Childhood Viral Diseases Flashcards
(40 cards)
What are the childhood viruses we need to know?
1) Measles Virus
2) Respiratory Syncytial Virus –> croup, bronchitis
3) Varicella Zoster Virus –> chickenpox
4) Rotavirus –> gastroenteritis
5) Poliovirus –> gastroenteritis
What is the biology of the Measles virus?
- Paramyxovirus
- Genome: (-)ssRNA
- Virion: enveloped
- Replication in the cell
- Fusion protein causes syncytia formation
How are you infected with measles?
Inhalation of aerosolized droplets
What is the incubation period of measles? Where is the primary infection?
10-14 days, in the respiratory epithelial tissues (primary viremia)
When/where is the symptom onset of measles?
- Coincides with 2nd round of virus replication.
- Occurs in LN, tonsils, lungs, GI tract, and spleen (secondary viremia)
How long after infection is the recovery from measles?
20 days
True or false: Measles is the most deadly of the childhood rash/fever illnesses.
True
Why does measles have a characteristic rash?
Because virus and immune response damages epithelial and endothelial cells (Koplik spots)
What are possible complications with measles?
- Immune suppression, allows for opportunistic infections
- Blindess in vitamin A deficient children
- ADEM (acute disseminated encephalomyelitis) - rare demyelinating disease
- SSPE (subacte sclerosing panencephalitis) - very rare, progressive neurological deterioration 7 to 10 years after infection
What are the symptoms of measles?
- 2-3 days= fever + cough, coryza, & conjunctivitis
- 2-3 days after infection - Rash: Kopik spots - small bright red spots with bluish centers on buccal mucosa, pathognomic for measles
How is measles diagnosed?
- Virus isolation in culture (very hard)
- Serology
- ELISA, RT-PCR
How is measles prevented?
- Vaccination with live attenuated vaccine, is primary option, provides life-long immunity, is safe
- Vitamin A can reduce severity
- No antivirals
True or false: Measles is one of the most contagious diseases known.
True: Ro is 15 to 20 (cases from one illness in a naive population)
True or false: Humans are the only host for Measles.
True
What is Respiratory Syncytial Virus Biology?
- Paramyxovirus
- Genome: (-)ssRNA
- Virion: enveloped
- Replication in the cell
- Infects ciliated cells in the rest. tract epithelium
- Fusion protein causes syncytia formation
- Virus buds from cellular surface
True or false: Respiratory Syncytial Virus is the most important agent of serious pediatric respiratory tract infections
True
How are you infected with Respiratory Syncytial Virus?
Inhalation of aerosolized droplets, fomites
What is the incubation period of Respiratory Syncytial Virus? Where is the infection?
4-5 days, limited to respiratory tract
What are the symptoms of Respiratory Syncytial Virus?
- Lower respiratory tract symptoms 1 to 3 days after upper resp. tract symptoms.
- Recovery 7 to 12 days after onset
How is Respiratory Syncytial Virus prevented?
- Infection does not yield life long immunity
- No antivirals
- No vaccine
- Passive immunoprophylaxis
True or false: True or false: Humans are the only host for Respiratory Syncytial Virus.
True
What are risk factors for infection with Respiratory Syncytial Virus?
- Attending day care
- School age siblings
What is a risk for more severe disease with Respiratory Syncytial Virus?
- Premature birth, male, second hand exposure to cigarette smoke, lack of breast feeding
What is Varicella Zoster Virus biology?
- Alphaherpesvirus
- Genome: dsDNA, large
- Virion: enveloped
- Protein: hundreds of proteins
- Replicates in cell (resting cell like neuron = latent infection), infects neighboring cells first
