Accreditation provides documentation that the laboratory has the capability and the capacity to detect, identify, and promptly report wild polioviruses that may be present in clinical and environmental specimens. The accreditation process further provides a learning opportunity, a mechanism for identifying resource and training needs, a measure of progress, and a link to the Global WHO Laboratory Network.
Accreditation of National Poliovirus Laboratories is reviewed annually by the WHO Regional Office and is based on laboratory performance during the preceding 12 months, with complete data, usually from 13 months to one month prior to evaluation. Accreditation is given for the upcoming calendar year.
There are seven criteria for accreditation of National and sub-National Laboratories within the Global Polio National Laboratory (GPNL.
1) Test results are reported by the laboratory on at least 80% of acute flaccid paralysis specimens within 28 days of receipt.
This criterion may be met for all virus-negative specimens after two passages in 14 days. Similarly, viruses that demonstrate cytopathic effect within the first week of incubation may be identified within the 28-day time frame. Viruses that appear late in passage, virus mixtures or viruses that present typing difficulties may require longer than 28 days.
2) Virological tests are performed on at least 150 stool specimens annually.
Fully active virus laboratories that maintain the appropriate cell cultures weekly and annually test 150 stool specimens of any origin for any enteric viruses are deemed to meet this criterion. Laboratories anticipating less than this number may collaborate with the EPI staff to develop protocols for sampling stools from children with aseptic meningitis, healthy children in high risk areas, or other epidemiologically sound virus surveillance activities.
3) The accuracy of poliovirus detection and identification among all virus isolates is at least 90%.
Accuracy is determined by the agreement in test results on all poliovirus isolates submitted by the NL to the RRL during the 12-month review period.
4) At least 80% of poliovirus isolates from acute flaccid paralysis cases are forwarded to the Regional Reference Laboratory for intratypic differentiation within seven days of obtaining typing result.
It is essential that the polio eradication programme be aware of all wild and suspected vaccine-derived poliovirus isolations as soon as possible. All poliovirus isolates from AFP, contacts and other suspected polio cases must be forwarded without delay to the RRL for intratypic differentiation. Polioviruses from non-AFP sources or supplementary surveillance activities (e.g. polioviruses from environmental samples) should also be subjected to ITD tests and should be forwarded to reference laboratories as soon as possible (ideally within seven days of detection).
5) Internal quality control procedures, including cell culture sensitivity, are implemented at least quarterly in accord with the WHO protocol.
Ideally, cell line sensitivity should be known for all frozen stocks and evaluated whenever fresh cells are resuscitated or received in the laboratory. It is recommended that cells be evaluated at least midway through their expected use of 15 passages. Assessing sensitivity before discarding at 15 passages can reassure the laboratory that sensitivity has been maintained throughout the period of use, but is not essential for accreditation. Original quality control (QC) data sheets and summaries of corrective action are retained for documentation and discussion with the reviewer.
6) The score on the most recent WHO approved proficiency test is at least 80%.
Proficiency test (PT) results must be reported within 28 days of panel receipt to receive full credit.
7) The score from the annual on-site review of laboratory operating procedures and practices is at least 80%.
For laboratories with consistently high annual scores, the Regional Laboratory Coordinator may waive the on-site review upon satisfactory completion of the annual checklist by the laboratory.
The annual non-polio enterovirus (NPEV) isolation rate from all stool specimens: The NPEV rate is not a criterion for accreditation because of the variability of findings, which are influenced by a number of factors, including the season of the year, elevation, or population hygienic levels. However, the rate may be a useful indicator of laboratory performance and should be discussed with the reviewer. The annual NPEV isolation rate in most tropical countries typically exceeds 10%.
There are five criteria for accreditation of RRLs:
1) ITD test results are reported to the Programme and the Regional Laboratory Coordinator on ³80% of all acute flaccid paralysis (AFP) poliovirus isolates within 14 days of receipt or completion of typing if specimens are processed in that laboratory.
This criterion applies to poliovirus isolates from AFP cases and contacts. ITD tests should be performed on poliovirus isolates from all sources, but those from AFP cases and their contacts should be given highest priority.
2) Wild poliovirus and suspected vaccine-derived poliovirus isolates from >80% of acute flaccid paralysis cases and contacts are referred for sequencing within seven days of detection.
