Paramyxovirus lec
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Transcript of Paramyxovirus lec
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Paramyxo viruses
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Paramyxo viruses
• Paramyxoviruses are enveloped RNA virus.
• Contain one piece single stranded RNA.
• Surface spikes are: hemagglutinin, nuraminidase and fusion protein.
• Paramyxo viruses are:
Measles virus
Mumps virus
Respiratory syncytial virus
Parainfluenza virus
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Paramyxo viruses
Virus Hemagglutinin Nuraminidase Fusion protein
Measles + - +
Mumps + + +
Respiratory syncytial
- - +
Parainfluenza + + +
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Paramyxoviridae structure
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Measles virus
Measles virus
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Measles virus
• Reservoir
– Humans
• Transmission
– Person-to-person via droplets during
prodormal period and a few days after
symptos.
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Measles virus
• Incubation period
– Average 10-14 days.
• Infectious period
– From 4 days prior to rash onset to 4 days
after rash onset.
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Measles pathogenesis
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Clinical features
• Prodrome:
• Fever,
• cough,
• coryza,
• conjunctivitis.
Koplik’s spots - Bright red lesion with a white central dot, located on the buccal mucosa.
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Clinical features
• Rash: maculopapular,
begins at hairline, progresses downward
• Complications– Diarrhea, – Otitis media– Pneumonia, – Encephalitis
• Measles in pregnancy cause stillbirth rather than congenital anomalies.
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Laboratory diagnosis
• Typical clinical presentation.
• Laboratory confirmation:
• Isolation of measles virus
• Significant rise in measles IgG by any
standard serologic assay
• Positive serologic test for measles IgM
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Control measures
• Prevented by immunization with a live
attenuated vaccine.
• Should be administered with mumps and
rubella as MMR, or with mumps, rubella
and varicella as MMRV
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Mumps virus
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Transmission
• Reservoir: Human
• Transmission: Respiratory droplet nuclei.
• Incubation period: 18-21 days.
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Mumps Pathogenesis
• Respiratory transmission of virus
• Replication in nasopharynx and regional
lymph nodes
• Viremia with spread to tissues
• Multiple tissues (parotid glands, testes,
ovaries, pancreas) infected during viremia
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Clinical conditions
• Prodromal symptoms: Fever, myalgia, malaise, headache.
• Followed by acute onset of cute onset of unilateral oror bilateral tender, self-limited self-limited swelling of the of the
parotid gland (s).
• Complications:
Orchitis, Ophoritisphoritis
Sterility, Pancreatitis
CNS involvement
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Laboratory Diagnosis
• Isolation of mumps virus in cell culture.
• Detection of mumps IgM antibody
• Detection of mumps IgM antibody
• A four-fold rise in IgG antibody
• Detection of mumps DNA by PCR,
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Mumps Vaccine
• Prevented by live, attenuated vaccine.
• Should be administered with measles and
rubella (MMR) or with measles, rubella and
varicella (MMRV)
Respiratory Syncytial Virus (RSV)
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Resp. Sync. Virus
• Enveloped, single stranded, RNA virus.
• Host range limited to humans; single
serotype
• Transmission via droplets, fingers, fomites
• Incubation period- 2-8 days
• Entry through mucosa of nose and eye
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Clinical Features
• Upper respiratory infection in older
children and adults:
Fever, Rhinitis, Pharyngitis & otitis media
• Lower Respiratory Infection in infants:
Bronchiolitis, Pneumonia, Cough, Poor
feeding, lethargy, Hypoxemia, Respiratory
Distress, Apnea
22RSV Bronchiolitis- clinical features
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Parainfluenza viruses
• Enveloped, single stranded, RNA virus.
• Four serotypes, host range limited to
humans,
• Transmission via respiratory droplet.
• Infections limited to respiratory tract,
generally non-systemic and viremia rare.
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Parainfluenza viruses
• Serotypes 1 and 2 cause cold-like symptoms,
bronchitis and croup.
• Serotypes 3 causes infection of children in lower
respiratory tract.
• Diagnosis
– Virus culture
– Syncytia formation
– A 4 foled rise of antibody titer.
– PCR
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