Authors: Nathan Wolfe
5. THE FIRST PANDEMIC
1
There is a class of viruses, the endogenous viruses, which don’t strictly speaking “infect” us but live in our genetic material. Some endogenous viruses may have an even higher prevalence than HPV, yet they differ fundamentally from the free-living, or exogenous, viruses that represent our primary concern here. We will see these fascinating viruses again in chapter 7.
2
HPV and other viruses cause a great deal of global cancer burden and provide nontraditional approaches for preventing cancer that we’ll revisit in detail in chapter 11.
3
We’ll also revisit GB virus in chapter 11. Some research suggests that not only is this virus harmless; under some circumstances, it might actually be good for you.
4
Viral hemorrhagic fevers, such as Lassa fever, Ebola, and others, all share severe symptoms, which include among other things a pronounced tendency toward swelling, broken capillaries, large-scale bleeding, low blood pressure, and shock.
5
While the human malaria parasites are transmitted by mosquitoes from person to person, they still are considered “exclusively human agents.” This is because they don’t have another known animal reservoir and can’t be sustained without
both
the mosquito and human part of their complex life cycles. If it’s determined that another mammal can be infected with one of these parasites, then they’ll be demoted to Category Four.
6. ONE WORLD
1
Wallace led a fascinating life. Rather than working from a cushy boat like his contemporary and natural selection codiscoverer Darwin, he traveled on the cheap, selling specimens along the way to fund his expeditions. An excellent scientific biography of him as well as an accessible but detailed discussion of his findings in the Indonesian archipelago can be found in David Quammen’s book,
The Song of the Dodo
.
2
The Polynesians had incredible navigation skills, and though their boats were simple, they were highly seaworthy. At a moment in history when boats in the West rarely went beyond the line of sight with land, Polynesians managed to negotiate huge swaths of the world’s largest ocean. They fabricated their ships from two canoes, each dug out from tree trunks, which were lashed to each other with crossbeam planks to form a deck. They used coconut fibers and sap to seal seams.
3
Sue Savage-Rumbaugh, a primatologist from Georgia State University, has reported that bonobos go so far as to leave trail markers to help other group members find their way when conditions don’t permit them to follow each other using footprints.
4
As discussed in chapter 2, HIV is a hybrid virus consisting of parts of two monkey viruses that chimpanzees acquired, almost certainly through the hunting of these monkeys. Note: There are multiple HIV viruses that have entered into humans (i.e., HIV-1 M, HIV-1N, HIV-2, etc.). Here, when I refer to HIV, I mean exclusively HIV-1 M, the dominant pandemic virus that is responsible for over 99 percent of human cases.
5
The
latent period
differs subtly but in an important way from the
incubation period
for some microbes. Where the latent period refers to the time between exposure and infectiousness, the incubation period refers to the time between exposure and the first signs of disease. In the case of HIV, for example, infected individuals become contagious within the first few weeks after exposure, yet at this point they experience only generic symptoms like fever and rash. Most cases of HIV transmission actually occur during this acute infection period rather than after the incubation period for AIDS itself, which is generally some years later.
7. THE INTIMATE SPECIES
1
As noted in the book
Charlatan
by Pope Brock, which provides excellent background on Voronoff, “The only thing that [the insemination] produced was a novel, Félicien Champsaur’s
Nora, la guenon devenue femme—Nora, the Monkey Turned Woman.”
2
The account is described in a book on the papacy by the contemporary historian Peter De Rosa.
3
Interestingly, the first documented intravenous blood transfusion was from an animal to human, rather than from one human to another. In June 1667, Dr. Jean-Baptiste Denys, the physician to none other than King Louis XIV of France, administered a transfusion of sheep blood into a fifteen-year-old boy. Nothing is known about the sheep, but we know the boy survived.
4
Sadly, there is huge variation in the extent to which blood banks screen. Screening in developed countries is generally excellent, while in some parts of the world, it remains virtually nonexistent.
