Far to the north of Cape York, in the coastal city of Lae, two healthy children have tested positive for a poliovirus that the world had worked for decades to push to the margins. Their infection, traced through wastewater and genetic sequencing to strains circulating in Indonesia, is a reminder that disease does not respect the lines we draw between neighbours, and that a region's protection is only as strong as its most under-vaccinated corner. For Australia, the assessment is measured rather than alarmed, though it asks a quieter question about how much a community's safety depends on the s
PNG's polio outbreak explained: how the virus resurfaced and whether it poses a risk to Australia
Two children in Lae, Papua New Guinea were infected with poliovirus, though they had no clinical illness reported.
Polio anywhere is a threat everywhere
Mark
Two healthy children, no illness. Why is this such a big deal?
Mimi
Because they carry the virus. Most infections cause no symptoms, so a healthy child can still spread it, and PNG's surveillance is weak at catching the rare paralytic cases.
Luke
Worth noting that no clinical case has been reported. The detection came from wastewater, an environmental sample and then testing of the two children.
Mark
How did the virus get there?
Mimi
Sequencing links the strain to polio circulating in Indonesia, according to the WHO.
Luke
That's a genetic link. The reporting doesn't say how or when it crossed, and I wouldn't guess.
Mark
And Australia's risk?
Mimi
Professor Selvey calls it fairly low, citing vaccination, sanitation and less crowding. The Torres Strait is the exception she flags.
Luke
That's one expert's judgement, not a measured figure. And she's candid that coverage has fallen.
Mark
How far has it fallen?
Mimi
One-year-olds went from 94.8 per cent in 2020 to 91.6 per cent in 2024. Two-year-olds dropped to 89.4.
Luke
Those are interim figures, and nothing here says what the Torres Strait rate is. That's still unknown.
O Pulso
- Two children in Lae, Papua New Guinea, have tested positive for poliovirus type 2, a disease many Australians believed had been left behind.
- Detection through wastewater and environmental samples means the virus may be moving through communities without anyone yet seeing a sick child.
- PNG has triggered a national emergency response, with the WHO, UNICEF and Australia's DFAT rolling out wider surveillance and a three-stage immunisation program.
- Australia's own childhood vaccination rates have slipped since 2020, and the Torres Strait is now the focus of watchful attention.
Far to the north of Cape York, in the coastal city of Lae, two healthy children have tested positive for a poliovirus that the world had worked for decades to push to the margins. Their infection, traced through wastewater and genetic sequencing to strains circulating in Indonesia, is a reminder that disease does not respect the lines we draw between neighbours, and that a region's protection is only as strong as its most under-vaccinated corner. For Australia, the assessment is measured rather than alarmed, though it asks a quieter question about how much a community's safety depends on the steady, unglamorous work of immunisation.
Two children in Lae, a city on Papua New Guinea's northern coast, have tested positive for poliovirus type 2. Both are healthy, yet their infections have set off a national emergency response in PNG, Australia's closest international neighbour. Lae sits just over 500 kilometres north-east of Queensland's Cape York, close enough that the detection feels near home.
The virus was first found in wastewater in Lae and in an environmental sample in the capital, Port Moresby. Further testing by the World Health Organization, PNG's Department of Health, UNICEF and provincial authorities confirmed it in the two children. Genetic sequencing linked the strain to polio circulating in Indonesia, which the WHO says poses a serious risk across the region. The finding is jarring: wild type 2 poliovirus was declared eradicated in 1999, and PNG itself was declared polio-free in 2000.
The WHO's representative in PNG, Dr Sevil Huseynova, pointed to low vaccine coverage and gaps in surveillance, particularly the acute flaccid paralysis monitoring that is the gold standard for catching polio. In communities with low immunisation, she warned, the virus spreads quickly. The WHO and UNICEF are now expanding that surveillance and rolling out a three-stage immunisation program to protect children.
