UK Standards for Microbiology Investigations, Surveillance of Polio in the UK

8/13/2019 UK Standards for Microbiology Investigations, Surveillance of Polio in the UK

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UK Protocols | P 1 | Issue no: 4| Issue date: 03.05.12 | Page: 1 of 19

UK Standards for Microbiology Investigations

Surveillance of Polio in the UK




UK Protocols |P 1 | Issue no: 4 | Issue date: 03.05.12 | Page: 2 of 19

UK Standards for Microbiology Investigations | Issued by the Standards Unit, Health Protection Agency

Acknowledgments

UK Standards for Microbiology Investigations (SMIs) are developed under the auspices of theHealth Protection Agency (HPA) working in partnership with the National Health Service (NHS),Public Health Wales and with the professional organisations whose logos are displayed below

and listed on the website http://www.hpa.org.uk/SMI/Partnerships. SMIs are developed,reviewed and revised by various working groups which are overseen by a steering committee(see http://www.hpa.org.uk/SMI/WorkingGroups).

The contributions of many individuals in clinical, specialist and reference laboratories who haveprovided information and comments during the development of this document areacknowledged. We are grateful to the Medical Editors for editing the medical content.

For further information please contact us at:

Standards UnitMicrobiology Services DivisionHealth Protection Agency

61 Colindale AvenueLondon NW9 5EQ

E-mail: [email protected]

Website: http://www.hpa.org.uk/SMI

UK Standards for Microbiology Investigations are produced in association with:

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UK Standards for Microbiology Investigations : Status

Users of SMIsThree groups of users have been identified for whom SMIs are especially relevant:

• SMIs are primarily intended as a general resource for practising professionals in the fieldoperating in the field of laboratory medicine in the UK. Specialist advice should be

obtained where necessary.

• SMIs provide clinicians with information about the standard of laboratory services theyshould expect for the investigation of infection in their patients and the documentsprovide information that aids the electronic ordering of appropriate tests from hospitalwards.

• SMIs also provide commissioners of healthcare services with the standard ofmicrobiology investigations they should be seeking as part of the clinical and publichealth care package for their population.

Background to SMIsSMIs comprise a collection of recommended algorithms and procedures covering all stages ofthe investigative process in microbiology from the pre-analytical (clinical syndrome) stage tothe analytical (laboratory testing) and post analytical (result interpretation and reporting)stages.

Syndromic algorithms are supported by more detailed documents containing advice on theinvestigation of specific diseases and infections. Guidance notes cover the clinical background,differential diagnosis, and appropriate investigation of particular clinical conditions. Qualityguidance notes describe essential laboratory methodologies which underpin quality, forexample assay validation, quality assurance, and understanding uncertainty of measurement.

Standardisation of the diagnostic process through the application of SMIs helps to assure theequivalence of investigation strategies in different laboratories across the UK and is essentialfor public health interventions, surveillance, and research and development activities. SMIsalign advice on testing strategies with the UK diagnostic and public health agendas.

Involvement of Professional OrganisationsThe development of SMIs is undertaken within the HPA in partnership with the NHS, PublicHealth Wales and with professional organisations.

The list of participating organisations may be found athttp://www.hpa.org.uk/SMI/Partnerships. Inclusion of an organisation’s logo in an SMI implies

support for the objectives and process of preparing SMIs. Representatives of professionalorganisations are members of the steering committee and working groups which developSMIs, although the views of participants are not necessarily those of the entire organisationthey represent.

SMIs are developed, reviewed and updated through a wide consultation process. The resultingdocuments reflect the majority view of contributors. SMIs are freely available to view athttp://www.hpa.org.uk/SMI as controlled documents in Adobe PDF format.

# UK Standards for Microbiology Investigations were formerly known as National Standard Methods.

Microbiology is used as a generic term to include the two GMC-recognised specialties of Medical Microbiology (which includes Bacteriology,Mycology and Parasitology) and Medical Virology.













Quality AssuranceThe process for the development of SMIs is certified to ISO 9001:2008.

