infectious disease


What’s Killing Us: Infographic Edition | 

Cause of Untimely Death

This awkward infographic comes to us from the Twitter feed of Bill Gates. Ther are some curious choices about the design choices, but it gets the facts across and alerts some things I did not know. For example, deaths caused by typhoid increased between 2005 and 2010. It is not surprising to see that natural disasters are taking more lives too early.

What stood out to you when first looking at the inforgraphic?

Why global health? Polio in Syria, Texas dengue, West Nile’s killer cousin | 

Dengue is spreading globally
Dengue is spreading globally

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.

Child receives polio vaccine
Child receives polio vaccine

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. Continue reading

Non-review of book ‘Spillover’ and the threat of deadly red herrings | 

Flickr, JudyGr

The risk of red herrings

I have always loved the work of David Quammen, someone I would describe as a science adventure writer. Quammen was in Seattle recently to promote his new book about the animal-human disease connection, Spillover. It’s getting good reviews, such as in Time magazine and the New York Times.

This is a non-review of Quammen’s book because I haven’t read it and missed the lecture.

My purpose here is only to use Quammen’s book tour to point out the risk of deadly red herrings. Continue reading

Mapping where new diseases come from: Zoonotics | 

Many, if not most, infectious diseases that afflict humans start out as animal diseases. That’s what the field of zoonotics is about — and why so many human disease experts worry about a flu that afflicts mostly birds (H5N1, aka avian influenza).

A mysterious killer of children in Cambodia is big news at the moment and it may well be a zoonotic disease.

A new study that mapped zoonotic hotspots reports one general finding that may challenge common wisdom — the finding that India and parts of Africa are responsible for most of the global animal-human disease transfer phenomenon.

News reports and expert commentary tend to focus on Asia, China especially, as central station for infectious disease (which does appear to be the case for bird flu anyway). This report may alter perspectives.

As this one map from the report showing poultry density indicates, India is actually a much bigger contributor to zoonotic disease:


Global poultry density

Other countries in sub-Saharan Africa like Ethiopia, Nigeria and Tanzania are also major zoonotic hotspots. As Reuters reports, this is an increasing problem that is not limited to poor or middle-income countries:

A global study mapping human diseases that come from animals like tuberculosis, AIDS, bird flu or Rift Valley fever has found that just 13 such diseases are responsible for 2.4 billion cases of human illness and 2.2 million deaths a year…. It also found the United States and Europe – especially Britain – Brazil and parts of Southeast Asia may be becoming hotspots of “emerging zoonoses”, which are infecting humans for the first time, are especially virulent or are becoming drug resistant.