Taken in isolation, the news reports that polio appears to have returned to Syria for the first time since the late 1990s, that dengue and yellow fever is showing up across the southern United States and that Texas has had its worst year ever for West Nile virus all seem like separate disease outbreaks.
And they are. But taken together, they should also serve as a reminder that disease, especially infectious disease, doesn’t spread independent of human behavior – and bad behavior on the other side of the planet can kill here.
If polio is confirmed in Syria, most would agree it’s legit to blame this on the disruption in public health services due to the civil war.
The rise of dengue and yellow fever in Los Angeles or Dallas is sometimes attributed to warming temperatures due to climate change, which it may be, but the spread of these ‘tropical diseases’ out of the tropics is also just as likely the result of growing global urbanization (the mosquitoes that carry these bugs seem to like cities), long-distance travel and ineffective disease control measures.
West Nile virus doesn’t make the news much anymore, now that it’s no longer new. Nobody’s quite sure how it got here from its original home in Uganda (it was first identified in New York City, in the late 1990s and in birds) but it appears here to stay – and has so far sickened an estimated 300,000 and killed about 1,200 people.
Most people who get WNV don’t get sick and die. But if its Asian cousin, Japanese encephalitis, JE, ever makes it to American shores we can plan on a media panic – since it kills one in four people who get the disease and looks a lot nastier. Fortunately, as Humanosphere recently reported, there’s a stepped up effort to vaccinate against JE in India and China.
Making the case that we should take the threat of infectious disease seriously has perhaps never been easier, since we now have so many new or expanding such threats to choose from. We haven’t even talked about the rise of drug-resistant forms of tuberculosis and malaria – or the Hollywood-spread virus that instantly turned most of humanity into zombies in World War Z.
Preventing these diseases, if not zombies, has been central to the global health agenda. We’ve made tremendous progress on a number of fronts through greatly expanded child vaccinations and massive increases in funding for fighting HIV, TB and malaria. But these outbreaks demonstrate the need for a stable and steadfast defense.
Infectious diseases are always threatening to break through our defenses. This makes them a constant threat, but also a good target for specific interventions like vaccines or bed nets. Non-infectious or non-communicable diseases are not carried by mosquitoes, or infected zombies, but they can be just as easily spread with global consequences. Take the rise of diabetes in China that is accompanying this nation’s rapid economic growth. The same trend is taking place here in the U.S., concentrated mostly among poor Americans.
It’s not a mosquito spreading this. It’s how we eat and live.
Health has never been more global. We have never been more connected, for better and for worse. We can learn from these trends if we can see these disease outbreaks in context – as not so much isolated risks we can ‘contain’ but as symptoms of an ever-changing, ever challenged, system.