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Polio, Emergency Medicine

Basics

Description

- Paralytic poliomyelitis 0.1%, which is further subdivided: - Spinal paralytic poliomyelitis (frank polio) - Bulbar paralytic poliomyelitis (10% of paralytic polio): Paralysis of muscle groups innervated by cranial nerves; involves the circulatory and respiratory centers of the medulla with high mortality - Mixed bulbospinal poliomyelitis

- Postpoliomyelitis syndrome: - New onset of increased muscle weakness, pain, and focal or generalized atrophy - Occurs 8 " “70 yr after the active illness, usually in the previously affected limb - Risk factors include age at time of infection, extent of recovery and female sex (increased risk with better recovery) - Gradual progression

- Polioviruses: - Picornaviruses - Small, nonenveloped RNA viruses of the enterovirus genera - 3 subtypes: 1, 2, 3

- Fecal " “oral route transmission - Enters through oral cavity - Replicates in pharynx, GI tract, and lymphatics

- Fever (37 ‚ °C " “39 ‚ °C) - Headache, photophobia - Nuchal rigidity - Neurologic changes: - Muscle soreness that becomes severe muscle spasm, progressing rapidly to spotty flaccid weakness and paralysis - Asymmetric paralysis more prominent in the lower than the upper extremities - Urinary retention (50% of paralytic cases) - Reflexes initially hyperactive, then absent - Apprehensive and irritable, occasionally drowsy - No sensory loss associated with the motor deficit

  • Caused by poliovirus infection
  • Incubation period 7 " “14 days
  • Duration <1 wk
  • Clinical manifestations are defined as follows:Subclinical (i.e., not apparent) 90 " “95%Abortive poliomyelitis 4 " “8%:Clinically indistinct from many other viral infections (fever, myalgias, malaise)Only suspected to be polio during an epidemicNonparalytic poliomyelitis 1 " “2%:Differs from abortive poliomyelitis by the presence of meningeal irritationCourse similar to any aseptic meningitisParalytic poliomyelitis 0.1%, which is further subdivided:Spinal paralytic poliomyelitis (frank polio)Bulbar paralytic poliomyelitis (10% of paralytic polio): Paralysis of muscle groups innervated by cranial nerves; involves the circulatory and respiratory centers of the medulla with high mortalityMixed bulbospinal poliomyelitisPostpoliomyelitis syndrome:New onset of increased muscle weakness, pain, and focal or generalized atrophyOccurs 8 " “70 yr after the active illness, usually in the previously affected limbRisk factors include age at time of infection, extent of recovery and female sex (increased risk with better recovery)Gradual progression

Etiology

  • Polioviruses:PicornavirusesSmall, nonenveloped RNA viruses of the enterovirus genera3 subtypes: 1, 2, 3
  • Fecal " “oral route transmissionEnters through oral cavityReplicates in pharynx, GI tract, and lymphatics
  • Humans are the only natural host and reservoir
  • Poliovirus selectively destroys motor and autonomic neurons
  • Natural (wild) virus has been completely eliminated in US since 1979
  • Oral poliovirus vaccine (OPV):Accounts for only poliomyelitis seen in US8 " “10 cases/yr of vaccine-associated paralytic poliomyelitis (VAP): Neurovirulent conversion of vaccine virus; decreased since widespread use of inactivated poliovirus vaccine (IPV)VAP occurs in poorly immunized regions by acquiring properties of wild-type virus.There has been a recent increase in some third word countries

Diagnosis

Signs and Symptoms

  • Primarily asymptomatic
  • Viral symptoms: Fever, headache, malaise. Respiratory symptoms: Sore throat, fatigue GI symptoms: Nausea, vomiting
  • Nonparalytic aseptic meningitis: Stiff neck, and or back
  • Muscle pain and weakness
  • Progressive weakness for <1 wk:
  • Dysphagia and dysarthria with bulbar involvement

History

  • Vaccination history
  • History of prior polio infection
  • Recent exposure to individual vaccinated with OPV
  • Recent travel to endemic countries (Nigeria, Pakistan, India, Afghanistan)
  • Comorbid conditions affecting immunocompetence especially B-lymphocyte disorders (e.g., hypogammaglobulinemia and agammaglobulinemia)

