Virus 2 Flashcards
Measles - spread through
respiratory droplets
shed before and after the onset of symptoms
most infections appear to be symptomatic
rash caused by immune response (CMI) to infected endothelial lining in the small BVs
Measles clinical features - incubation period is
1 to 2 weeks
Measles clinical features - prodrome
stepwise increase in fever to 103 or higher
cough, coryza, conjunctivitis
Koplik spots!
Measles - koplik spots
small white spots on bright red mucus membranes of the mouth and throat
Measles - clinical features - rash
2 to 4 days after prodrome, 14 days after exposure
Begins on face and hand and persists 2 to 6 days
Rash fades in order of appearance
Measles complications
Diarrhea (8%) Otitis media (7%) Pneumonia (6%) Encephalitis (0.1 to 0.5%) Death (0.2%) Hospitalization (18%)
Measles complications - pneumonia accounts for __ deaths
60% of deaths caused by measles
Measles complications - persistent diarrhea
major cause of mortality in children in underdeveloped regions
Measles complications - post infectious encephalitis
Autoimmune in nature
Occurs in less than 1% of those infected more often in older children and adults
15% fatality rate
Measles vaccine
A live attenuate vaccine been used in US since 1963
Administered to children as part of MMR (2-5% dont respond to first dose)
Most states require first dose at 1-2 yrs and then second before starting school
Rubella is what
relatively benign infection in children
arthritis and arthralgia in adults
congenital infection can result in cataracts, mental retardation, and deafness
Rubella vaccination
has reduced number of cases in US by 99%
Rubella - transmission
respiratory
replication in nasopharyx and regional lymph nodes
Rubella - viremia
viremia 5-7 days after exposure with spread to tissues
placenta and fetus infected during viremia
Rubella - immune complexes
rash and arthralgia are the result of immune complexes associated with the infection
Rubella clinical features
incubation 2-3 weeks
prodrome of low grade fever
maculopapular rash appears 14-17 days after exposure
Progresses from head to foot!
Is fainter than measles rash, does not coalesce
Epidemic rubella - US
1964-1965
12.5 million rubella cases
Rubella -workers exposed to rubella virus who do not have documented immunity need to
be excluded from duty until 21 days after last exposure
Mumps are what
same family as measles virus
Prior to routine vaccination (1960s) - 150-200,000 cases annually! now typically less than 1000
Mumps - outbreaks
large and small outbreaks still tend to occur
Cases peak in later winter and early spring - commonly acquired at school, secondary spread to family members
Mumps - acquired by what
transfer or respiratory droplets
virus replicates in the nasopharynx and regional lymph nodes (1-3 wks)
Mumps - a primary viremia spreads the virus to
multiple tissues including salivary glands, testes, ovaries, and meninges
inflammation of the infected tissues leads to the characteristic clinical symptoms of parotitis, orchitis, oophoritis, and meningitis
Mumps - clinical disease
short, non specific prodrome (myalgia, malaise, fever)
50% develop salivary gland swelling and pain (parotitis)
Virus shed from 3 days before to 4 days after onset of active disease
Mumps - complications - CNA involvement
15-50% show signs of meningitis or encephalitis
Mumps - complications - orchitis
testicular inflammation
most common complication in postpubertal males
20-50% of males
mostly unilateral
develops within 4-10 days of onset of parotitis
following resoluation, can have atrophy (sterility is rare though)
Mumps - complications - oophoritis
ovarian inflammation
occurs in 5% of postpubertal females
no evidence that it impacts fertility
Mumps - complications - deafness
1/20,000 infected individuals
typically unilateral
results from direct damage to cochlea by virus
may be transient or permanent
Mumps - diagnosis
clinical manifestations - parotitis
Mumps - tx
symptomatic relief
Mumps - prevention/control
Vaccination - first dose is typically given at 1 yr in cobined MMR and second dose at 4-6 yrs
Mumps - prevention/control - workers exposed to mumps virus who do not have documented immunity be
excluded from duty until 26 days after last exposure
Pink eye - acute conjunctivitis/pharyngoconjunctivitis - most common cause is
adenovirus
measles and rubella can cause it too though
Pink eye is spread through
respiratory droplets or contaminated surfaces
Pink eye infections usually occur in
winter and summer
Epidemic keratoconjunctivitis
adult pink eye
corneal and conjunctival infection
inflammaion can cause coreal opacity
pain, photophobia and blurre vision are common
epidemic keratoconjunctivitis - virus shed for
1-2 weeks after resolution of symptoms
Pink eye (children) and epidemic keratoconjunctivitis (adults) are caused by
different adenovirus types
Pink eye - incubation period
3-14 days prior to the onset of symptoms
pain, foreign body sensation, photophobia may accompany tearing
virus shed for 7-10 days after onset of sx
self-limited with resolution in 7-10 days
infection can be uni or bilateral
Pink eye prevention - workers
working should be excluded from patient care during duration of illness
