2. Introduction
Includes
. RSV & Parainflunzavirus causing RTI in infants & Children
. Measles & mumps , most contagious disease of child hood.
ARI- cause of death of 4million children per year
Paramyxoviruses – major respiratory pathogen in this age
group.
RSV & parainfluenzavirus ; limited to RT
Measles & mumps disseminate throughout the body.
3.
4. Properties
Structure and composition
Pleomorphic, enveloped
Diameter occasionally 150 nm or more
ranging up to 700 nm.
The nucleocapsid consists of the
negative-sense, single stranded non
segmented RNA associated with the
nucleoprotein (NP),polymerase
phospho protein (P), and large (L)
protein.
5. Contd..
The nucleocapsid associates with the matrix (M) protein
lines the inside of the virion envelope.
The envelope contains two glycoproteins, a fusion(F)
protein, which promotes fusion of the viral and host cell
membranes, and a viral attachment
protein(hemagglutinin-neuraminidase [HN],
hemagglutinin [H],or G protein)
6. The difference between the orthomyxo &
paramyxoviruses
Orthomyxoviruses Paramyxoviruses
Diseases caused
in humans
Influenza types A, B and C Parainfluenza 1-4 infections,
RSV diseaes, mumps and
measles
genome ssRNA
8 segmented,
-ve sense
ssRNA
nonsegmented
–ve sense
Fusion of virus
with cell
Endosome Plasma membrane
Transcription of
viral RNA
HOST CELL NUCLEUS Host cell cytoplasm
Genetic
reassortment
frequent Rare
Rate of antigentic
change
high low
7. Classification
Paramyxoviridae family has 2 sub families
Paramyxovirinae
Respirovirus : Parainfluenza 1,3
Rubulavirus: Mumps, Parainfluenza 2, 4a,4b
Morbili Virus: measles
Henipavirus: Hendra, Nimph
10. Replication
Takes place in cytoplasm
Virus attaches via hemagglutinin to sialic acid containing
receptor on the cell surface.
F protein fuses the viral envelope with the cell
membrane releasing the nucleocapsid into the cell.
RNA-dependent RNA polymerase carried within the virion
produces subgenomic sized mRNA transcripts, which are
translated to produce some of the early virus specific
poly peptides.
11. Early proteins include a second RNA polymerase which
copies the genome into full length positive
complementary strand which is later copied back into
negative strand for transcription of later mRNA (coding
for structural proteins) and for incorporation into new
virions.
12. Viral components are assembled beneath the cell
membrane and the surface HN and F proteins are
incorporated into a stretch of membrane converting it to
viral envelope.
This evaginates and buds off enclosing a nucleocapsid
forming a new virion.
15. Para influenza virus
Para influenza viruses are ubiquitous and cause
common respiratory illness of varying severity in all age
groups.
Transmission: droplet
TYPE 1,2,& 3 are particularly considered major
pathogens of severe respiratory tract disease in infants
& young children
Type 4 does not cause severe disease even on primary
infection
16. Primary infections in young children
usually result in
Rhinitis
Pharyngitis
However children with primary infection
caused by serotypes 1,2 or 3 may have
serious illness ranging from:
Laryngeotracheobronchitis (croup)
Bronchiolitis & pneumonia mainly type 3
age < 6month
17. Pathogenesis
Incubation period 3 to 6 days.
In immuno competent host, infection is limited to
respiratory epithelia
Type 1 &2 involve the infection of larynx and upper
trachea resulting in croup.
Croup: Respiratory obstruction caused by swelling of the
larynx and related structure.
18. Type 3 infection may spread deeper to lower trachea and
bronchi resulting in pneumonia or bronchiolitis.
The duration of parainfluenza virus shedding is about 1
week after onset of illness.
Type 3 may be excreated for up to 4 weeks, this
persistent shedding from young children facilitates
spread of infection.
19.
20. Clinical findings
Primary infection caused by parainfluenza virus type 1,2
& 3 may have serious illness which ranges from
laryngitis and croup (Type 1 & 2) to bronchiolitis and
pneumonia (Type3)
Severe illness is associated with type3 mainly in infants
younger than 6 months.
Type 4 doesn’t cause serious disease even on first
infection.
21. The most common complication of parainfluenza virus
infection is ottitis media.
