An outbreak of polio has been confirmed in Papua New Guinea, 18 years after the country was declared free of the disease. The World Health Organization (WHO) says the virus was detected in a six-year-old boy in April.
The same strain of the virus has now been detected in other healthy children in the same community, making it officially an outbreak.
Polio has no cure and can lead to irreversible paralysis. It mainly affects children under the age of five, and can only be prevented by giving a child multiple vaccine doses.
The country's last case of the disease occurred in 1996 and the country was declared polio free in 2000, along with the rest of the Pacific region.
Polio | Key facts
* Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children
* The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by contaminated water or food. It multiplies in the intestine, from where it can invade the nervous system and can cause paralysis
* Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. In a small proportion of cases, the disease causes paralysis, which is often permanent
* There is no cure for polio, it can only be prevented by immunisation
* Just three countries in the world are yet to be declared polio free: Afghanistan, Pakistan and Nigeria
- Source: News websites