5
Patients with AIDS are not the only ones who are immunosuppressed. Transplant recipients commonly receive drugs that suppress the immune system in order to prevent organ rejection, which likely means that everyone receiving organs today, whether afflicted with AIDS or not, are at an increased risk of infection.
6
Marx and his colleagues argue that such multiple injections would naturally simulate the “serial passage” experiments done in laboratories with viruses. In these experiments, viruses are moved from animal to animal in a way that produces extensive opportunity for the accumulation of mutations that permit the virus to survive in a novel host.
8. VIRAL RUSH
1
While the changes we’ve experienced with large-scale industrialization of livestock production currently outweigh the benefits when it comes to microbes, that is not a necessary outcome. Industrial scale efficiencies in animal farming have the potential for better disease monitoring, and if done well could ultimately ensure that domestic animals remain separated from wild animals. Industrialization also serves to decrease the number of humans who have contact with living animals, which decreases the points when microbes can spill over. At the far end of this continuum would be fully artificial, or in vitro, meat. In vitro meat is animal flesh grown on cultures entirely independently from animals. The idea of cultured meat is currently unappetizing to many, and the health and other risks must be examined in depth. Nevertheless, it could have amazing benefits. Cheap factory-produced in vitro meat could address hunger issues and decrease the need for use of domestic and wild animals for meat, a situation that would radically decrease the introduction of novel microbes. Decreasing contact with domestic animals means decreasing contact with their microbes and the microbes they’ve acquired from their wild kin.
2
Cows are not the only species that have acquired prions by consuming their own kind. Another fascinating prion, kuru, a fatal neurodegenerative disease, moved in exactly this way among the Fore people of the Eastern Highlands Province of Papua New Guinea. The Fore practiced ritual cannibalism, consuming relatives and community members who had died and smearing the deceased’s brains on their bodies to help free their spirits. These mortuary feasts were determined to be the way kuru was transmitted. Following the prohibition of ritual cannibalism in the 1950s, the epidemic has now effectively come to an end.
10. MICROBE FORECASTING
1
Such swarms are also referred to as viral quasispecies in the scientific literature.
2
Ushahidi is a pioneering nonprofit technology company that works to improve collection, visualization, and mapping of information. The word
ushahidi
means “testimony” in Swahili, and the company was started after the postelection violence in Kenya in 2008 to help consolidate and map reports of violence.
3
The Google team that discovered that search trends correlate with actual influenza incidence included Larry Brilliant and Mark Smolinski, formerly of the
Google.org
Predict and Prevent project. It also included young Google engineers, who through Google policies can devote a percentage of their time to philanthropic or other endeavors. Both Larry and Mark have now joined Jeff Skoll, the entrepreneur, filmmaker, and philanthropist in his new endeavor, the Skoll Global Threats Fund, which focuses on ways to mitigate the threat from some of the most important risks of our time—they include, of course, pandemics.
4
Social networks are not the only social science approaches to early detection. Another approach is to use
prediction markets
. In the 2004–5 influenza season, researchers at the University of Iowa set up a futures market where nurses, pharmacists, and other health workers could trade and make money (in the form of an educational grant) on their sense of what was going on with influenza. The researchers showed that looking at market activity of local experts incentivized to choose correctly can also provide early warning.
11. THE GENTLE VIRUS
1
You may question the ethical decision of Jenner to experiment on a child with an unproven vaccine and then to expose the child to a known deadly disease. Yet while he has been critiqued for it, a more careful examination reveals something quite different. Because the rate of smallpox was relatively high, many adults would likely already have been exposed, making them inappropriate for the study, necessitating a study in children. Also, when he injected Phipps with smallpox it was part of an even earlier form of smallpox vaccination called variolation, in which patients were exposed to small amounts of actual smallpox virus (i.e., variola) in a controlled way to illicit an immune response to protect from natural infection. Variolation killed 1–3 percent, a crazy level by today’s standards but much lower than the 30 percent mortality among those who were naturally infected. Considering these factors, and that he also included his own son in these experiments, I think we can probably let Jenner off the hook.
