Quotes About Epidemiology

So much of what we are currently seeing as far as human suffering and misery comes from diseases that should have been preventable but were not.

Center for Disease Control in Atlanta is a striking case in point. Its network of sample hospitals allowed it to first "discover"—in the epidemiological sense—such hitherto unknown diseases as toxic shock syndrome, Legionnaire's disease, and AIDS.

Seventy-five percent of all emerging diseases in the past century—Ebola, HIV, COVID-19—were passed to the human population from animals, known as zoonotic transmission.

This was a Third World disease attacking First World people. The world is now divided into Third and First, not Old and New. Pathogens once confined to the Third World are now making deadly inroads into the First. This is the future trajectory of disease on planet Earth.

That European diseases ran rampant in the New World is an old story, but recent discoveries in genetics, epidemiology, and archaeology have painted a picture of the die-off that is truly apocalyptic; the lived experience of the indigenous communities during this genocide exceeds the worst that any horror movie has imagined.

Epidemiologists generally agree that smallpox is the cruelest disease ever to afflict the human race.

In his groundbreaking book Guns, Germs, and Steel, biologist Jared Diamond poses the question: Why did Old World diseases devastate the New World and not the other way around? Why did disease move in only one direction?* The answer lies in how the lives of Old World and New World people diverged after that cross-continental migration more than fifteen thousand years ago.

Here are the names of some emerging viruses: Lassa. Rift Valley. Oropouche. Rocio. Q. Guanarito. VEE. Monkeypox. Dengue. Chikungunya. The hantaviruses. Machupo. Junin. The rabieslike strains Mokola and Duvenhage. LeDantec. The Kyasanur Forest brain virus.

What made it particularly interesting was that it multiplied easily in various species, in monkeys, humans, guinea pigs. It was extremely lethal in these species, which meant that its original host was probably not monkeys, humans, or guinea pigs but some other animal or insect that it did not kill. A virus does not generally kill its natural host.

When the Next Big One comes, we can guess, it will likely conform to the same perverse pattern, high infectivity preceding notable symptoms. That will help it to move through cities and airports like an angel of death.

It comes and it goes. But epidemiologists have recognized that, with measles virus, as with other pathogens, there's a critical minimum size of the host population, below which it can't persist indefinitely as an endemic, circulating infection. This is known as the critical community size (CCS), an important parameter in disease dynamics.

Lyme disease, psittacosis, Q fever: These three differ wildly in their particulars but share two traits in common. They are all zoonotic and they are all bacterial.

I think the virus is present all the time, within reservoir species," he told me. "And sometimes there is transmission from reservoir species to other species.

If you look at the world from the point of view of a hungry virus," the historian William H. McNeill has noted, "or even a bacterium—we offer a magnificent feeding ground with all our billions of human bodies, where, in the very recent past, there were only half as many people. In some 25 or 27 years, we have doubled in number. A marvelous target for any organism that can adapt itself to invading us.

Lyme disease, psittacosis, Q fever: These three differ wildly in their particulars but share two traits in common. They are all zoonotic and they are all bacterial. They stand as reminders that not every bad, stubborn, new bug is a virus.

Hamer was especially interested in why diseases such as influenza, diphtheria, and measles seem to mount into major outbreaks in a cyclical pattern—rising to a high case count, fading away, rising again after a certain interval

Now here's the part that, as it percolates into your brain, should cause a shudder: Scientists think that each of those twelve groups (eight of HIV-2, four of HIV-1) reflects an independent instance of cross-species transmission. Twelve spillovers.

Zoonoses from wildlife represent the most significant, growing threat to global health of all EIDs

It worries the flu scientists because they know that H5N1 influenza is (1) extremely virulent in people, with a high lethality though a relatively low number of cases, and yet (2) poorly transmissible, so far, from human to human. It'll kill you if you catch it, very likely, but you're unlikely to catch it except

Zoonotic pathogens can hide. That's what makes them so interesting, so complicated, and so problematic.

Everything comes from somewhere, and strange new infectious diseases, emerging abruptly among humans, come mostly from nonhuman animals.

A zoonosis is an animal infection that's transmissible to humans.

The event of transmission, when a pathogen passes from one kind of host to another, is called spillover.

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