NHS Evidence has accredited the process used by the HPA to produce SMIs. Accreditation isvalid for three years from July 2011. The accreditation is applicable to all guidance producedsince October 2009 using the processes described in the HPA’s Standard Operating Procedure

SW3026 (2009) version 6.SMIs represent a good standard of practice to which all clinical and public health microbiologylaboratories in the UK are expected to work. SMIs are well referenced and represent neitherminimum standards of practice nor the highest level of complex laboratory investigationpossible. In using SMIs, laboratories should take account of local requirements and undertakeadditional investigations where appropriate. SMIs help laboratories to meet accreditationrequirements by promoting high quality practices which are auditable. SMIs also provide areference point for method development. SMIs should be used in conjunction with other SMIs.

UK microbiology laboratories that do not use SMIs should be able to demonstrate at leastequivalence in their testing methodologies.

The performance of SMIs depends on well trained staff and the quality of reagents andequipment used. Laboratories should ensure that all commercial and in-house tests have beenvalidated and shown to be fit for purpose. Laboratories should participate in external qualityassessment schemes and undertake relevant internal quality control procedures.

Whilst every care has been taken in the preparation of SMIs, the HPA, its successororganisation(s) and any supporting organisation, shall, to the greatest extent possible underany applicable law, exclude liability for all losses, costs, claims, damages or expenses arising outof or connected with the use of an SMI or any information contained therein. If alterations aremade to an SMI, it must be made clear where and by whom such changes have been made.

SMIs are the copyright of the HPA which should be acknowledged where appropriate.

Microbial taxonomy is up to date at the time of full review.

Equality and Information GovernanceAn Equality Impact Assessment on SMIs is available at http://www.hpa.org.uk/SMI.

The HPA is a Caldicott compliant organisation. It seeks to take every possible precaution toprevent unauthorised disclosure of patient details and to ensure that patient-related recordsare kept under secure conditions.

Suggested Citation for this DocumentHealth Protection Agency. (2012). Surveillance of Polio in the UK. UK Standards for

Microbiology Investigations. P 1 Issue 4. http://www.hpa.org.uk/SMI/pdf.




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Contents

ACKNOWLEDGMENTS ............................................................................................................ 2 UK STANDARDS FOR MICROBIOLOGY INVESTIGATIONS: STATUS ............ ............ ......... ............ ..... 3 AMENDMENT TABLE ............................................................................................................... 6 SCOPE OF DOCUMENT ........................................................................................................... 7 INTRODUCTION ..................................................................................................................... 7 1 THE ROLE OF HPA AND NHS LABORATORIES ................................................................... 8 2 THE ROLE OF VIRUS REFERENCE DEPARTMENT, MICROBIOLOGICAL SERVICES DIVISION,

COLINDALE .............................................................................................................. 10 3 THE ROLE OF HEALTH PROTECTION SERVICES AT HPA COLINDALE .................................. 10 APPENDIX 1 TECHNICAL INFORMATION ON THE LABORATORY DIAGNOSIS OF POLIOVIRUS

INFECTION ............................................................................................................... 12 APPENDIX 2 POLIO SURVEILLANCE FORM ................................................................................ 13 APPENDIX 3. LETTER TO CLINICIANS ....................................................................................... 13 APPENDIX 4. PUBLIC HEALTH RESPONSE TO POTENTIAL WILD POLIOVIRUS INFECTION............. ..... 14 APPENDIX 5. CASE DEFINITIONS FOR PARALYTIC POLIOMYELITIS ............ ............ ......... ............ ... 18






Amendment Table

Each SMI method has an individual record of amendments. The current amendments are listedon this page. The amendment history is available from [email protected].

New or revised documents should be controlled within the laboratory in accordance with thelocal quality management system.

Amendment No/Date. 32/03.05.12

Issue no. discarded. 3.3

Insert Issue no. 4

Section(s) involved. Amendment.

Whole document. Document presented in a new format.

Introduction. Contents updated

Appendix 2. Surveillance form now embedded in to the document

Amendment No/Date. 31/29.11.05

Issue no. discarded. 3.2

Insert Issue no. 3.3

Section(s) involved. Amendment.

Whole document. Document updated










Scope of Document

This SMI covers the surveillance of Polio within the UK and should be used in conjunction withother SMIs.

