4. Discussion
The study is one of the larger scale surveys of the knowledge, attitudes, and practices (KAP) of Cambodian smallholder livestock farmers on cattle health and production issues, providing information on FMD management and vaccination programs. The study intended to identify opportunities for improving the uptake of FMD vaccination and implementing biosecurity interventions in rural communities. The study identified that although smallholder farmers undertake a range of farming and off-farming activities, large ruminants contribute a large proportion of total household income (KC 30%; PS 25%) at the rural community level (Ashley et al., 2018; Samkol et al., 2015) and deserve investments to mitigate disease risk, despite the majority of surveyed farmers still practicing the traditional method of cattle raising. Although all cattle in the household herd were tethered under the house during the night, as they are commonly permitted to graze on available pastures, paddy fields and shrubs or common grassland areas further from the village, there are ample opportunities for disease transmission within and between large ruminant village populations, as previously reported (Kawasaki, Young, Suon, Bush, & Windsor, 2015).
With most farmers using communal grazing method, the movement of large ruminants to communal grazing areas enables contact with animals from other locations, increasing the risk of contracting diseases, particularly FMD, as previously reported by other studies (Chamnanpood, Cleland, Baldock, & Gleeson, 1995; Cleland, Chamnanpood, Baldock, & Gleeson, 1995), and recently reviewed by (Blacksell et al., 2019). During FMD outbreaks, confining and feeding cattle on cut grasses reduces the likelihood of infection, with this practice proposed to reduce the risk of spread of FMD virus by reducing the direct contact between healthy and infected animals (Cleland, Baldock, Chamnanpood, & Gleeson, 1996). The growing of improved grass forage species has achieved positive production and socioeconomic outcomes (Stur et al., 2002; Young et al., 2014a; Young et al., 2014b) and if more widely adopted, a higher proportion of farmers employing cut and carry (stall feeding) to raise their animals will help reduce the risk of FMD transmission, improving rural livelihoods (Nampanya et al., 2015).
FMD was rated as a significant factor affecting livestock production by the surveyed farmers with most appearing to know and recognize FMD clinical signs and understand the main purpose of vaccination. Farmers revealed that people within the village were the most preferred persons to communicate new cases of diseases, indicating that the farmer disease communication network generally remained local. Local authorities such as district or provincial veterinarians were not acknowledged as important contact persons by the majority of farmers. This implies that VAHWs should have a more important role in assisting disease surveillance by receiving disease information from farmers and rapidly conveying this information to the district and provincial veterinary officials and local authorities for the disease intervention, as described by others (MacPhillamy et al., 2020; Stratton et al., 2015). However, as disease reporting is most effective when followed by a rapid disease response, particularly after the index case in the outbreak, strengthening of the role of the VAWH requires considerable effort in disease response training (MacPhillamy et al., 2020). Emergency disease reporting, investigation and response in Cambodia remain a critical weakness in FMD disease prevention and control (Blacksell et al., 2019; MacPhillamy et al., 2020), with the lack of urgency in FMD reporting indicating that many stakeholders tend to think FMD is not a serious disease due to low fatality rate (Sieng & Kerr, 2013).
The study found that three-quarters of interviewed farmers did not isolate the first FMD infected animal from the household herd, resulting in all cattle in the herd developing the disease. Of those who separated their ill animals, many of them only separated infected cattle during the day and usually regrouped them after the livestock returned from the grazing areas, as was identified in previous studies (Christley, Robinson, Lysons, & French, 2005; Gleeson, 2002; Sumption, Rweyemamu, & Wint, 2008). In rural communities, it is unlikely that smallholder farmers would have a safe alternative place at night to isolate the first infected animal and consider they have no choice but to keep all animals together at night. However, the poor knowledge and understanding of disease transmission and biosecurity practices of farmers identified in this and other studies indicate the enormous challenge facing animal health programs that aim to achieve FMD control in Cambodia and beyond (Blacksell et al., 2019; Kerr, Sieng, & Scoizec, 2012; Perry et al., 2002; Rast, Windsor, & Khounsy, 2010; Sieng & Kerr, 2013; Windsor et al., 2008; Young et al., 2012).
