Tag Archives: plague

Professor Peter Piot

No, he didn’t pick a peck of pickled peppers. He “co-discovered the Ebola virus in 1976“. And in 2015, just now, he said this:

“Our world is getting more vulnerable to big epidemics, because of population expansion, huge mobility and more intense contact between animals and people.

“My concern,” he said, “is that when [the Ebola outbreak] is over we will just forget about it. We need to be better prepared and we need to invest in vaccines and treatment.

“It’s like a fire brigade – you don’t start to set up a fire brigade when some house is on fire.”

JAMA on Ebola

Here’s a Journal of the American Medical Association editorial on the level of preparedness in the United States for something like Ebola:

The Dallas case raises significant concerns about national preparedness for public health emergencies. Health emergencies (eg, anthrax, SARS, novel influenzas, and hurricanes Katrina and Sandy) spurred federal preparedness planning and funding, including the Pandemic and All-Hazards Preparedness Act (reauthorized in 2013),2 to ensure that federal, state, and more than 3500 local health departments coordinate their efforts effectively in disasters. Significant investments have been made in staff training, interagency coordination, legal reform, and planning.

Preparedness efforts like these are essential, but inadequate. Overall, investment in key health system functions has been in decline. The CDC’s 2013 budget declined 10%, or nearly $1 billion, from 2012.3 Since 2008, state and local public health agencies have lost more than 50 000 staff (almost 20% of their workforce),4 requiring cuts to preparedness programs. Many EMS agencies and hospitals are also strained, leading the Institute of Medicine to warn in 2012 of an “enormous potential for confusion, chaos, and flawed decision-making”5 in a public health emergency. Insufficient funding in a research and data infrastructure limits the ability to identify weaknesses and learn from mistakes. Rare, novel infections such as Ebola expose the difficulty of diagnosis and adherence to arduous infection control protocols. Following the nurses’ EVD diagnosis in Dallas, future Ebola patients may be directed to centers with advanced training, PPE, and well-equipped isolation rooms. Vinson was transferred to Emory Hospital in Atlanta on October 15.

Now, the American Medical Association is a special interest group. The United States has the world’s largest economy and spends more than any other country on health care, even as a fraction of that economy. So I don’t like to hear that the answer is throwing more money at the problem. I think we have a patchwork of doctors, hospitals, and insurance companies each looking out for their own interests, and what it adds up to shouldn’t really be called a “health care system”. But we’ve been warned – we need to get a lot smarter before we have to deal with something like SARS or a novel influenza.

“how plagues really work”

This article from Aeon argues that we shouldn’t worry so much about some random mutation of an animal virus coming out of the jungle and destroying us. Instead, it is the conditions in human society that allow new diseases to evolve and adapt to us that we should be more concerned about.

According to this argument, new germs that erupt into our species will be potential triggers for pandemics, while germs that have a long history in a host species will have evolved to be relatively benign.

Many health experts take the notion further, contending that any coming plague will come from human intrusion into the natural world. One risk, they suggest, comes when hungry people in Africa and elsewhere forge deep into forests and jungles to hunt ‘bushmeat’ – rodents, rabbits, monkeys, apes – with exposure to dangerous pathogens the unhappy result. Those pathogens move silently among wild animals, but can also explode with terrifying ferocity among people when humans venture where they shouldn’t. According to the same line of thought, another proposed risk would result when birds spread a new pandemic strain to chickens in factory farms and, ultimately, to us.

But there’s something in these scenarios that’s not entirely logical. There is nothing new in the intimate contact between animals and people. Our hominid ancestors lived on wildlife before we ever evolved into Homo sapiens: that’s why anthropologists call them hunter-gatherers, a term that still applies to some modern peoples, including bushmeat hunters in West Africa. After domesticating animals, we lived close beside them, keeping cows, pigs and chickens in farmyards and even within households for thousands of years. Pandemics arise out of more than mere contact between human beings and animals: from an evolutionary point of view, there is a missing step between animal pathogen and human pandemic that’s been almost completely overlooked in these terrifying but entirely speculative ideas.

According to the evolutionary epidemiologist Paul W Ewald of the University of Louisville, the most dangerous infectious diseases are almost always not animal diseases freshly broken into the human species, but diseases adapted to humanity over time: smallpox, malaria, tuberculosis, leprosy, typhus, yellow fever, polio. In order to adapt to the human species, a germ needs to cycle among people – from person to person to person. In each iteration, the strains best adapted to transmission will be the ones that spread. So natural selection will push circulating strains towards more and more effective transmission, and therefore towards increasing adaptation to human hosts. This process necessarily takes place among people.

