ACUTE FLACCID PARALYSISSUBIN S MATHEWVINITHA

DEFINITION OF AFPAcute flaccid paralysis is defined as sudden onset of weakness (

Classification of causes of AFPCan be classified acc to the levels of motor units involved a) Muscles - hypokalemic paralysis, myoglobinuric myopathy b) Neuromuscular junction- myasthenia gravis, botulism c) Peripheral nerves- Guillian Barre syndrome, diphtheric neuropathy d) Anterior horn cells- poliomyelitis

APPROACH TO A PATIENT OF AFPHistory - complaints -weakness of all 4 limbs -onset;proximal /distal;symmetry -all 4 limbs involved at the same time or in ascending pattern -h/o pain -h/o respiratory distress -h/o swallowing difficulty,nasal regurgitation, weak cough,pooling of secretions,nasal twang

HISTORY -h/o sensory disturbances -bladder and bowel disturbances -autonomic disturbances -features of raised ICT -h/o IM injection -h/o tonsillectomy -h/o diarrhea and fever

HISTORY -h/o trauma -h/o similar episodes in community -h/o rash associated with fever -h/o pica -h/o recent throat pain in unimmunised

HISTORYImmunisation history (polio vaccines,vaccine assoc.paralysis)Socioeconomic history( sewage disposal, latrine facilities- polio)

Examination- Complete CNS examination - RS (involvement of diaphragm)

InvestigationsLumbar punctureEMG/ NCVSTOOL surveillance in polioCPK in myositisSerum K levelXray spine for paravertebral abscess in TBMRI spine if tumor compression is suspected

Differential Diagnosis for AFPCommon diagnosis in a child - poliomyelitis - Guillian Barre syndrome - Transverse myelitis - Traumatic neuritis - Polymyositis - Spinal cord compression by tumor,TB

Differential diagnosis-contdRare - diphtheria - porphyria - Pb poisoning - Botulism - Myasthenia gravisPseudoparalysis - Scurvy, rheumatic fever, osteomyelitis, syphilis etc.

In India, the most common causes for AFP are polio, GBS, traumatic neuritis and transverse myelitis of which polio is the leading one

DDS for AFP

PoliomyelitisCaused by poliovirus types 1,2,3Transmitted person to person via feaco- oral routeMaximum excretion of the virus just before the paralysis and in the first 2 weeks after the onset of paralysisHumans are the only reservoirsHighly communicable; 1 week before and 2 weeks after the onset of paralysis

Contd All unimmunised are susceptible to polioImmunity( humoral and local intestinal) obtained on exposure to either the wild virus or through immunisationOPV should be given as early as possible in the newborn

Stages in poliomyelitisInapparent infectionAbortive polio- minor febrile illnessNon paralytic aseptic meningitisParalytic polio- minor and major i) Spinal polio ii) Bulbar polio iii) Bulbospinal polio

Strategies for polio eradication in IndiaConduct Pulse or Polio Immunization days every yr for 3-4 yrs or until polio is eradicatedSustain high levels of routine immunization coverageMonitor OPV coverage at district level and belowImprove surveillance capable of detecting all cases of AFP due to polio and non-polio aetiology

ContdEnsure rapid case investigation,including colletion of stool samples for virus isolationArrange followup of all cases of AFP at 60 days to check for residual paralysisConduct outbreak control for cases confirmed or suspected to be polio to stop tansmissionMopping up door-to-door immunization in high risk districts.

Polio Vaccines2 vaccines- IPV and OPVOPV is widely used because of ease of administration, induction of circulating and intestinal immunity Dosage- 1 dose( 2 drops) at birth, 6, 10, 14 weeks

AFP SurveillanceSurveillance should be done for all cases of AFP and not only for poliomyelitisAFP surveillance helps identify the areas of priority and to measure the quality and impact of polio immunisation activitiesBackground rate of AFP: at least 1 case of non polio AFP occurs for every 100,000 population children

Surveillance - contdSteps for reporting include:Network of AFP reporting units - hospitals, community health centres etc. - each unit reports every week even when no cases of AFP identified.b) Initial identification and reporting of AFP cases- nodal officer reports to the District Immunisation Officer by quickest means

Cont..Initial investigation of reported AFP cases -All reported cases should be investigated by DIO within 48 hrs after notification,in order to confirm the presence of AFP and to obtain stool specimens of cases -He should assign the EPID number and fill out the case investigation form

Cont.60 day follow up DIO must re-visit every case of AFP 60 days after the onset of paralysis to confirm the presence or absence of residual weakness -measurement of mid arm or mid thigh circumference,asymmetry in the skin folds on the medial aspect of thighs

Cont.Weekly reporting -at the end of each week, the DIO should report to the state EPI officer the line lists of all new cases reported to DIO in that week -nil reporting

ContActive surveillance -most critical unit in reporting system is hospital -case finding through the emergency department, pediatric and neurology wards as well as through out patient clinics

AFP case classificationShould be classified within 90 days as :Polio : if wild virus isolated from any stool specimenCompatible polio: stool specimens inadequate/ residual weakness present 60 days after onset of paralysis/ 60 day follow up was not done( death or absenceNon-polio AFP

VIROLOGICAL CASE CLASSIFICATIONWILD POLIOVIRUSCONFIRMCOMPATIBLEDISCARD (non-polio AFP)DISCARD(non-Polio AFP)DISCARD(non-Polio AFP)Expert reviewResidual weakness,Died or lost to fluInadequate stool specimensNo residual weakness2 adequate stool specimensNo wild PoliovirusAFP

CASE INVESTIGATIONCollect all available demographic and clinical information on the caseFill out the API case investigation form and send to the state EPI officerDetermine whether the infection is local or acquired. Ask about outside travel or visitors from outside community[ 33 days maximum ] preceding onset of paralysis

4. Fill out an AFP case line listing form and report weekly to the State EPI Officer5.Collect 2 stool samples 24 -48 hrs apart from the case[

7.Onset of paralysis a)2 months earlier,additional focus given to the area during the next PPI

OUT BREAK RESPONSE IMMUNISATION - ORI should begin as one or more cases of AFP that fit the case definition is detected - ORI should cover a minimum of 500 children < 5 yrs around the reported AFP cases -vaccine trivalent OPV - stool specimen should be collected before initiating of ORI

SPECIMEN COLLECTIONVirus can be found in the feces from 72 hrs to upto 8 or more weeks after infectionAdequate specimen --- 2 specimens , at least 24 hrs apart, collected within 14 days of onset of paralysis, each of adequate volume[ 8-10 g] and arriving at a WHO accredited lab in good condition[ no dessication , no leakage , adequate documentation,and evidence of maintenance of cold chain

Programme surveillance indicators Rate of non polio AFP annual rate of 1 AFP case per 100,000 children < 15 yrs of ageProportion of AFP cases with 2 adequate stools taken within 2 weeks after onset of paralysis >or = 80 %

DATA ANALYSIS AND MONITORINGMonitoring a) case reporting b) investigations c) laboratory d) control response

ReferencesSurveillance of Acute Flaccid Paralysis 3rd editionIAP textbook of PaediatricsO.P.GhaiParks Textbook of Community Health

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