Report of the Australian National Polio Reference Laboratory: 1 January to 30 June 2000

This report published in Communicable Diseases Intelligence Volume 24, No 10, October 2000 contains A report on the Australian National Polio reference laboratory

Page last updated: 10 November 2000

A print friendly PDF version is available from this Communicable Diseases Intelligence issue's table of contents.


Vicki Stambos, Kerri Anne Brussen, Ann Turnbull, Aishah Ibrahim, Margery Kennett, Epidemiology and Public Health Division, Victorian Infectious Diseases Reference Laboratory, Carlton South,Victoria1

Introduction | Methods and results | Discussion | Acknowledgements | Abbreviations | References

Abstract

The Australian National Polio Reference Laboratory (NPRL) is responsible for virological confirmation of poliomyelitis in Australia. Since 1995, 1,204 untyped enterovirus or poliovirus isolates from six States have been identified and characterised. Of these, 666 were Sabin vaccine-like poliovirus, 498 were non-polio enteroviruses and 39 were other viruses or negative; one non-Sabin vaccine-like poliovirus was identified as a laboratory contaminant. Early in 2000, the Victorian Infectious Diseases Reference Laboratory (VIDRL) was funded to coordinate surveillance of acute flaccid paralysis (AFP). From 1 January to 30 June 2000, 23 specimens from 13 patients with AFP were processed and cultured for the presence of enterovirus; none was detected. A National Coordinator has been appointed to work with the VIDRL and the Commonwealth Department of Health and Aged Care (CDHAC) to implement the Australian component of the World Health Organization's global plan for containment of wild polioviruses. During April 2000 staff of the NPRL and CDHAC met with the Regional Commission and staff of the World Health Organization (WHO) office of the Western Pacific Region (WPR) to discuss documentation required to certify Australia as poliovirus free. Commun Dis Intell 2000;24:300-303.

Introduction

In order for the Western Pacific Region (WPR)* of the World Health Organization (WHO) to be declared wild poliovirus free, each country in the WPR must demonstrate high quality surveillance of acute flaccid paralysis (AFP), good polio vaccine coverage, an outbreak response plan and the containment of laboratory-sourced wild poliovirus.

The National Certification Committee (NCC) provides to the Regional Certification Commission (RCC) documentation on national surveillance and immunisation data, and an annual summary of the progress towards certification. The laboratory component is an essential part of the documentation process. The National Coordinator of Poliovirus Containment in Australia - located at the Victorian Infectious Diseases Reference Laboratory (VIDRL) - is working with the Australian National Poliovirus Reference Laboratory (NPRL) and the Commonwealth Department of Health and Aged Care (CDHAC) to develop and implement a national plan for containment of wild poliovirus infectious materials.

Surveillance of AFP began in Australia in March 1995 and is used for detection of wild poliovirus in the community. Based on experience of other countries, there should be one AFP case per annum for every 100,000 children below 15 years of age. In collaboration with the Australian Paediatric Surveillance Unit (APSU) and the VIDRL, AFP surveillance was coordinated by staff of the National Centre for Disease Control at the CDHAC from 1995 to early 2000, when the coordination was transferred to the VIDRL.

As well as AFP surveillance, another approach to detecting wild polioviruses is to characterise all polioviruses isolated from all patients regardless of their illness or age. In a country where oral poliovirus vaccine (OPV) is administered there will always be incidental isolations of OPV strains. To ensure that all polioviruses are identified and subsequently characterised as wild or Sabin vaccine-like, the NPRL tests polioviruses and untyped enteroviruses referred from virology laboratories in all Australian States. Earlier reports on activities of the NPRL for 19981 and the two halves of 19992,3 have been published. This report is for the period 1 January to 30 June 2000.

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Methods and results

Certification

The Australian National Poliovirus Certification Committee (ANPCC) has addressed the important issue of containment of wild poliovirus infectious and potentially infectious materials. For Australia's submission to the Regional Certification Commission (RCC) the NPRL has documented the history of poliomyelitis in Australia, and reported on laboratory findings and laboratory containment of wild poliovirus.

AFP surveillance

Paediatricians are requested to report all cases of AFP to the APSU by mail, and to contact the national coordinator of AFP surveillance without delay. Arrangements are made for two faecal samples to be collected at least 24 hours apart and within 14 days of onset of paralysis. The samples are transported to the NPRL at the VIDRL for testing. In order to investigate the case at its early phase a questionnaire is sent to the paediatrician; after 60 days another is sent to obtain follow-up information on the patient's condition. The Polio Expert Committee reviews the completed questionnaires and laboratory findings on all reported cases, and classifies them using the WHO virological classification.4

Within 24 hours of receipt, faecal samples are processed and inoculated into six different cell lines including the two cell lines (RD and L20B) recommended by the WHO. The L20B cells possess receptors for human poliovirus and are used to select poliovirus. RD cells support the growth of various enteroviruses including poliovirus.

In all 23 faecal samples from 13 patients presenting with AFP were sent to the NPRL during the first 6 months of 2000 (Table 1). Seven samples were dispatched to the NPRL within the recommended 3 days after collection, eleven were sent after 3 to 7 days and five after 8 to 14 days. Six patients were in Queensland, three in New South Wales and two each in Victoria and South Australia. Of these, six patients had two samples collected at least 24 hours apart within 14 days of onset of illness. One patient had two samples collected only 12 hours apart but still within the recommended 14 days of paralysis and another patient had a single sample collected more than 14 days after onset. Onset dates were not available for five patients, two of whom had single samples collected. No virus was detected in any of these 23 samples.

Top of pageTable 1. Testing of specimens for enteroviruses from patients with acute flaccid paralysis, Australia, 1 January to 30 June 2000

State/ Territory
District/city
Specimen date (and time)
Result
Qld Kippa Ring 17.1.00 (0700) Negative
    17.1.00 (1900) Negative
Vic Bundoora 24.1.00 Negative
    27.1.00 Negative
Qld Yeppoon 1.2.00 Negative
SA Klemzig 18.2.00 Negative
Qld Caboolture 4.3.00 Negative
    5.3.00 Negative
Qld Oakey 28.3.00 Negative
SA Hackham West 28.4.00 Negative
    1.5.00 Negative
NSW Kurri Kurri 3.5.00 Negative
    4.5.00 Negative
ACT Canberra 17.5.00 Negative
    18.5.00 Negative
Qld Cairns 21.5.00 Negative
    23.5.00 Negative
Qld Biggenden 22.5.00 Negative
    25.5.00 Negative
NSW Bonnells Bay 5.6.00 Negative
    7.6.00 Negative
Vic Brunswick 24.6.00 Negative
    25.6.00 Negative