The importance of containment
Containment of poliovirus is critical to achieving and maintaining global polio-free status. To minimise the risk of an accidental release of the virus, global containment standards require all poliovirus materials destroyed or safely and securely contained in a Polio Essential Facility (PEF). The National Enterovirus Reference Laboratory (NERL) is the only laboratory in Australia that is classed as a PEF and is also the WHO Polio Regional Reference Laboratory.
What are PIMs?
Poliovirus potentially infectious materials (PIM) are human faecal, respiratory, or concentrated sewage samples (or their derivatives) that are stored in conditions that support poliovirus survival and were collected at a time and place where poliovirus was in circulation, or when oral polio vaccine was in use.
For samples that were collected in Australia, the critical dates are in or before December 1972 for wild poliovirus (since this was when the last locally acquired case of polio was reported), and between January 1973 to June 2006 (which was when the oral polio vaccine was being administered). There are still cases of wild poliovirus and/or active use of oral polio vaccines worldwide, and for this reason any samples that have been bought into Australia from overseas are considered to be potentially infectious, independent of when they were collected.
The conditions under which the samples are stored is also important. For the polio virus to survive, the samples need to have been stored at -20ºC or lower.
Therefore, PIMs in Australian facilities include human faecal or respiratory samples, sewage samples or specimens from animals used in polio research that were either collected in Australia in June 2006 or earlier, or outside Australia at any time and have been stored at or below -20ºC since collection.
The classification of samples as PIMs is based on the publication: “Guidance to minimize risks for facilities collecting, handling or storing materials potentially infectious for polioviruses”, published by the World Health Organization; 2018. https://polioeradication.org/wp-content/uploads/2018/06/polio-containment-guidance-for-non-poliovirus-facilities-20180614-en.pdf
What to do if you have PIMs
- Fill in the survey declaring that you have PIMs and specifying the type of samples
- If you find out you have PIMs in your facility, immediately contact the Department of Health or the National Enterovirus Reference Laboratory (NERL)
- In most cases, the best option is for PIMs to be destroyed, and the Department of Health or NERL will be able to advise how to do this safely
- If samples need to be retained for ethical or other reasons, they should be transferred to the NERL for long-term storage
Further information on PIMs can be found in the WHO document FREQUENTLY ASKED QUESTIONS (PIM GUIDANCE)