Abstract
Background:
A case of paralytic poliomyelitis in New York, and evidence of community transmission of poliovirus in London, raise questions about the potential risk of polio transmission in Aotearoa. The New Zealand Paediatric Surveillance Unit contributes to the global polio eradication initiative through active surveillance of acute flaccid paralysis (AFP) and consideration of other data. The most recent case of wild poliovirus in Aotearoa was identified in a new arrival in 1977. The most recent case of vaccine-associated paralytic polio was in 1998, with no such cases since introduction of inactivated polio vaccine in 2002. Over 200 people enter Aotearoa each year from countries “infected or at risk of exporting polio”.
Methods:
A monthly survey is sent to paediatricians in Aotearoa, augmented by reports from Neurology Nurse Specialists at Starship Hospital, to identify cases of AFP. A detailed questionnaire and analysis of stool samples for poliovirus and nasopharyngeal swabs for enterovirus (including D68) are requested on reported cases. Opportunistic wastewater sampling for poliovirus is planned for 2023.
Results:
Reporting of 9–13 AFP cases per year meets the World Health Organization sensitivity requirement. From 2017–2021 there were 53 children aged under 15 years with AFP reported from 13 district health boards. Paediatricians reported 49% of cases with 51% direct from Neurology Nurse Specialists. Stool samples (provided for 58%–89% of cases) were negative for poliovirus, and NP swabs were negative for enterovirus. All cases were classified as ‘non-polio’. The most common clinical diagnosis was Guillain-Barré Syndrome. Wastewater testing for poliovirus is planned for 2023.
Conclusion:
Active surveillance of AFP by paediatricians and specialist nurses in Aotearoa improves the chances of identifying polio should it occur. Wastewater surveillance may be justified in the context of falling immunisation rates and open international borders.