November 30, 2012
Changes in how humans live and travel have increased the spread of diseases we get from animals, a new series of reports says. The new reports, published in the journal Lancet, focus on zoonotic infections. These are diseases that spread from other animals to humans. Infections in wildlife may be spread to humans by carriers such as mosquitoes and ticks. Sometimes they are spread by direct contact. All of these contacts have increased, the Lancet articles say. Reasons include widespread changes in land use and more world trade and travel. For example, people may be exposed to wildlife for the first time when an area opens up to logging or farming. Some infections that spread to humans from animals, such as HIV, have become pandemics. This means they affect many people across a wide area. Until now, scientists have never predicted that an infection would become a pandemic. But scientists now have tools to make such predictions possible in the future, the Lancet articles say. They say that preventing and controlling infections will require scientists and public health officials to work together. National Science Foundation News wrote about the articles November 30.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Have you ever heard of a "zoonosis?" It may be the most important medical condition you've never heard of.
Zoonoses are infections spread between species of animals. Usually, the term is used to describe infections spread from animals to humans. In fact, zoonoses account for about 60% of all human infections.
The most harmful zoonoses are ones that spread rapidly between humans across a large region. This is called a pandemic. Some pandemics are notorious for how deadly they are and how quickly they spread. Some notable examples include:
More recent pandemics include malaria. This disease accounts for about 650,000 deaths each year. The HIV pandemic has caused about 25 million deaths since the early 1980s.
None of the major pandemics was predicted before it emerged as a serious health threat.
For these reasons and because new infections continue to be discovered, the journal Lancet has a new series of articles about pandemics caused by zoonoses.
Here are some of the highlights:
What Changes Can I Make Now?
Zoonotic infections represent some of the biggest health threats worldwide. Fortunately, they are also among the most preventable.
Public health measures play a big role in preventing the spread of infections. One of the most important is ensuring clean water supplies. But you also can take steps to reduce the chances that you will become sick from a zoonotic infection. For example:
What Can I Expect Looking to the Future?
These reports about zoonotic infections were published in advance of a conference to be held in Washington, D.C., next month. It is sponsored by the Forum on Microbial Threats, part of the Institute of Medicine. Look for more news from this meeting.
As outlined in this series of articles, the future should bring important progress in our ability to predict and respond to outbreaks of zoonotic infections. I hope this will happen well before the next big pandemic.