Outbreak investigations and molecular characterization of foot‐and‐mouth disease viruses circulating in south‐west Niger

In Niger, the epidemiological situation regarding foot‐and‐mouth disease is unclear as many outbreaks are unreported. This study aimed (i) to identify Foot‐and‐mouth disease virus (FMDV ) strains currently circulating in cattle herds, and (ii) to identify risk factors associated with Foot‐and‐mouth disease (FMD )‐seropositive animals in clinical outbreaks. Epithelial tissues (n  = 25) and sera (n  = 227) were collected from cattle in eight districts of the south‐western part of Niger. Testing of clinical material revealed the presence of FMDV serotype O that was characterized within the O/WEST AFRICA topotype. The antigenic relationship between one of the FMDV isolates from Niger (O/NGR /4/2015) and three reference vaccine strains was determined by the two‐dimensional virus neutralization test (2dmVNT ), revealing a close antigenic match between the field isolate from Niger and three FMDV serotype O vaccine strains. Serological analyses using a non‐structural protein (NSP ) test provided evidence for previous FMDV infection in 70% (158/227) of the sera tested. Multivariate logistic regression analysis revealed that only the herd composition (presence of both cattle and small ruminants) was significantly associated with FMDV seropositivity as defined by NSP ‐positive results (p ‐value = .006). Of these positive sera, subsequent testing by liquid‐phase blocking ELISA (LPBE ) showed that 86% (136/158) were positive for one (or more) of four FMDV serotypes (A, O, Southern African Territories (SAT ) 1 and SAT 2). This study provides epidemiological information about FMD in the south‐western part of Niger and highlights the complex transboundary nature of FMD in Africa. These findings may help to develop effective control and preventive strategies for FMD in Niger as well, as other countries in West Africa.     

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

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.     

Serotype Specificity of Antibodies against Foot‐and‐Mouth Disease Virus in Cattle in Selected Districts in Uganda

Uganda had an unusually large number of foot‐and‐mouth disease (FMD) outbreaks in 2006, and all clinical reports were in cattle. A serological investigation was carried out to confirm circulating antibodies against foot‐and‐mouth disease virus (FMDV) by ELISA for antibodies against non‐structural proteins and structural proteins. Three hundred and forty‐nine cattle sera were collected from seven districts in Uganda, and 65% of these were found positive for antibodies against the non‐structural proteins of FMDV. A subset of these samples were analysed for serotype specificity of the identified antibodies. High prevalences of antibodies against non‐structural proteins and structural proteins of FMDV serotype O were demonstrated in herds with typical visible clinical signs of FMD, while prevalences were low in herds without clinical signs of FMD. Antibody titres were higher against serotype O than against serotypes SAT 1, SAT 2 and SAT 3 in the sera investigated for serotype‐specific antibodies. Only FMDV serotype O virus was isolated from one probang sample. This study shows that the majority of the FMD outbreaks in 2006 in the region studied were caused by FMDV serotype O; however, there was also evidence of antibodies to both SAT 1 and SAT 3 in one outbreak in a herd inside Queen Elizabeth national park area.     

Serological Evidence Indicates that Foot‐and‐Mouth Disease Virus Serotype O,C and SAT1 are most Dominant in Eritrea

Foot‐and‐mouth disease (FMD) is endemic in Eritrea and in most parts of Africa. To be able to control FMD using vaccination, information on the occurrence of various foot‐and‐mouth disease serotypes in Eritrea is needed. In this cross‐sectional study, 212 sera samples were collected from FMD infected and recovered animals in Eritrea. These samples were tested for the presence of antibodies against FMD non‐structural proteins (NSP) and neutralizing antibodies against six of the seven (all but SAT 3) serotypes of FMD virus (FMDV). Of these, 67.0% tested positive to non‐structural protein antibodies in the FMD NS ELISA. By virus neutralization, FMDV serotype O antibodies were shown to be the most dominant (approximately 50%). Virus neutralization test results indicate that infection with serotype C and SAT 1 might have occurred, although there are no reports of isolation of these two serotypes. Because the samples were not randomly selected, further random serological surveillance in all age group animals is necessary both to estimate the prevalence of FMD in the country and to confirm the serological results with serotype C and SAT 1.     

