For this column today, I am summarizing the article bearing the same title written by Jim Robbins, an American writer of the Science section of the New York Times. The topic is well within the theme of my column, which is Environment.
The term “ecosystem services” is widely known to both biologists and economists to mean the benefits that humans derive from natural ecosystems such as forests and coral reefs.
Common examples include filtering of the water we drink by forests, pollination of plants by insects and birds, production of fish by coral reefs, protection from erosion of land by mangroves and reefs, and many other services.
If humans fail to protect these natural ecosystems, they will degrade and break down and give us problems that we never anticipated.
The author, Jim Robbins, gives an example of a “developing model of an infectious disease that shows that most epidemics –AIDS, Ebola, West Nile, SARS, Lyme disease, and hundreds more that have occurred over the last several decades — don’t just happen. They are the result of things people do to nature….Disease, it turns out, is largely an environmental issue. Sixty percent of emerging infectious diseases that affect humans are zoonotic — they originate in animals. And more than two-thirds of those originate in wildlife.”
The infectious zoonotic diseases are not only a public health issue but they are also an economic one. An estimate by the World Bank of a severe influenza pandemic is $3 trillion U.S. dollars.
The International Livestock Research Institute reported that two million people are killed each year by diseases that spread to humans from wild and domestic animals.
The Nipah virus in South Asia, and the closely- related Hendra virus in Australia (both belonging to henipah viruses) is an urgent example of how disrupting an ecosystem can cause disease.
The virus originated with flying foxes or fruit bats, Pteropus vampyrus, which is also found in the Philippines. These bats eat fruits by masticating the pulp, and then spitting out the pulp and the seeds.
This virus has co-evolved with bats, and does not cause severe disease in bats, but when it enters species that did not co-evolve with them, a horror show can occur.
This occurred in 1999 in Malaysia when a fruit bat probably dropped a piece of chewed fruit into a piggery near a forest. The pigs became infected with the virus, amplified it, and it jumped to humans. The result: 276 people got infected, of whom 106 died, and many others suffered permanent and crippling neurological disorders.
And there are no cures. There are no vaccines. There were 12 smaller outbreaks in South Asia.
The Hendra virus has killed four people and dozens of horses in Australia. The virus could evolve further to become easily transported throughout Asia , and it is predicted to spread throughout Asia and the world.
It is important to know the real causes of the emerging diseases. These diseases in the last 30 to 40 years have come about because of human encroachment into wildlands as well as the fragmentation of forests.
A project called PREDICT funded by USAID is studying zoonotic diseases. One objective is to spot them before they spread to a wider area.
The program ONE HEALTH has been established at Silliman University and the University of the Philippines-Los Banos by Dr. George W. Beran and his colleagues at the Iowa State University to deal with the rabies problem and zoonotic diseases.
