1. Paramyxoviruses
Dr. Nehal Draz

2. Myxoviruses Paramyxo viruses Orthomyxo viruses
Myxo = affinity to mucin
Myxoviruses
Paramyxo viruses
Orthomyxo viruses
Smaller
Segmented RNA genome
Liable to Agic variation
Larger
Single piece of RNA
Not liable to Agic variation
- Parainfluenza
- Mumps vairus
- Measles virus
- Respiratory syncytial virus
Influenza viruses

3. Large Spherical envelopped
Unsegmented –ve sense RNA
The lipid envelope is associated with 2-virus specific glycoptns; Haemaglutinin-Neuraminidase (HN) ptn& fusion (F) ptn

4. Respiratory Sncytial Virus
Commonest cause of bronchitis & pneumonia among infants< 1yr.
Causes repeated infections throughout life, usually associated with moderate- to severe cold –like symptoms
Severe lower respiratory tract disease may occur at any age, especially elderly & those with compromised cardiac, pulmonary or immune systems

5. Laboratory Diagnosis
Specimens: nasal secretions-nasopharyngeal aspirate 1- Direct virus demonstration: - DIF: for detection of viral Ag - RT-PCR for detection of viral RNA 2- Viral isolation: - nasal secretions inoculated onto (HeLa) - Growth is recognized by development of CPE in the form of giant cells & syncytia

6. Treatment Symptomatic treatment for mild disease
Oxygen therapy & may be mechanical ventilation in children with severe disease
Ribavirin aerosol
No vaccine is yet available

7. Human Parainfluenza Viruses(1,2,3,4)
HPIVs are second to RSV as a common cause of lower respiratory tract disease in young children
Similar to RSV, HPIVs can cause repeated infections throughout life, usually upper respiratory tract illness
Can also cause severe lower respiratory tract infections ammong immunocompromised patients

8. Each of the four HPIVs has different clinical & epidemiologic features
The most distinctive clinical feature of HPIV-1& HPIV-2 is croup
HPIV-3 is more associated with bronchiolitis & pneumonia
HPIV-4 is infrequently detected, because it is less likely to cause severe disease
Croup (laryngotracheobronchitis
difficulty in breathing, hoarseness and
a seal bark-like coughing

9. Laboratory Diagnosis
Specimens: nasal secretion-nasopharyngeal aspirate- bronchoalveolar lavage 1- Direct virus demonstration: - DIF: for detection of viral Ag - RT-PCR for detection of viral RNA 2- Viral isolation: - Specimens are inoculated onto (MKTC) - Growth is recognized by hemadsorption using guinea pig RBCs or by direct IF

10. 3- Serological tests:
Based on Nt, HI, or ELISA for detection of IgM or IgG
Paired acute & convalescent sera are necessary for IgG detection
A four fold or more rise in the titre indicates infection

11. Mumps Viruss
Causes epidemic parotitis ( non suppurative inflammation of parotid)
Mode of transmission:
Via aerosols & fomites
The virus is secreted in urine so urine is a possible source of infection
saliva

12. Pathogenesis & clinical picture
Infects children 5-15years
Replicates in the nasopharynx &regional LNs
Incubation period: 2-25 d
Lasts 3-5 d
viremia
Salivary
Pancreas
Testes
ovaries
glands
meninges
Long life immunity due to IgG neutralizing Abs

14. Complications Severe aseptic meningitis in adults
Orchitis in adult males which might cause sterility
Pancreatitis
Oophritis & thyroiditis

15. Laboratory Diagnosis
Specimens: - saliva - CSF - urine 1- Direct virus demonstration: - RT-PCR for detection of viral RNA 2- Viral isolation: - Specimens are inoculated onto (MKTC) or chick embryo - Growth is recognized by hemadsorption or by direct IF & by characteristic CPE giant cell formation

17. 3- serology:
ELISA is used for detection of IgM or IgG
For IgG, paired acute & convalescent sera are necessary
Four fold or more rise in IgG titer indicates infection

18. Prevention Active immunization Mumps vaccine Live attenuated
Given by subcutaneous injection
Long term immunity
Monovalent form or MMR vaccine

19. Measles virus Causes measles (robeola)
One of the most contagious respiratory infections
It can nearly affect every person (in a given population) by adolescence, in the absence of immunization programs
Mode of transmission:
- Large repiratory droplet
-airborne
Most infectious in the early stage
Before the rash appears

20. Pathogenesis & clinical picture
Replication initially in the upper & lower respiratory tract
Followed by LNs replication
Viremia & growth in a variety of epithelial tissue
Incubation period: 1-2 wks
In 2-3 days, no rash but fever, running nose, cough & conjunctivitis

21. Koplick spots: slightly raised white dots, 2-3 mm in diameter are seen on the inside of the cheek shortly before rash onset persist for 1-3 days
A characteristic maculopapular rash extending from face to extremities involving palms & soles : this seems to be associated with T-cells attacking virally infected endothelial cells in small blood vessels
The rash lasts from 3-7 d & may be followed by skin exfoliation

23. Disappear after the rash onset Lasts for 3-7 days
1-Respiratory
symptoms
2-3 days
2-Koplick spots
3-Maculopapular rash
Persist 1-3 days
Disappear after the rash onset
Lasts for 3-7 days
4-Skin exfoliation
Long life immunity due to IgG neutralizing Abs

24. The virus invades the body via blood vessels
reaches surface epithelium
first in the respiratory tract where
there are only 1-2 layers of epithelial cells
Then in mucosae (Koplik's spots)
and finally in the skin (rash).

