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The Covid-19 pandemic has abated in much of the world and, with it, most of the social restrictions implemented to curb its spread, as people have been desperate to return to pre-lockdown life.
But instead have emerged a series of viruses behaving in recent and peculiar ways.
Take seasonal influenza, more commonly referred to as the flu. The 2020 and 2021 U.S. winter flu seasons were among the mildest on record each by way of deaths and hospitalizations. Yet cases ticked up in February and climbed further into the spring and summer as Covid restrictions were stripped back.
“We have never seen a flu season within the U.S. extend into June,” Dr. Scott Roberts, associate medical director for infection prevention on the Yale School of Medicine, told CNBC Tuesday.
“Covid has clearly had a really big impact on that. Now that individuals have unmasked, places are opening up, we’re seeing viruses behave in very odd ways in which they weren’t before,” he said.
And flu is just the start.
We’re seeing very atypical behaviors in plenty of ways for plenty of viruses.
Dr Scott Roberts
associate medical director for infection prevention, Yale School of Medicine
Respiratory syncytial virus, a cold-like virus common during winter months, exhibited an uptick last summer, with cases surging amongst children in Europe, the usand Japan. Then, in January this 12 months, an outbreak of adenovirus 41, often accountable for gastrointestinal illness, became the apparent reason behind a mysterious and severe liver disease amongst young children.
Elsewhere, Washington State has been experiencing its worst flare-up of tuberculosis in 20 years.
And now, a recent outbreak of monkeypox, a rare viral infection typically present in Central and West Africa, is baffling health experts with over 1,000 confirmed and suspected cases emerging in 29 non-endemic countries.
Viruses behaving badly
At the least two genetically distinct monkeypox variants are actually circulating within the U.S., likely stemming from two different spillover infections from animals to humans, the U.S. Centers for Disease Control and Prevention said last week.
The World Health Organization noted earlier last week that the virus, whose symptoms include fever and skin lesions, can have been going undetected in society for “months or possibly a few years.”
A piece of skin tissue, harvested from a lesion on the skin of a monkey, that had been infected with monkeypox virus, is seen at 50X magnification on day 4 of rash development in 1968.
CDC | Reuters
“The 2 strains probably indicate this has been occurring longer than we first thought. We’re at a concerning time straight away,” said Roberts. He noted that the approaching weeks might be telling for the course of the virus, which has an incubation period of 5 to 21 days.
It shouldn’t be yet clear whether the smallpox-like virus has mutated, though health experts have reported that it’s behaving in recent and atypical ways. Most notably, it appears to be spreading inside the community — mostly through sex — versus via travel from places where it is often found. Symptoms are also appearing in recent ways.
“Patients are presenting in another way than we were previously taught,” said Roberts, noting that some infected patients are bypassing initial flu-like symptoms and immediately developing rashes and lesions, specifically and unusually on the genitals and anus.
“There’s quite a lot of unknowns that do make me uneasy. We’re seeing very atypical behaviors in plenty of ways for plenty of viruses,” he said.
Restrictions reduce exposure, immunity
One explanation, in fact, is that Covid-induced restrictions and mask-wearing over the past two years have given other infectious diseases little opportunity to spread within the ways they once did.
Where viruses did manage to slide through, they were incessantly missed as public health surveillance centered largely on the pandemic.
That indeed was the case in Washington’s tuberculosis outbreak, in line with local health authorities, who said parallels between the 2 illnesses allowed TB cases to go undiagnosed.
Through the Covid pandemic, access to primary care, including childhood vaccinations, was unavailable to many children.
Jennifer Horney
professor of epidemiology, University of Delaware
Now, as pandemic-induced restrictions have eased and usual habits resumed, viruses that were in retreat have found a fertile breeding ground in newly social and travel-hungry hosts.
The recent monkeypox outbreak is believed to have stemmed, a minimum of partially, from two mass events in Europe, a lead adviser to the WHO said last month.
Meantime, two years of reduced exposure have lowered individual immunity to diseases and made society as a complete more vulnerable. That is very true for young children — typically germ amplifiers — who missed opportunities to achieve antibodies against common viruses, either through their mother’s womb or early years socializing.
Missed childhood vaccinations
That would explain the uptick in curious severe acute hepatitis cases amongst children, in line with health experts who’re looking into possible links to Covid restrictions.
“We’re also exploring whether increased susceptibility as a result of reduced exposure in the course of the Covid-19 pandemic could possibly be playing a task,” the U.K. Health Security Agency said in April.
Morsa Images | Digitalvision | Getty Images
The Centers for Disease Control and Prevention has also expressed concern that lockdowns can have caused many children to miss childhood vaccinations, potentially raising the risks of other vaccine-preventable illnesses similar to measles and pertussis.
“Through the Covid pandemic, access to primary care, including childhood vaccinations, was unavailable to many children,” Jennifer Horney, professor of epidemiology on the University of Delaware, told CNBC.
“To forestall increases in these diseases, catch-up vaccination campaigns are needed globally,” she added.
Beware surveillance bias
That said, there may be also now greater awareness and surveillance of public health issues within the wake of the pandemic, making diagnoses of some outbreaks more commonplace.
“Covid has raised the profile of public health matters in order that we’re perhaps paying more attention to those events once they occur,” said Horney, adding that public health systems set as much as discover Covid have also helped diagnose other diseases.
Professor Eyal Leshem, infectious disease specialist at Sheba Medical Center, agreed: “The final population and the media have turn into rather more fascinated by zoonotic outbreaks and infectious diseases.”
It isn’t that the disease is more prevalent, but that it gets more attention.
Professor Eyal Leshem
infectious disease specialist, Sheba Medical Center
Nonetheless, he also warned of the role of “surveillance bias,” whereby individuals and medical professionals usually tend to report cases of diseases as they grow more high profile. That implies that some viruses, similar to monkeypox, may look like growing when in actual fact they were previously underreported.
“It isn’t that the disease is more prevalent, but that it gets more attention,” Leshem said.
Still, the increased monitoring of infectious disease outbreaks is not any bad thing, he noted. With the increased spread and mutation of infectious diseases — as seen with Covid-19 — the more awareness and understanding of the changing nature of diseases, the higher.
“The general public and media attention will help governments and global organizations direct more resources into surveillance and protection of future pandemics,” Leshem said, highlighting research, surveillance and intervention as three key areas of focus.
“These investments must occur globally to stop and mitigate the following pandemic,” he said.