During the outbreaks, treatment was identified to be the first intervention preference for the majority of farmers, seeking treatment services from VAHWs (72%), with some more knowledgeable farmers commencing the treatment of FMD infected cattle by themselves (53%) with the assistance from relatives, friends, and neighbors. It is a Cambodian custom, especially in remote communities, to assist each other to restrain and treat infected cattle and this strong rural cultural practice is indicative of good communal relationships, although increases FMD transmission risk without improved hygiene practices. Most of the surveyed farmers reported that the majority of neighboring farmers’ cattle were also sick during the outbreak offering assistance before (57%) or after (43%) their cattle got infected with FMD.
Even though farmers appear to have some knowledge of FMD, it is disturbing that they were unaware that the risk of FMD spread via their movements, contaminated clothing, hands and feet equipment to livestock in other households is considerable. During an FMD outbreak, the social visits from family members, neighbors, and friends were reported to have contributed 25% of contacts with animals (Nielen et al., 1996). Several studies in developing countries revealed that the movement of people including traders, village chiefs, extension staff between villages and movement of animals from different villages in grazing areas is reported to be significant risk factors for the spread of FMD (Hunter, 1998; Kerr et al., 2012; Khounsy et al., 2008; Perry et al., 2002; Sumption et al., 2008).
The sale and purchase of infected animals were not reported by the majority of farmers in this study, although it is suspected that farmers preferred not to admit to this practice, particularly as compliance with restrictions on livestock trade and movements during the outbreaks is considered poor, with both infected and dead animals likely to be traded with local traders and local slaughterhouses. Trading of FMD infected animals during FMD outbreaks appears to be ongoing practice within rural communities in Cambodia, leading to the persistence of annual FMD outbreaks, with a morbidity rate exceeding 30% revealed in this study. High morbidity rates up to 74% were identified in an unvaccinated village in Lao PDR (Rast et al., 2010).
Previous studies with traders in Cambodia confirmed that farmers did sell sick livestock to avoid animals dying and to salvage some animal’s value before death, and animal owners were more likely to sell sick animals, and more stock was available when diseases were prevalent in an area (Sieng, Hawkins, Madin, & Kerr, 2012; Young et al., 2014c). Interestingly, more than half of traders admitted that they had traded FMD infected animals, due to the low prices accepted by farmers for sick animals (Kerr et al., 2012; Sieng et al., 2012) although a survey of traders identified their preference for FMD vaccinated animals (Young et al., 2014c). Previous studies have consistently identified that the movement of infected animals and animal products are the most important factors increasing the spread of disease (Blacksell et al., 2019; Christley et al., 2005; Perry et al., 2002; Sumption et al., 2008; Young et al., 2014c). Lack of basic KAPs on disease transmission and biosecurity by farmers and other stakeholders at the village level remains a major concern for the veterinary authorities attempting to control a most infectious disease such as FMD.
In Cambodia, FMD control has relied only on ring vaccination around outbreaks. This study identified that over three-quarters of farmers (79%) had not vaccinated their cattle against FMD during the previous three years. Of those vaccinated, most cattle were vaccinated by VAHWs once every year or once in three years, and booster FMD vaccination had not been administered, as is recommended by vaccine manufacturers (Doel, 2003). This study found that only a small proportion of cattle in each village were vaccinated, suggesting that effective herd immunity was not achieved, as this would likely require at least 75% (Lombard & Schermbrucker, 1993) to 80% (Chamnanpood, Gleeson, & Robertson, 1993; Jori et al., 2009) of the population to be effectively vaccinated. Ring vaccination of all susceptible animals implemented with sanitary measures had been proposed as a means to reduce the spread and shorten the outbreak duration (Barteling & Vreeswijk, 1991). A case study of an FMD outbreak in Lao PDR (Rast et al., 2010) indicated that vaccinating the whole large ruminant population reduced the losses from FMD per animal by a factor of about four times compared to vaccinating only just over half the population.
In this study, the farmers identified that their most important reasons for not vaccinating were an unwillingness to pay for vaccination when their cattle were healthy and that they had not received information about vaccination. This finding indicates that the majority of farmers had a poor understanding of the usefulness and importance of vaccination, tend to rely entirely on free FMD vaccines supported by the veterinary authorities as a private FMD vaccination service was unavailable during the study period. As many farmers still perceive FMD as being far less important than other diseases due to the low mortality rate, private vaccination services may be more difficult to implement compared to other higher mortality diseases, such as Haemorrhagic Septicaemia (Kawasaki et al., 2015). Poorly delivered vaccination campaigns also contribute to the low vaccination coverage even when the vaccine is available. This is not surprising, considering FMD vaccination delivery was based on government support, and the finding likely reflects those study villages may have been excluded from the list of villages vaccinated under the provincial FMD vaccination plan.