It goes on to talk about some major plagues in history, including the 1918 influenza which is “the rod by which all other pandemics are measured”.

We could take some comfort in all this – the diseases that cause the most suffering are the ones that evolve within and amongst people, suggesting that there should always be sub-groups of people who develop immunity to them. This suggests that despite terrible suffering, they shouldn’t represent an existential threat to the species. There is a plague in history that I find even more horrifying that 1918 or the Black Death, and that is the almost complete ravaging of Native American populations after 1492. That was a case of diseases that evolved in and amongst human populations, that were then unleashed on another isolated population (possibly a very large one) that had no resistance to them. So as much as we worry about international travel spreading germs, maybe it means it would be harder for some germ to completely sneak up on us, since there are virtually no human populations that are truly isolated anymore.

There is still the worst possible scenario though – somebody taking one of the ugly human-adapted diseases mentioned in this article, and purposely modifying it into something that the population has no immunity to.

more on Ebola

Spillover: Animal Infections and the Next Human Pandemic

NPR has an interview with the author of this book. An excerpt:

How did we go from a virus that’s found largely in animals to a virus that can be deadly for humans — and spread across four countries?

Human behavior is causing this problem. More and more, we’re going into wild, diverse ecosystems around the world, especially tropical forests.

Some scientists believe that each individual species of animal, plant, bacterium and fungus in these places carries at least one unique virus, maybe even 10 of them.

We, humans, go into those wild ecosystems. We cut down trees. We build mines, roads and villages. We kill the animals and eat them. Or we capture them and transport them around the world.

In doing that, we expose ourselves to all these viruses living around the world. That gives the viruses the opportunity to spill over into humans. Then in some cases, once the virus makes that first spillover, it discovers that it might be highly transmissible in humans. Then you might have an epidemic or a pandemic…

The experts I talk to say the next big one will almost certainly be caused by a zoonotic virus, coming out of animals. And it’s likely to be one that is transmissible through the respiratory route — that is, through a sneeze or cough.

Ebola is not an easily transmissible virus. It requires direct contact with bodily fluids. It doesn’t travel on the respiratory route.

Viruses such as the and SARS are much more of a concern to scientists that study these things than Ebola because they are already transmissible through the respiratory route. They are also highly adaptable, and they mutate quickly.

In terms of the next big one, SARS and MERS stand higher on the watch list than Ebola.

do airplanes spread horrible plagues?

Are you more likely to be exposed to germs on an airplane because of the recirculation of air? No, according to Wired, because the air is very well filtered and constantly exchanged with outside air. Now, I too have gotten that cold right after traveling. So I probably got that cold from something I touched at the airport T.G.I. Fridays. So the moral of the story, I think, is always remember to wash your hands at the airport before you pick your nose. Other theories I have come up with, without trying to collect a shred of scientific evidence, is that the dry air on planes dries out your mucous membranes so there is less of a barrier to germs, and/or that the general stress and lack of rest when you travel just wears down your body’s defenses to the ordinary garden-variety germs you encounter every day.

the zombie cat virus

If there’s one thing I don’t put a whole lot of stock in, it’s scientific and medical information provided by random websites. Like this one, Corante, which claims that toxoplasma, a virus that incubates in cats, affects rats’ brains so that they are less afraid of cats. Then it goes on to suggest that half of all people are infected with this virus, and that it has unknown, subtle but possibly harmful effects on people. It just makes me think about how little we really know about most of the vast community of microorganisms inhabiting our bodies. The scariest thing would be something that is harmful, but has a long incubation period so it can infect a large fraction of the population before we are even aware of it.

Ebola

The Ebola situation makes for some scary headlines. From the CDC, the number of cases as I write this (July 31) in Guinea, Liberia, and Sierra Leone is 1,322 of which 728 (55%) have died.

Ebola is a disease with no known cure which incubates in bats. To put these numbers in perspective, Wikipedia says that 8,231 people in Haiti have died of cholera since 2010, a disease we know the exact cause of and exactly how to prevent (clean drinking water) and treat (staying hydrated with clean drinking water).