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

Abstract

Summary 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.

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

“…Further studies may be warranted to also include serotypes C and SAT 3, although serotype C has not been detected in any country since 2004. SAT 3‐specific antibodies have been recorded in sera from west and central Africa (Ehizibolo et al., ; Ludi et al., ) and from eastern Africa (Ayebazibwe et al., ; Dhikusooka et al., ; Mwiine et al., ; Namatovu et al., ), although this serotype has not previously been detected in Niger. Although the sampling strategy is different to that implemented by Ludi et al.…”

“…Although the sampling strategy is different to that implemented by Ludi et al. (), our results appear to be similar regarding the presence of different serotypes in unvaccinated animals. Serological tests also reveal that antibodies to four FMDV serotypes were present among the animals sampled although only one FMDV serotype (O) was detected by viral isolation and sequencing.…”

Quality of veterinary pharmaceuticals and their use by pastoralists in the Far North Region of Cameroon

“…However, other infectious diseases, like FMD, are endemic in the region, and the rates of infection are high (Ludi et al 2016). At the time of our study, there were no vaccines available in the region for FMD.…”

“…We have chosen to use foot-andmouth disease (FMD) as a focal disease because it is prevalent (over 70% seroprevalence using a conservative estimate from Ludi et al (2016)) and easily recognized by cattle herders of this region (recognizable signs noted in Grubman and Baxt (2004) and Spickler et al (2010)), so herders can easily answer questions about treating the disease from memory. While FMD is a viral disease with no known effective treatment, our previous work with this population (Ludi et al 2016) informed us that pastoralists treat their cattle for this disease and report success in many cases, perhaps due to the mild, self-limiting nature of the disease in partially immune adults and perhaps due to effective treatment of secondary and concurrent infections/infestations.…”

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

“…The presence of multiple FMDVs in the same geotemporal space hinders disease control and may pose an increased risk of emergence of new strains. Numerous studies have reported serological evidence of infection with multiple serotypes within the same animal, which indicates evidence of cumulative, lifetime exposure (Eldaghayes et al., ; Ludi et al., ; Namatovu et al., ; Sikombe et al., ; Wungak et al., ). However, simultaneous coinfection is a distinct subcategory of multiple exposures and has been reported rarely in clinical samples from cattle (Jamal, Ferrari, Ahmed, Normann, & Belsham, ; Souley Kouato et al., ; Ullah et al., ; Wungak et al., ), but is believed to occur more frequently in oropharyngeal fluid samples from African Cape buffalo (Anderson, Doughty, Anderson, & Paling, ; Hedger, ; Vosloo et al., ).…”