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

Continuous surveillance for foot‐and‐mouth disease (FMD) in endemic settings such as West Africa is imperative to support improved local and regional control plans, with the long‐term goal of regional eradication. This paper describes the genetic characterization of FMD viruses (FMDV) obtained from outbreaks in Nigeria (n = 45) and Cameroon (n = 15) during 2016 and from archival samples (n = 3) retrieved from a 2014 outbreak in Nigeria. These viruses were analysed in the context of previously published FMDV sequences from the region. Four FMDV serotypes: O, A, SAT1 and SAT2, were detected. Phylogenetic analyses of the VP1 coding sequences indicate the continuity of FMDV serotype O East Africa‐3 (O/EA‐3), serotype A AFRICA genotype G‐IV (A/AFRICA/G‐IV) and serotype South African Territories (SAT) 2 lineage VII (SAT2/VII). The FMDV SAT1 topotype X (SAT1/X), which emerged in Nigeria in 2015, continued to be associated with outbreaks in the region during 2016, and SAT1 is reported for the first time from Cameroon. Additionally, a re‐emergence or re‐introduction of the serotype O West Africa (O/WA) topotype in Nigeria is described herein. Our findings indicate a consistent, pan‐serotypic relationship between FMDV strains detected in Cameroon and Nigeria. Additionally, FMDV strains from West Africa obtained in this study were genetically related to those occurring in East and North Africa. These phylogenetic relationships suggest that animal movements (pastoralism and/or trade) are important factors for virus spread across the African continent. These data provide critical baselines which are a necessary component of Stages 0 and 1 of the Progressive Control Pathway of FMD (PCP‐FMD). Specifically, characterizing the existing virus strains (risk) provides the basis for the comprehensive risk‐based control plan which is the requisite criteria for Nigeria's transition to Stage 2 of PCP‐FMD, and for coordinated regional control of FMD.     

Antibodies Against Foot‐and‐mouth Disease (FMD) Virus in African Buffalos (Syncerus caffer) in Selected National Parks in Uganda (2001–2003)

In East Africa, the foot‐and‐mouth disease (FMD) virus (FMDV) isolates have over time included serotypes O, A, C, Southern African Territories (SAT) 1 and SAT 2, mainly from livestock. SAT 3 has only been isolated in a few cases and only in African buffalos (Syncerus caffer). To investigate the presence of antibodies against FMDV serotypes in wildlife in Uganda, serological studies were performed on buffalo serum samples collected between 2001 and 2003. Thirty‐eight samples from African buffalos collected from Lake Mburo, Kidepo Valley, Murchison Falls and Queen Elizabeth National Parks were screened using Ceditest^® FMDV NS to detect antibodies against FMDV non‐structural proteins (NSP). The seroprevalence of antibodies against non‐structural proteins was 74%. To characterize FMDV antibodies, samples were selected and titrated using serotype‐specific solid phase blocking enzyme linked immunosorbent assay (ELISAs). High titres of antibodies (≥1 : 160) against FMDV serotypes SAT 1, SAT 2 and SAT 3 were identified. This study suggests that African buffalos in the different national parks in Uganda may play an important role in the epidemiology of SAT serotypes of FMDV.     

Serological and phylogenetic characterization of foot and mouth disease viruses from Uganda during cross‐sectional surveillance study in cattle between 2014 and 2017

Here, we report the results of a cross‐sectional study designed to monitor the circulation and genetic diversity of foot and mouth disease virus (FMDV) in Uganda between 2014 and 2017. In this study, 13,614 sera and 2,068 oral‐pharyngeal fluid samples were collected from cattle and analysed to determine FMDV seroprevalence, circulating serotypes and their phylogenetic relationships. Circulation of FMDV was evidenced by the detection of antibodies against non‐structural proteins of FMDV or viral isolations in all districts sampled in Uganda. Sequence analysis revealed the presence of FMDV serotypes A, O, SAT 1 and SAT 2. FMDVs belonging to serotype O, isolated from 21 districts, were the most prevalent and were classified into six lineages within two East African topotypes, namely EA‐1 and EA‐2. Serotype A viruses belonging to the Africa G‐I topotype were isolated from two districts. SAT 1 viruses grouped within topotypes I and IV and SAT 2 viruses within topotypes VII, IV and X were isolated from six and four districts respectively. Phylogenetic analysis of SAT 1 and SAT 2 sequences from cattle clustered with historical sequences from African buffalo, indicating possible interspecies transmission at the wildlife‐livestock interface. In some cases, Uganda viruses also shared similarities to viral strains recovered from other regions in East Africa. This 3‐year study period provides knowledge about the geographical distribution of FMDV serotypes isolated in Uganda and insights into the genetic diversity of the multiple serotypes circulating in the country. Knowledge of circulating FMDV viruses will assist in antigenic matching studies to devise improved FMDV control strategies with vaccination and vaccine strain selection for Uganda.     

