ד"ר אלכס גורי מחלות זיהומיות בילדים, ב"ח קפלן Poliomyelitis ד"ר אלכס גורי מחלות זיהומיות בילדים, ב"ח קפלן

Introduction “Polios” = “gray”, “myelos”= “spinal cord” First descriptions Medin (Sweden) 1890 First epidemics – Scandinavia, USA 189* 1950++ regular epidemics 25/100.000 1952 USA 58000 cases, 3145 fatalities, 21269 handicapped

Virology Enterovirus 3 serotypes, lifelong specific immunity to each serotype Humans are only natural host Wild type, live-attenuated, VDPV (vaccine-derived)

Pathogenesis

Clinical Incubation 9-12 (range 5-35) from contact to prodrome, 11-17 day to paralysis

Clinical features 60-1000/1 unapparent/clinically recognized (95% unapparent) Abortive pm (4-8%) 2-3 dd fever, headache, sore throat, abd pain, vomiting Nonparalytic pm = enteroviral meningitis Spinal paralytic pn 0.1% of all infections Meningitis, muscle pain, involuntary spasm and then asymmetric flaccid paralysis, almost never sensory, 66% permanent Bulbar pn Cranial nerves involvement 5-35% of paralytic cases

Increased incidence in pregnant women Girls and boys equal infection, boys>girls paralysed Exercise during illness increases severity IM injection provocation Tonsillectomy increases risk of bulbar PM Postpoliomyelitis syndrome (20-30%) 30yy after Overall mortality 5-10% for paralytic disease

DD Entero 71 West Nile virus Guillain-Barre (symmetrical, ascending, lost of sensation, 1-2 weeks of progress, protein in CSF)

Dx Isolation (RT-PCR) in stool, rarely in CSF/brain biopsy, serology (no vaccine/wild differentiation)

IPV Jonas Salk 1955

IPV High titers of ab, no secretory ab

OPV Sabin OPV field trials 1955-59 Monovalent originally VAPP 1:2.6 million 25%(VAPP) inimmune deficient (B-cell) Chumakov Mikhail

Epidemiology

VDPD outbreaks

Advantages and Disadvantages

ב01.09.2013 משרד הבריאות הפיץ המלצה לפיה יש להקפיד לחסן את הפגים לפי הגיל הכרונולוגי גם אם עודנו מאושפז כאשר גיל מינימום למתן IPV הוא 37 שבועות