The multivariable logistic regression analysis indicates that age, education, number of household members livestock management and husbandry were not associated with the FMD vaccination practices of farmers. However, farmers reporting their cattle were vaccinated by a VAHW through a government-subsidized vaccination, indicated they were more likely to have their cattle vaccinated for FMD than those who did not avail themselves of VAHWs’ services. The numerous issues arising with the delivery of large scale regional FMD vaccination programs over several years in the GMS have been identified and reported from Lao PDR (Blacksell et al., 2019; Nampanya, Khounsy, Abila, & Windsor, 2018).
Although FMD is not perceived as high mortality risk in most outbreaks (less than 1% in this study), the disease is highly infectious and debilitating, leading to significant economic losses for individual farming families, plus village, provincial and national levels (Nampanya et al., 2015; Young et al., 2014b; Young et al., 2012; Young et al., 2017). The economic impacts of FMD were identified in our study, with 8 of the participating farmer households having lost approximately one-third of their household herd during the most recent FMD outbreak. Several studies on the impact of FMD indicated that regular FMD outbreaks cause economic hardship for farmers due to loss of cattle body weight (Young et al., 2012), loss of production and/or death of affected animals (Muleme et al., 2012) and reduced sale value (Muleme et al., 2012; Perry et al., 2002; Young et al., 2012). Most of the interviewed farmers realized that the cost of treatment is much higher than the full fee bi-annual FMD vaccination, with some farmers likely wishing to pay for the private FMD vaccination services from the local VAHWs (Stratton et al., 2015), although FMD vaccines were rarely available.
However, a major reason contributing to the absence of private FMD vaccination services and the challenge of addressing the need for improved biosecurity change management (Young, Evans‐Kocinski, Bush, & Windsor, 2015), is the likely farmer resistance following the long-standing practice of farmers receiving and expecting government-subsidized FMD vaccination. It is a challenging task for the DAHP and POAHP to convince farmers to change their attitudes and practices towards FMD vaccination and encourage them to participate and accept full fee-based FMD vaccination services for their cattle.
Thus, the quality of vaccination campaign delivery and extensive farmer training is essential in moving the rural Cambodian community to accept the inevitably of self-funding vaccination that can be delivered by private vaccination services in their communities. If the effectiveness of vaccination delivery can be improved and cattle can be protected during outbreaks, with adequate training to motivate farmers and overcome their resistance to change, the recognition that full fee bi-annual FMD vaccination is an important measure to protect cattle from FMD is perhaps achievable. As the study identified the average cost of treatment plus nursing a sick animal (USD41.00) was more than 10 times the cost of full fee bi-annual FMD vaccination (USD3.00), this information can form the basis of future extension programs on FMD management.
The feasibility of delivery and the potential success of TAD control measures, including vaccination programs, depends on the cooperation of farmers with local authorities at the village level, although provincial and national level service providers, international donors and stakeholders are also of relevance. A significant educational effort on vaccination and biosecurity is required to explain the benefits that disease risk management provides. Existing FMD control strategies, especially FMD vaccination delivery in Cambodia, require review, with appropriate surveillance and emergency response capabilities upgraded to enable provincial and central level services to enhance their abilities to reduce the occurrence of FMD outbreaks and improve the uptake of FMD vaccination. Full fee-based FMD vaccination services should be considered and introduced in rural communities by the veterinary authorities, although this requires that GDAHP and POAHP discuss this new concept with the VAHWs and village chiefs that will be essential in assisting extension workers in promotion of the vaccination campaign and ensuring farmers well understand the cost-benefits of full fee bi-annual FMD vaccination.
This field survey involved 300 smallholder farmers, although there is usually an issue with the accuracy of some responses as interviewed stakeholders may be reluctant to provide correct and true information if they know it is against the existing government or social policy. Further studies on the benefit and cost analysis of fee-based bi-annual FMD vaccination are required for the future improvement of FMD vaccination uptake as well as the FMD control program in Cambodia. Further, research questions to identify the cost and benefits of combined cattle health and production programs that include establishing forage with stall feeding, persistent vaccination and deworming programs, and importantly biosecurity including movement control, should be prioritized for future research study in Cambodia.