Detection and Molecular Characterization of Foot and Mouth Disease Viruses from Outbreaks in Some States of Northern Nigeria 2013–2015

Control measures for foot and mouth disease (FMD) in Nigeria have not been implemented due to the absence of locally produced vaccines and risk‐based analysis resulting from insufficient data on the circulating FMD virus (FMDV) serotypes/strains. In 2013‐2015, blood and epithelial samples were collected from reported FMD outbreaks in four states (Kaduna, Kwara, Plateau and Bauchi) in northern Nigeria. FMDV non‐structural protein (NSP) seroprevalence for the outbreaks was estimated at 80% (72 of 90) and 70% (131 of 188) post‐outbreak. Antibodies against FMDV serotypes O, A, SAT1, SAT2 and SAT3 were detected across the states using solid‐phase competitive ELISA. FMDV genome was detected in 99% (73 of 74) of the samples from FMD‐affected animals using rRT‐PCR, and cytopathic effect was found in cell culture by 59% (44 of 74) of these samples. Three FMDV serotypes O, A and SAT2 were isolated and characterized. The phylogenetic assessments of the virus isolates showed that two topotypes of FMDV serotype O, East Africa‐3 (EA‐3) and West Africa (WA) topotypes were circulating, as well as FMDV strains belonging to the Africa genotype (G‐IV) of serotype A and FMDV SAT2 topotype VII strains. While the serotype O (EA‐3) strains from Nigeria were most closely related to a 1999 virus strain from Sudan, the WA strain in Nigeria shares genetic relationship with three 1988 viruses in Niger. The FMDV serotype A strains were closely related to a known virus from Cameroon, and the SAT2 strains were most closely related to virus subtypes in Libya. This study provides evidence of co‐occurrence of FMDV serotypes and topotypes in West, Central, East and North Africa, and this has implication for control. The findings help filling the knowledge gap of FMDV dynamics in Nigeria and West Africa subregion to support local and regional development of vaccination‐based control plans and international risk assessment.     

Characterization of SAT2 foot‐and‐mouth disease 2013/2014 outbreak viruses at the wildlife–livestock interface in South Africa

The Southern African Territories (SAT)‐type foot‐and‐mouth disease viruses (FMDV) are endemic to the greater Kruger National Park (KNP) area in South Africa, where they are maintained through persistent infections in African buffalo. The occurrence of FMDV within the Greater KNP area constitutes a continual threat to the livestock industry. To expand on knowledge of FMDV diversity, the genetic and antigenic relatedness of SAT2‐type viruses isolated from cattle during a FMD outbreak in Mpumalanga Province in 2013 and 2014 were investigated. Cattle from twelve diptanks tested positive on polymerase chain reaction (PCR), and molecular epidemiological relationships of the viruses were determined by VP1 sequencing. Phylogenetic analysis of the SAT2 viruses from the FMD outbreak in Mpumalanga in 2013/2014 revealed their genetic relatedness to other SAT2 isolates from topotype I (South Africa, Zimbabwe and Mozambique), albeit genetically distinct from previous South African outbreak viruses (2011 and 2012) from the same topotype. The fifteen SAT2 field isolates clustered into a novel genotype with ≥98.7% nucleotide identity. High neutralization antibody titres were observed for four 2013/2014 outbreak viruses tested against the SAT2 reference antisera representative of viruses isolated from cattle and buffalo from South Africa (topotype I) and Zimbabwe (topotype II). Comparison of the antigenic relationship (r₁ values) of the outbreak viruses with reference antisera indicated a good vaccine match with 90% of r₁ values > 0.3. The r₁ values for the 2013/2014 outbreak viruses were 0.4 and above for the three South African vaccine/reference strains. These results confirm the presence of genetic and antigenic variability in SAT2 viruses and suggest the emergence of new variants at the wildlife–livestock interface in South Africa. Continuous characterization of field viruses should be performed to identify new virus strains as epidemiological surveillance to improve vaccination efforts.     

