigeria.
positive [PI% 50 -70%] and 269 strong positive [PI% However, the 72.62% evidence of FMD non-structural >70] (Table -4).This High percentage occurrence of protein antibodies reported for cattle in some states positive sera indicated poor vaccination control especially in the North West and North Eastern Nigeria attempts amongst Nigerian local and trade cattle along [25] connotes this finding probably as those areas were the West Africa sub region as this technique screened Nigerian border towns and first portal of entry for trade off vaccinated cattle thus clarifying the doubtful cattle from East and Central Africa.
vaccination status of the cattle during this survey.This The distribution of sero-positive reactors by population of cattle with unknown FMD vaccination location in different Local Government Areas in the history had made the disease endemic with mild course state (Fig. 1) indicated that Ilesha baruba LGA recorded and mortality as earlier reported [11].Previous studies the highest occurrence of 22.48% (76/338).This was demonstrated antibodies to SAT1 and SAT 2 serotypes closely followed by Ilorin East LGA 20.71% (70/338).
[7] however, serotyping of positive sera in this study is Ilesha and Ilorin showed association with the ongoing.occurrence of FMD.This could be attributed to influx

Conclusion and recommendation
of large number of cattle to meet up high demand for meat to satisfy the robust human population in the state This study provides preliminary information on capital (Ilorin) as well as heavy traffic and the prevalence and endemicity as well as risk factors congregation of cattle from different sources at the associated with FMD as FMD carriers was found in all Ilesha cattle market, especially those from West sex, ages and breeds of unvaccinated trade cattle in African trade route thus contaminating environment kwara State of Nigeria as well as those imported by with FMDV.The variation of occurrence by location cattle trading partners along the West African coast.was similar to previous report [11].
This confirms FMD as a transboundary cattle disease.strains are also advocated.
12. Hamblin, C., Barnett, I. T. R. and Hedger, R.S. (1986) A new enzyme linked immunosorbent assay (ELISA) for the Authors' contributions detection of antibodies against foot-and-mouth disease virus,

Ethical approval: The research procedure was approved by the staff and postgraduates seminar Serological assay using FMDV-NS ELISA: FMDV
50% was considered negative and it was The distribution of sero-positive FMD carriers interpreted that the animal tested had not been exposed according to breeds in this study (Table-2) showed that to FMD for 40 days.A PI of > 50% was considered out of the 306 white Fulani (Bunaji) sampled 77.21% positive and recent exposure <40> days to FMD.More (261/338) was positive which indicated the highest specifically, a PI value of > 50% but < 70% was occurrence over the other breeds of cattle.Red bororo considered a weak positive result and a PI value of > (Rahaji) and Sokoto Gudali (Bokoloji) had 11.83% 70% was considered a strong positive result[16].(40/338) and 10.94% (37/338) respectively.However, Statistical analysis: The positive reactors as well as the the seroprevalence of FMD in association with breed associated risk factors were expressed as simple showed statistical significance (P<0.05) with white 5gateway' State because of its location between the On the second day, the test plates were coated with Northern and Southern parts of Nigeria.This State is a 3ABC specific monocolonal antibody (mAb), using first order administrative division located on the 80µl ELISA buffer to wells of the plates.Twenty longitude N 8° 30' 0'' and latitude E 5° 0' 0'' 8.5/ 5 (Geo microliter (20µl) negative control was dispensed in Name Id : 2332785) [20] with 16 Local Government wells A1 and B1, and 20ul of weak positive control was Areas namely: Asa, Baruten, Edu, Ekiti, Ifelodun, dispensed in wells C1 and D1 while 20µl of positive Ilorin East, Ilorin West, Irepodun, Isin, Kaiama, Moro, control was dispensed in wells E1 and F1.The test was Offa, Oke-Ero, Oyun, Ilorin south and Pategi.This performed by dispensing the 20µl of test samples to the state shares common boundaries with Niger and Kebbi remaining wells of a Test plates, sealed using enclosed States to the North, Oyo, Ondo and Edo States to the plate sealer and shaked gently prior to overnight South, Benue, Plateau and Federal Capital Territory to o incubation at 22+3 C.After incubation the plates were the East [21].It maintains an international boundary washed six times with 200-300µl of washing solution with the Republic of Benin to the West.and 100ul conjugate was added to all wells.The test plates were sealed using enclosed sealers and incubated Study design: A cross-sectional study was designed
Sex distribution indicated serpositivity was Thus, circulating FMDV strains responsible for this highest amongst female (cows) 62.13% (210/338) with seropositivity should be established in order to design highest occurrence in Ilesha 27.14% (57/210), Ilorin appropriate control strategy to limit FMD effect.23.80% (50/210) which showed association with It is therefore, recommended that continuous FMDV antibody reactors.However, contrast previous surveillance and quarantine of cattle within herds and study that stated no difference in risk association with inter-state and national borders should be encouraged.FMD transmission between male and female animals Eradication strategy through compulsory vaccinations disease in cattle in Jos south local government area of Plateau using cost-effective vaccines made of circulating state.Vom J. Vet.Sci.8: 16-21.