1 March 2007
POLIOMYELITIS – ACUTE FLACCID PARALYSIS AND STOOL VIROLOGY
I write on behalf of the Poliomyelitis Expert Committee of the Commonwealth Department of Health and Ageing, to stress the importance of submitting stool specimens for virological analysis, in cases of acute flaccid paralysis (AFP), and particularly in those cases where poliomyelitis, however, unlikely, must be included in the differential diagnosis.
The last case of wild-type poliomyelitis occurred in Australia in the early 1970s, and the last case of vaccine-associated poliomyelitis occurred in 1996. Since that time, Australia has been poliomyelitis-free. Nevertheless, every year there have been cluster outbreaks of poliomyelitis in countries that Australians visit and from which Australians return. The 2005/6 outbreak of clinical poliomyelitis in Indonesia was of significant concern to all monitoring bodies. Currently, almost three million Australians travel overseas each year and almost six million overseas visitors come here. The current immunisation-completion rate for poliomyelitis, for Australians, is 86% after the age of 6 years. There is obviously great need for meticulous surveillance, early diagnosis in the event of any clinical case occurring in Australia, and continued promotion of immunisation.
The poliomyelitis virus remains viable and potentially infectious outside the body for some 8 weeks in faecal-contaminated soil or water. If poliomyelitis were reintroduced into Australia, the personal, logistic and administrative costs of eradication would be great, and have huge repercussions. Such would be further exacerbated by delayed diagnosis.
The national Poliomyelitis Expert Committee, a committee of the Commonwealth Department of Health and Ageing, functions executively from the Victorian Infectious Diseases Reference Laboratory based in Melbourne. The Poliomyelitis Expert Committee monitors every case of AFP reported to it from multiple sources of case finding, principally through reports from the Australian Paediatric Surveillance Unit. Approximately 70 cases of AFP are reviewed in detail each year with final diagnoses ranging from Guillaine–Barré syndrome to tick paralysis.
The ‘gold standard’, by which children with various forms of paralysis can be certified not to have poliomyelitis, is by negative culture of two stool-specimens submitted for virological culture, collected 24 h apart and within 14 days of onset of paralysis. Currently, the rate of submission of such stool specimens is only 16%. It is essential, in any newly presenting child with AFP, in which acute poliomyelitis or other neurotropic viruses must be considered in the differential diagnosis, to have such stool specimens submitted for culturing. This is done through one’s own local hospital pathology laboratory, to be forwarded to the National Polio Reference Laboratory located at the Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia (Tel: 03 9342 2600; Fax: 03 9342 2665; email: firstname.lastname@example.org).
In the context of the ongoing ever-present risk of a poliomyelitis case occurring in Australia, may I join with many colleagues in promoting the strongest advocacy for the submission of stool specimens for virological analysis in all non-traumatic patients with AFP.