2
Interestingly Rous didn’t win the Nobel for another fifty-five years, probably the longest period of time between a key discovery and the award of the prize! His finding was not well received in the field at the time, but some scientists recognized the importance of the discovery as he was nominated to the Nobel Committee in 1926.
3
Interestingly,
Toxoplasma gondii
may provide a scientific explanation for a commonly stereotyped set of behaviors. Recent attention to the “crazy cat lady syndrome,” as it is referenced in an article in the
New York Times
, points out that cat-hoarding behavior resembles the behavior of rodents infected with toxoplasma—affinity toward cats and immunity to the smell of their urine, for example. To date there have not been scientific studies to prove or disprove this hypothesis.
4
There is still debate on the relationship between viruses and cell-based life. In fact, viruses may not even all be related to each other. Some may have originated as the DNA of cell-based life forms while others may be descendants of life forms that predated the emergence of cell-based life.
5
My doctoral research was conducted largely in Borneo, in the Malaysian state of Sabah. I was lucky enough to get the assistance of the world’s most prominent wildlife veterinarian, Billy Karesh, who at the time was at the Wildlife Conservation Society. Billy took me under his wing, let me take part in his project, and introduced me to his Malaysian colleagues. I watched them conduct absolutely amazing work, tranquilizing wild orangutans with dart guns and moving them from small disappearing forest fragments to a large reserve that the Malaysian government had set aside for conservation. From my own research perspective, I had the invaluable opportunity to get specimens from elusive wild orangutans while they were being transported! During my time there, I spent many months working on a daily basis with Annelisa Kilbourn, the extraordinary wildlife veterinarian who died tragically during a plane crash some years later while working with gorillas in central Africa.
SOURCES
This section provides sources I used either directly to obtain figures or facts or indirectly as background. It also includes books (marked with an *) for those interested in further reading on topics raised in the individual chapters.
INTRODUCTION
Balfour, F. “A Young Life Ended by Avian Flu.”
Businessweek.com
, February 3, 2004.
*Barry, J. M.
The Great Influenza: The Epic Story of the Deadliest Plague in History.
New York: Viking, 2004.
“Bird Flu Claims First Thai Victim—January 26, 2004.”
CNN.com
World, January 26, 2004.
Centers for Disease Control and Prevention. “Childhood Influenza-Vaccination Coverage—United States, 2002–3 Influenza Season.”
MMWR
53 (2004): 863–66.
Chokephaibulkit, K., M. Uiprasertkul, P. Puthavathana, P. Chearskul, P. Auewarakul, S. F. Dowell, and N. Vanprapar. “A Child With Avian Influenza A (H5N1) Infection.”
Pediatric Infectious Disease Journal
24, no. 2 (2005): 162–66.
Clayton, D. H., and N. Wolfe. “The Adaptive Significance of Self-Medication.”
Trends in Evolution and Ecology
8 (1993):60–63; doi: 10.1016/0169-5347(93)90160–Q.
“Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO.” Global Alert and Response (GAR), World Health Organization, December 9, 2010;
www.who/int/csr/disease/avian_influenza/country/cases_table_2010_12_09/en/index.html
.
Duffy, S., L. A. Shackelton, and E. C. Holmes. “Rates of Evolutionary Change in Viruses: Patterns and Determinants.”
Nature Reviews Genetics
9 (2008): 267–76; doi: 10.1038/nrg2323.
“Epidemiology of WHO-Confirmed Human Cases of Avian A (H5N1) Infection.”
Weekly Epidemiological Record
(
WER
) 81, no. 26 (2006): 249–60.
“Historical Estimates of World Population.” International Programs, U.S. Census Bureau;
www.census.gov/ipc/www/worldhis.html
.
Johnson, N. P., and J. Mueller. “Updating the Accounts: Global Mortality of the 1918–1920 ‘Spanish’ Influenza Pandemic.”
Bulletin of the History of Medicine
76, no. 1 (2002): 105–15; doi:10.1353/bhm.2002.0022.