Polio is a deadly infectious disease and leaves one crippled for life. The last wild Polio-virus case in Australia was in 1972 and the last imported case of wild polio-virus was reported in 2007.
Last month, a Polio-virus case was confirmed in the Philippines despite the fact that the country was declared free of disease in 2000. In June 2018 it was confirmed that poliovirus is circulating once more in Papua New Guinea after 18 years of being polio-free.
Neena Bhandari said both these cases were caused by vaccine-derived poliovirus type 2 (VDPV2).
“These strains form when the weakened live virus in the oral vaccine mutates," she told SBS Hindi.
"It spreads fast where immunity is low in population.”
She explained further that to combat this, the WHO has declared that once a region has been declared free of the wild virus that vaccines be swapped from the trivalent version of OPV which covers all three types of poliovirus to a bivalent one, which lacks the type 2 component.
“Hence the problem is not with the vaccine itself but low vaccination coverage. If a population is fully immunised, they will be protected against both vaccine-derived and wild polioviruses,” Ms Bhandari added
So is Australia at risk?
“Polio still poses a threat because of the nature of global travel, any under-vaccinated area could potentially be at risk even in countries like Australia where polio had long since been eradicated," she said.
"Polio is only a flight away because there is a pool of unvaccinated people in Australia.”
Ms Bhandari cited the case of a 22-year old Pakistani student who in 2007 became the first confirmed Australian case of polio in 21 years. Tests showed the man, who arrived on a Thai Airways flight from Bangkok was carrying a strain of polio similar to types circulating in Pakistan’s North-West Frontier Province, one of the country’s last remaining polio-infected areas.
Polio is caused by a virus that mainly affects children under five years of age. The virus enters the body through the mouth and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, and stiffness in the neck and pain in the limbs.
"Fewer than 1 per cent of people infected suffer paralysis, but the other 99 per cent are still able to transmit the virus. Polio is a highly contagious virus and immunisation is important, “ Ms Bhandari emphasised
Immunisation is most effective and is currently the only form of defence against polio.
Polio vaccine is funded for children under the national program, “Polio Vaccines Funded For Children”. Booster vaccines doses are recommended for adults and health care workers, if at risk, and for travellers visiting polio-endemic countries.
