Food Security Issues related to meat-borne parasites
Communities related to global health have recognized that parasites have great influence on human economic activities, health and nutrition but unfortunately the same consideration has not been achieved by the animal parasites with the same outcomes. This is of utmost importance because almost half of the world population, particularly the poor, depend upon livestock systems for earning and their nutritional needs. Thus we can say that poverty, diseases and malnutrition caused by parasites to livestock enterprises, are directly related to human health. Sale of animals and animal products (milk, meat and eggs) is carried out in the markets as a source of food for human consumption to eliminate poverty. Usually two factors are responsible for malnutrition due to food security in poor population: (i) shortage of nutrient dense foods due to inadequate access to nutrients; (ii) disease caused by food-borne parasites resulting in reduction of nutrients or their inhibited uptake. Usually disease control programs like chemotherapeutic agents and vaccines are available for human health, but this system is lacking for poor livestock keepers due to non-availability, undervalued and cost prohibitive products.
Historically, meat has always been considered to be a supreme food in different cultures and contexts, being a complete package of nutrients. Out of 24 highest ranked foodborne parasites, five are Taenia saginata, T. solium, Sarcocystis spp. Toxoplasma gondii and Trichinella spiralis caused due to consumption of undercooked or raw meat. Consumption of undercooked or raw meat causes taeniosis, toxoplasmosis, trichinellosis and sarcocystosis due to the presence of encysted stages in undercooked meat. For control of sarcocystosis and taeniosis, inspection at abattoir level has been ensured to prevent their entry in the human food chain due to meat. However, these methods are not good enough to stop the entry of these foodborne parasites to human foods and good diagnostic protocols are still need to be developed. Trichinellosis is a serious foodborne parasitic disease because 65818 cases have been recorded from 1986-2010 causing 42 mortalities in 41 countries with 50% in Romania and 87% in other European countries. Globalization of meat caused a major outbreak of 1998-1999 in Germany and majority of these reports were due to local production of wild boar. Toxoplasmosis, on the other hand, is responsible to infect almost 33% population of the whole world mostly due to T. gondii. People of Western countries and Asia are considered to be infected by this parasite due to the consumption of undercooked or raw food. Poultry meat is considered to be a less cause of foodborne meat diseases because this meat is transported in frozen form and is cooked well before consumption.
Aquaculture industry has made enormous progress in sea foods trade because it was 30 million tonnes annually in 1990 and now has exceeded 60 million tonnes annually. Almost 85% of the total fish aquaculture production comes from Asia and many species are consumed and traded globally. At the same time, potential of chemical and biological agents has also increased to contaminate the aquaculture products. Fish-borne zoonotic trematodes (FZT) are economically the most important because their prevalence is up to 50-70% in Asia, leading to food security issues of aquaculture products. The sustainable control of FZT in aquaculture can be achieved by protecting the fishponds from the contamination of FZT eggs and to control the snail population. This control measure has not been applied on a larger scale because farmers are not well aware about the importance of FZT and the knowledge about their control is also inadequate. The outcomes received by controlling FZT revealed the complexity related to ecosystem where fish farming continues because some fish farms were found to be free of snails but still had a high prevalence of FZT. Such study suggested that the security of these farms was compromised perhaps due to the shedding of cercariae by snails as a result of water exchange from nearby rice fields or canals. Control programs are specifically important in countries where aquaculture is of economic importance for farmers, thus the policy makers need to devise programs for public health caused by FZT in aquaculture dependent systems.
Previous policies were based on the control of contamination of human food from animal sources while the future is dependent upon the control of sources that cause foodborne parasitism in animals. Globalization is expected to create hurdles for this control system of parasites because almost 107 species of different parasites have the ability to cause foodborne illness. Furthermore, infrequent and uncommon cases of foodborne parasites in animals will be difficult to identify, ultimately a great challenge for health professionals. Transportation of livestock, wildlife, companion animals and aquatic animals between different countries can introduce those parasites which were considered to be exotic in a specific area despite the international guidelines to minimize foodborne parasitic illness. Global demand for different kinds of meats like beef, poultry and fish has been increased many fold but meat inspection for parasites could not be managed accordingly. International organizations for health and food still need to develop better control strategies for the most important parasites related to food safety. Training capacities combined with advanced diagnostic tools and international communication need to be globalized for medical and veterinary parasitology to overcome these threats.