Over the last few decades, around seventy per cent of new diseases which infect humans have made the species jump from animals, as our proximity to them and their habitat grows closer. A UN Report claims that a now, more holistic approach is needed to tackle this problem.
The report drawn up by the UNO's Food and Agricultural Organization, FAO, called World Livestock 2013: Changing Disease Landscapes (*) paints an alarming picture about growing numbers of new diseases infecting humans originating in wildlife. In fact, around seventy per cent of new human diseases come from animals.
As contact between the human population and wildlife becomes closer, due to invasion of habitat and due to the greater consumption of animal products, the propensity for infection increases. This in turn, according to the report, is exacerbated by globalization and climate change, which "are redistributing pathogens, vectors, and hosts, and pandemic risks to humans caused by pathogens of animal origin present a major concern". At the same time, antibiotic resistance and food safety hazards are growing.
Ren Wang, FAO Assistant Director-General for Agriculture and Consumer Protection, explains that "livestock and wildlife are more in contact with each other, and we ourselves are more in contact with animals than ever before," adding that "What this means is that we cannot deal with human health, animal health, and ecosystem health in isolation from each other - we have to look at them together, and address the drivers of disease emergence, persistence and spread, rather than simply fighting back against diseases after they emerge".
The trend for diseases which have made the species jump from animals to humans began in the 1940s and today, there are some thirteen zoonoses (diseases which newly affect humans, have become virulent or have become drug resistant) which claim some 2.2 million human lives every year. The majority of these deaths occur in low- and middle-income countries, the highest rates of incidence being in India, Ethiopia, Tanzania and Nigeria. These are countries were there is a high concentration of poor livestock farmers, many of them under-nourished, rendering them more vulnerable.
60 per cent of all human diseases are zoonotic, and between 70 and 75 per cent of emerging infectious diseases are zoonotic, the source of many of these being poultry, pigs, goats, sheep, cows and camels. The most common diseases are zoonotic gastrointestinal disease; leptospirosis; cysticercosis; zoonotic tuberculosis (TB); rabies; leishmaniasis; brucellosis; echinococcosis; toxoplasmosis; Q fever; zoonotic trypanosomiasis (sleeping sickness); anthrax.
Other examples are SARS, possibly MERS-CoV and HIV/AIDS.