For Australia, the risk is judged fairly low, but experts are watching closely. Public health researcher Linda Selvey said her larger worry is for PNG, where a child could be infected without anyone noticing. In Australia, the greatest vulnerability lies in the Torres Strait, where people move between the two countries and housing conditions can be poor. Australian childhood vaccination rates have also slipped since 2020, with one-year-olds dropping from 94.8 to 91.6 per cent. DFAT says it is supporting PNG's National Polio Response Plan, and the question now is how quickly protection reaches the children who need it most.
Two children in Lae, a city on Papua New Guinea's northern coast, have tested positive for poliovirus type 2. Both are healthy. They live just over 500 kilometres north-east of Queensland's Cape York, and the detection has prompted PNG, Australia's closest international neighbour, to trigger a national emergency response.
The World Health Organization confirmed the findings on Thursday. The virus was first picked up in a wastewater sample in Lae and an environmental sample in the capital, Port Moresby. Further testing by the WHO, PNG's Department of Health, UNICEF and provincial health authorities then found it in the two children. Genetic sequencing tied the strain to polio circulating in Indonesia, which the WHO says poses a serious risk to other countries in the region.
The detection is jarring against the global record. The WHO says wild poliovirus type 2 was eradicated in 1999 and type 3 in 2020. Since the Global Polio Eradication Initiative began in 1988, worldwide cases have fallen by 99 per cent. Only Afghanistan and Pakistan are still considered endemic, meaning wild strains are being transmitted there. PNG itself was declared free of polio in 2000. It had a small outbreak in 2018, controlled within the same year, and no cases were detected again until now. The WHO says the country remains vulnerable because of low immunisation rates and suboptimal surveillance. In a DFAT statement, Australia described the detection as vaccine-derived poliovirus.
Polio is a highly infectious disease that mostly affects children under five. It has no cure and can be prevented only by vaccination. It spreads mainly through the accidental ingestion of infected faecal matter, and can also travel through contaminated water or food. According to Healthdirect, 95 per cent of infected people have no symptoms, though the virus can incubate for up to 35 days. Others develop flu-like symptoms for up to 10 days. In fewer than one in 100 cases it causes acute flaccid paralysis, usually in the limbs, and it can be fatal if it reaches the muscles used for breathing.
The WHO's representative in PNG, Dr Sevil Huseynova, pointed to low vaccine coverage and the virus's transmissibility. She said gaps in surveillance for vaccine-preventable diseases, including acute flaccid paralysis, which she called the gold standard for detecting polio, make the problem worse. In communities with low immunisation, she said, the virus spreads quickly from person to person. The WHO and UNICEF are rolling out wider surveillance for acute flaccid paralysis and a three-stage immunisation program meant to protect children and lift the country's vaccination rates.
For Australia, the assessment is calm. Linda Selvey, an honorary associate professor at the University of Queensland's School of Public Health, told ABC radio's PM program the risk of spread here would be fairly low. Australia has been polio-free since 2000 and has had no major outbreak since 1961. Dr Selvey, who has worked on polio eradication in India and Nepal, said her larger concern is for PNG, where low coverage and weak health services mean a child could be infected without anyone noticing. She said the greatest risk in Australia would be in parts of Queensland, particularly the Torres Strait, where people move more closely between the two countries and housing is less optimal.
Australia's own numbers are slipping, though. Interim 2024 figures from the National Centre for Immunisation Research and Surveillance, released Thursday, show full vaccination among one-year-olds at 91.6 per cent, down from 94.8 per cent in 2020. For two-year-olds it was 89.4 per cent, down from 92 per cent, and for five-year-olds 92.7 per cent, down from 94.8 per cent.
DFAT says Australia is working with PNG, the WHO and UNICEF, including targeted technical assistance for PNG's National Polio Response Plan. What to watch next is how quickly that immunisation response reaches children in PNG, and whether Australian coverage, especially in the Torres Strait, holds up.
Citações Notáveis
The risk of polio spreading to Australia would be fairly low, with the greatest risk in parts of Queensland such as the Torres Strait.— Linda Selvey, University of Queensland School of Public Health
In communities with low polio immunisation rates, the virus quickly spreads from one person to another.— Dr Sevil Huseynova, WHO representative in PNG
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Leia o original em ABC (Australian Broadcasting Corporation) ↗
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