Epidemics have sickened and killed millions of people throughout history. HIV/AIDS has claimed 25 million lives since it was first identified in 1981. It's one of the new infectious diseases, but much older diseases still cause countless deaths and suffering: cholera, yellow fever, tuberculosis and malaria, to name a few.
A simple bite from a mosquito can end someone's life or change it forever. A sneeze, a handshake or even sharing of a desk can do the same thing. That's how H1N1 - or swine flu - spread around the world a few years ago. Infectious diseases such as malaria, HIV/AIDS and tuberculosis are among the leading causes of death globally. Diarrheal diseases like cholera kill more than 100,000 people every year. Haiti and the Dominican Republic say they need $2 billion to fight the cholera epidemic that first erupted in 2010. Since then, it has killed nearly 8,000 people and sickened more than half a million.
At a Washington symposium, leading U.S. health experts met to discuss the challenge of confronting persistent and newly-emerging infectious diseases. Dr. Anthony Fauci, with the National Institutes of Health, said most of these diseases result from the fact that as human populations grow, people come into closer contact with animals.
"When you have encroachment upon the environment, and you put humans in greater contact with animals that they would not have been in contact with, often that is one of, not the only, but one of the major contributors to the issue of emerging infectious diseases," said Fauci.
New threats, better tools
New infectious diseases also emerge when bacteria or viruses mutate and no longer respond to drugs that once killed them. An example is drug-resistant tuberculosis. Other factors include climate change or the expanded habitat of an infectious agent. Dengue is now found in half the countries of the world. It's caused by a bite from a mosquito infected with the virus.
While these threats are great, we now have better tools to fight these diseases, said Dr. Thomas Frieden, head of the U.S Centers for Disease Control and Prevention:
"We’ve got new technology, we’ve got better communication, we’ve got better lab work, more people who are trained," he said.
Vaccines prove crucial
This means less time elapses between the discovery of a new disease, identifying its genetic makeup and developing drugs or a vaccine to protect against it.
"Immunization is really one of the great discoveries of the past century. Today’s vaccines prevent about three million deaths every single year. And the vaccines that are being rolled out can prevent millions more," said Frieden.
Controlling these diseases depends on the continued vigilance of public health systems throughout the world. A recent study found that weaknesses in public health infrastructure are the major driving factors in infectious disease outbreaks. A case in point: the cholera outbreak in Haiti after the massive 2010 earthquake destroyed the country's ability to care for its sick.