Polio comeback in a number of countries: Should India be worried?

In the last one year or so, polio has made a comeback in countries such as the Philippines, Malaysia, Ghana, Myanmar, China, Cameroon, Indonesia and Iran, mostly as vaccine-derived polio infection.

About the Polio disease

• Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus.
• The virus spreads from person to person and can infect a person’s spinal cord; causing paralysis (can’t move parts of the body).
• It can spread easily from person to person.
• The World Health Organiation (WHO) aim is to eradicate polio completely and, if this happens, it will be only the third disease to have been beaten in this way, after smallpox and rinderpest.
• Nigeria, Pakistan, and Afghanistan are the only three countries in which polio has not successfully been stopped.

Symptoms

• Most people who get infected with poliovirus will not have any visible symptoms.
• About 1 out of 4 people with poliovirus infection will have flu-like symptoms.
• It may include
  • Sore throat
  • Fever
  • Tiredness
  • Nausea
  • Headache
  • Stomach pain
• A smaller proportion of people with poliovirus infection will develop other, more serious symptoms that affect the brain and spinal cord.

Transmission

• Poliovirus is very contagious and spreads through person-to-person contact.
• It lives in an infected person’s throat and intestines.
• Contact with the feces (poop) of an infected person.
• Droplets from a sneeze or cough of an infected person.

Vaccine

• There are two vaccines available to fight polio:
  • inactivated poliovirus (IPV)
  • oral polio vaccine (OPV)
• IPV consists of a series of injections that start 2 months after birth and continue until the child is 4 to 6 years old. The vaccine is made from inactive poliovirus. It is very safe and effective and cannot cause polio.
• OPV is created from a weakened form of poliovirus. It is low cost, easy to administer, and gives an excellent level of immunity. However, in very rare cases, OPV has been known to revert to a dangerous form of poliovirus, which is able to cause paralysis.

Which are the countries that have seen polio outbreaks in recent months?

• In December, 2019, the Ministry of Health in Malaysia announced the country’s first case of polio since 1992.
• In September last year, the Philippines had declared an outbreak of polio.
• Both caused by vaccine-derived poliovirus type 2.
• Last month, the CDC published a list of Asian countries where polio outbreaks have been reported. These are Afghanistan, Burma (Myanmar), China, Indonesia, Malaysia, Pakistan, Papua New Guinea and the Philippines. Except for Afghanistan and Pakistan, all these countries are new entrants into the list.

Where does India stand?

• In January 2014, India was declared polio-free after three years on zero cases, an achievement that is widely believed to have been spurred by the successful pulse polio campaign in which all children were administered polio drops.
• Lessons from the programme were later incorporated in Mission Indradhanush to bump up India’s immunisation campaign, and with great success.
• India introduced the injectable polio vaccine in the Universal Immunisation Programme. This was to reduce chances of vaccine-derived polio infection, which continues to happen in the country.

Polio-free V/S Eradication

• There are three variants of the polio virus, numbered 1 to 3.
• For a country to be declared polio-free, wild transmission of all three kinds has to be stopped.
• For eradication, cases of both wild and vaccine-derived polio infection to be reduced to zero.