This blog is intended to go along with Population: An Introduction to Concepts and Issues, by John R. Weeks, published by Cengage Learning. The latest edition is the 13th (it will be out in January 2020), but this blog is meant to complement any edition of the book by showing the way in which demographic issues are regularly in the news.

You can download an iPhone app for the 13th edition from the App Store (search for Weeks Population).

If you are a user of my textbook and would like to suggest a blog post idea, please email me at: john.weeks@sdsu.edu

Thursday, January 14, 2016

Can Ebola Be Wiped Out?

We all came out of Africa historically, and a lot of nasty diseases also seem to have originated there. That is one of the many reasons that the highest mortality rates in the world are in Africa, as pointed out a few days ago by Joseph Chamie, former director of the UN Population Division.
Despite remarkable reductions in mortality, 13 sub-Saharan African countries — 1 out of every 20 people in the world — have yet to achieve life expectancies at birth of 55 years, the global average attained a half century ago...The world’s lowest life expectancies at birth that fall just under 50 years old are found in the Central African Republic, Lesotho and Swaziland.
In recent times, HIV came out of Africa as did, of course, Ebola. The World Health Organization today announced that the latest round of Ebola is over--for now. It won't be over for good, however, until we figure out exactly where it "lives" between flare-ups. Nature has a good summary today of the search for the source of this devil of a disease.
It is no easy task. Since the disease first emerged in Zaire (now the Democratic Republic of the Congo) 40 years ago, efforts to trace the origins of the outbreaks, including the most recent one, have come up frustratingly empty. Wild gorillas and chimpanzees in central Africa have experienced occasional Ebola outbreaks. But like humans, these species are too ravaged by the virus to serve as its natural host. Experts say that a reservoir species is likely to harbour the virus only at low levels, and without becoming sick.
The leading candidates are several species of fruit bat from across central and West Africa — where all known Ebola outbreaks have originated — that are often hunted for meat. A 2005 study1uncovered Ebola genetic material in some fruit bats from Gabon and the Democratic Republic of the Congo, and detected Ebola antibodies in the blood of others. Marburg virus, which is closely related to Ebola, is thought to be transmitted by fruit bats.
But the evidence is not yet convincing that fruit bats are, in fact, the culprits.
Some researchers advise casting the net even wider. “I don’t buy the bat story for Ebola virus, not at all,” says virologist Jens Kuhn of the US National Institute of Allergy and Infectious Diseases at Fort Detrick, Maryland. He thinks that bats are much too abundant and too closely associated with humans to explain an infection that has emerged just two dozen times over the past four decades. “It’s going to be a strange host,” he says. Even arthropods or fungi could be possibilities, he adds.
However, one of the themes that runs through the story is that the disease is most likely spread when humans eat animals that act as a reservoir for the disease. You can see where I'm going. If we give up meat, we may stop the spread of a lot of diseases. Just saying... 

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