Poliomyelitis (Polio)
Transmission
Poliomyelitis (or "polio") is a viral infection that can cause paralysis and death. It is a life-threatening disease caused by a virus that affects the nervous system and is usually spread from one person to another when stool (poop) or, less commonly, droplets from a sneeze or cough of an infected person gets into the mouth of another person. You can get polio if you:
Eat raw or undercooked food or drink water or other drinks that are contaminated with the stool of an infected person.
Put a contaminated object such as a toy in your mouth.
Touch a contaminated object and put your fingers in your mouth.
Have close contact with a person sick with polio, for example when caring for them.
In the past, polio was common, especially in children. Since the late 1980s, the World Health Organization (WHO) has led a campaign to eradicate polio, including mass vaccination against polio, and ongoing surveillance for cases.
Polio is now rare in most parts of the world.
In some developing countries, however, polio continues to circulate. There are three types of ‘wild’ polio (known as WPV): type 1, type 2 and type 3. Type 2 and type 3 no longer exist. Only WPV type 1 remains.
Symptoms
Most people infected with polio do not get symptoms. 10% of people who are infected with the virus get minor symptoms, including:
fever
fatigue
headache
nausea and vomiting
sore throat
pain or stiffness in the back, neck, arms or legs
weak or tender muscles
Most of these people completely recover.
A small proportion of people experience more severe paralysis symptoms, including:
severe muscle pain with back or neck stiffness, due to a type of meningitis (inflammation of the lining of the brain without weakness)
severe weakness in the arms and legs and muscles of the head and neck
difficulty breathing due to weak diaphragm muscle.
Most people with acute paralysis symptoms recover, although the recovery is not complete in all people and some people die.
The time from being exposed to polio and getting sick can range from 3 to 35 days but is commonly between 7-14 days.
Cases are most infectious from 10 days before the onset of symptoms to 10 days after the onset of symptoms.
People can continue to shed the virus in their faeces (poo) for up to six weeks. Typically, the virus remains in the throat for 1-2 weeks.
⚠️ If you experience any of these symptoms after returning from overseas, you should immediately contact your doctor or go to an emergency department. Tell your doctor about your symptoms and which country you visited.
Who is at Risk?
Polio is still a concern in some places. If you are not up to date with your polio vaccines, you are at risk of getting polio. If you are up to date on your polio vaccines but travelling to a polio-affected country, you may need a one-time polio adult booster.
The European Centre for Disease Prevention and Control website includes a map indicating the risk of polio transmission in different countries - here. Additionally, a list of affected countries can be found on the Global Polio Eradication Initiative (GPEI) website - here.
Prevention
Travellers can get the polio vaccine.
⚕️ People planning to visit polio-affected countries should seek advice from their doctor or a travel clinic at least 4-6 weeks before departing.
The Centers for Disease Control and Prevention (CDC) website includes details of the polio vaccine and schedule - here.
Some countries use a live, weakened form of polio as the vaccine. In some rare instances, the live polio vaccine can mutate and lead to people developing the infection and being able to spread it from person to person (known as circulating vaccine-derived polio, or cVDPV). This is uncommon but can occur in a setting with poor hygiene and sanitation, and low vaccination coverage.
You cannot get polio from a vaccine that uses a dead virus, which other countries utilise.
⚠️ Travellers may be required to show evidence of polio vaccination prior to entry or exit to some countries.
More Information
Discover more about Polio at the following sites:
🇺🇸 United States - Center for Disease Control & Prevention (CDC)
🇳🇿 New Zealand - Ministry of Health
🇪🇺 European - Centre for Disease Prevention & Control
🇬🇧 United Kingdom - Travel Health Pro
🏴 United Kingdom (NHS Scotland) - Fit to Travel
🇨🇦 Canada - Public Health Services
🌐 World Health Organization (WHO)
General Travel Advice Disclaimer - here.