The World Health Organisation has declared a polio outbreak in Papua New Guinea and called for an immediate vaccination campaign. According to media reports, samples of the highly infectious virus were found in healthy children during a routine screening in Lae, a coastal city in the country’s northeast. Polio is caused by the highly infectious poliovirus, which spreads through contact with an infected person’s faeces or respiratory droplets when they cough or sneeze. It mostly affects children under five years old. Despite global efforts to eradicate polio, the virus has resurfaced in some areas, including Papua New Guinea, where fewer than half of the population is immunised. The country was declared polio-free in 2000, but a brief outbreak in 2018 led to a swift containment response.