Vaccine-Preventable Viral Flashcards
5 common childhood viral exanthems
rashes
Rubella (German Measles): pink coalescing macule begin at head and move down -> fine rash on trunk.
Rubeola (Measles): begins at head and moves down; rash preceded by other sx.
Roseola (human herpes virus (HSV) 6 and 7): asymptomatic rose-colored macules after high fever, can have febrile seizures.
Fifth Disease (human parvovirus B19): slapped cheek on face; hydrops fetalis in pregnant women.
paramyxoviruses
Disease in kids.
Measles, mumps, respiratory syncytial virus (RSV - bronchiolitis, pneumonia), parainfluenza (croup).
Large, enveloped, linear, non-segmented -RNA viruses.
ss RNA-dependent RNA polymerase.
Replication in cytoplasm.
Glycoproteins (F fusion protein) on surface mediate adhesion –> giant cell syncitia - respiratory epithelial cells fuse and form multinucleate cells.
Rubella virus (German measles)
Togavirus
Infects only humans
Only one serotype
Excellent vaccine:
Transmitted via respiratory droplets.
Fever, post auricular and other lymphadenopathy, arthralgia, fine rash on face spreads to trunk and extremities (blueberry muffin appearance).
Triad: Eye (cataract), Ear (deafness), Congenital Heart Disease.
Mild disease in kids, but serious congenital TORCHeS infection.
neurological diseases
Measles and mumps (transmission is respiratory) Other enteroviruses (Polio; Coxsackie; echovirus)
Parainfluenza viruses
Paramyxovirus.
Causes croup (laryngotracheobronchitis) - seal-like barking cough and inspiratory stridor.
Steeple sign on x-ray due to narrowing of upper trachea and sub glottis.
If severe can –> upper airway obstruction –> pulsus paradoxes.
RSV
Paramyxovirus.
Infants < 6 months.
Infects by attaching to respiratory epithelium via G protein.
Bronchiolitis, pneumonia, rhinitis, pharyngitis.
Most common cause of pneumonia and bronchiolitis in infants.
Tx: ribavirin for adults, palivizumab to prevent in high risk kids (premies).
Rubeola Virus (Measles)
Paramyxovirus.
3 C’s: Cough, Coryza, Conjunctivitis.
Prodromal fever w cough, coryza (rhinitis), conjunctivitis, then Koplik spots on buccal mucosa (bright red w blue-white center).
Then 1-2 days later maculopapular rash starting at head/neck and heading down.
Serious complications: subacute sclerosis panencephalitis, encephalitis, giant cell pneumonia.
Vitamin A can reduce morbidity and mortality.
Poliovirus
Picornavirus, enterovirus (fecal-oral spread).
3 serotypes.
Humans only susceptible host.
Distributed globally. On course to be eradicated (Afghanistan and Pakistan).
Parvovirus B19
Erythema infectiosum (5th disease). Slapped cheek rash on face. Hydrops fetalis in pregnant women. Arthritis/arthralgias associated, esp in adults. Can cause aplastic crisis. No vaccine. Smallest DNA virus - only ss DNA virus.
Varicella Zoster Virus (VZV)
Primary infection - chicken pox. Recurrent - shingles. Also encephalitis and pneumonia. Live attenuated vaccine. HHV-3 (enveloped, ds linear DNA) Respiratory secretions. Most common complication of shingles is post-herpetic neuralgia. Latent in dorsal root or trigeminal ganglia.
Hepatitis A
ss+RNA picornavirus, small icosahedral non-enveloped.
Stable to acid, detergents, temp, dryness, not destroyed by gut.
Fecal-oral transmission.
Short incubation (weeks).
Usually asymptomatic, acute.
Tropism for liver - Councilman bodies.
Fever, jaundice, ^AST and ALT.
Human Papilloma Virus (HPV)
Non-envelopes, ds circular DNA. HPV warts (1, 2, 6, 11), CIN, cervical cancer (16, 18). Gardasil, cervarix, gardasil 9 - all protect against 16 and 18.
Mumps
Paramyxovirus Uncommon due to MMR vaccine POM-Poms: Parotitis Orchitis (can cause sterility after puberty) aseptic Meningitis Pancreatitis
