INTRODUCTION
Cameroon, with a population of almost 28 million people, is located in central Africa, bordering the Gulf of Guinea. It is a key transit link, sharing borders with six countries: Nigeria, Chad, Central African Republic, Republic of Congo and Equatorial Guinea. The gross domestic product (GDP) per capita of Cameroon is estimated at USD3,700 (CIA, 2017). The approximately 7.1 million cattle in Cameroon are susceptible to regular outbreaks from Foot-and-Mouth Disease (FMD), and endemic disease in much of Africa. With no preventive control programs in place and no access to commercial FMD vaccination, farmers are focused on treatment choices for affected cattle, with antibiotics and/or traditional therapies commonly used and prolonged periods for animals to recover.
FMD is a most important global viral pathogen of artiodactyl farmed and wildlife animals. The disease is characterised by lesions in and around the mouth and feet (Fakhrul-Islam et al., 2016). Globally, there are seven pools of circulating FMD viruses recognised. Each pool represents independently circulating and evolving FMD virus (FMDV) genotypes (Russo, 2018). Within the pools, cycles of emergence and spread occur that usually affect multiple countries in the region. In the absence of specific and laboratory-confirmed reports, it should be assumed that the prevalent serotypes are continuously circulating in parts of the pool area and would be detected if sufficient surveillance was in place (Russo, 2018). Cameroon sits in the West/Central African region designated as Pool 5. FMD causes huge economic losses in Cameroon, with estimation of the total annual cost of FMD management at USD112 million (FAO, 2015).
Of the seven FMDV serotypes, four (O, A, SAT 1 & SAT2) occur in Cameroon (Ludi et al., 2016; Sevidzem et al., 2019b; Ehizibolo et al., 2019). There is no mass vaccination program for FMD and no commercial FMD vaccines are available in Cameroon (Bertram et al., 2018). A pilot trial using commercial trivalent vaccine (Aftovax®) was conducted in 2015 in Ngaoundere, with observations that clinical infection of FMD appeared to have been prevented, although persistent infection occurred. Cattle owners in Cameroon routinely manage the disease using a range of therapies, including anti-inflammatory preparations, antibiotics and traditional formulations (Sevidzem et al., 2019a).
In the absence of strategic preventive control programs, there are urgent needs for alternative FMD management options for endemic FMD-infected countries, including Cameroon. With affordable and efficacious vaccine candidates for managing FMD unlikely in the near future, the review and rationalizing of FMD therapies is advisable. Several topical treatments with ethno-veterinary and recognized veterinary pharmaceuticals have been examined in FMD endemic settings in Africa (Gakuya et al., 2011; Misk et al., 2015; Fakhrul-Islam et al., 2016; Al-Lethie et al., 2018). However, the widespread use of parenteral antibiotics for FMD globally, including numerous countries in Africa and Cameroon in particular, presents antimicrobial resistance (AMR) and potential food safety residue risks that need to be addressed.
Recently, an Australian wound dressing formulation, Tri-Solfen® (Medical Ethics Pty Ltd, Australia; TS) registered for use in cattle and small ruminant husbandry in Australia and New Zealand, was registered for FMD therapy in large ruminants in Laos in south east Asia (Windsor et al., 2020). The wound and lesion dressing formulation contains two local anaesthetics (lignocaine and bupivacaine), adrenalin and cetramide in a gel matrix that creates a barrier effect, numbing the pain of lesions, rapidly reducing their infectivity, and hastening healing, potentially reducing the weight loss in affected individuals (Windsor et al., 2020). If made available for purchase and administration by farmers, this product could provide a viable alternative approach for managing FMD in Cameroon, other African countries and developing countries globally. This formulation offers numerous advantages over current therapies as it provides efficacious pain relief and more rapid healing of wounds and lesions (Windsor et al., 2016; Roberts and Windsor, 2019; Windsor et al., 2020). Further, with a pH of ~2.7, and containing the antiseptic cetrimide, it potentially has viricidal impacts and anti-bacterial properties respectively, avoiding the need for other treatments, including antibiotics (Windsor et al, 2020).
In November 2019, TS was provided to the Cameroon research team for trials during FMD outbreaks in cattle. This report describes a field trial in Cameroon aimed at evaluating the efficacy of this therapy for FMD lesion management, particularly for enhancing recovery and wound healing, comparing the clinical responses to the most commonly used and available antimicrobial therapy currently in use. If TS is proven to be as efficacious for FMD in this current study as it appeared to be on first use in Laos as described (Windsor et al., 2020), it is likely that the product could offer an important innovation for improving FMD lesion treatment, potentially globally, with reduced animal welfare burdens, risks of AMR issues and possibly, increased transboundary disease reporting and surveillance.