Immuno compromised children and adults are
susceptible to severe infection.
Newcastle disease virus is an avian paramyxovirus
that produce pneumoencephalytis in young chicken and
influenza in other birds .
22. In humans it may produce inflammation of conjunctiva.
Disease is limited to workers handling the infected birds.
Recovery is complete in 10-14 days.
23. Widely distributed geographically,
Type 3 is most pravalent 1&2 occur at lower rate.
24. Lab Diagnosis
Nucleic acid detection:
Preferred diagnostic method because of their
sensitivity and specificity.
Reverse transcription PCR (RT- PCR) assays can be used to
detect viral RNA in nasopharyngeal washes or nose and
throat swabs.
25. Antigen Detection :
Direct identification of the viral antigen is commonly done.
Antigen is detected in exfoliated nasopharengeal cells by
direct or indirect immuno fluorescence test.
26. Isolation & Identification:
Rapid cell culture technique
Slow to produce results.
Serology:
Neutralization test, Hemagglutination or ELISA
27. Treatment and prevention
Isolation of the infected patient.
Gowning and hand washing by medical persons
Ribavirin is used in treatment of immuno compromised
patient with lower respiratory tract disease
No vaccine available.
30. Most important cause of LRT infection in infants and
young children
Major cause of bronchiolitis and pneumonia in infants
and below 1 year.
Labile paramyxovirus, produces a characteristic syncytial
effect. ( Fusion of human cells in human cell culture)
Slightly smaller(80-120 nm) than other paramyxovirus.
33. Pathogenesis
Replication occurs initially in epithelial cells of
nasopharynx.
May also spread to LRT and cause bronchiolitis or
pneumonia.
I.P. 3-5 days. Viral shedding may persist for 1-3 weeks
from infants and young children but adults shed virus for
only 1-2 days.
Viremia occurs rarely
34. Intact immune system seems to be important in
resolving the infection.
The spectrum of respiratory illness caused by RSV
ranges from inapperant infection or the common cold
through pneumonia to bronchiolitis in the very young
children.
Bronchiolitis is the distinct clinical syndrome associated
with the virus.
35. One third of the primary infection involve the LRT
severely enough to rewuire the medical attention.
Progression of the symptoms may be very rapid
resulting in death.
Reinfection is common in both young and adults.
36. It accounts for about one third of the respiratory
infection in the bone marrow transplanted patients.
Infection in elderly adults may cause symptoms similar
to influenza virus disease.
38. Lab diagnosis
Nucleic acid detection:
Reverse transcription PCR (RT- PCR) assays can be used to
detect viral RNA in nasopharyngeal washes or nose and
throat swabs.
Antigen Dectation: Detected in exfoliated
nasopharengeal cells by direct or indirect immuno
fluorescence test.
39. Treatment and prevention
Treatment of serious RSV depends primiraly on
supportive care
Ribavirin is approved for treatment of LRT, administered
in aerosoles.
No vaccine is available.
42. Introduction
It causes mumps; an acute contagious disease
characterised by non suppurative enlargement of one or
both of the parotid glands.
It is a typical paramyxovirus.
Mostly causes mild childhood disease but in adults
complications including meningitis and orchitis are
sometimes seen.
43. Time course of Mumps infection
Local
replication
Systemic
infection
Inoculation EC of
URT
Viremia
Virus multiplies in ductal
epithelial cells. local
inflammation causes
Marked swelling
Parotid glandpancreas
Testes
Ovaries
Peripheral nerves
Eye
Inner ear
CNS
44. Pathogenesis
Humans are the only natural host
Primary replication occurs in nasal or upper respiratory
tract epithelial cells.
Viremia dissiminates the virus to salivary glands and
parotid gland.
Incubation period is 2-4 weeks.
45. Virus sheds in the saliva from about 3 days before to 9
days after the onset of salivary gland swelling.
About one third of infected individuals do not exhibit
symptoms but are equally capable of transmitting the
infection.
Systemic viral disease with propensity to replicate in
epithelial cells of various visceral organs.
46. Virus frequently infects kidney and can be detected in
urine of most patients.
The central nervous system is also commonly infected.
47. Lab diagnosis
Nucleic acid detection:
By Reverse transcription polymerase chain reaction.
