Health officials are on high alert due to fears of a comeback of polio in the US; a virologist discusses the history of this terrifying disease.

The US experienced polio fears in the middle of the 20th century. Parents avoided birthday parties, public pools, and other places where kids congregate. Children in wheelchairs provided a striking reminder of the disease's devastation.

The US experienced polio fears in the middle of the 20th century. Parents avoided birthday parties, public pools, and other places where kids congregate. Children in wheelchairs provided a striking reminder of the disease's devastation.

Government officials employed COVID-19-era strategies to stop polio outbreaks, including closing down restaurants, swimming pools, and other meeting places.

.In 1952, two years before an experimental polio vaccine was released, there were 58,000 cases of polio and 3,145 deaths. These cases included kids who would permanently be paralyzed. However, those figures sharply decreased after a comprehensive polio vaccination programme started in 1955.

Less than 10 cases of polio-related paralysis were reported in the US by the 1970s, and by 1979, the polio virus was deemed to be extinct in the country. Since that time, most of the public's fear of the virus has been consigned to history; many individuals alive now are fortunate not to know anyone who has had polio.

As a result, when word spread in July 2022 that an adult man who had not received the polio vaccine had contracted the disease and became paralyzed in New York, it sent shockwaves across the public health profession. It sparked concerns about whether an old foe was making a comeback.

.I teach and research how viruses cause disease. I'm a virologist and immunology/microbiology professor.

Polio has no known treatment. Prevention is the only kind of treatment. Vaccination, which was also used to eradicate polio in the US in the first place, is the prevention method.

The poliovirus's life cycle.

The polio virus, which spreads from person to person through the mouth, causes polio, also known as poliomyelitis. And although no one would intentionally consume a virus, touching a contaminated object, such as a spoon or glass, or unintentionally drinking contaminated water can cause illness.

People who have the poliovirus excrete the contagious virus in their faeces. This is why the recent news that the poliovirus has been found in three New York counties and has been circulating in New York City wastewater for months is particularly alarming.

The state health agency is "seeing the one case of polio as only the tip of the iceberg of a much wider potential spread," according to Mary Basset, commissioner of health for New York State, in August 2022.

She continued, "New Yorkers should be aware that for every instance of paralytic polio observed, hundreds of more persons may be afflicted, based on prior polio epidemics.

Because most of those infected either don't exhibit any symptoms or experience a very mild sickness with symptoms comparable to the flu, one incidence of polio represents a more significant potential spread of the virus. Even if a person has no signs, they can still spread the virus because they excrete it in their faeces.

The virus can quickly be disseminated by surface contamination and is relatively stable in the environment. Because of this, hand washing is an essential preventative measure. While many disinfectants, including alcohol or diluted Lysol, cannot render the virus inactive, chlorine bleach does so. To inactivate the polio virus, this is why public health officials began chlorinating swimming pools decades ago.

The human body often uses stomach acid to defend itself from ingested pathogens. However, the poliovirus can pass through stomach acid and enter your digestive system. There, the virus multiplies to cause an illness.

What is poliomyelitis paralysis?

Sadly, paralysis will occur in one out of every 200 people who contract the poliovirus. Scientists are still unsure why certain people are more prone to paralytic sickness than others.

The virus can damage the lower motor neurons in the brain stem and spinal cord, which are crucial for regulating muscles, in the tiny subset of individuals who contract paralytic polio—the paralysis of the forces that characterize paralytic polio results from infection of those neurons. Usually, only one side of the body, usually the legs, is affected, and the paralysis can be minor to severe. Additionally, other muscle groups may be impacted.

The virus can harm the nerve system's breathing control centres in paralytic polio's most severe cases. Early medical devices called "iron lungs" or respirators let people with damaged respiratory muscles breathe until their forces recover sufficiently to function independently. When the paralysis is severe and prolonged, patients risk dying.

severe levels.

Most people's immune systems can fight off polio, even though the severe form of it can be disastrous for individuals who catch it. Researchers can find poliovirus-fighting antibodies in the blood when someone recovers from polio.

However, post-polio syndrome, also known as late-onset muscle weakness and weariness, can appear in paralytic polio survivors who have been living for a long time. Post-polio syndrome can cause various symptoms in addition to its well-known effects on the muscles, such as chronic discomfort, sleep problems, a cold intolerance, and trouble swallowing.

Post-polio syndrome is diagnosed primarily with symptoms. Therefore, estimates range from 15% to 80%.

Polio prevention is essential.

The development of vaccines and the general public's willingness to embrace them are the leading causes of the drop in polio in the US and worldwide. In 1988, the World Health Organization, Rotary International, the CDC, and other national governments formed the Global Polio Eradication Initiative.

In 125 nations, there were still thought to be 350,000 children living with polio at the time this campaign was started. There were just six cases documented in 2021.

Worldwide, there are two different polio vaccines in use. Since 2000, an injectable manufactured from inactivated poliovirus has been utilized in the US. The virus is killed, and its spread is stopped via inactivation. In the US, children receive this vaccination at two months, four months, and between 6 and 15 months of age, and it practically offers lifetime polio protection.

The second vaccine type is an oral dose of an attenuated or weakened form of the virus that is still used in many regions of the world. The oral vaccine is chosen in areas where community transmission is still prevalent, such as Pakistan, since it protects against polio while simultaneously preventing person-to-person transmission.

The inactivated vaccine is recommended in the US because there is less concern about viral propagation there than there is elsewhere in the world since person-to-person transmission of the poliovirus has been nearly nonexistent for decades.

However, the vaccination virus might occasionally change after being eliminated in faeces. Additionally, this poliovirus might spread disease if immunization rates drop below a crucial level, as in some parts of the world. A mutant poliovirus connected to the newest case of polio in New York likely originated overseas.

The majority of people in the US receive routine childhood vaccines. The CDC does not advise booster immunizations for the general population for those who finished the complete series because immunity against polio following vaccination is a lifetime. The CDC does recommend getting vaccinated against the polio virus for everyone, even adults, who have not yet done so.

I have a painting of Dr Jonas Salk, the virologist who created the first polio vaccine, hanging in my office. It reminds me of the significance of biomedical research in assisting in eradicating the pain brought on by infectious diseases.