IntroductionThe World Health Organization continues its efforts to eradicate polio worldwide and believesthat this goal is attainable, even in the most challenging settings in the world. Onceeradication is achieved, and prior to any decision to stop mass immunisation against polio, itwill be essential to demonstrate that all countries are free of wild poliovirus infections.Certification of a country or region as polio-free requires demonstration that surveillancesystems are adequate to detect any endemic wild poliovirus infections.

In 1997/8, the Public Health Laboratory was asked to prepare part of the UK submission to theWHO commission for the certification of eradication of polio in the European region. Thisaimed to demonstrate that current clinical and laboratory practice was adequate to detect

cases of paralytic illness, aseptic meningitis and asymptomatic infection due to wild poliovirus.The UK submission was forwarded from the Department of Health in Spring 1998 and it wasaccepted by the commission that the UK is now free of wild poliovirus. Formal certificationcould not proceed, however, until the whole region had been free of wild polio for three years.Europe was declared polio-free in 2002. It is essential that enhanced surveillance of polioviruscontinues as importation from endemic regions is still possible. Furthermore, outbreaks ofpoliomyelitis caused by vaccine derived recombinant strains have occurred in countriescertified as polio-free and where vaccine uptake has fallen. We need to demonstrate thatcases with a possible diagnosis of poliomyelitis are adequately investigated to excludeinfection with wild poliovirus. Supporting evidence is also provided by the ability to identifycorrectly non-polio enteroviruses and vaccine strains of poliovirus. Detailed review of the

clinical and laboratory data from all suspected cases of paralytic poliomyelitis (including casesof acute flaccid paralysis with persistent paralysis) should be performed by the UK ExpertPanel. Cases of paralysis which are not adequately investigated should also be subjected toclinical review.

In 2004, the UK changed from using live oral polio vaccine (OPV) to inactivated vaccine (IPV).All poliovirus isolates, unless known to have come from persons recently given OPV, must nowbe regarded as potentially non-vaccine strains.

The UK will minimise the risk of reintroduction of polio through release from facilities holdingpoliovirus or samples that may contain poliovirus. Substantial steps have already been madetowards meeting the requirements of the initial phase of the WHO Global Action Plan, 2nd

edition. (http://www.polioeradication.org/content/publications/WHO-VB-03-729.pdf). As partof the UK response to the WHO initiative the Public Health Laboratory Service compiled aNational Inventory of facilities holding polio materials, starting in 2001 (see Annex 4.5). Anaudit of the inventory by the Health Protection Agency (the successor to Public HealthLaboratory Services), completed in 2009, shows that only 26 sites now retain poliovirus, ormaterial that potentially contains the virus. Any additional laboratory that acquires or isolateswild poliovirus or vaccine virus or stores untyped enterovirus should inform the UK poliocontainment co-ordinator ([email protected]). All laboratories are encouraged to findalternatives to the use of wild poliovirus and to destroy all unneeded material.

In laboratories that continue to isolate, store or use poliovirus, the current legal requirementsfor work with biological agents that present a risk to human health are outlined in the Control

of Substances Hazardous to Health (COSHH) 2002 regulations(http://www.hse.gov.uk/COSHH/index.htm). At present in the UK poliovirus is a hazard group 2

http://www.polioeradication.org/content/publications/WHO-VB-03-729.pdf





http://www.hse.gov.uk/COSHH/index.htm











pathogen and work involving this virus, or materials containing the virus, should be undertakenat CL2. However, the WHO recommends that containment measures go beyond thoserequired by CL2 in Schedule 3 of COSHH. The WHO recommendations, BSL-2/polio, are notcurrently legally required in the UK, but laboratories that continue to work with poliovirus areadvised to implement enhanced BSL-2/polio measures for safe handling of the virus. The WHOguidelines are detailed in the Global Action Plan, 2nd edition

(http://www.polioeradication.org/content/publications/WHO-VB-03-729.pdf).This document sets out the HPA’s role in maintaining surveillance of polio in the UK untilcertification is completed worldwide.

1 The Role of HPA and NHS Laboratories

Laboratories should try to ensure that poliovirus infection is excluded in all cases of acuteflaccid paralysis (including Guillain-Barré syndrome) according to the WHO criteria. Thisinvolves the submission of two stool samples for viral culture which can be performed in theVirus Reference Division, HPA Colindale if virus isolation or enterovirus PCR is not available

locally. Samples should be taken 48 hours apart and within two weeks of onset (see Appendix1).

