An investigation into the efficacy of foot-and-mouth disease control programs in cattle in Cambodia

Abstract

Foot and mouth disease (FMD) is a highly contagious viral disease which impacts national and regional economies and the livelihoods of smallholder farmers. Due to the limited human and financial resources and difficulties in enforcing animal, people and product movement regulations, it is almost impossible to control FMD in Cambodia. The best option for control would be to implement an efficient and equitable vaccination program with the support of all stakeholders, neighbouring countries and multilateral donors. The aim of this thesis is to investigate the efficacy of FMD cattle vaccination programs in Cambodia. This required information and data collection from smallholder farmers (livestock producers), village animal health workers (local animal health service providers) and vaccine retailers (vaccine suppliers) as well as other inputs from relevant stakeholders. This initial analysis identified the importance of cold storage temperature variation and the potential effects this may have on vaccine efficacy and smallholder's desire to participate in FMD control programs. It also identified the important role that smallholders play in the potential success of these programs and their perceptions of household benefit. Two major research activities were undertaken. Firstly, two FMD vaccination experiments to identify the effect of vaccine storage temperatures and dose rate on antibody responses to FMD vaccination and secondly, an on-farm economic analysis (benefits and costs) of an FMD vaccination program. FMD vaccination programs were implemented using unreliable and limited government support. Private FMD vaccination services did not exist in the study areas. Vaccine handling and cold storage management were poor in both veterinary drugstores and Provincial Offices of Animal Health and Production. The experimental study on the effect of vaccine storage temperatures and dose rate on antibody responses to FMD vaccination found that freezing vaccines for a week did have a deleterious effect on the antibody response while ambient temperature well above recommended temperature range did not have an effect on antibody response. Halving the dose significantly reduced the antibody response to vaccination. A significant deviation from recommended temperature range for up to a week had significant effects on antibody titre. The results highlight the need for improvements to avoid ongoing exposure of vaccines to freezing and high ambient temperatures. Current vaccination coverage could not be expected to ensure herd immunity. The economic analysis suggested that FMD vaccination, including farmer training and deworming programs, can be justified if properly planned and implemented. The economic benefits of participating in an FMD vaccination program were influenced by; the success of vaccination, the success of treatment and nursing and the proportion of sick animals treated. Economic losses to affected farmers were also influenced by the severity of FMD outbreaks. The results will be useful inclusions in the farmer training and vaccination campaigns. Based on the results of this study, it is concluded that current FMD vaccination efforts are ineffective in the study areas. The complex issues along the whole livestock production chain and the endemic nature of the disease pose real challenges. This study calls for improvements in future vaccination practices and FMD awareness campaigns. In order to improve the efficacy of the FMD control programs, the Department of Animal Health and Production requires significant government financial support and vaccination programs would be more effective if only targeted in FMD high risk areas. It is recommended that private FMD vaccination program is developed and implemented to reduce the number of susceptible animals in Cambodia. To achieve this the national and provincial offices of animal health and production need to ensure that farmers and village animal health workers understand and can implement their roles in the government subsidised and private FMD vaccination programs. It is suggested that a training program to teach proper storage and handling of livestock vaccines is required for both government and commercial vaccine managers. The control of FMD within the country will have significant benefits for individual smallholder farmers, and also the Cambodian economy.