Enteroviruses Dr M Karimi Genera of Picornaviruses n

Enteroviruses Dr M. Karimi

Genera of Picornaviruses n n n Enterovirus: Polio, Coxsackie A and B Echo, Other enteroviruses Rhinovirus Cardiovirus Hepatovirus Aphthovirus Others

With only six polio endemic countries left in the world, polio transmission could be stopped by end 2005. The world could then be certified polio-free by end-2008.

Enteroviruses n n RNA Viruses Polio Include some group of Coxackieviruses Polio viruses Picornaviruses Echoviruses ina

Clinical manifestation of Enterovirus Infections n n n n Aseptic meningitis Nonspecific febrile illness Colds Conjunctivitis Pharyngitis Herpangina Hepatitis n n n n Exanthems Encephalitis Paralytic polio Vomiting Diarrhea Pericarditis Myocarditis Hand-foot-mouth syndrome

Epidemiology n n n Transmission from person to person: Fecal-Oral Respiratory Peak incidence : Summer & Fall Male =Female Age: Young children Incubation period: 3 -6 Days

Pathogenesis n n n URI Infection Regional lymph nodes involvement Low-Grade viremia (Heart, Skin, Pericardium , Lung. . ) Clinical illness & Major viremia Antibody appearance on 7 th day GI Replication

Pathophysiology 1. 2. Polio→Motor neurons (Pathogonomic finding) Coxackieviruses → Herpangina → Hand foot-mouth → Myocarditis Meningoencephalitis, Adrenal glands, Pancrease, Liver, Pleura 3. Echovirus → Hepatic necrosis

Clinical manifestation Polioviruses (1) • Asymptomatic infection(95%) • Abortive form: Fever, Headache, Malaise, Anorexia , Nausea, Vomiting, Pharyngitis, Abdominal pain • Nonparalytic form: Abortive form symptoms, Menengeal sign, Decrease deep and superficial tendon reflexes,

Clinical manifestation Polioviruses (2) • Paralytic form: Similar to nonparalytic form+Muscle weakness, BP changes, Respiratory and cardiac arrhythmia, Weakness, Falccid Paralysis(Typically asymetric proximal muscle involvement) • Spinal form: Axial and extremity muscle weakness • Bulbar form: Cranial nerve involvement (Dysphagia) • Encephalitic form: irritability, disorientation , drowsiness, tremor

Polioviruses n n n Prodrome: Headache, Malaise, Menengeal sign, CSF pleocytosis Sever myalgia, Meningismus, Weakness, Flaccid paralysis Asymetric distribution Proximal muscles involve more than distal muscles Sensory function remains intact

Respiratory Insufficiency symptoms n Anxiety Tachypnea Respiratory distress symptoms Decrease cough Paradoxic abdominal movement Immobility of intercostal spaces n Arm&Deltoid weakness n n n

Bulbar Polio n n n n Palatal & Pharyngeal weakness (nasal voice) Pooling of saliva Poor cough Nasal regurgitation of saliva Deviation of palate, uvula, tongue Hoarseness , Aphonia BP Changes

Differential diagnosis n n n Guillain-Barre syndrom Other viral encephalomyelitis Tick paralysis CNS Tumor Trauma Vaccine associated paralytic polio

Prognosis n n n Determined during 1 month after infection Some degree of permanent damage Bulbar paralysis generally recover completely TYPICAL CONTRACTURES IN POLIO

Nonpolio Enteroviral Infection n n Asymptomatic: (Less than 50%) Nonspecific febrile illness: (Lasts 3 days) (Most common manifestation of all types of entroviral infections) Fever, Malaise, Headache, Pharyngitis, Myalgia, GI symptoms in neonate n Respiratory tract illness: Conjunctivitis, Herpangina, Pharyngitis, Stomatitis, Parotitis , Croup, Bronchitis, Pneumonia, Pleurodynia,

Herpangina: Fever, Oral ulcers and vesicles Duration 3 -6 days

Pleurodynia n n n Acute febrile illness Intense pleuritic pain Upper abdominal muscular pain CXR: Normal WBC: Normal or elevated myeloid cell

Nonpolio Enteroviral Infection Gasterointestinal manifestation: Vomiting, Non bloody diarrhea, Abdominal pain, Pseudoappendicitis n Acute hemorrhagic conjunctivitis: Eye pain, Photophobia, Blurred vision, Lacrimation, Erythma, Conjunctivitis n Pericarditis&Myocarditis: High mortality especially in neonate n

Nonpolio Enteroviral Infection n Hand-foot-mouth syndrome: Small intraoral ulcer, Macular or vesicular lesion on hands and feet&buttock

Hand-foot-mouth syndrome:

Nonpolio Enteroviral Infection n Aseptic meningitis syndrome: Rash, Sore throat, Muscle pain, Sign of meningeal irritation CSF (PMN pleocytosis, High protein, Normal glucose), n Seasonal Encephalitis: n Paralysis: Acute hemiplegia, Perphral neuritis n Genitourinary: Orchitis, Epididymitis, Cystitis , Hematuria n Myositis&Arthritis: Dermatomyositis-like syndrome

Nonpolio Enteroviral Infection n Neonatal nonspecific febrile illness: Duration 3 -4 days, Fever, Anorexia , Irritability, Mild vomiting, Diarrhea, PMN leuckocytosis n Neonatal myocarditis: Fever, Tachycardia, Cardiomegaly , ECG changes , Transient systolic murmur , Shock, Respiratory distress n Fulminant encephalomyocarditis

Diagnosis n n Age, Season, Location, Exposure Clinical manifestation PCR Culture from sterile sites biopsy

Treatment: n n n Supportive therapy Pleconaril in immunocompetent No Steroids Prevention: n OPV/IPV

Vaccination program n n n n At Birth: BCG’ OPV’ Hepatitis B* 2 Month: DPT’ OPV’ Hepatitis B 4 Month: DPT’ OPV 6 Month: DPT’ OPV’ Hepatitis B 12 Month: MMR 18 Month: DPT’ OPV 4 -6 years old: DPT’ OPV’MMR 14 -16 years old: Td