This criterion applies to isolates from AFP cases and contacts. It is essential that the Polio Eradication Programme be able to get information about the characteristics of wild poliovirus or VDPV isolates as soon as possible. Wild polioviruses and suspected VDPV isolates must be forwarded without delay to a Global Specialized Polio Reference Laboratory for sequencing.
3) The score is ³90% on the most recent WHO poliovirus intratypic differentiation proficiency test.
PT results must be reported within 14 days of panel receipt to receive full credit.
4) The score is ³90% on the most recent WHO poliovirus isolation/ identification proficiency test .
PT results must be reported within 28 days of panel receipt to receive full credit.
5) The score from the annual on-site review of laboratory operating procedures and practices is ³90%.
For those that also serve as NLs:
6) Test results are reported to the programme on ³80% of AFP specimens within 28 days of receipt.
Viruses that appear late in passage, virus mixtures, or viruses that present typing difficulties may require longer than 28 days.
7) Internal QC procedures for L20B and human rhabdomyosarcoma (RD) cell culture sensitivity are implemented at least quarterly in accordance with the WHO protocol.
Ideally, cell line sensitivity should be known for all frozen stocks and evaluated whenever fresh cells are resuscitated or received in the laboratory. It is recommended that cells be evaluated at least midway through their expected use of 15 passages. Assessing sensitivity before discarding at 15 passages can reassure the laboratory that sensitivity has been maintained throughout the period of use, but is not essential for accreditation. Original QC data sheets and summaries of corrective action are retained for documentation and discussion with the reviewer.
Some NLs that test large numbers of AFP stool specimens from endemic or recently endemic areas have been requested by WHO to perform ITD tests on polioviruses isolated in the laboratory. Combining poliovirus isolation/ identification and ITD in the same laboratory can shorten wild virus and suspected VDPV reporting time by several weeks.
Supplemental accreditation provides documentation that the National Poliovirus Laboratory performing ITD tests has the capability and the capacity to detect, identify and promptly report wild polioviruses that may be present in any specimen. Full accreditation as a NL is a prerequisite for ITD accreditation. The accreditation process further provides a learning opportunity, a mechanism for identifying resource and training needs, a measure of progress, and a link to the Global WHO Laboratory Network.
1) Intratypic differentiation test results are reported to the Programme and the Regional Laboratory Coordinator on ³80% of all acute flaccid paralysis poliovirus isolates within 14 days of typing in the laboratory.
This criterion applies to isolates from AFP cases and contacts of AFP cases from investigations. ITD tests should be performed on polioviruses isolated from all sources, but those from AFP cases and their contacts should be given highest priority.
2) The score is ³90% on the most recent WHO poliovirus intratypic differentiation proficiency test .
PT results must be reported within 14 days of panel receipt.
3) Wild poliovirus and suspected vaccine-derived poliovirus isolates from >80% of acute flaccid paralysis cases and contacts are referred for sequencing within seven days of detection.
This criterion applies to isolates from AFP cases and contacts. It is essential that the polio eradication programme be able to get information about the characteristics of wild poliovirus or VDPV isolates as soon as possible. Wild polioviruses and suspected VDPV isolates must be forwarded without delay to a Global Specialized Polio Reference Laboratory for sequencing
4) The score from the annual on-site review of laboratory operating procedures and practices is ³90%.
The specialized functions carried out by the GSLs are not equally distributed between the laboratories, with some laboratories being the sole provider of certain functions. All Global laboratories, however, perform the roles of RRLs, and several also act as NLs. It is therefore most appropriate to accredit the GSLs using the criteria for RRLs, but expecting a more than adequate level of performance. These laboratories are regarded as centres of excellence, and should be expected to be able to provide a performance compatible with expectations.
The additional category of “provisionally accredited” should be used for laboratories that achieve a passing score in the proficiency panel test, but fail to meet one of the remaining criteria. Provisional accreditation is given at the discretion of the Regional Laboratory Network Coordinator. In such cases the laboratory, in conjunction with the reviewer and the WHO Regional Office, must develop a detailed plan of action to resolve problems within one year. The laboratory must receive another accreditation review visit by the end of that year. A laboratory that again fails to meet all accreditation criteria cannot be given provisional accreditation status for a second year in succession. Such laboratories must be given the status of “not accredited”, and an accredited laboratory must confirm the test results on all specimens from AFP cases that are reported by the non-accredited laboratory.
