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.