Laboratories should ensure investigation of all possible polioviruses isolated in the laboratory ordetected by PCR is undertaken --- including from asymptomatic individuals.

To supplement acute-flaccid paralysis surveillance, enhanced surveillance of aseptic meningitisis also recommended, particularly as poliovirus causes aseptic meningitis far more frequentlythan paralytic poliomyelitis and the majority of enteroviruses are detected in CSF samples. It istherefore recommended that enterovirus positive CSF samples and positive nucleic acidextracts are also submitted to the Virus Reference Department for typing.

Laboratories should discuss all cases of suspected polio with Virus Reference Department or

Health Protection Services, HPA Colindale at an early stage. Such cases should be reported tothe local CCDC or equivalent in the devolved administrations.

Laboratories should recommend the following additional investigations in cases of suspectedpolio (see Appendix 1):

• Enterovirus PCR on stool, CSF or throat swabs / NPAs.

• Biochemistry, microscopy and viral culture of CSF specimens.

• Viral culture of throat swabs / NPAs.

• Viral culture and/or PCR of stool from household contacts.

The following poliovirus-specific investigations are available at Virus Reference Department• Poliovirus-specific PCR on stool, CSF or throat swabs/ NPA.

• Virus culture and neutralisation tests (stool, CSF, throat swabs/NPA).

• Intratypic poliovirus neutralisation tests.

• Confirmation of poliovirus and differentiation through sequence analysis of vaccine andwild-type poliovirus strains.

• Acute and convalescent serum for the detection of neutralising antibody to poliovirus1, 2 and 3 in acute and convalescent serum samples (available at Virus Reference

Department).• Poliovirus IgM assay (arranged through Virus Reference Department if appropriate).










Laboratories should perform all routine investigations according to the UK Standards forMicrobiology Investigations (where appropriate/when available).

As part of enhanced surveillance, laboratories should refer the following to the Enteric VirusUnit, Virus Reference Department (see Appendix 2):

a. All poliovirus isolates or clinical samples from which poliovirus has been detected by

molecular or serological methods.b. Untypable enterovirus isolates (these can be tested in suitably trained local

laboratories if preferred. If they can not type them then they should be sent toColindale for typing).

c. CSF samples that are enterovirus positive by PCR (these can be tested in suitablytrained local laboratories if preferred. If they can not type them then they should besent to Colindale for typing).

d. Enterovirus isolates and PCR-positive enterovirus samples from cases with paralyticsymptoms.

e. Enterovirus isolates and PCR-positive enterovirus samples from cases with neurologicalconditions (include those that mention meningitis / encephalitis / meningism /irritability / headache / convulsions / apnoea and sudden death on the request form).

f. Enterovirus isolates and PCR-positive samples from immunosuppressed persons.

g. Enterovirus PCR-positive clinical samples and enterovirus isolates from people withmyocarditis.

NB: cDNA should only be sent if generated through reverse transcription with random priming(random hexamers).

Laboratories should facilitate the Health Protection Services obtaining copies of clinicalinformation on cases of suspected paralytic polio (see Appendix 3). Furthermore, assistance

should be given to obtain further clinical information whenever a poliovirus is detected in thelaboratory. This includes:

• Clinical history (presence of any polio-like symptoms)

• Immune status (immunocompromised or immunocompetent)

• Polio vaccination history.

• Travel history in case and family members.

The appropriate samples should be sent urgently to Virus Reference Department to ascertainif the virus is a vaccine or wild strain. If the former, it should be ascertained if it is a vaccine-

derived poliovirus (VDPV) by intratypic differentiationLaboratories should assist the Health Protection Services and the local CCDC with the publichealth response to suspected cases (see Appendix 4).

To contribute to containment: if wild or vaccine related polio is isolated in the laboratory thenall relevant sample(s) should be either:

• Sent to Virus Reference Department;

• Notified to the ‘‘Poliovirus register’’ if the samples are to be retained in local laboratory

• Discarded






2 The role of Virus Reference Department,Microbiological Services Division, Colindale

The Virus Reference Department will perform routine investigation on clinical samplescollected from suspected polio cases and proceed to intratypic characterisation of any

poliovirus isolates or poliovirus-specific PCR samples. In particular information on the followingshould be sought at an early stage;

• All poliovirus isolates.

