The coronavirus disease, known as COVID-19, is a frightening reminder of the imminent global threat posed by emerging infectious diseases. Although epidemics have arisen during all of human history, they now seem to be on the rise. In just the past 20 years, coronaviruses alone have caused three major outbreaks worldwide. Even more troubling, the duration between these three pandemics has gotten shorter.
I am a virologist and associate director of the Animal Diagnostic Laboratory at Penn State University, and my laboratory studies zoonotic viruses, those that jump from animals and infect people. Most of the pandemics have at least one thing in common: They began their deadly work in Asia or Africa. The reasons why may surprise you.
Population explosion and changing urban landscapes
An unprecedented shift in human population is one reason why more diseases originate in Asia and Africa. Rapid urbanization is happening throughout Asia and the Pacific regions, where 60% of the world already lives. According to the World Bank, almost 200 million people moved to urban areas in East Asia during the first decade of the 21st century. To put that into perspective, 200 million people could form the eighth most populous country in the world.
Migration on that scale means forest land is destroyed to create residential areas. Wild animals, forced to move closer to cities and towns, inevitably encounter domestic animals and the human population. Wild animals often harbor viruses; bats, for instance, can carry hundreds of them. And viruses, jumping species to species, can ultimately infect people.
Eventually, extreme urbanization becomes a vicious cycle: More people bring more deforestation, and human expansion and the loss of habitat ultimately kills off predators, including those that feed off rodents. With the predators gone – or at least with their numbers sharply diminished – the rodent population explodes. And as studies in Africa show, so does the risk of zoonotic disease.
The situation is only likely to get worse. A major proportion of East Asia's population still lives in rural areas. Urbanization is expected to continue for decades.
Subsistence agriculture and animal markets
Tropical regions, rich in host biodiversity, already hold a large pool of pathogens, greatly increasing the chance that a novel pathogen will emerge. The farming system throughout Africa and Asia doesn't help.
On both continents, many families depend on subsistence farming and a minuscule supply of livestock. Disease control, feed supplementation and housing for those animals is extremely limited. Cattle, chickens and pigs, which can carry endemic disease, are often in close contact with each other, a variety of nondomestic animals and humans.
And not just on the farms: Live animal markets, commonplace throughout Asia and Africa, feature crowded conditions and the intimate mixing of multiple species, including humans. This too plays a key role in how a killer pathogen could emerge and spread between species.
Another risk: bushmeat hunting and butchering, which is particularly widespread in sub-Saharan Africa. These activities, as they threaten animal species and irrevocably change ecosystems, also bring people and wild animals together. Bushmeat hunting is a clear and primary path for zoonotic disease transmission.
So is traditional Chinese medicine, which purports to provide remedies for a host of conditions like arthritis, epilepsy and erectile dysfunction. Although no scientific evidence exists to support most of the claims, Asia is an enormous consumer of traditional Chinese medicine products. Tigers, bears, rhinos, pangolins and other animal species are poached so their body parts can be mixed into these questionable medications. This, too, is a major contributor to increasing animal-human interactions. What's more, demand is likely to go up, as online marketing soars along with Asia's relentless economic growth.
A matter of time
The viruses, thousands of them, continue to evolve. It's just a matter of time before another major outbreak occurs in this region of the world. All the coronaviruses that caused recent epidemics, including the COVID-19, jumped from bats to another animal before infecting humans. It's difficult to predict precisely what chain of events cause a pandemic, but one thing is certain: these risks can be mitigated by developing strategies to minimize human effects which contribute to the ecological disturbances.
As the current outbreak has shown, an infectious disease that starts in one part of the world can spread globally in virtually no time whatsoever. There is an urgent need for constructive conservation strategies to prevent deforestation and reduce animal-human interactions. And a comprehensive global surveillance system to monitor the emergence of these diseases – now missing – would be an indispensable tool in helping us fight these deadly and terrifying epidemics.
Suresh V Kuchipudi is Clinical Professor and Associate Director of Animal Diagnostic Laboratory, Pennsylvania State University
This article originally appeared on The Conversation. You can read it here.
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Will your current friends still be with you after seven years?
Professor shares how many years a friendship must last before it'll become lifelong
Think of your best friend. How long have you known them? Growing up, children make friends and say they’ll be best friends forever. That’s where “BFF” came from, for crying out loud. But is the concept of the lifelong friend real? If so, how many years of friendship will have to bloom before a friendship goes the distance? Well, a Dutch study may have the answer to that last question.
Sociologist Gerald Mollenhorst and his team in the Netherlands did extensive research on friendships and made some interesting findings in his surveys and studies. Mollenhorst found that over half of your friendships will “shed” within seven years. However, the relationships that go past the seven-year mark tend to last. This led to the prevailing theory that most friendships lasting more than seven years would endure throughout a person’s lifetime.
In Mollenhorst’s findings, lifelong friendships seem to come down to one thing: reciprocal effort. The primary reason so many friendships form and fade within seven-year cycles has much to do with a person’s ages and life stages. A lot of people lose touch with elementary and high school friends because so many leave home to attend college. Work friends change when someone gets promoted or finds a better job in a different state. Some friends get married and have children, reducing one-on-one time together, and thus a friendship fades. It’s easy to lose friends, but naturally harder to keep them when you’re no longer in proximity.
Some people on Reddit even wonder if lifelong friendships are actually real or just a romanticized thought nowadays. However, older commenters showed that lifelong friendship is still possible:
“I met my friend on the first day of kindergarten. Maybe not the very first day, but within the first week. We were texting each other stupid memes just yesterday. This year we’ll both celebrate our 58th birthdays.”
“My oldest friend and I met when she was just 5 and I was 9. Next-door neighbors. We're now both over 60 and still talk weekly and visit at least twice a year.”
“I’m 55. I’ve just spent a weekend with friends I met 24 and 32 years ago respectively. I’m also still in touch with my penpal in the States. I was 15 when we started writing to each other.”
“My friends (3 of them) go back to my college days in my 20’s that I still talk to a minimum of once a week. I'm in my early 60s now.”
“We ebb and flow. Sometimes many years will pass as we go through different things and phases. Nobody gets buttsore if we aren’t in touch all the time. In our 50s we don’t try and argue or be petty like we did before. But I love them. I don’t need a weekly lunch to know that. I could make a call right now if I needed something. Same with them.”
Maintaining a friendship for life is never guaranteed, but there are ways, psychotherapists say, that can make a friendship last. It’s not easy, but for a friendship to last, both participants need to make room for patience and place greater weight on their similarities than on the differences that may develop over time. Along with that, it’s helpful to be tolerant of large distances and gaps of time between visits, too. It’s not easy, and it requires both people involved to be equally invested to keep the friendship alive and from becoming stagnant.
As tough as it sounds, it is still possible. You may be a fortunate person who can name several friends you’ve kept for over seven years or over seventy years. But if you’re not, every new friendship you make has the same chance and potential of being lifelong.