1. Picornaviruses

2. Picornaviruses
Small (pico)
RNA
Naked capsid
>230 members
5 genera

3. Picornaviruses 5 genera Enterovirus Rhinovirus Heparnavirus
Cardiovirus Aphtovirus

4. Picornaviruses Enteroviruses At least 72 serotypes Polioviruses
Coxsackieviruses
Echoviruses

5. International Virus Taxonomi committee
Enterovirus genus (EV):
Poliovirus
and EV A, B, C and D.
Parechovirus cinsi (PeV): echovirus 22 ve 23

6. Picornaviruses Enteroviruses (EV) At least 72 serotypes
Polioviruses
Coxsackieviruses
Echoviruses
Human parechoviruses 1-3 (HPeV)

7. Picornaviridae Enterovirus Rhinovirus types 1 to 100+ Cardiovirus
Poliovirus type 1, 2, and 3
Coxsackie A virus types 1 to 22 and 24
Coxsackie B virus types 1 to 6
Echovirus (ECHO virus) types 1 to 9, 11 to 27, and 29 to 34
Enterovirus 68 to 71
Rhinovirus types 1 to 100+
Cardiovirus
Aphtovirus
Heparnavirus
HAV

8. Picornaviruses Enteroviruses
Capsid very resistant facilitates transmission by the fecal-oral route
Infection initiated in the gastrointestinal tract
“Rarely cause enteric disease”
Infections are usually asymptomatic

9. Picornaviruses/Replication
The specifity of the picornavirus interaction for cellular receptors is the major determinant of the target tissue tropism and disease
VP1 and “canyon”
80% of rhinoviruses and several serotypes of of coxsackieviruses recognize ICAM-1
polio a different molecule

10. Enteroviruses/Pathogenesis&Immunity
The diseases produced by the enteroviruses are determined mainly by differences in tissue tropism and cytolytic capacity of the virus
Poliovirus with the narrowest tissue tropism recognize a receptor expressed on anterior horn cells of the spinal cord, dorsal root ganglia, motor neurons, skeletal muscle cells, and few other cells

11. Enteroviruses/Pathogenesis&Immunity
Portal of entry:
URT
Oropharynx
Intestinal tract
Most enteroviruses are cytolytic
Excp: HAV
Viral shedding
From oropharynx
From the intestine (> 30 days)

12. Enteroviruses/Pathogenesis&Immunity
“Antibody is the major protective immune response to the enteroviruses”

13. Enteroviruses/Epidemiology
“The enteroviruses are exclusively human pathogenes”
Spread by the fecal-oral route
Asymptomatic shedding can occur
Poor sanitation and crowded living conditions foster transmission of the viruses
Enterovirus epidemics sewage contamination of water supplies
Outbreaks in schools & day care centers (summer)
Spread via resp. tract coxsackie & echov.

14. Enteroviruses/Epidemiology
Poliovirus has been eliminated from the Western Hemisphere, but
“not from the world”
Polio cause more severe disease in late childhood, the adolescent years, or adulthood
Coxsackie A mor severe in adults than children
Coxsackie B & some echo“s” can be particularly harmful to infants

15. Enteroviruses/Clinical syndromes
Poliovirus infections
Asymptomatic illness (90%)
Abortive poliomyelitis (minor illness)
Nonspecific febrile illness (5%)
Nonparalytic poliomyelitis or aseptic meningitis
1 to 2%, symptomes of the minor illness + CNS sm
Paralytic polio, the major illness
0.1 to 2.0%

17. Enteroviruses/Clinical syndromes
Poliovirus infections
Paralytic poliomyelitis
Asymmetrical flaccid paralysis with no sensory loss
Poliovirus type 1 is responsible for 85% of cases
Vaccine-associated disease (reversion of type 2&3)
Recovery, within 6 months to 2 years
Bulbar poliomyelitis
More severe, 75% death, iron lungs (1950’s)
Postpolio syndrome (30-40 years later) in 20-80% of the original victims)

19. Enteroviruses/Clinical syndromes
Coxsackievirus and echovirus infections
Herpangina
Several types of Coxsackie A
Hand-foot-and-mouth disease ( a vesicular exanthem)
Usually caused by coxsackievirus A16
Pleurodynia (Bornholm’s disease)(Devil’s grip)
Fever + unilateral low thoracic, pleuritic chest pain
Coxsackie B

20. Enteroviruses/Clinical syndromes
Coxsackievirus and echovirus infections
Myocardial and pericardial infections*
Coxsackie B
Occur sporadically in older children and adults
Most threatening in newborns
Febrile illness, sudden unexplained onset of heart failure high mortality

21. Enteroviruses/Clinical syndromes
Coxsackievirus and echovirus infections
Viral (aseptic meningitis)*
Acute febrile illness + CNS symptoms
Petechia or a rash
Summer and autumn outbreaks with Echo 11
Fever, rash and common cold-like symptoms
Other diseases
Acute hemorrhagic conjunctivitis
Enterovirus 70 and coxsackie A24

22. Enteroviruses/Clinical syndromes
Coxsackievirus and echovirus infections
Other diseases
Acute hemorrhagic conjunctivitis
Enterovirus 70 and coxsackie A24
transplacental infection
Insulin-dependent diabetes
Coxsackie B

23. PeV
Respiratory infections
Gastrointestinal infections

24. Enteroviruses/Laboratory Diagnosis
Nükleic acit detection
Isolation
Serology: Antibody

25. Enteroviruses/Treatment
Pleconaril new antiviral drug

26. Enteroviruses/ Prevention & control
“The prevention of paralytic polyomyelitis is one of the triumphs of modern medicine”
Poliovirus vaccines:
IPV, developed by Jonas Salk
OPV, developed by Albert Sabin (live attenuated)

27. 'Poliosuz Ülke Sertifikası’
Rutin aşılama çalışmalarına ek olarak Ulusal Aşı Günleri (UAG) ve Mop-up gibi destek aşılamalar düzenlemesi gerekmiştir.
1998 yılında tip 1 poliovirüse bağlı son çocuk felci vakası Ağrı ilinde saptanmıştır.
Bu vaka aynı zamanda DSÖ Avrupa bölgesi’nin de son polio vakası olmuştur.
Türkiye, Dünya Sağlık Örgütü Avrupa bölgesi ile birlikte 21 haziran 2002 tarihinde çocuk felci hastalığından (polio) arındırılmış olarak sertifikalandırılmıştır.

28. Iron lung

29. Polio sekeli

30. Rhinoviruses Most important cause of the common cold and URTI ICAM-1
Unable to replicate in the GIT
Labile to “ pH”
Grow 33oC
Infection can be initiated by as little as 1 (one) infectious viral particle
“Runny nose”

31. Rhinoviruses Most important cause of URTI ~ 50% Common cold:
Enteroviruses
Coronaviruses
Adenoviruses
Parainfluenza viruses

32. Rhinoviruses Sneezing Rhinorrhea nasal obstruction
Common cold symptoms
Sneezing
Rhinorrhea nasal obstruction
Mild sore throat
Headache
Malaise
Cough
Fever & rigors

33. Rhinoviruses
The clinical syndrome of the common cold is usually so characteristic that laboratory diagnosis is unnecessary!!