Office of the National Certification Commission for Poliomyelitis Eradication

• National enterovirus surveillance
• Laboratory Network Enterovirus Diagnostics (LaNED)
• Laboratory Containment

Head: Dr. Kathrin Keeren

National enterovirus surveillance

Since 2010 surveillance of polio free status in Germany rely entirely on an enterovirus surveillance system. This system offers a free of charge enterovirus diagnostics to all hospitals for patients with viral meningitis or encephalitis as well as those with acute flaccid paralysis regardless of the patient’s age. For this purpose a Laboratory Network for Enterovirus Diagnostics (LaNED) was established in Germany.

The following objectives are pursued with enterovirus diagnostics in viral meningitis/encephalitis patients:

• Surveillance of polio free status in Germany as part of the commitment undertaken within the Global Polio Eradication Initiative (GPEI) of WHO
• Contribution to the aetiological clarification of aseptic meningitis/encephalitis
• Improvement of patient management
• Detection of disease clusters as requirement for initiation of further preventive measures
• Assessment of the pathogen and age specific incidence of central nervous infections

Within the enterovirus surveillance system one sample per patient (stool or CSF) is examined free of charge. For different reasons (high virus load, longer time of excretion, non-invasive sampling, and sufficient sample quantity) stool samples are specimens of choice, followed by CSF taken within the first days after onset of disease. The clinician should send the sample (of a patient with the given indication) to a LaNED laboratory of choice using the “Einsendeschein für die Enterovirus Surveillance” (cover sheet and copy). This lab will provide the results and send the copy of the sheet with the pseudonymised data and the laboratory results for epidemiological assessment to the office at the Robert Koch Institute. For evaluation of the data special submission sheets must be used which may not be copied. New submission sheets can be requested from the office using the form under “Further Information”.

Summarized information and recommendations for the practical implementation can be found in the information sheet “Enterovirus Diagnostics”.

Updated information on the global polio situation and the results of enterovirus surveillance are published regularly in the leaflet “Polio Info”.

In 2015, the WHO declared global eradication of type 2 polio wild virus after it has not been last detected since 1999. In 2019 type 3 polio wild virus has also been declared eradicated (last detection 2012).

Thus, only type 1 polio wild virus circulates in two countries only (Pakistan and Afghanistan).

Nonetheless, there are polio cases in other countries that are triggered by vaccine-derived polioviruses (VDPV). Oral live vaccine (OPV) is used in many countries. In a population with a low vaccination rate, the attenuated but reproductive viruses of the vaccine can continue to be transmitted and change in the process. This can lead to the harmless vaccine viruses becoming disease-causing again. The type 2 component of the life vaccine is particularly prone to reversion. Therefore, after eradication, the type 2 component was removed from the live vaccine. Protection against type 2 polioviruses has since been achieved by additional vaccination with the inactivated polio vaccine (IPV). IPV does not contain any reproductive viruses and therefore cannot cause VDPV. However, IPV is administered by injection, which requires certain conditions (hygiene, cold chain), but is a challenge for vaccination teams in many countries. In addition, IPV protects the vaccinated against illness (individual protection), but not against infection. Therefore, a person vaccinated against polio can continue to become infected with polioviruses after exposure. The polioviruses can multiply, excreted and thereby transmitted. In this case, OPV vaccinated people, shed polioviruses significantly shorter than IPV vaccinated people.

In Germany, only the inactivated polio vaccine is used since 1998.

Especially in terms of globalization and migration, it is essential to take all necessary measures to monitor and maintain polio free status in Germany until poliomyelitis is eradicated globally.

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Laboratory Network Enterovirus Diagnostics (LaNED)

For implementation of enterovirus surveillance a network of 14 competent enterovirus laboratories was established in Germany in 2006. It is supervised by the National Reference Laboratory at RKI, which also serves as the Regional Reference Laboratory for WHO/Europe. All participating labs have to prove their competence in biannual appropriate proficiency tests organized by the National Reference Laboratory in accordance with WHO criteria and performed in cooperation with INSTAND (WHO Collaboration Centre for QA and Standardization in Laboratory Medicine). The competence of the National Reference Laboratory is proven by WHO proficiency tests for cultivation and typing of enteroviruses as well as for intratypic differentiation and sequencing of polioviruses. The laboratories carry out primary diagnostics with PCR, cultivation and typing. All enteroviruses which cannot be serotyped, PCR positive and cultivation negative samples as well as all polio viruses are sent to the National Reference Laboratory for further analysis.

For patients with suspected viral meningitis or encephalitis as well as acute flaccid paralysis the use of enterovirus diagnostics is offered to hospitals free of charge. Faecal specimens should be the favoured material for enterovirus diagnostics, but CFS samples are investigated as well. Samples may be sent to one of the LaNED laboratories.

Further information and submission sheets for enterovirus diagnostics can be ordered from the office at the RKI (see “Further Information”).

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Laboratory Containment

After global certification of polio eradication laboratories, which store infectious or potentially infectious material containing wild polioviruses, can constitute a risk. For that reason containment (the safe storage of such material) is the third important element for the certification of a WHO region as polio free, in addition to a high vaccination rate and a functioning surveillance. After the WHO Region Europe received this certification in 2002, containment became increasingly important in Germany, too. Its implementation, i.e. the interrogation of laboratories concerning the use / storage of wild polioviruses and the establishment of a nationwide inventory, was started at the Lower Saxony Regional Health Office in Hanover.

In 2010 the laboratory containment has also been shifted to the RKI, which is responsible for all polio eradication activities in Germany.

In 2015, the WHO declared global eradication of type 2 polio wild viruses. In 2016, the trivalent polio live vaccine was replaced by bivalent (polio 1 + 3) in OPV vaccinating countries.

The possession of all type 2 polio viruses has no longer been permitted outside polio essential facilities (PEF) since 2016. In Germany there is no PEF.

In October 2019, type 3 polio viruses were also declared eradicated. This affects laboratory containment.

With an amendment of the Infection Protection Act (IfSG), polio containment was given a legal basis with the new paragraph 50a ("Laboratory containment and eradication of the polio virus"). Since July 25, 2017, possession of polio viruses or material that may contain polioviruses (PIM) must be reported to the responsible authority (usually the health authority). The responsible authority immediately transmits information on the facility, the responsible person, the type and quantity of t polioviruses / the material as well as the intended purpose to the highest national health authority, which immediately sends it to the Office of the National Commission for polio eradication (at RKI).

In addition, the new paragraph authorizes the Federal Ministry of Health to determine the dates.

1. for which polioviruses and material that may contain polioviruses must be destroyed at latest in accordance with paragraph 2,
2. from which only a central facility may have type 1 and 3 polio wild viruses, type 1 and 3 polio vaccine viruses and material which may contain such polioviruses.

If there is a suspicion that a person has polioviruses or material that may contain polioviruses without being notified, the competent authority can carry out the necessary investigations.

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