1. ENTEROVIRUSES Properties: @ Family: Picornaviruses @ Small, spherical, non-enveloped. @ Icosahedral, Single stranded RNA

3. Classification of Enteroviruses: @ Poliovirus: types 1,2,3 @ Coxsackie virus : divided into: * Group A: types 1-24 * Group B: types 1-6 @ ECHO virus: types 1-34 @ Enterovirus 70: causes conjunctivitis @ Enterovirus 71: causes meningitis, encephalitis, and paralysis. @ Enterovirus 72: is hepatitis A virus

5. Poliovirus @ Poliovirus causes poliomyelitis. @ It is transmitted by the fecal-oral route. @ It replicates in the oropharynx and the intestinal tract. @ Humans are the only natural hosts. @ Poliomyelitis is common in areas where hygiene and sanitation are poor @ No carrier state

6. Poliovirus

7. Symptoms of P oliomyelitis : @ Sometimes no symptoms @ Fever, headache, sore throat, vomiting @ Symptoms of meningitis @ Muscle spasms and paralysis

8. Muscle spasms and paralysis

9. Lab. Diagnosis of P oliomyelitis : @ Specimens: faeces, throat swabs @ Inoculate: monkey kidney, or human embryo lung cell cultures. Look for CPE. @ Type by neutralization tests @ Serology by ELISA

11. Vaccination against P oliomyelitis : @ Two vaccines are available: 1. Sabin live attenuated vaccine: * Contains the three polioviruses, and prepared in monkey kidney tissue culture. * Administered in three oral doses at 2,3, 4 months of age, and booster on school entry * Good protection, good safety, * Vaccinated children are infectious @ Albert Sabin (inventor of the vaccine) is giving the oral dose

13. 2. Salk inactivated vaccine: @ Contains the three polioviruses @ Given in three injections. @ Good protection against paralysis, and has high potency. @ Jonas Salk (inventor of the vaccine) is injecting a child

15. Coxsackieviruses @ Named for the town of Coxsackie, USA @ Transmitted by the fecal-oral route, and by respiratory aerosols @ Coxsackieviruses replicate in the oropharynx and the intestinal tract. @ Humans are the only natural hosts.

16. Coxsackievirus

17. Diseases of Coxsackieviruses: @ Upper respiratory tract infection @ Fever, skin rash, meningitis. @ Transient paralysis. @ Associated with hand-foot-mouth disease

19. Lab. Diagnosis of Coxsackieviruses @ Specimens: faeces, throat swabs, @ Inoculate suckling mice and observe for signs of paralysis in the mice. @ ELISA to detect IgM antibodies No vaccination for Coxsackie infection

21. Echoviruses @ ECHO is an abbreviation of Enteric Cytopathic Human Orphan. @ It causes: * Meningitis, URT infection, * Fever, skin rash, diarrhea, * Conjunctivitis. @ Echoviruses has over 30 serotypes @ Transmitted by the fecal-oral route

23. Lab. Diagnosis of ECHO viruses: @ Specimens: faeces, throat swabs, CSF @ Isolation in human embryo lung cell cultures. Look for CPE using a light microscope. @ Serology not done because of the large number of serotypes. No vaccine available.