L 64 Viral Skin Disease 1 Rubeola/Rubella Flashcards
Difference between rubeola and rubella
Rubeola= measles Rubella= german measles
Measles reservoir
No known natural reservoir, thought to be a disease of civilization. Humans only.
Measles incubation period
10-14 days
How is measles spread?
Sets up shop in the respiratory epithelium, virus spread through respiratory droplets that remain in environment for considerable amount of time
Measles Prodromal stage
1-12 days post infection
Fever, Coryza, cough, conjunctivitis
Koplick’s spots on buccal mucosa pathognomonic for measles
When does measles rash appear? What accompanies it?
3-4 days after exposure
Starts below ears, spreads to face and then down
High fever accompanies it
When is it best to get measles?
Better to get while young, like polio, because much of the unpleasant symptoms come from the reaction of the immune system so an immature immune system will not react so severely
Atypical measles
First vaccine produced antibodies that actually didn’t completely inactivate the virus and instead sensitized the person to the virus so when they encountered the actual virus they got a sickness worse than if they had not received the vaccine.
Second vaccine fixed this problem.
Complications of measles
Measles would often lead to secondary complications
Pneumonia–most common and life threatening
Diarrhea–in children
Used to cause death in many cases and rarely encephalitis
SSPE: subacute sclerosing panencephalitis, fatal complication, child would get better, but virus would remain in the brain and grow slowly and eventually cause death, now extinct
Immune depression: can cause TB exacerbation
Why did lots of other diseases drop off after introduction of measles vaccine?
Stopping measles stopped a significant drop in immunity in kids and prevented them from getting lots of other diseases
Measles type of virus
Paramyxovirus
Enveloped
ssRNA
Measles trasmission
Respiratory droplets
HIGHLY contagious, surprisingly able to find those who are not vaccinated
Likes drier climates
What vitamin can reduce severity of measles infection?
Vitamin A helps
When is patient most contagious?
During prodrome until 4-5 days after rash erupts
Does vaccination to measles last a lifetime?
It is questionable, not entirely perfect
Measles diagnosis
Rash and Koplick’s spots
IgM antibody capture ELISA
Swabs of mouth show multinucleated giant cells
Measles treatment
Treat the symptoms
No antiviral therapy
Measles control
MMR-II vaccine
Live attenuated
Given in 2 doses at least 1 month apart
Contraindications: egg sensitivity, pregnancy, immunocompromised
Not all MMR’s used around the world are the same
How do most people in US get measles?
Usually from travel
Not from immigrants
What can be done to protect someone who can’t receive the vaccine?
BayGam immunoglobulin can be given to help protect them
How is rubella different from measles?
Like measles, but very mild in comparison
Rubella clinical manifestations
14-21 day incubation Minimal prodromal Rash face then down body Mild fever, conjunctivitis, coryza Spread through respiratory
How is rubella spread?
Respiratory
Prolonged and close contact probably needed
Measles would find everyone in their youth, but rubella was less aggressive
Rubella type of virus
Togavirus
Rubella epidemiology
Usually infects older children, adolescents, young adults
Young children often escape infection
Rubella complications
Usually a benign infection except for CRS
CRS: Congenital Rubella Syndrome= mother infected while pregnant, spreads through placenta to fetus during first trimester and causes major malformations–cardiac, eye, hearing, CNS
How was CRS found?
Cataracts found in newborns
Rubella diagnosis
Serology detection of antibody
Rubella treatment and prevention
Symptomatic relief
Isolate patients for 7 days after rash
Kids with CRS infectious for at least 1 year
MMR vaccine is live attenuated, some kids get a rash, contraindicated in pregnancy
Why do we get a rubella vaccine if it is concidered a “nothing” disease?
It is to protect the next generation by preventing infection of mothers and thereby newborns to prevent CRS