Physical Exam

  • Fever (37 ‚ °C " “39 ‚ °C)
  • Headache, photophobia
  • Nuchal rigidity
  • Neurologic changes:Muscle soreness that becomes severe muscle spasm, progressing rapidly to spotty flaccid weakness and paralysisAsymmetric paralysis more prominent in the lower than the upper extremitiesUrinary retention (50% of paralytic cases)Reflexes initially hyperactive, then absentApprehensive and irritable, occasionally drowsyNo sensory loss associated with the motor deficit

More likely to have a biphasic acute course: ‚

  • Viral-type syndrome for 1 " “2 days
  • Symptom-free period of 2 " “5 days
  • Then an abrupt onset of the major illness

Essential Workup

  • Clinical diagnosis
  • Differentiate from other causes of acute paralysis.
  • Notify public health officials when diagnosis suspected.

Diagnosis Tests & Interpretation

Lab

  • CBC:WBC normal or mildly elevated
  • Diagnosis confirmed by:Comparing acute with convalescent sera for antigen titersIsolation of virus from blood, CSF, stool, throat secretions (within week 1 of infection)

Diagnostic Procedures/Surgery

  • Lumbar puncture/CSF analysis:Abnormalities typical of aseptic meningitis (increased lymphocytes and elevated protein)Poliovirus rarely isolated from the CSF
  • Electrodiagnostics:Normal to slow motor functionSensory function intact

Differential Diagnosis

  • Abortive poliomyelitis is similar to many viral illnesses.
  • Nonparalytic poliomyelitis is indistinguishable from any viral, aseptic meningitis.
  • Paralytic poliomyelitis:Amyotrophic lateral sclerosisGuillain " “Barre (not febrile, symmetric, not ill appearing)Acute transverse myelitisSpinal cord compression/infarctionMultiple sclerosisRhabdomyolysisAcute intermittent porphyriaWest Nile virusDiphtheriaBotulismTick paralysisEncephalitis

Treatment

Rare fatal cases come from respiratory insufficiency, which requires prompt ventilatory support. ‚

Initial Stabilization/Therapy

Aggressive pulmonary toilet and early intubation mandated for respiratory insufficiency ‚

Ed Treatment/Procedures

  • Supportive and symptomatic management
  • Analgesics for severe muscle pain and spasm
  • Bed rest to prevent augmentation or extension of paralysis
  • Paralytic poliomyelitis tends to localize to a limb that has been the site of intramuscular injection or injury within 2 " “4 wk prior to the onset of infection:Avoid any unnecessary tissue damage in suspected casesNo antiviral agents availablePrevention
  • Prevention
  • IPV:CostlyPainfulNo conferred immunityNo VAP, which previously accounted for all poliomyelitis cases in US
  • OPV:Accounted for only poliomyelitis seen in US (8 " “10 cases/yr)Incidence of VAP: 1/900,000 (immunocompromised: 1/1,000):Most at risk are the underimmunized young and their caretakers.Confers immunity to unvaccinated contacts by fecal " “oral spread.InexpensiveNo longer available in USStill remains the vaccine recommended by WHO Expanded Program on Immunization

Follow-Up

Disposition

Admission Criteria

All acute-phase paralytic poliomyelitis for strict bed rest and observation for respiratory symptoms: ‚

  • Isolate from nonvaccinated personnel.

Discharge Criteria

No evidence of nervous system involvement and no danger of contact with nonvaccinated population: ‚

  • Deterioration of muscle strength usually ends after 3 " “5 days

Followup Recommendations

Physical therapy: ‚

  • Only 1/3 of the people with acute flaccid paralysis regain full strength
  • Lamotrigine may decrease pain, improve symptoms and quality of life.
  • IV immunoglobulin (IVIg) may improve muscle strength, has not been proven to decrease pain or improve quality of life.

