Man’s worst friend
If you live in the USA, you’re 40 times more likely to end up in hospital due to a Christmas tree decoration than a shark attack, but (rough guess) 40 billion times less likely to end up on the news. Sharks have a bad press, and rightly so judging by some of the stories in Juliet Eilperin’s Demon Fish. For instance, did you know that baby tiger sharks eat each other in the womb? I didn’t, but I was sure that other animals were far more dangerous to human life than the Great White. There were 216 million cases of malaria in 2010 according to the WHO with 537 000 to 907 000 deaths, and mosquitoes also transmit the dengue fever that infects 50 to 100 million people each year and kills 12,500 to 25,000.
The worst killers though are chickens, cows and other livestock. Mapping of poverty and likely zoonoses hotspots, a report for the UK’s Department for International Development, estimates that each year 2.5 billion people fall ill and 2.7 million die from zoonoses, diseases transmitted by animals, with 1.5 million victims killed by gastrointestinal diseases alone, after eating infected meat, eggs or dairy products.
Some of the findings are what you might expect, for example the strong association of poverty, hunger, livestock keeping and zoonoses. Nineteen developing countries account for 75% of the global burden of disease due to zoonoses. Among the surprises (for me anyway) was the high figure for the urban poor depending on livestock: 10% (versus 70% in rural areas), although thinking about it, a lot of this may be poultry and not need much space or investment.
Emerging zoonotic diseases are a big worry. HIV/AIDS is the most dramatic example of a condition that appeared first in animals before crossing the species barrier, and there are fears that more recent diseases such as avian influenza may evolve to become transmittable by humans to other humans. There are more such emerging diseases than you may think. The report reviews 43 new or newly reported events since 2004. Most are viral and originate in wild animals and occur on every continent. But here’s another surprise: there appear to be clusters in the northeast US, Europe, South America and South East Asia.
That may simply reflect better surveillance in these areas. The chances of a new disease being spotted are slim when, as the authors point out, 99.9% of livestock losses in sub-Saharan Africa do not appear in official reports and at least half of these losses are probably due to notifiable diseases. Even so, some countries do have successful disease monitoring and control systems. Botswana is one of the case studies in a forthcoming OECD report Livestock Diseases: Prevention, Control and Compensation Schemes. The country exports beef to the EU and other high-value markets and has put in place an efficient system for controlling foot and mouth disease (FMD).
The UK report was co-written by researchers from the Hanoi School of Public Health, and Vietnam is another of the case studies. Nearly 50 million birds were culled in Vietnam because of avian influenza over 2003-2010, but the report says the compensation scheme hasn’t changed livestock owners’ behaviour much because it’s too little, too late and too complicated. Or top put it another way “if the appropriate agents do not consider it in their own best interests to adopt practices of animal husbandry for disease prevention, and reporting and reacting to disease outbreaks, no policy framework can be expected to work well.”
And in case you’re wondering what compensation you can expect for a shark attack, the Egyptian government paid $50,000 dollars to a Russian tourist whose hand was bitten off. Appropriately enough, the web site where I read this story has an ad for “5 foods never to eat”.