25. complications I- Respiratory
Otitis media & bacterial pneumonia: common
Giant cell pneumonia in patients with impaired CMI ( rare but fatal)
II- Neurological
Postinfectious encephalitis. Few days after the rash (1:1000)
Subacute sclerosing panencephalitis (SSPE) (1: )

26. Laboratory Diagnosis
Specimens: nasal secretions-nasopharyngeal aspirate or swab- urine 1- Direct virus demonstration: - DIF: for detection of viral Ag - RT-PCR for detection of viral RNA 2- Viral isolation: - nasal secretions inoculated onto (MKTC) - Growth is recognized by development of CPE in the form of multinucleated giant cells containing both intranuclear & intracytoplasmic IBs

27. 3- serology:
ELISA is used for detection of IgM or IgG
For IgM single serum specimen 1-2 wks after the rash onset
For IgG, paired acute & convalescent sera are necessary
Four fold or more rise in IgG titer indicates infection

28. Prevention Passive immunization Measles IGs Active immunization
- For immunocompromised patients
Intramuscular within 6 days of exposure
Prevent measles symptoms in 80% of cases
Active immunization
Mumps vaccine
Live attenuated
Given by subcutaneous injection
Long term immunity
Monovalent form or MMR vaccine

29. Rubella Virus
Causes German measles which is the mildest of common viral exanthems
It is a member of rubiviruses but not an arbovirus
Envelopped +ve sense ss RNA
Posseses hemaglutinating ability

30. Diseases
1- German measles: acute febrile illness with rash & lymphadenopathy affecting children & young adults
2- Congenital Rubella Syndrome: Serious abnormalities of the fetus as a consequence of maternal infection during early pregnancy

31. Postnatal rubella (German measles) Pathogenesis & clinical picture
Mode of transmission: droplet
Initial viral replication occurs in the respiratory mucosa followed by multiplication in the cervical lymph nodes
Viremia develops with spread to other tissues. As a result the disease symptoms develop in 50% of cases after an incubation period of days
Possibly 50% of infections are apparently subclinical

32. Fever & malaise (prodromal symptoms) for 1-2 days
Maculopapular rash appears on the face,then the trunk, then the extremities and disappears within 3 days
Suboccipital and postauricular lymphadenopathy
Extremely rare complications, self limiting encephalopathy

33. complications Extremely rare (1/6000) Rubella encephalopathy
6 days after the rash appears
Complete recovery with no sequalae

34. Laboratory Diagnosis
Specimens: nasal secretions-nasopharyngeal aspirate or swab 1- Direct virus demonstration: - DIF: for detection of viral Ag - RT-PCR for detection of viral RNA 2- Viral isolation: - nasal secretions inoculated onto (MKTC) - Growth is recognized by interference with coxsakie virus

35. 3- serology:
ELISA is used for detection of IgM or IgG
For IgM single serum specimen
For IgG, paired acute & convalescent sera are necessary
Four fold or more rise in IgG titer indicates infection

36. Congenital rubella
Congenital rubella is a group of physical problems that occur in an infant when the mother is infected with the virus that causes German measles.

37. Congenital rubella is caused by the destructive action of the rubella virus on the fetus at a critical time in development. The most critical time is the first trimester (the first 3 months of a pregnancy). After the fourth month, the mother's rubella infection is less likely to harm the developing fetus.
The rate of congenital rubella has decreased dramatically since the introduction of the rubella vaccine.

38. Risk factors for congenital rubella include:
Not getting the recommended rubella immunization
Contact with a person who has rubella (also called the 3-day measles or German measles)
Pregnant women who are not vaccinated and who have not had rubella risk infection to themselves and damage to their unborn baby.

39. Clinical picture Transient symptoms:
growth retardation, anemia & thrombocytopenia
Permanent defects: congenital heart diseases, total or partial blindness, deafness & mental retardation
Progressive rubella panencephalitis:
Extremely rare slow virus disease, develops in teens with death within 8 yrs

40. Laboratory Diagnosis During Pregnancy After Birth
Detection of maternal IgM or rising IgG in serum
Then, detection of rubella Ag in the amniotic fluid by DIF
Live newborn: detection of IgM antirubella Abs in the serum of the baby by ELISA
Stillbirth: virus isolation on MKTC
During Pregnancy
After Birth

41. Prevention of congenital rubella
vaccinate
Women in the childbearing age
School age children
Pregnancy should be avoided 3 months after vaccination
Maternal rubella infection confirmed during the first trimester????
Therapeutic
abortion

42. MMR Contains 3 live attenuated viruses: mumps, measles and rubella
Given in 2 doses
The first dose: to children months of age by subcutaneous injection
Why not before that?
When is the second dose?
Contraindications?

43. Thank you