• Enterovirus PCR-positive clinical samples and enterovirus isolates from cases withparalytic symptoms.

• Enterovirus PCR-positive clinical samples (including CSF) and enterovirus isolates frompeople with possible neurological disease.

• Enterovirus PCR-positive clinical samples and enterovirus isolates from people withmyocarditis.

• Enterovirus PCR-positive CSF and cell culture isolates from immunosuppressed persons.

• Enterovirus PCR-positive CSF and cell culture isolates from high risk (under-vaccinated)populations.

Virus Reference Department will report routine poliovirus investigations on specimens fromcases with paralytic or other neurological symptoms as outlined above within one week ofreceipt.

Virus Reference Department will perform further investigation of cases of suspected polioaccording to WHO and HPA-approved SOPs. These investigations include:

• Neutralising antibody for poliovirus types 1, 2 and 3.• Enterovirus PCR on stool, CSF or throat swab / NPA.

• Poliovirus PCR on stool, CSF or throat swab / NPA.

• Characterisation of polioviruses through sequencing of the VP1 region.

Virus Reference Department will provide advice on appropriate investigation of suspectedcases.

Virus Reference Department will support laboratories and the Immunisation Department in apublic health response to a suspected case.

3 The Role of Health Protection Services at HPAColindale

Health Protection Services will offer advice on the appropriate investigation of suspectedpoliovirus cases to laboratories and CCDCs.

Health Protection Services will offer advice and support to CCDCs in a public health responseto a suspected case (see Appendix 4).

Health Protection Services will liaise with local laboratories, CCDCs and clinicians to obtainfurther clinical information from all suspected cases of polio (see Appendix 3).

Health Protection Services will collate clinical and laboratory information for review by the UKexpert panel for:






• All cases of paralysis which are investigated for poliovirus infection.

• For cases of paralysis where stool samples were not taken at the appropriate stage.

• All enterovirus identifications.

Health Protection Services will collate information on poliovirus and enterovirus isolates and

identifications reported to Health Protection Services and referred to EVU, Virus ReferenceDepartment.

Health Protection Services will collate data on cases of suspected poliomyelitis from any source(notified to ONS, paralysis reported to the Medicines Control Agency, referred to EVU, VirusReference Department or reported to Health Protection Services) according to agreed casedefinitions (see Appendix 5).






Appendix 1 Technical Information on the LaboratoryDiagnosis of Poliovirus Infection

1 APPROPRIATE SPECIMENSThroat swabs first week of illness.

Faeces up to fourth week of illness.

CSF early.

Serum first week and 2 - 3 weeks later.

2. VIRUS ISOLATION

2.1 Preparation of specimensThroat swabs: clarify transport medium containing swab by low speed centrifugation.

Faeces: make 10% suspension and clarify by low speed centrifugation.

CSF: use neat

2.2 Inoculation of cell culturesInoculate specimens into cell cultures following local laboratory procedures. Examine cellsheet daily for cytopathic effects. If no cytopathic effects are visible after 1 week, scrape cellsinto tissue culture medium, freeze and thaw and reinoculate into fresh cells.

2.3 Recommended cellsPoliovirus grows in a wide range of all cultures of human and primate origin. RD(Rhabdomyosarcoma) cells are particularly sensitive for isolation of poliovirus and enteroviruses

(and can be supplied by Virus Reference Department if required). Other suitable cells includeMRC5 or other human fibroblasts, primary and secondary monkey kidney, Hep2, Hep2C, HeLaand PLC/PRF5.

2.4 Virus typingIsolates should be identified and typed eg by neutralisation, fluorescence etc.

Commercial fluorescence tests are available for the identification of polioviruses and a limitedrange of enteroviruses.

3 POLIOVIRUS ISOLATES

Poliovirus isolates should be sent to EVU, Virus Reference Department for intratypic vaccinemarker tests and genotyping, together with the completed form for Enhanced Surveillance ofPolio.

3.1 PCRPCR can be used for the detection of polioviruses and enteroviruses in faeces, throat swabs,CSF and early serum specimens.

4 SEROLOGYAntibody tests for polio infection are available at EVU, Virus Reference Department (minimumvolume required is 300 uL). Sera should be sent together with the ‘‘Polio Surveillance’’ form.