A laboratory that achieves less than the passing score on any one of the applicable criteria will work with the Regional Laboratory Coordinator to:
· identify areas where improvement is needed;
· develop and implement a work plan;
· monitor laboratory progress;
· provide for retesting where required;
· continue steps to achieve full accreditation.
The aim of every laboratory should be to achieve full accreditation. However, if a laboratory has passed the most recent proficiency test but failed to reach one of the other performance criteria (reporting time, number of specimens tested, confirmation of isolates, internal QC, review of operating procedures and work practices) it may be considered for provisional accreditation. The Regional Laboratory Coordinator can make the decision to award provisional accreditation status.
A laboratory that fails to achieve a passing PT test score within six months of an annual review is deemed non-accredited and arrangements must be made for an accredited Laboratory to perform duplicate tests on all specimens.
Laboratories that repeatedly fail to achieve accreditation status pose a problem for the Programme. In some instances, with the agreement of the national government and the WHO Regional Director, these laboratories can be excluded from the Global Polio Laboratory Network. In other instances, however, it will not be possible to exclude laboratories, and attempts must continue to be made to improve laboratory performance by providing support through consultant visits and laboratory staff training. In these cases, arrangements must be made for an accredited laboratory to confirm all results on specimens from AFP cases reported by the non-accredited laboratory. These arrangements should be viewed as long-term and may require provision of additional support for the laboratory and for specimen transport.
National and sub-National Laboratories: Accreditation of National and recognized sub-National laboratories is the responsibility of the WHO Regional Offices. Ideally, all national and recognized sub-national laboratories should be visited by the Regional Polio Laboratory Network Coordinator at least once a year. Where this is not possible, laboratory consultants or other experts should visit the laboratories on behalf of WHO. These visits should be combined with the annual accreditation review visit.
On completion of an accreditation review the WHO Regional Office should be informed of the result. It is the responsibility of the Regional Office to make an official announcement of the accreditation review result. The Regional Office should report the result to:
· the national authorities through the office of the WHO Representative;
· the head of the national surveillance or EPI programme;
· the director of the institute hosting the laboratory;
· the head of the laboratory;
· the WHO Global Laboratory Network Coordinator.
Regional Reference Laboratories: Accreditation of Regional Reference Laboratories (RRLs) is the responsibility of WHO Headquarters. Ideally, the WHO Global Laboratory Network Coordinator, accompanied by the Regional Laboratory Network Coordinator, will make accreditation review visits to all RRLs. Where this is not possible the Regional Laboratory Network Coordinator accompanied by a representative acting on behalf of WHO/HQ should make the visit.
On completion of an accreditation review WHO Headquarters should be informed of the result. It is then the responsibility of the WHO Headquarters to make an official announcement of the accreditation review result. The result should be reported to:
· the WHO Regional Office;
· the director of the institute hosting the laboratory;
· the head of the laboratory.
Global Specialized Laboratories: Accreditation of Global Specialized Laboratories (GSLs) is the responsibility of WHO Headquarters.
On completion of an accreditation review WHO Headquarters should make an official announcement of the result to:
· the WHO Regional Office;
· the director of the institute hosting the laboratory;
· the head of the laboratory.
National and recognized sub-national laboratories that have been fully accredited and continue to meet WHO laboratory performance criteria need not receive an accreditation review visit every year. In these cases the laboratory can be accredited by the Regional Laboratory Network Coordinator on the basis of:
at least 80% of test results reported within 28 days;
at least 150 specimens tested annually;
at least 90% of poliovirus isolates confirmed by the Regional Reference Laboratory;
at least 80% of AFP poliovirus isolates forwarded for ITD within seven days;
at least 80% scored on the most recent WHO-approved proficiency test;
internal quality control procedures implemented at least quarterly.
Under these circumstances the WHO Regional Office should inform the following that the laboratory has been fully accredited for the coming year and that because of continued high quality performance no accreditation review visit is necessary:
- the national authorities through the office of the WHO Representative;
- the head of the national surveillance or EPI programme;
- the director of the institute hosting the laboratory;
- the head of the laboratory; and
- the WHO Global Laboratory Network Coordinator.
The decision not to carry out the accreditation review visit is at the discretion of the Regional Laboratory Network Coordinator. It is expected, however, that even a high performance national and recognized sub-national laboratory should receive at least one accreditation review visit every three years.