Androgenic Anxiety and COVID-19

sperm quality
Normal (left) and abnormal forms of sperm

Early this morning, January 1, 2021, three minutes after midnight, the last human being to be born on earth was killed

Thus begins Children of Men, a dystopian novel by P.D. James (1992). A sudden and unexplained loss of human fertility tipped the world toward apocalypse. Whereas the book held testes to be responsible, the movie version directed by Alfonso Cuaron switched the cause to gynecology, sparing those precious nuts from blame!

It’s possible for a scientist to suspend disbelief in science fiction, but he/ she always prefers to have facts. I had a professional interest in fertility, both female and male. When I first read about a dip in sperm counts, I dismissed it as a statistical quirk or fiction, but no longer. A study combining 185 studies amounting to 42,000 men found average sperm counts have dropped almost 60% in 40 years to 2011 in Western cultures. The trend continues. The paper didn’t report sperm quality (depicted above), a pity because ours is much poorer than in any other species.

The cause is unknown although experts offer similar suggestions to James—lifestyle and/ or pollution. The average count has fallen below 50 million per milliliter, the range of subfertility. While worrying for people who plan to start a family, I wonder what else it portends. Not a plunging population, but possibly raising other alarms if sperm are honest biomarkers.

During development, sperm are shorn of the apparatus that protects and repairs other cells. Short-lived, they only live a couple of days under the best conditions. They could be harmed by toxins in testicular fluids or further along from glandular secretions that contribute to semen. Bad enough if only these specialized cells are harmed, but what if the damage is already done to their stem cell parents? If they are vulnerable to a hidden threat perhaps other cells are affected, and in women as well as men. Could discovery of the affliction of sperm lead to a better understanding of today’s prevalence of some chronic diseases and impacted immune systems?

One in four men who develop mumps have orchitis as fluid builds up to create pressure inside the rigid capsule of testes. Hence, they lose fertility. That the MMR vaccine has greatly reduced the risk of the disease makes the population-wide decline in sperm counts more striking.

But what role for other airborne RNA viruses, especially from the onslaught in recent SARS epidemics and now a pandemic? Cells in testes and ovaries express the ACE-2 receptor, the spike protein that binds the SARS-COVID-19 virus so it can step into cells. A recent study at Columbia University, New York, reported only one covid patient with a low sperm count and virions in his semen, so the risk of infertility or sexual transmission of covid seems slight. Science is still pending a final decision but already concluded the vaccine does no harm to fertility, quashing anxieties in the media.

The human population won’t crash even if every living person became infertile overnight. Vast numbers of semen samples are stored in freezers around the world and frozen cells are good for decades if not centuries. Besides, a few sperm can be found in almost every clinically sterile testis, all that is needed for fatherhood by injecting eggs using the ICSI technique launched the same year as James published her book.

Don’t Write Off the Bat

It was a perfect evening for a spin in the Batmobile with a team of three amateur chiroptologists. The air was warm and still when the sun went down.

After leaving the carpark, we were overtaken by every vehicle along the Colonial Parkway as we crawled at 15 mph, hugging the kerb. Fortunately, the traffic was light. It was too dark to see if the faces passing us were puzzled by the tall aerial sticking out of our sunroof or if they guessed what we were up to from the sticker on our trunk illuminated in their headlights: Bat Monitoring – Pass Safely.

Although I rarely hear bats nowadays, I love to watch their silhouettes against the last glow of a darkening sky. Their acrobatic flights look sheer joy, although I know they are to satisfy voracious appetites, twisting and turning to skim the air of mosquitoes, moths and lumbering beetles.  After years of wondering what species lived here, I now had an opportunity to find out.

The passenger sitting beside the driver held the aerial with one hand and used the other to control the tracker pad of a laptop perched in front. I watched over her shoulder as she loaded the SonoBat software.

SonoBat
All set in the Batmobile

We hadn’t gone far along the tree-lined parkway when the computer chirped. It was our first hit. A chirogram on the screen (like a sonogram) showed regular pulses as a bat called for echolocation to detect prey and avoid obstacles. A machine-learning algorithm identified the species, saved data to a spreadsheet and could mark ambiguous results, if necessary. The passenger in the seat beside me backed up results by writing on a notepad. We had detected a Red bat, named for its red fur. It was impossible to see it or any others through impenetrable night.

This was my first time for a bat positively identified while flying free in the wild. Soon, there was another chirping, then another, often in a different tone and frequency. After two hours on the road we gathered 125 recordings, mostly ascertained. The total number of individuals was, however, unknown, and we probably had duplicates because bats of a given species have the same voice. But we were more confident that seven species flew close enough to detect that night, including the Big-eared, Big brown, and Silver bat. I never knew we had so many.

chirogram fromSonoBat
Chirogram of Red bat

The software program identified calls by referencing a library of thousands of recordings of species from across the continent.  We mostly detected Red bats, a common and widespread species. The Seminole bat has a similar chirogram, but being near the northern limit of its range it was unlikely to be mistaken for the closely related species.

When I joined the survey one night last year, bats were getting more attention from conservationists and there was growing public interest in their dwindling populations from loss of habitat to human development, Insectageddon threatening their food supply, and the toll from white-nose syndrome.  They haven’t lost friends who always cared about them. But people who were indifferent before or harbored superstitions can find a better excuse for fearing them than the old myth that bats get caught in young girls’ hair.

Evidence is growing that the COVID-19 virus originated in bats before it infected humans, perhaps via an intermediate host. The species and country of origin are still unclear. Bats harbor coronaviruses to which they evolved enviable tolerance from long association and robust immunity. They have orthologs of our ACE-2 protein, a molecule with a physiologic role and widely distributed on our cells that offers the virus a gateway for infecting us by binding its spike protein.

To persecute bats as suspects of this or other zoonoses (certainly they can carry the rabies virus, like any other mammal) is no more justified than putting people in jail for spreading disease before they understood the menace or knew they were infected. Solutions to our problem lie not with the animal but in our connected world and with global travel.

Bats flying at night
Thanks to Ruth Rios on Unsplash

Bats are fascinating creatures in the web of life. They cling to familiar habitats and if left alone they help us as insect-eaters and providers of pollination services.

When contact distancing is revoked after the pandemic, I hope to board the Batmobile again to watch pulses on the glowing screen that spark imagination about the peregrinations of bats outside in the night.

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