Polio serology may be requested for reasons other than investigation of neurological illness egimmune status for travellers, patients who are immunocompromised and for Occupational






Health purposes. These will be treated as referred tests. Serum samples should be submittedwith the ‘‘Polio Surveillance’’ form.

5 FURTHER INFORMATIONFor further information contact EVU, Virus Reference Department 020 8327 6225

Main switchboard and out of hours 020 8200 4400 Appendix 2 Polio Surveillance form

http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1287144477120

Appendix 3. Letter to Clinicians

Polio eradication

Dear Dr ___________________

Re: Case name / identifier: ___________ Reported on/by: _______________

As you may know, the World Health Organization aims to eradicate wild poliovirus. Before any decisionto stop vaccination can be made, however, it will be important to demonstrate that wild poliovirus isabsent in every country. This requires a process of certification, where the surveillance data from eachcountry is presented to the WHO regional commission for critical review. The UK has been certified aspolio-free. To maintain this status, the UK needs to demonstrate that it has appropriate surveillancesystems in place to rapidly detect and investigate suspect polio cases.

The criteria that will be used will be extremely stringent and, in particular, evidence that wild poliovirusinfection was excluded in each case of paralysis is required. The WHO has established a gold standardthat all suspected cases of acute flaccid paralysis should be investigated by the submission of stool

samples for virology. In the UK, however, where the diagnosis of paralytic polio is considered extremelyunlikely, many such cases are excluded by clinical or other criteria. It will therefore be necessary for usto document the clinical findings and investigations in all suspected cases and to submit these forexpert review. I am therefore writing to the clinicians of all cases which have been reported as acuteflaccid paralysis, including those where the diagnosis of poliomyelitis has since been rejected, toobtain further details for this review.

I would therefore be very grateful if you could send to me a copy of the discharge summary and/oroutpatient letters (or the notes if you prefer) from the above case which was reported in (enter year). Inparticular we are interested in history of vaccination or travel, in laboratory investigations (eg.specimens sent for virology, examination of cells in the CSF), in the clinical presentation (eg. presenceof sensory or upper motor neurone symptoms) and in the outcome (residual paralysis at least 60 daysafter onset). If you could please forward any information that we may not already have as soon as

possible I would be very grateful.

With many thanks for your help with this important initiative.

Consultant EpidemiologistImmunisation DepartmentHealth Protection Agency, Colindale









Appendix 4. Public Health Response to Potential WildPoliovirus Infection

Level one:

A. single case of poliovirus detection in an otherwise healthy person

Defined as: Poliovirus (non-drifted variant) isolated from healthy person with:

EITHER recent oral polio vaccination or history of travel to area using OPV

OR contact with family member with recent history of OPV vaccination or recent travel to anarea using OPV

OR no recent vaccination or travel history and no family or vaccination history

1. Ensure appropriate investigations (see Appendix 1) are initiated in cases and contacts

2. Resample case and all household contacts and test at 4 weekly intervals. Report toHealth Protection Services /Virus Reference Department

3. Repeat sampling until two negative samples 48 hours apart

4. Ensure close family contacts are fully vaccinated with IPV- containing vaccine

5. Need to discuss further management and contact tracing urgently with HealthProtection Services and Department of Health if no clear risk factor

B. single case of poliovirus an immunosuppressed person

Defined as: Poliovirus (non-drifted variant) isolated from immunosuppressed person with orwithout symptoms of paralysis

1. Ensure appropriate investigations (see Appendix 1) are initiated in case and contacts.

2. Report to Health Protection Services / Virus Reference Department. InformDepartment of Health.

3. Refer case to clinician

4. Advise adequate personal hygiene and exclusion from food handling work

5. Recheck stools monthly for continued excretion until three stools negative for polio atmonthly intervals -> then review with HPA Colindale (Virus Reference Department andHealth Protection Services)

6. Specialist advice should be sought before travel (regarding possible use of IVg or polioimmunisation)

7. Ensure close family contacts are screened and vaccinated with IPV-containing vaccineregardless of vaccination status

C. single case of suspected vaccine associated paralytic polio

Defined as: Compatible illness in recent oral polio vaccine recipient or (with or withoutpoliovirus isolate)

1. Ensure appropriate investigations (see Appendix 1) are initiated in case and contacts.Report to the Immunisation Department and Virus Reference Department. InformDepartment of Health.

