Viruses everyone forgot about during COVID are back - behaving in unexpected ways

As the COVID pandemic disrupted life around the world, other infectious diseases took a backseat for almost two years. Now that the world is lifting covid measures, viral and bacterial diseases are making a comeback. And they behave in an unexpected way, reports Stat News.

Think about what we've been seeing lately.

The past two winters have been some of the mildest flu seasons on record. However, flu hospitalizations have increased over the past few weeks - and this is in May! Adenovirus type 41, previously thought to cause harmless attacks of gastrointestinal illness, is fraught with severe hepatitis in otherwise healthy young children.

The respiratory syncytial virus, or RSV, which usually causes illness in the winter, caused major outbreaks in children last summer and early fall in the United States and Europe.

And now, monkeypox. The virus, normally found only in West and Central Africa, is causing an unprecedented outbreak in more than a dozen countries in Europe, North America, the Middle East and Australia. And only in the United Kingdom, as of Tuesday, more than 70 cases of the disease were registered.

These viruses are no different from those that were before, but we have become different

Due to COVID-related restrictions, we have much less newly acquired immunity. We are more vulnerable now, so larger waves of disease could occur. Diseases are able to circulate at times or places where they would not normally occur.

“I think the course of some diseases will be unusual,” said Petter Brodin, professor of pediatric immunology at Imperial College London.

Marion Koopmans, Head of Virology at the Erasmus Medical Center in Rotterdam, said we are facing a period when it is difficult to know what to expect from common illnesses.

Violation of the normal structure of infections can be especially pronounced in diseases in which children play an important role.

Young children are usually magnets for bacteria. But their lives have changed dramatically during the pandemic. Most of them had not attended kindergarten or school for some time, they had much less contact with people outside their homes. And when they encountered other people, these people were wearing masks.

“Children in the second year of the pandemic had much less antibodies to a set of common respiratory viruses. They just became more vulnerable,” she said.

Such factors may explain the recent outbreak of unusual cases of hepatitis in young children. Scientists believe it is caused by adenovirus type 41, as it has been found in a significant number of affected children. This was puzzling because the virus had not been seen to cause this type of disease in the past. There have been many more cases of adenovirus type 41 infection in the past eight months due to increased susceptibility among children.

“Sometimes, in my opinion, to tie together rare complications of common diseases, you just need enough cases to start putting the pieces together,” said Kevin Messakar, a pediatric infectious disease specialist at Colorado Children’s Hospital. And there are suspicions that this may be due to cases of hepatitis.

The disruption caused by the pandemic means that even adults do not produce sufficient levels of antibodies when exposed to bacteria on a regular basis.

Influenza viruses are returning in serious form, and crowding of people who have not had a recent infection could lead to a very severe flu season.

After a one- or two-year period during which influenza transmission is low, the number of people who have high levels of influenza antibodies is significantly reduced. We are talking about endemic diseases that had a certain predictability. And this pattern was partly seasonal, but was also due to the size of the immune or non-immune population. And the latter has increased.

On the subject: In New York, an outbreak of two rare diseases at once: the symptoms of one of them are similar to COVID-19

How would this happen? This fall, all attention will be directed to children's hospitals. To see if there will be a spike in cases of a polio-like disease called acute flaccid myelitis (or AFM) caused by an infection with enterovirus D68.

Messacar has been studying AFM for the past eight years. The first of a series of biennial disease waves occurred in the late summer and early fall of 2014, 2016 and 2018. Then, in 2020, nothing. The same is true in 2021. Does this mean that the number of cases could rise significantly in the fall of 2022 as more children are susceptible to enterovirus D68? According to the doctors, we must be prepared for this. “Now we have kids of four who have not seen this virus. We don't know what will happen,” he said.

Health care workers fear outbreaks of vaccine-preventable diseases. And all because many children in the world missed vaccinations during the pandemic. Young children, who were protected from the bacteria in the early stages of the pandemic, may catch them when they get older. Some diseases cause more severe symptoms if contracted at an older age.

The cancellation of pandemic control measures may have contributed to the spread of monkeypox during the current outbreak in Europe, North America and beyond

Many cases of monkeypox have been diagnosed in men who have sex with men.

After two years of limited travel and social distancing, people are shedding their covid shackles and returning to pre-pandemic lives. According to media reports, recent raves in Spain and Belgium have resulted in the transmission of the virus among some passengers.

The monkeypox outbreak could have smoldered at low levels in the United Kingdom or somewhere else outside of Africa for quite some time. But it may have only caught public attention when international travel became available again.

While all of this could lead to troubling times over the next few years, things will eventually calm down, Brodin predicted.

“In my opinion, once you infect a few people, there is herd immunity, and the virus disappears,” he said, referring to viruses in general. “We haven’t fundamentally changed the rules for fighting infectious diseases.”