Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases

Abstract

Foodborne diseases (FBDs) are a major concern worldwide since they are associated with high mortality and morbidity in the human population. Among the causative agents of FBDs, Taenia solium, Echinococcus granulosus, Toxoplasma gondii, Cryptosporidium spp., and Trichinella spiralis are listed in the top global risk ranking of foodborne parasites. One common feature between them is that they affect domestic livestock, encompassing an enormous risk to global food production and human health from farm to fork, infecting animals, and people either directly or indirectly. Several approaches have been employed to control FBDs caused by parasites, including veterinary vaccines for livestock. Veterinary vaccines against foodborne parasites not only improve the animal health by controlling animal infections but also contribute to increase public health by controlling an important source of FBDs. In the present review, we discuss the advances in the development of veterinary vaccines for domestic livestock as a strategy to control foodborne parasitic diseases.

Keywords: animal health; domestic livestock; foodborne parasites; helminths; protozoa; veterinary vaccine.

Figure 1

Livestock play a major role in the transmission of FBDs caused by parasites. They may be involved in the direct foodborne route of infection from animal to human via the consumption of raw meat (e.g., T. solium, T. gondii, T. spiralis infective form in meat), but they may also contribute to human infection through many other indirect and direct routes. Just to name a few, indirect routes include contamination of water or soil (e.g., Cryptosporidium spp. oocysts shed by cattle), contamination of fresh produce with eggs/oocysts (e.g., Cryptosporidium spp. oocysts shed by cattle), vertical transmission from mother to fetus after consumption of infected meat (e.g., T. gondii), infection of definitive hosts (companion animals such as cats and dogs) through the consumption of infected meat from livestock (e.g., E. granulosus infected sheep meat consumed by farm dogs) and among other direct routes, the human/animal contact represents an important one (e.g., Cryptosporidium spp and T. spirallis in farms and slaughterhouses sources). In the scheme, the arrowhead indicates the sense of the infection route.