Outbreaks of polio

The international poliovirus situation is evolving, likely due to impacts of the COVID-19 pandemic such as interruptions to immunisation and other health services, exacerbated by conflict and/or complex emergencies in some fragile states. The New Zealand Ministry of Health continues to closely monitor the situation.

Transmission and symptoms

Polio is an infectious disease caused by a virus that can spread from person to person or through contaminated water or food. Many people who are infected don’t feel sick or have symptoms. Some people have only minor symptoms such as fever, nausea, headache, nasal congestion, sore throat, cough, stiffness in the neck and back, and pain in the arms and legs. A small proportion of those with symptoms develop paralysis.

Where to take care?

The World Health Organization (WHO) has advised of an increase in polio activity in areas which have previously seen eradication. On 28 March 2024, the Director-General for the WHO determined that the poliovirus situation continues to constitute a Public Health Emergency of International Concern (PHEIC).

Below we highlight some countries where the polio situation has recently changed. 

Afghanistan and Pakistan

Afghanistan and Pakistan continue to have evidence of ongoing transmission of naturally occurring polio in the community. As of 10 April 2024, both Afghanistan and Pakistan have reported two cases so far this year, compared with six each in 2023.

WHO reports a significant increase in environmental detections in both countries indicating the spread of polio from the traditional endemic zones to the neighbouring districts and regions.

Angola, Liberia, Senegal, Sierra Leone, South Sudan

Angola, Liberia, Senegal, Sierra Leone, and South Sudan are five newly reinfected countries reporting circulating poliovirus since December 2023.

Indonesia

In 2023, a total of six cases of polio were detected in Indonesia. Two cases were reported in December 2023, the first case from Klaten district, Central Java province, with a history of recent travel to Sampang district, East Java province. The second case from Pamekasan district in East Java province. Two environmental samples taken from the Saksak River, Bangkalan district East Java province in December 2023, also tested positive for polio. There have been four cases reported in Indonesia in 2021 and one case in 2022.

In response to this polio outbreak, Indonesia has initiated several public health responses including contact tracing, active case finding and risk assessment. Catch-up on routine immunisation is being initiated to enhance vaccine coverage.

The overall risk is assessed as high at the national level in Indonesia and moderate at the western pacific regional level.  

Prevention advice for travellers

There is no cure, but polio can be prevented through vaccination. WHO recommends that all travellers to polio-affected countries be fully vaccinated against polio. 

Good hand washing practices can help prevent the spread of this disease. Because the virus that causes polio lives in the faeces (poop) of an infected person, people infected with the disease can spread it to others when they do not wash their hands well after using the toilet. People can also be infected if they drink water or eat food contaminated with infected faeces.

Health advice

Infections from vaccine-derived poliovirus occur on occasion in countries still using live poliovirus vaccine, and has now been seen in countries that do not use live poliovirus vaccine (e.g. USA). Vaccination against polio before travel will protect against these outbreaks. New Zealand does not use live poliovirus vaccine.

New Zealanders travelling to polio-affected areas please refer to the list of endemic countries or countries with poliovirus outbreak via Polio this week  should be up to date with routinely recommended vaccinations against polio, including boosters, prior to departure. More specifically:

• New Zealand residents planning to visit these areas for less than 4 weeks should be up to date with their polio vaccination. For adults, this is a 3 dose primary course, with a booster within the last 10 years. For children, a 3 dose primary course with a booster at 4 years old is currently recommended. These recommended vaccines may be given before arrival into the region.
• New Zealand residents intending to stay for longer than 4 weeks should have a documented polio booster within 4 weeks to 12 months prior to the date of departure. The booster may be given before arrival, as long as it is given within 4 weeks to 12 months prior to leaving the region.
• Individuals who are already residing in the affected region for 4 weeks or longer should have a documented polio booster within 4 weeks to 12 months prior to departure. The booster may have been given before arrival, as long as it has been given within 4 weeks to 12 months prior to leaving. Individuals leaving in less than 4 weeks should still receive a polio booster as this will still have benefit.
• Travellers should be provided with a written record of such vaccination, preferably using the International Certificate of Vaccination or Prophylaxis, and keep this record during international travels.

This advice is in addition to any other travel-specific vaccinations that may be required.

Polio has been eradicated from New Zealand and from most of the countries around the world.

Useful links

• World Health Organisation -  poliomyelitis
• Global Polio Eradication Initiative
• Polio this week – list of countries with recent polio detections