Rise of the bugs

Microscopic beasties have not suddenly bubbled up from nowhere

[Audio Available] The world has not suddenly overflowed with microscopic beasties, so why does it feel like someone kicked over Pandora’s box?

Microscopic beasties have not suddenly bubbled up from nowhere.

These pathogens — viruses, bacteria, fungi, protozoa, worms, and infectious proteins called prions — make headlines with increasing frequency and no sign of slowing.

We now see three new infectious diseases per year.

70% of those are zoonotic, meaning the infection jumped from an animal to a human. About 1.67 million undiscovered viruses, one half-million of which could infect people, continue to hide in mammals and birds globally.

So, what’s behind the host-hopping trend?

Photo by engin akyurt on Unsplash

Often, it’s many things coming together to create a scene where a microbe finds a human. These spillover events happen when a virus (or other pathogens) spills out of an animal and infects a human. If the virus has pandemic-potential will depend on whether it can spread human-to-human.

Many viruses cannot enter human cells. Our cells won’t let just anyone pass through the cell membrane, but the viruses that enter can trick our cells into making “baby” viruses that spread to other people. If that happens easily enough, then we have a problem because the virus no longer needs the host animal to continue infecting people.

Most zoonotic diseases find us 1 of 3 ways.


The animal poo finds you. A dangerous example is E. coli O157, which contaminates food through cow feces. Bat feces also reach humans through farming or bats roosting close to residences. Spillover can happen in a domestic setting, from pet cats- or dogs to owners.

Photo by Stijn te Strake on Unsplash


Butchering of game animals or eating the undercooked meat. A study focusing on people who raised duiker — a small deer-like animal — found that workers had a higher rate of exposure to Ebola. People hunt wild game all over the world, so it’s important to know how people can safely butcher meat privately — and not just in the US.

Photo by Hunter Brumels on Unsplash


Bites from animals and insects that carry a pathogen can FastTrack an infectious agent past your skin barrier. Mosquitoes are the most threatening disease vector — a vector is something that takes a virus (or another pathogen) from wherever it lives and brings it to you — and they spread diseases all around the world, infections like malaria, Chagas disease, or Zika virus, for example.

Areas with tropical and mild climates see more of these diseases because the weather allows these disease vectors to breed for much longer. This is a big reason developing nations are mostly tropical and developed nations generally have winters. When more people are sick or dying, it’s hard to have the workforce needed to climb out of poverty.

It’s less about the superior work ethic than we’d like to think — Womp, Womp, WOMP.

Photo by Егор Камелев on Unsplash

Why is it happening more often, though?

Two words: Humans. OK, I only needed one word.

The more in-depth answer involves seven factors that push humans and strange microbes together. Each of these factors represents a driving force that evidence has led relevant experts to believe are driving the increase.

NOTE: I’m sure there’s disagreement among those outside the field, but it’s kind of like asking your therapist to change your oil. Don’t do it.

Without further delay, I give thee: The disease drivers

Emerging, Re-emerging, and Deliberately Emerging Infectious Diseases


Fengshui-ing the planet
Humans, in ever-growing numbers, repurpose land from its natural state to develop residential areas and farming land. This increasingly encroaches on wildlife territory, but the wildlife, and the pathogens they carry, have always been there.

We just didn’t come in contact before the changes. Land-use changes as we call them can throw a wrench in nature’s finely tuned balance, and what shakes out are viruses we are ill-equipped to handle.

One popular theory suggests wildlife and humans share microbes when pig and duck farming happens close together. The ducks catch bird flu from wild birds and give it pigs. Humans also give viruses to pigs. I know, poor pigs. Pigs — closer to humans genetically — become the “party mixer” where viruses infecting the same pig cell can trade pieces of genetic material.

Viruses exit the pig with new genes that may do nothing or may allow it to infect humans and jump person-to-person.

Photo by Pascal Debrunner on Unsplash


Booming cities 
Small farms declined over the last century, and people moved to more densely populated cities. Cities make quick work of finding a new person to infect, and more people can also mean more waste and poorer sanitation.

When a problem arises, it affects a sizeable group of people in a hurry. Infections spread slower when we spread more evenly over land. Mass migration, war, political unrest, and many other social situations can favor pandemics.

Pandemics can also cause any of these population shifts.

Photo by Clément Falize on Unsplash


Jet setting and the open road
The novel Coronavirus showed with spectacular drama how fast a virus can go from obscure to global. Airplanes serve as highly effective disease spreading mechanisms. Unless we all agree to settle as pen-pals, this is unlikely to change. This also eliminates the option of living in an every-person-for-him or herself-world.

To quote the 2018 National Biodefense Strategy, “Infectious disease threats do not respect borders.”


Microbes evolve
This is evolution but microscale. Natural selection favors changes that allow an organism to survive. High-pressure natural selection happens when antibiotics kill all but a few resistant bacteria. These repopulate. It’s evolution sped up.

Introducing colossal amounts of something toxic speeds up the process for resistant individuals to become the future.


Falling vaccination rates
As recently as the 1950s, one out of every four to five children died. Even today, the best gift we can offer children is to never get sick.

The World Health Organization listed vaccine hesitancy as a major threat to global health and security with excellent reason. Even a “small” outbreak may alter trade, lead to food or medication shortages, overwhelm healthcare systems, destroy political agreements, crater money markets, end travel, and promote panic-driven behavior.

The public widely misunderstands measles, a disease that wipes the immune system’s memory. Children may recover, only to die from a subsequent, ordinarily mild infection or they may die years later of measles encephalitis.

Measles rarely kills immediately in the US; this has led to misinformation about the dangers. Few diseases spread as readily as measles.


Slashed public health budgets 
Tremendous inequality exists already, and time further erodes whatever protections we might have. US society, in particular, follows a cyclical pattern of suffering catastrophic loss from a preventable threat. In the aftermath, we divert funding to public health measures. As time goes, we enjoy the benefit of these protections, and nothing happens. Without the memory of why we fund such measures in the first place, we divert funding elsewhere.

Although the greatest threat to Americans today comes from the rapidly emerging infectious diseases, we spend 0.0003% of what we spend on defense, on health security and preparedness. Yes, you heard that correctly. Aside from the current pandemic, the recent Flint water crisis comes to mind, along with the outbreak of Cryptosporidium in Wisconsin because of nonfunctional water treatment. These crises could have been lessened with preparedness.

Cholera burst back into the public consciousness thanks to areas that lost access to chlorinated water. That’s all it takes for the bacteria to grip a population and bring us to our knees. If we can’t remember why we have these measures, we will get a reminder.

When public health measures fail elsewhere, they can lead to astronomical global costs.


Climate change: I know — this, again? It’s a costly mistake by humankind.
More extreme weather likely contributed to the emergence of the hemorrhagic Hantavirus in the southwestern United States. More mild winters equal longer breeding seasons for vectors that spread disease, like mosquitoes and ticks.

If vectors grow more numerous, so too will human cases of the diseases they carry.

Changing weather patterns put new species and environments into contact, and changes have already created more breeding grounds for the scourge of humanity: the mosquito.

Climate change has likely played a role in increasing or spreading: Lyme disease, Avian Influenzas, West Nile Virus, Malaria, Dengue

Disclaimer: The views expressed in this article reflect only me and have not been approved by any other person or institution.

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