Source CDC – How Ebola likely jumped to humans
Although we’ll never know the exact route of its spillover, the Ebola outbreak tragedy in West Africa likely began when a bat (or perhaps some other small forest mammal), passed the virus on to some kind of bushmeat animal, which was then captured, killed and consumed by a human.
MERS-CoV, which has killed hundreds in the Middle East, likely also originated in bats, and moved on to humans through an intermediary host; camels (see CIDRAP: More Evidence for Camel-to-Human MERS-CoV Transmission).
The list of zoonotic diseases is long, and getting longer with each passing year.
The intermingling of wild birds, ducks, and poultry over the past two decades have produced dozens of new clades of avian flu viruses that endanger humans, including subtypes H5N1, H7N9, H10N8, H9N2, and H5N6 (see EID Journal: Predicting Hotspots for Influenza Virus Reassortment).
Similarly, we’ve seen one pandemic virus (2009’s H1N1), and a number of swine variant viruses (H1N1v, H1N2v, H3N2v) emerge from pig herds and go on to infect humans (see Keeping Our Eyes On The Prize Pig) over the past decade.
Whether an `old’ scourge like Tuberculosis, or a `new’ disease like Lyme Disease, SFTS, or Hantavirus, 70% of the infectious diseases that plague mankind appear to have originated in other species, and then jumped to humans.
Most of these diseases only began to appear in humans after we – as a species – began to domesticate animals roughly 10,000 years ago (see The Third Epidemiological Transition).
Today, between large CAFO operations, and the long-distance transporting of livestock, we’ve created even more opportunities for zoonotic diseases to emerge and spread. When you add in our increasingly mobile society, and a zoonotic outbreak anywhere in the world can soon becomes global concern.
This week the FAO, at a conference in Indonesia, stressed the importance of animal disease surveillance as an integral tool in protecting human health.
"Weak link" in public health protection efforts must not be neglected
Tissue samples from chickens await testing at a Nigerian laboratory.
20 August 2014, Rome - FAO today told ministers of health and agriculture meeting in Indonesia that animal disease monitoring systems require sustained support and have a critical role to play in preventing human disease threats.
"Animal health remains one the weakest links in terms of how the world deals with disease risks," FAO Chief Veterinary Officer Juan Lubroth said in remarks delivered at a meeting on the Global Health Security Agenda (GHSA) in Jakarta, Indonesia (20-21 August) being attended by human and animal health authorities and experts from around the globe
According to Lubroth, the current Ebola outbreak in West Africa is a "tragic reminder" not only of the need for increased support for public health systems in the developing world, but also of the importance of ensuring that countries are able to monitor and respond to animal health diseases as well.
While curbing human-to-human transmission remains the most important focus in West Africa, the epidemic there is thought to have started when the virus crossed over from infected wildlife into the human population.
Other recent outbreaks of diseases affecting humans -- including avian influenza, Severe Acute Respiratory Syndrome (SARS) and Middle East respiratory syndrome (MERS) -- are believed to have had their start in animals. Indeed, an FAO report published last year highlighted that 70 percent of new infectious human diseases detected in recent decades are of animal origin.
Preparedness is key
"Zoonootic diseases that can make the jump from animals to humans are a real concern, but there is much that we can do before the jump occurs and outbreaks take place, causing loss of life and disrupting fragile livelihoods," said Lubroth.
"To be more resilient in the face of such risks, countries need the resources to be able to better understand where disease is coming from and to prevent it from ever reaching people in the first place. By understanding animal health threats, we have the potential to be ahead of the curve and help prevent human tragedies from happening," he added.
According to FAO, there is a need to rethink how the international community provides global health support, with a new focus on investment in infrastructure, systems and capacities at the national level to help reduce the risks of such emergencies happening in the first place and increase the resilience of communities and health systems to respond when they do.
To support such a transition, FAO and its partners are advocating what is known as the "One Health" approach, which looks at the interplay between environmental factors, animal health, and human health and brings human health professionals, veterinary specialists, sociologists, economists, and ecologists together to work on disease risks in a collaborative way.
At the Jakarta conference some 60 countries as well as international organizations like FAO, the World Health Organization (WHO), and the World Organisation for Animal Health (OIE) are discussing how to collaborate under the auspices of the GHSA, an international effort to strengthen health systems to help prevent, detect and respond to emerging disease threats.
In Jakarta, FAO is also making the point that better prevention of disease has long term-development benefits as well. Both animal and human diseases have broad impacts on societies, including reductions in food production and food availability that impact food security in the short term, as well as disruptions to rural economies and livelihoods that can linger for years.