Antigen detection:
by ELISA or HI test
Isolation of the virus from saliva CSF and urine
Monkey kidney cells are preferred for viral isolation.
48. Treatment and prevention
Immunization with attenuated mumps virus vaccine is
the best approach for control.
Vaccine is available in combination with measles and
rubella. (MMR)
Two doses of MMR vaccine are recommended.
51. Introduction
Measles is a morbilli virus, morphologically
indistinguishable from parainfluenza virus, mumps virus
and NDV.
Glycoprotein spike carries hemagglutinin but not
nuraminidase function.
F protein and M protein also present.
There is only one serotype of measles no subtypes have
been recognised.
52. Measles
Serious and highly contagious
Usually found in non-immunized or partially-immunized (single
vaccine, no booster)
Most born before 1957 have had measles
Measles virus is spread easily
Through air by coughs or sneezes
By direct contact with nose or throat secretions
Symptoms
Rash that starts on the face and neck, then spreads
High fever
Runny nose
Red, watery eyes
Cough
53. Measles
Symptoms start about 10 days after exposure
Average 10 days from exposure to onset of fever
Average 14 days from exposure to onset of rash
Other symptoms and complications
Ear infection
Pneumonia
CNS/ brain infection (as SSPE, subacute sclerosing panencephalitis)
Complications may be lethal
More serious in infants and adults, less in children and teens
Vaccine
Measles (Paramyxoviridae), mumps (Paramyxoviridae), rubella (Togaviridae, +
sense) (MMR) vaccine is a live vaccine
Has been very effective in limiting spread
Links of vaccine to autism have been proposed but not shown
Management
Antibiotics should be used to combat side-effects such as ear infetions pneumonia.
Giving vitamin A at the time of diagnosis can help to prevent blindess
55. Incubation period 7-14 days.
Human are the only natural host.
Entry via respiratory tract,multplies locally infection
spreads to the regional lymphoid tissue where further
multplication occurs.
Primary viremia disseminates the virus which then
multplies in reticuloendothelial system.
Finally second viremia seeds the epithelial surface of the
body (skin, respiratory tract, conjunctiva)
61. With decline of acute symptoms in 1 to 2 days typical
wide spread maculopapular rashes (morbiliform) rash
appear on skin
Begins on face and thorax and spreads preipherally.
The rash last approximately for 5 days.
Skin rash is due to cytotoxic T cells attacking the
measles virus infected vascular endothelial cellsin skin.
64. Rubella virus is a member of Togaviridae family.
Although its morphologic feature and physiologic
properties place it in togavirus group its is not
transmitted by arthropods.
Causes Postnatal and congenital infections.
65. The name rubella is derived from a Latin term meaning
"little red."
Rubella is sometime called German Measles or 3-day
Measles.
The synonym "3-day measles" derives from the typical
course of rubella exanthema that starts initially on the
face and neck and spreads centrifugally to the trunk and
extremities within 24 hours.
It then begins to fade on the face on the second day and
disappears throughout the body by the end of the third
day.
It is a generally mild disease caused by the rubella virus.
66. Source of infection – Respiratory secretion
Transmission – droplet, vertical transmission
I.P – 2-3 weeks average 18 days
67. Clinical Symptoms.
• Eye pain on lateral and upward eye movement
(a particularly troublesome complaint)
• Conjunctivitis
• Sore throat
• Headache
• General body aches
• Low-grade fever
• Chills
• Anorexia
• Nausea
• Tender lymphadenopathy (particularly posterior
auricular and suboccipital lymph nodes)
68. Forchheimer sign (an enanthem observed in 20% of
patients with rubella during the prodromal period; can
be present in some patients during the initial phase of
the exanthem; consists of pinpoint or larger petechiae
that usually occur on the soft palate)
69. Image in a 4-year-old girl with a 4-day history of low-grade fever,
symptoms of an upper respiratory tract infection, and rash.
Courtesy of Pamela L. Dyne, MD.
71. Age Vaccines Note
9 months Measles
Deep subcutaneous injection
into the upper arm.
12-15
months MMR -1
Deep subcutaneous injection
into the upper arm.
5 years MMR -2
Deep subcutaneous injection
into the upper arm.
Treatment and control