Pearls and Pitfalls

  • Most cases are asymptomatic, with symptoms ranging from viral illness to acute flaccid paralysis.
  • IPV is the only vaccine available in US; however OPV is still the vaccine of choice for global eradication.
  • Diagnosis is primarily clinical and is confirmed by virus isolation from blood, CSF, stool, or throat secretions.
  • Treatment is supportive; all acute-phase paralytic poliomyelitis patients should be admitted for observation with close monitoring of the respiratory system.
  • If the patient survives the acute stage, paralysis of respiration and deglutition usually recovers completely.
  • Paralytic poliomyelitis may occur decades after initial infection and manifests with neurologic and non-neurologic symptoms.

Additional Reading

  • Alexander ‚ L, Birkhead ‚ G, Guerra ‚ F, et al. Ensuring preparedness for potential poliomyelitis outbreaks: Recommendations for the US poliovirus vaccine stockpile from the National Vaccine Advisory Committee (NVAC) and the Advisory Committee on Immunization Practices (ACIP). Arch Pediatr Adolesc Med. 2004;158:1106 " “1112.
  • American Academy of Pediatrics: Report of the Committee on Infectious Diseases. 29th ed. Elk Grove, Il; 2012.
  • Bouza ‚ C, Mu ƒ ±oz ‚ A, Amate ‚ JM. Postpolio syndrome: A challenge to the health-care system. Health Policy. 2005;71(1):97 " “106.
  • Centers for Disease Control and Prevention (CDC). Imported vaccine-associated paralytic poliomyelitis " ”United States, 2005. MMWR Morb Mortal Wkly Rep. 2006;55(4):97 " “99.
  • Centers for Disease Control and Prevention (CDC). Updated recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding routine poliovirus vaccination. MMWR Morb Mortal Wkly Rep. 2009;58(30):829 " “830.
  • Centers for Disease Control and Prevention (CDC). Tracking progress toward global polio eradication " ”worldwide, 2009 " “2010. MMWR Morb Mortal Wkly Rep. 2011;60(14):441 " “445.
  • Howard ‚ RS. Poliomyelitis and the postpolio syndrome. BMJ. 2005;330(7503):1314 " “1318.
  • Ropper ‚ AH, Samuels ‚ MA. Chapter 33. Viral infections of the nervoussystem, chronic meningitis, and prion diseases. In:Ropper ‚ AH,Samuels ‚ MA, eds. Adams and Victors Principles of Neurology. 9thed. New York, NY: McGraw-Hill; 2009.
  • Shahzad ‚ A, K ƒ ¶hler ‚ G. Inactivated polio vaccine (IPV): A strong candidate vaccine for achieving global polio eradication program. Vaccine. 2009;27(39):5293 " “5294.

See Also (Topic, Algorithm, Electronic Media Element)

  • Amyotrophic lateral sclerosis
  • Botulism
  • Encephalitis
  • Guillain " “Barre Syndrome
  • Multiple Sclerosis
  • Rhabdomyolysis
  • Spinal Cord Syndromes
  • Tick Bite
  • West Nile Virus

Codes

ICD9

  • 045.00 Acute paralytic poliomyelitis specified as bulbar, poliovirus, unspecified type
  • 045.20 Acute nonparalytic poliomyelitis, poliovirus, unspecified type
  • 045.90 Acute poliomyelitis, unspecified, poliovirus, unspecified type
  • 045.91 Acute poliomyelitis, unspecified, poliovirus type I
  • 045.92 Acute poliomyelitis, unspecified, poliovirus type II
  • 045.93 Acute poliomyelitis, unspecified, poliovirus type III
  • 045.9 Unspecified acute poliomyelitis

ICD10

  • A80.30 Acute paralytic poliomyelitis, unspecified
  • A80.4 Acute nonparalytic poliomyelitis
  • A80.39 Other acute paralytic poliomyelitis
  • A80.9 Acute poliomyelitis, unspecified

SNOMED

  • 240460008 Acute paralytic poliomyelitis
  • 14535005 Acute nonparalytic poliomyelitis
  • 240459003 Abortive poliomyelitis
  • 398102009 Acute poliomyelitis (disorder)
  • 446958005 acute paralytic poliomyelitis due to Human poliovirus 1 (disorder)
  • 447262002 acute paralytic poliomyelitis due to Human poliovirus 2 (disorder)
  • 447378002 acute paralytic poliomyelitis due to Human poliovirus 3 (disorder)