Foot‐and‐mouth disease virus serotype SAT1 in cattle,Nigeria

The knowledge of foot‐and‐mouth disease virus (FMDV) dynamics and epidemiology in Nigeria and the West Africa subregion is important to support local and regional control plans and international risk assessment. Foot‐and‐mouth disease virus serotype South African territories (SAT)1 was isolated, identified and characterized from an FMD outbreak in cattle in Nigeria in 2015, 35 years after the last report of FMDV SAT1 in West Africa. The VP1 coding sequence of the Nigerian 2015 SAT1 isolates diverges from reported SAT1 topotypes resulting in a separate topotype. The reporting of a novel FMDV SAT1 strain in the virus pool 5 (West and Central Africa) highlights the dynamic and complex nature of FMDV in this region of Africa. Sustained surveillance is needed to understand the origin, the extent and distribution of this novel SAT1 topotype in the region as well as to detect and monitor the occurrence of (re‐)emerging FMDV strains.     

Genetic diversity and comparison of diagnostic tests for characterization of foot‐and‐mouth disease virus strains from Pakistan 2008–2012

We report the laboratory analysis of 125 clinical samples from suspected cases of foot‐and‐mouth disease (FMD ) in cattle and Asian buffalo collected in Pakistan between 2008 and 2012. Of these samples, 89 were found to contain viral RNA by rRT ‐PCR , of which 88 were also found to contain infectious FMD virus (FMDV ) by virus isolation (VI ), with strong correlation between these tests (κ = 0.96). Samples that were VI ‐positive were serotyped by antigen detection ELISA (Ag‐ELISA ) and VP 1 sequence acquisition and analysis. Sequence data identified FMDV serotypes A (n  = 13), O (n  = 36) and Asia‐1 (n  = 41), including three samples from which both serotypes Asia‐1 and O were detected. Serotype A viruses were classified within three different Iran‐05 sublineages: HER ‐10, FAR ‐11 and ESF ‐10. All serotype Asia‐1 were within Group VII (Sindh‐08 lineage), in a genetic clade that differs from viruses isolated prior to 2010. All serotypes O were classified as PanAsia‐2 within two different sublineages: ANT ‐10 and BAL ‐09. Using VP 1 sequencing as the gold standard for serotype determination, the overall sensitivity of Ag‐ELISA to correctly determine serotype was 74%, and serotype‐specific sensitivity was 8% for serotype A, 88% for Asia‐1 and 89% for O. Serotype‐specific specificity was 100% for serotype A, 93% for Asia‐1 and 94% for O. Interestingly, 12 of 13 serotype A viruses were not detected by Ag‐ELISA . This study confirms earlier accounts of regional genetic diversity of FMDV in Pakistan and highlights the importance of continued validation of diagnostic tests for rapidly evolving pathogens such as FMDV .     

Emergence and Distribution of Foot‐and‐Mouth Disease Virus Serotype A and O in Bangladesh

Foot‐and‐mouth disease (FMD) is endemic in Bangladesh and is predominantly due to FMDV serotype O. In 2012, FMD outbreaks were identified in five different districts of Bangladesh. Of 56 symptomatic cattle epithelial tissue samples, diagnostic PCR assay based on 5′‐URT detected 38 FMDV infections. Viral genotyping targeting VP1‐encoding region confirmed emergence of two distinct serotypes, A and O with an abundance of serotype A in Chittagong and Gazipur districts and serotype O in Pabna and Faridpur. Only single lineage of both A and O was retrieved from samples of five different regions. Sequencing and phylogenetic analysis of VP1 sequences revealed that serotype O sequences were closely related to the Ind 2001 sublineage of Middle East–South Asia (ME‐SA) topotype that was previously circulating in Bangladesh, and serotype A sequences belonging to the genotype VII that was dominant in India during the last decade. The results suggest that extensive cross‐border animal movement from neighbouring countries is the most likely source of FMDV serotypes in Bangladesh.     

Direct detection and characterization of foot‐and‐mouth disease virus in East Africa using a field‐ready real‐time PCR platform

