Enteroviruses and polio
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The document details various families of enteroviruses, including poliovirus, coxsackie virus, and rotavirus, highlighting their properties, transmission routes, and related diseases. It discusses the clinical features, pathogenesis, laboratory diagnosis, management, and prevention strategies for infections caused by these viruses. The document emphasizes the importance of vaccination and treatment protocols to manage and prevent viral infections, particularly in infants and children.
Enteroviruses and polio
- 1. 1 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 2. LEARNING OBJECTIVES At the end of the session students will be able to: • Describe the family of Picornavirus • Enumerate the members of enteroviruses • Give a brief descriptions on enterovirus and the diseases: – Coxsackie virus – Polio virus – Rota virus 2 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 3. Brief classification of enterovirus PICORNA VIRIDIAE FAMILY ENTEROVIRUS RHINOVIRUS Coxsakie virus Polio virus Rota virus Adenovirus HEPATOVIRUS PARECHOVIRUS CARDIOVIRUS Hepatitis A virus 3 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 4. Important properties of enteroviruses • Virion: Icosahedral • Genome: ssRNA, positive sense • Viral proteins: Four , VP1-VP4 (VP: Viral proteins) • Envelope: None • Site of replication: Cytoplasm • Diseases: Ranges from poliomyelitis to aseptic meningitis to common cold (Rhinovirus only) 4 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 5. Medically important enteroviruses and Type Syndrome Poliovirus Coxsackie Enterovirus Aseptic meningitis √ (type 1-3) √ (A+B) √ ( type 71) Paralysis √ (type 1-3) √ (A+B) √ (type 70,71) Encephalitis √ (A+B) √ (type 70,71) Herpangina √ (Group A) √ ( type 71) Hand-foot and mouth disease √ (Group A) √ ( type 71) Pleurodyna √ (Group B) Carditis √ (Group B) 5 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 6. Pathogenesis of enterovirus 6 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 7. Coxsackie virus • A large subgroup of enterovirus • Two antigenic types: Coxsackie A and Coxsackie B virus • 24 serotype of Coxsackie A • 6 serotypes of Coxsackie B • Group A virus produce: Myositis and Flaccid paralysis • Group B virus produce: Lesion in heart, pancreas, CNS 7 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 8. Pathogenesis and pathology of Coxsackie virus • Initial replication in oropharynx and gastrointestinal tract • Spread to blood (viremia) • Type A attacks the mucus membrane • Type B attacks heart, pleura, pancreas, liver 8 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 9. Clinical features Herpangina : Hand foot mouth disease: Tender vesicle in oropharynx Vesicular lesion on hand-foot-mouth 9 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 10. Pleurodynia: Pericarditis: Severe pleuritic type chest pain Inflammatory cells in pericardium Clinical features 10 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 11. Hemorrhagic conjunctivitis Generalized disease of infants involving many organs caused by Coxsackie B Clinical features 11 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 12. Laboratory diagnosis • SAMPLES: – Throat washing, Stool, Nasal secretion, CSF, Conjunctival swab • VIRUS ISOLATION – Monkey kidney cell line, human embryonic lung fibroblast cell • NUCLEIC ACID DETECTION – Reverse transcriptase PCR • SEROLOGY – Neutralizing antibody appears early in life – Immunofluorescence test is done with antibody against infected cell culture 12 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 13. Immunity and management • Neutralizing antibodies are transferred from mother to fetus • Immunity is type specific, life long and mediated by IgG • TREATMENT – There is no antivirals • PREVENTION – No vaccines 13 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 14. Polio virus • RNA non envelope virus • Belongs to picorna virus family • Infective hosts limited to primates • Three serologic types • Transmission: Fecal- oral route 14 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 15. Immunopathogenesis of poliomyelitis • Virus preferentially replicates in the anterior horn cells of motor neuron result in death of these cells and paralysis of muscle(Flaccid type paralysis) • Immune response generates both IgA and IgG 15 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 16. Polio virus Pathogenesis 16 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 17. Poliomyelitis: Clinical features • Asymptomatic • Abortive poliomyelitis: – Mild fever, headache ,sore throat, nausea, vomiting • Non paralytic poliomyelitis: Aseptic meningitis – Fever, headache, neck stiffness • Paralytic poliomyelitis: – Flaccid paralysis 17 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 18. 18 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 19. Poliomyelitis: Laboratory diagnosis • Sample: Stool, throat swab, CSF • Culture: Isolation and identification • Serology: Rising antibody titer against the virus 19 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 20. Poliomyelitis: Management • Treatment: Symptomatic – Respiratory support – Physiotherapy • Prevention: By vaccination • Two types of vaccines: – Live attenuated vaccine(Sabin, OPV)) – Killed vaccine(Salk vaccine, IPV) 20 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 21. Rota virus Belongs to Reoviridae family Double stranded RNA genome Genome is segmented (11 segments) Non envelope Replicates in cytoplasm Common cause of infantile diarrhea Cart-wheel appearance in EM Five serotypes have been identified Group A is the main human pathogen 21 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 22. Transmission and pathogenesis • TRANSMISSION: Fecal-oral route • PATHOGENESIS: 1. Virus infects the enterocytes lining villi of small intestine and causes damage and sloughing of cells 2. Rotavirus encoded protein also acts as an enterotoxin • In both cases there is impaired absorption of sodium and glucose and increase excretion of water and electrolytes leading to watery diarrhea. • Sloughing enterocytes contain virus and infectious for 2-12 days in otherwise healthy patient. 22 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 23. Geographic distribution of Rota virus 23 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 24. Clinical features and complications • CLINICAL FEATURES • Commonly affects infants • Incubation period: 1-3 days • Watery diarrhea, fever, abdominal pain and vomiting leading to dehydration. • Adult can be infected by children, but disease milder • COMPLICATIONS • Water and electrolyte imbalance • Hypovolumic shock • Acidosis 24 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 25. Laboratory diagnosis • SAMPLES: Stool • Detection of viral antigen: ELISA • Detection of viral antibody: ELISA • Detection of virus: EIA, IEM (Immunoelectron Microscopy) • Detection of nucleic acid: PCR 25 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 26. Treatment and Prevention • TREATMENT • Fluid replacement and correction of electrolyte by oral or intravenous rehydration therapy. • Correction of acidosis. • PREVETION • Transmission control: Improvement of water supply and sanitation. • New live attenuated oral vaccines is safe. 26 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 27. Reference • Review of Medical Microbiology and Immunology. Warren Levinson, 12th May 2012. Mc Graw-Hill (Lange) • Jawetz, Melnick and Adelberg’s Medical Microbiology George F. Brooks, Karen C. Carroll, Janet S. Butel, 25th Mar 2010. Mc Graw-Hill (Lange) 27 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com
- 28. 28 Copy right: Dr. Tarek Mahbub Khan/ tarekviro@yahoo.com