Thursday, October 23, 2014

David Quammen's "Spillover: Animal Infections and the Next Human Pandemic" follows on Garret's book in the 90s

Author: David Quammen

Title: "Spillover: Animal Infections and the Next Human Pandemic"

Publication: W.W. Norton. 2012, ISBN 978-0-393-06680-7, 588 pages, indexed, 9 long chapters, 115 short sections.
Amazon link here
Quammen, well known for non-fiction for National Geographic, has provided a detailed historical examination of almost all major infectious disease capable of causing pandemics. 

One of the most obvious reactions is the variability of the way infectious disease works and plays out.  Epidemiology principles are similar for viruses, bacteria, fungi or protists.  Many but not all infectious agents have reservoirs in animal hosts, and some are brought to humans by insects. Others arrive at the human body through cultural practices in hunting and preparing food, or sometimes having poultry or animals in close proximity to households.  Diseases spread in a variety of ways, but the three main patterns are airborne, direct blood or body fluid contact on any surface or in extremely close contact, and sexual contact or other very deep contact such as with intravenous needles.

Quammen discusses many agents that are relatively obscure, starting with Hendra in horses in Australia. But in time he gets to the important and well known epidemics.  He gives a detailed history of SARS, in Singapore and southeast Asia, where contact tracing did get it under control.  It isn’t long before he gets into the mathematics of epidemiology, with a touch of differential equations.  
In chapter 6, he discusses how viral infections work and why RNA viruses mutate more rapidly than DNA viruses.  Among RNA viruses, retroviruses behave very differently because of the use of reverse transcriptase and the use of the nucleus of the cell to create more copies. 

The book predates the current outbreak of Ebola in West Africa, and the recent cases in the United States (in Dallas, and as of today, New York City).  The author gives two detailed case histories of Marburg (Europeans who explored caves in Uganda frequented by bats) one of whom survived only to lose her hair, to have it grow back gray afterwards.  

There has been controversy in the media about speculation as to whether Ebola could become more contagious (it doesn’t naturally go to the respiratory tract), or whether the incubation period is longer than supposed, and maybe even asymptotically indefinite. I see that Quammen has a new short book “Ebola: The Natural and Human History of a Deadly Virus”, published Oct. 20, 2014, which I have just ordered.  (It’s on Kindle, too.) 

But the most interesting part of the book is the history of HIV (“The Chimp and the River”), which splits into the history of several viruses.  There was a virus called HTLV-1, which causes leukemia, known before HTLV-III which became called HIV.  The author traces the original infection of man by primates in Africa, in the area known as the Congo, back in 1908.   The virus slowly percolated, causing immune dysfunction that would not be noticed at first in a society with so many diseases.  But when hypodermics were introduced (and reused because of cost), infection probably increased rapidly in the 1960s and 1970s.  Quammen maintains that infection was probably propagated then my mostly heterosexual sex.  Although transmission from women to men was not as efficient as from men to women (or to other men in anal intercourse), it was probably sufficient to sustain the epidemic (according to his calculus homework, anyway) in Africa.

I’ve often related the scary history of the politics of AIDS in Texas in the early 1980s, especially before HIV was identified and a test could be developed.  Some members of the religious right (the “Dallas Doctors Against AIDS”) tried to introduce some very draconian anti-gay legislation in 1983, claiming that gay men, as a closed group practicing anal intercourse, “amplified” the presence of the (then) putative virus to the point that I might mutate and threaten the general population.  Quammen’s book shows that the history of viruses, especially slow viruses like HIV, is so pervasive that this idea is just nonsense. 
Quammen’s penultimate chapter does deal with influenza, particular swine and bird flu, and the issue of whether avian influenza would ever become efficiently transmitted from human to human. 
Quammen’s verbal description of life in Africa is often quite detailed and colorful. 
The book is a logical sequel to Laurie Garrett's "The Coming Plague: Newly Emerging Diseases in a World out of Balance" (1995, Penguin) and even Robert Preston's "The Hot Zone" (1994).
Also consider the ABC TV movie "Fatal Contact" Bird Flu in America" (2005) by David Pearce.   

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