Effective control and monitoring of foot‐and‐mouth disease (FMD ) relies upon rapid and accurate disease confirmation. Currently, clinical samples are usually tested in reference laboratories using standardized assays recommended by The World Organisation for Animal Health (OIE ). However, the requirements for prompt and serotype‐specific diagnosis during FMD outbreaks, and the need to establish robust laboratory testing capacity in FMD ‐endemic countries have motivated the development of simple diagnostic platforms to support local decision‐making. Using a portable thermocycler, the T‐COR ™ 8, this study describes the laboratory and field evaluation of a commercially available, lyophilized pan‐serotype‐specific real‐time RT ‐PCR (rRT ‐PCR ) assay and a newly available FMD virus (FMDV) typing assay (East Africa‐specific for serotypes: O, A, Southern African Territories [SAT ] 1 and 2). Analytical sensitivity, diagnostic sensitivity and specificity of the pan‐serotype‐specific lyophilized assay were comparable to that of an OIE ‐recommended laboratory‐based rRT ‐PCR (determined using a panel of 57 FMDV ‐positive samples and six non‐FMDV vesicular disease samples for differential diagnosis). The FMDV ‐typing assay was able to correctly identify the serotype of 33/36 FMDV ‐positive samples (no cross‐reactivity between serotypes was evident). Furthermore, the assays were able to accurately detect and type FMDV RNA in multiple sample types, including epithelial tissue suspensions, serum, oesophageal–pharyngeal (OP ) fluid and oral swabs, both with and without the use of nucleic acid extraction. When deployed in laboratory and field settings in Tanzania, Kenya and Ethiopia, both assays reliably detected and serotyped FMDV RNA in samples (n  = 144) collected from pre‐clinical, clinical and clinically recovered cattle. These data support the use of field‐ready rRT ‐PCR platforms in endemic settings for simple, highly sensitive and rapid detection and/or characterization of FMDV.     

Epidemiological Analysis,Serological Prevalence and Genotypic Analysis of Foot‐and‐Mouth Disease in Nigeria 2008–2009

The epidemiological situation of foot‐and‐mouth disease virus (FMDV) is uncertain in Nigeria, where the disease is endemic, and the majority of outbreaks are unreported. Control measures for FMD in Nigeria are not being implemented due to the absence of locally produced vaccines and an official ban on vaccine importation. This study summarizes the findings of a 3‐year study aimed at quantifying the seroprevalence of FMD, its distribution in susceptible species and the genetic diversity of FMDV isolated from the Plateau State of Nigeria. A 29% FMD prevalence was estimated using 3ABC enzyme‐linked immunosorbent assay (3ABC ELISA). Farms with suspected FMD nearby, with contact with wildlife, that used drugs or FMD vaccines or with >100 animals, and animals of large ruminant species and in pastures other than nomadic grazing were significantly (P < 0.05) associated with FMD. Antibodies against five FMDV serotypes, (A, O, SAT1, SAT2 and SAT3) were detected by the virus neutralization test (VNT) at various titres (<100–>800) from all tested sera from most parts of the region. This is probably the first report of the presence of FMDV SAT3 in Nigeria. Further studies to investigate the potential probable presence and prevalence of SAT 3 virus in Nigeria are required. Tissue samples collected from clinical animals were positive for FMDV. Virus isolates were sequenced and confirmed as serotype A. All of the isolates showed marked genetic homogeneity with >99% genetic identity in the VP1 region and were most closely related to a previously described virus collected from Cameroon in 2000. This study provides knowledge on the epidemiological situation of FMD in Plateau State, Nigeria, and will probably help to develop effective control and preventive strategies for the disease in Nigeria and other countries in the West African subregion.     

Analysis of Recent Serotype O Foot‐and‐Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages

Foot‐and‐mouth disease (FMD) is endemic in Kenya where four serotypes (O, A, SAT 1 and SAT 2) of the virus are currently in circulation. Within 2010 and 2011, the National Laboratory recorded an increase in the number of FMD outbreaks caused by serotype O virus. The characteristics of these viruses were determined to ascertain whether these were independent outbreaks or one single strain spreading throughout the country. The sequences of the complete VP1‐coding region were analysed from viruses sampled within different areas of Kenya during 2010 and 2011. The results indicated that the 2010 to 2011 outbreaks in Kenya were caused by four independent strains. By comparison with earlier type O isolates from Eastern Africa, it was apparent that the outbreaks were caused by viruses from three different lineages of topotype EA‐2 and a fourth virus strain belonging to topotype EA‐4. The topotypes EA‐1 and EA‐3 were not detected from these outbreaks. Implications of these results for FMD control in Eastern Africa are discussed.     