2. Offer IPV vaccine to unvaccinated close (household / health carers) contacts

3. Encourage opportunistic IPV vaccination of unvaccinated persons in school / locality.






Level two: possible single case of wild poliovirus infection

Defined as: Poliovirus isolate from a person with paralytic symptoms who has no history ofrecent vaccination or contact with a vaccinee.

Poliovirus isolate from a person returning from a possible endemic area (any countryoutside Western Europe, North America, or Australasia).

Poliovirus isolate from a child in an itinerant family.

Poliovirus isolate from a child in a community which may refuse vaccination (eg Steinercommunities).

1. Initiate appropriate investigations (see Appendix 1) of case and contacts immediately.Report immediately to Health Protection Services and / or Virus Reference Department.Contact Department of Health to obtain supply of OPV.

2. Ensure all close family contacts are vaccinated with OPV immediately, regardless ofvaccination status.

3. Immediately investigate vaccination coverage in population at risk (eg school,

residential community, locality). If vaccine coverage in local child population issuspected to be below 85% consider a mop up campaign involving:

• A single dose of OPV to persons of all ages if case occurs in a well definedcommunity (regardless of vaccine history) or

• A single dose of OPV in all children of pre-school and school-age in locality(regardless of vaccine history) and

• Encourage opportunistic IPV vaccination (completion of vaccine course in allunvaccinated and partially vaccinated persons in locality).

4. If the target population (defined in 3) refuses vaccine

• Consider giving a single dose of vaccine to persons in adjacent communities.

• Institute active surveillance for paralytic and non-paralytic polio infection inlocality.

Level three: confirmed single case of wild poliovirus

Defined as: Poliovirus isolate confirmed as wild by intratypic differentiation or sequencing atVirus Reference Department

1. Collect stool samples from household contacts. Consider collection of stool samplesfrom wider population.

2. Report immediately to HPS. Department of Health and WHO will be informed.3. Institute active surveillance for paralytic and non-paralytic infection in locality.

• Advise local laboratories and clinicians.

• Encourage stool samples in all acute neurological illnesses.

• Consider stool survey in healthy contacts.

4. If the infection appears to be imported. Immediately investigate vaccination coveragein population at risk (eg school, residential community, locality). If vaccine coverage inlocal childhood population is suspected to be below 85% consider a mop up campaigninvolving:






• A single dose of IPV/OPV to persons of all ages if case occurs in a well definedcommunity (regardless of vaccine history) or

• A single dose of IPV/OPV in all children of pre-school and school-age in locality(regardless of vaccine history) and

• Opportunistic IPV vaccination (encourage completion of vaccine course in allunvaccinated and partially vaccinated persons in the locality).

5. If the infection appears to be indigenous perform retrospective case-finding

• Contact local laboratories to obtain any recent enterovirus isolates.

• Perform stool survey in health persons at risk.

6. If infection is thought to be indigenous, conduct a mop up campaign involving:

• A single dose of IPV/OPV to persons of all ages if case occurs in a well definedcommunity (regardless of vaccine history) or

• A single dose of IPV/OPV in all children of pre-school and school-age in locality(regardless of vaccine history) and

• Opportunistic IPV vaccination (encourage completion of vaccine course in allunvaccinated and partially vaccinated persons in the locality).

7. If the target population (defined in 4 or 6) refuses vaccine

• Consider giving a single dose of vaccine to person in adjacent communities.

8. Consider a mop-up campaign in other age groups / populations depending on theepidemiological circumstances

Level 3: confirmed single circulating vaccine-derived poliovirus (c-VDPV*) case

Defined as: Poliovirus isolate confirmed as cVDPV drifted variant on sequencing at VirusReference Department from a person with or without paralytic symptoms

Public health management as level 3 wild polio-virus incident

* Vaccine-derived polioviruses (VDPV) are defined as live, attenuated strains of the viruscontained in the oral polio vaccine (OPV) which have changed and reverted to a form that cancause paralysis in humans and with capacity for sustained circulation. These are identified asdrift variants by intratypic differentiation.

