Serological and molecular epidemiology of foot‐and‐mouth disease viruses in agro‐pastoralist livestock herds in the kachia grazing reserve, Nigeria

Abstract

The Kachia Grazing Reserve (KGR) is located in Kaduna state in north-western Nigeria and consists of 6 contiguous blocks housing 744 defined households (HH), all engaged in livestock keeping. It is considered as a homogenous epidemiological unit and a defined study area. In 2012, all cattle and sheep of 40 selected HH were sampled to determine sero-prevalence of antibodies to foot-and-mouth disease virus (FMDV) and of FMDV. The overall sero-prevalence of antibodies to the non-structural 3ABC protein (NSP-3ABC ELISA) was 28.9% (380/1,315) (30.6% cattle; 16.3% sheep), and in 4.5% (62/1,380) (5% cattle; 0.6% sheep) of the examined sera FMD viral RNA could be detected by real-time RT-PCR (rRT-PCR). Additionally, in 2012 and 2014 serum, epithelium and probang samples were collected from cattle in reported FMD outbreaks and the causative FMDVs were molecularly characterized. Approximately half (28/59) of the outbreak sera reacted positive in NSP-3ABC ELISA, and 88% (52/59) of the outbreak sera contained detectable viral RNA. Overall, antibodies against five FMDV serotypes (O, A, SAT1, SAT2 and SAT3) were detected by solid phase competitive ELISA with combinations of two or more serotypes being common. Of the 21 FMDVs that could be isolated 19 were sequenced and 18 were confirmed as SAT2 (lineage VII) while one was characterized as serotype O (EA-3 topotype).Phylogenetic analysis revealed a close relationship between Nigerian FMDV strains and strains in this region and even with strains in North-Africa. Our findings indicate that FMD constitutes an endemic health problem to cattle rearing in the agro-pastoralist community in the KGR and that the KGR is not a closed epidemiological unit.Insight into the local FMDV epidemiology and in the circulating FMDV serotypes/ strains is of support to the relevant authorities in Nigeria when considering the need for an FMD control policy to improve animal production in grazing reserves. K E Y W O R D Sfoot-and-mouth disease, Kachia Grazing Reserve, Nigeria, phylogeny, serology, virus characterization

Characterization of transboundary foot‐and‐mouth disease viruses in Nigeria and Cameroon during 2016

“…Foot‐and‐mouth disease viruses is endemic in Nigeria and Cameroon, and 5 topotypes within 4 serotypes of FMDV were detected in the current study (2014 and 2016), confirming previous studies (Ehizibolo et al, , , , ; Fasina et al, ; Ularamu et al, ). Frequent, poorly regulated animal movement between Nigeria, Cameroon, and neighbouring West and Central African countries (Niger, Chad, Benin) facilitates FMDV circulation within the region.…”

“…Three serotypes (O, A and SAT1) were associated with outbreaks in 2016, whereas SAT2 was detected in a 2014 outbreak. This finding is consistent with recent studies in Nigeria (Ehizibolo et al, , , , ; Ularamu et al, ) and Cameroon (Bertram, Bravo de Rueda, et al, ; Bertram, Delgado, et al, ; Bronsvoort et al, ; Ludi et al, ), indicating the continued presence of multiple FMDV serotypes (O, A, SAT1, SAT2)/topotypes/lineages (O/EA‐3, O/WA, A/AFRICA/G‐IV, SAT1/X, SAT2/VII) over recent years and the complex epidemiological situation of the disease in these regions.…”

Complex Circulation of Foot-and-Mouth Disease Virus in Cattle in Nigeria

“…Within this group, we observed ∼1% of difference in VP1 nt identity per year. One isolate from Plateau (2017) clustered with other Nigerian isolates from 2016 (14) and with an isolate from Ghana (GHA, 2018), another country in West Africa, and with an isolate from 2014 from the Kachia Grazing Reserve in the neighboring Kaduna State, i.e., O/NIG/2/14 (13). Between this isolate from Plateau (2017) and the other isolates from 2017, we observed ∼95% VP1 nt identity.…”

“…FMD is considered endemic in domesticated livestock in Nigeria, and four different serotypes of FMDV are circulating at present: A, O, SAT1, and SAT2 (11)(12)(13)(14)(15). Remarkably, FMDV serotype SAT1 was never isolated from clinical cases of FMD in Nigeria in the period between 1981 and 2015 (12,16).…”

“…As in many other countries in sub-Saharan Africa, livestock movement is not controlled and FMD spreads in Nigeria due to unrestricted local and transboundary trade and due to the pastoral farming system which is characterized by long distance migration of livestock in search for greener pasture and watering points. Apart from trade practices and transhumance activities, other factors that contribute to the spread of FMD in Nigeria may be political conflict, which increases movements of nomadic people and their herds, conflict between arable farmers and pastoralists resulting from competition for resources, and the presence of game reserves as a possible source of infection for susceptible livestock (9,13).…”