Characteristics of Foot‐and‐Mouth Disease Viral Strains Circulating at the Wildlife/livestock Interface of the Great Limpopo Transfrontier Conservation Area

Foot‐and‐mouth disease (FMD) inflicts severe economic losses within infected countries and is arguably the most important trade‐restricting livestock disease in the world. In southern Africa, infected African buffaloes (Syncerus caffer) are the major reservoir of the South African Territories (SAT) types of the virus. With the progressive expansion of transfrontier conservation areas (TFCAs), the risk of FMD outbreaks is expected to increase due to a higher probability of buffalo/livestock contacts. To investigate the dynamics of FMD within and around the Great Limpopo TFCA (GLTFCA), 5 herds of buffaloes were sampled in June 2010 to characterize circulating viruses in South Africa and Zimbabwe. Three SAT‐2 and three SAT‐3 viral strains were isolated in both countries, including one that was genetically linked with a recent SAT‐2 outbreak in Mozambique in 2011. In addition, two groups of unvaccinated cattle (n = 192) were serologically monitored for 1 year at the wildlife/livestock interface of Gonarezhou National Park (GNP) in Zimbabwe between April 2009 and January 2010, using the liquid‐phase blocking ELISA (LPBE) and a test for antibodies directed against non‐structural proteins (NSP). Neither clinical signs nor vaccination of cattle were reported during the study, yet a high proportion of the monitored cattle showed antibody responses against SAT‐3 and SAT‐1. Antibodies against NSP were also detected in 10% of the monitored cattle. The results of this study suggest that cattle grazing in areas adjacent to the GLTFCA can be infected by buffalo or other infected livestock and that cattle trade movements can act as efficient disseminators of FMD viruses to areas several hundred kilometres from the virus source. Current methods of surveillance of FMD at the GLTFCA interface seem insufficient to control for FMD emergence and dissemination and require urgent reassessment and regional coordination.     

Serotype Diversity of Foot‐and‐Mouth‐Disease Virus in Livestock without History of Vaccination in the Far North Region of Cameroon

Little information is available about the natural cycle of foot‐and‐mouth disease (FMD) in the absence of control measures such as vaccination. Cameroon presents a unique opportunity for epidemiological studies because FMD vaccination is not practiced. We carried out a prospective study including serological, antigenic and genetic aspects of FMD virus (FMDV) infections among different livestock production systems in the Far North of Cameroon to gain insight into the natural ecology of the virus. We found serological evidence of FMDV infection in over 75% of the animals sampled with no significant differences of prevalence observed among the sampled groups (i.e. market, sedentary, transboundary trade and mobile). We also found antibodies reactive to five of the seven FMDV serotypes (A, O, SAT1, SAT2 and SAT3) among the animals sampled. Finally, we were able to genetically characterize viruses obtained from clinical and subclinical FMD infections in Cameroon. Serotype O viruses grouped into two topotypes (West and East Africa). SAT2 viruses grouped with viruses from Central and Northern Africa, notably within the sublineage causing the large epidemic in Northern Africa in 2012, suggesting a common origin for these viruses. This research will guide future interventions for the control of FMD such as improved diagnostics, guidance for vaccine formulation and epidemiological understanding in support of the progressive control of FMD in Cameroon.     

Generation of monoclonal antibodies against foot‐and‐mouth disease virus SAT 2 and the development of a lateral flow strip test for virus detection

Foot‐and‐mouth disease (FMD) remains a major economic concern for the livestock productivity in many developing countries and a continued threat to countries that are disease free because of its potential devastating impact on agricultural, food chain and tourism sectors. FMD virus (FMDV) is recognized as having seven serotypes: O, A, C, Asia 1, South African Territories (SAT) 1, 2, 3 and multiple subtypes within each serotype. FMD outbreaks due to SAT 2 have been reported in many African countries. The development of a rapid and easily performed test for FMD detection is critical for controlling FMD outbreaks and containing its spread. The present project developed a lateral flow immunochromatographic (LFI) strip test for the rapid detection of FMDV SAT 2. A panel of monoclonal antibodies (mAbs) against FMDV serotype SAT 2 was produced and characterized. One mAb (#10) was selected as the capture mAb because it reacted to all 23 SAT 2 isolates archived at the National Center for Foreign Animal Disease. The LFI strip test was developed using biotin‐conjugated mAb #10, and the colloid gold‐conjugated FMDV serotype‐independent mAb as the detection mAb. A generic Rapid Assay Device (gRAD) with one test line and a control line was used for the test. The LFI strip test detected all 23 tested SAT 2 isolates and recent outbreak strains. The results indicated that the diagnostic specificity and sensitivity of the LFI strip test were greater than the double antibody sandwich (DAS) DAS ELISA. The ability of the LFI strip test to produce rapid diagnostic results will be useful for early on‐site diagnosis during FMD outbreaks.