E2- Viral Skin Infections Flashcards
In which populations can Measles be severe in?
Can be severe in malnourished and/or vitamin A deficient persons
What is the causative agent of measles?
Rubeola
What are the four stages of Measles infection?
- Incubation
- Prodromal
- Rash
- Resolution
Where does Measles replicate?
Measles disseminates to other tissues by what?
Respiratory epithelium and lymph nodes
Monocytes
Multiplication of virus in respiratory epithelium and lymph nodes and dissemination to other tissues by monocytes is seen in which stage of Measles?
Incubation period
What is the characteristic presentation in the prodromal stage of Measles?
High fever
Coryza, persistent cough, conjunctivitis (the 3 Cs)
Koplik’s spots on buccal mucosa (diagnostic)
What is diagnostic for Measles?
Koplik’s spots on buccal mucosa
When does a Measles rash appear?
3-4 days after prodrome initiates
What is seen in the rash stage of Measles?
Highest fever (sickest patient) Begins below ears, spreads
What is seen in the resolution stage of Measles?
Rise in antibody titers, viremia stops
Rash fades in same order that it appears
What are complications of Measles?
Pneumonia
Diarrhea
CNS involvement (Encephalitis)
What is the most common cause of Measles death?
Pneumonia (bacterial superinfection common)
What CNS effects can Measles cause?
Acute symptomatic encephalitis
High fatality rate
SSPE - subacute sclerosing panencephalitis (very rare in U.S.)
Besides humans, what is the only other species that can act as a Measles host?
Monkeys
Is there a healthy carrier state of Measles?
NO
What age group is most commonly affected by Measles?
Disease of children (most immune by age 10)
Rare in infants under 6 mo (maternal immunity)
How is Measles transmitted?
Respiratory droplets (highly contagious)
How is Measles dx?
Rash and/or Koplik’s spots
Serology
Fluorescent antibody test on cells obtained from swabs of pharynx, nasal and buccal cavities
(multi-nucleated giant cells)
How is Measles controlled?
MMR vaccine
What can you use for patients exposed to measles who are non-immune subjects?
Immune globin (BayGam) - must be used within 6 days of exposure
When is the MMR vaccine given?
15 months -first dose
4-6 -second dose
+/- 3rd dose
May vaccinate children under 15 mo with monovalent measles vaccine if exposure is likely
What type of MMR vaccine is used in the US?
MMR II
Live, attenuated vaccine, not suitable for all patients
What percent of the population must be vaccinated to halt Measles persistence in the population?
95%
What is the most common cause of Measles outbreaks in the US?
Non-vaccinated person and air travel to foreign locations
What is the causative agent of German Measles?
Rubella
What is probably needed for Rubella infection?
Close and prolonged contact
many children often escaped infection
Maternal infection (viremia) during _____ may lead to placental infection and fetal infection.
First trimester of pregnancy
What is a complication of Rubella?
Congenital Rubella Syndrome (CRS)
How does Congenital Rubella Syndrome (CRS) present?
Cardiac defects
Eye defects (cataracts, glaucoma)
Hearing loss
CNS involvement
Who should never receive the MMR vaccine?
Pregnant women (especially in first trimester; live vaccine)
If non-immune mother is exposed to Rubella, what may you give prophylatically?
Immunoglobin (IVIG)
What two properties influence the disease capacity of HSV?
Capacity to invade and replicate in CNS
Ability to establish latent infections