1. cVDPVs that are associated with sustained person-to-person transmission and considered tobe circulating in the environment;

2. iVDPVs (immunodeficiency related vaccine-derived poliovirus) isolated fromImmunodeficient patients who have prolonged infections after exposure to OPV.

Level four: epidemiologically linked cases of paralytic polio

Defined as: Compatible illness occurring in 2 or more people in the same locality within an8 week period where 2 or more individuals have no history of recent vaccination or contactwith a recipient (with or without poliovirus isolates).

1. Initiate appropriate investigations of case and contacts immediately. Reportimmediately to HPS and/or Virus Reference Department. Inform Department of Heatlh.

2. Ensure close family contacts are vaccinated with OPV immediately - regardless ofvaccination status.






3. Institute active surveillance and retrospective case-finding for paralytic and non-paralytic infection in locality.

• Advise local laboratories and clinicians.

• Encourage stool samples in all acute neurological illnesses.

• Perform stool survey in healthy contacts.• Contact local laboratories to obtain any recent enterovirus isolates.

4. Conduct a mop up campaign involving:

• A single dose of OPV to persons of all ages if case occurs in a well definedcommunity (regardless of vaccine history) or

• A single dose of OPV in all children of pre-school and school-age in locality(regardless of vaccine history) and

• Opportunistic vaccination (completion of all unvaccinated persons in locality)

5. Consider a mop-up campaign in other age groups / populations depending on theepidemiological circumstances.

Level 4: Epidemiologically linked cases of c-VDPV

Defined as: Two or more poliovirus isolates from persons in the same locality presentingwith paralytic/non-paralytic/or no symptoms and confirmed as cVDPV on sequencing at VirusReference Department

Public health management as level 4 wild polio-virus incident






Appendix 5. Case Definitions for Paralytic Poliomyelitis

Definition of a case of paralytic poliomyelitisA patient with clinical features compatible with paralytic poliomyelitis from whom eithervaccine or wild poliovirus has been isolated from a clinical specimen.

Clinical features compatible with paralytic poliomyelitis

• Acute flaccid paralysis.

• Decreased or absent tendon reflexes in affected limbs.

• No sensory or cognitive loss.

• No other cause identified despite laboratory investigation.

• Neurological deficit present 60 days after onset of symptoms unless the patienthas died.

Definitions of categories of cases

1. Vaccine recipient (Va R)

• Clinical features compatible with paralytic poliomyelitis, and

• No laboratory evidence of wild-type virus*, and

• Paralysis onset between 4 and 30 days after patient received oral polio vaccine†

# vaccinated abroad or in a patients with underlying immunodeficiency previously vaccinatedwith OPV

* confirmation by isolation of vaccine virus† for immunocompromised individuals these periods can be considerably longer

2. Vaccine contact (Va C)


• No laboratory evidence of wild-type virus*, and

• Contact with a vaccinee, and

• Paralysis onset between 4 and 75 days after vaccine received oral poliovaccine†

* confirmation by isolation of vaccine virus

† for immunocompromised individuals these periods can be considerably longer

3. Wild indigenous


• Wild-type virus isolation, and

• No travel to and no contact with anyone who has travelled to or resided in, aarea where wild poliovirus is known to circulate within 30 days before symptomonset.





UK St d d f Mi bi l I ti ti | I d b th St d d U it H lth P t ti A

4. Wild imported



• Travel to or residence in a country where wild poliovirus is known to circulate

within 30 days before symptom onset (see 5 below).

5. Other categories

5.1 Wild virus - import related



• Contact with anyone who has travelled to or resided in a country where wildpoliovirus is known to circulate within 30 days before symptom onset, orcontact with anyone who has acute poliomyelitis thought to have travelled to

or resided in a country where wild poliovirus is known to circulate within 30days before symptom onset

5.2 Vaccine associated case - possible or no known contact


• Vaccine virus isolation but no known direct contact with a vaccinee and nohistory of the patient receiving oral polio vaccine

5.3 Compatible case*


• No poliovirus isolation from clinical specimens, and• With or without serological evidence of recent poliovirus infection, and

• No evidence for infection with other neurotropic viruses

*These cases are referred for expert review and subsequent categorisation

UK Standards for Microbiology Investigations, Surveillance of Polio in the UK

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