Paramyxovirus and Rubella Flashcards
Describe the structure of Paramyxovirus
Negative sense single-stranded RNA viruses, Helical Nucleocapsid, Enveloped virus
What is Paramyxovirus susceptible to as an enveloped virus?
drying, acid, detergents, and hand sanitizers
How is Paramyxovirus spread?
Primarily by respiratory secretions, person-to-person, fomites, and hands
All paramyxoviruses are considered ______ viruses
contagious
The paramyxovirus infected cell can fused membranes of neighboring cells to form a large multinucleated cell called a ________
syncytium
Syncytia are a common feature of paramyxoviruses. Virsues that can use syncytium to spread cell to cell can more easily…..
escape neutralizing antibodies
Respiratory syncytial virus (RSV) is spread how? Does it have seasonality?
Spread is person-to-person via respiratory droplets with winter/spring seasonality, Nov. to April
What type of infection is RSV?
RSV is a local infection, it has a short incubation time and starts with an upper repertory tract infection
If RSV spreads to the middle and lower respiratory tract, what can occur?
A more severe disease like bronchiolitis or pneumonia can occur
RSV is restricted to ________ cells and spread through the respiratory tract mostly by…..
epithelial; cell-to-cell spread or aspiration of upper respiratory tract secretions
What is the #1 cause of lower respiratory tract infections in children <1 yr old and <5 yr olds, and the primary cause of bronchiolitis in children <1 yr old
RSV
Why does RSV cause a high risk of severe complication in premature infants?
Because they have less developed lungs and not as many maternal antibodies
What other age group also has a very high burden or RSV infections?
Older people >65
RSV infections happen at all ages but are worse in….
infants and the elderly
Describe the immunity to RSV
Immunity is not long-lasting, and it is possible to get reinfected with the same strain
Why do elderly have a high risk of pneumonia with RSV?
-Because of waning immunity and underlying comorbidities
-This can lead to increased severity of the infection
What happens to older children and adults who get infected with RSV?
Usually have mild upper respiratory tract infections, probably due to partial immunity; they still get sick; just not as bad, or are asymptomatic
Is there a vaccine for RSV?
There is a new vaccine for people 60 or greater and pregnant people. The idea of vaccinating pregnant people is to have maternal ab spread to the infant
_______ can be used as a treatment for RSV but it not that effective
Ribavirin
One preventative tx for RSV is _______, a monoclonal antibody to the surface protein of RSV
Palivizumab
-It is costly, only given to certain preterm infants, and only in the RSV season
-Does help reduce RSV hospitalizations
What is Human Metapneumovirus (HMPV)
Another paramyxovirus similar to RSV (but tends to infect slightly older children)
What is Parainfluenza Virus (PIV)?
Another paramyxovirus that causes a respiratory infection
What are the general characteristics of PIV?
-Spread via respiratory droplets
-Local infection
-Shorter incubation time
-Enveloped virus
-Considered ‘contagious’
________ is the primary cause of croup (inflammation of the larynx and trachea)
Parainfluenza (PIV)
What can PIV cause in young children?
Sever lower respiratory tract infections
Is there immunity to parainfluenza?
Partial immunity to reinfection, you can still get reinfected, but generally milder and stay in the upper respiratory tract or is an asymptomatic infection
How does Parainfluezna affect adults? The elderly?
-Adults are commonly infected but have mild symptoms
-It is not known how it affects the elders
PIV can cause severe illness in the ________
immunocompromised
Describe the general characteristics of Mumps
-A generalized/systemic infection
-That means longer incubation times, the virus can affect several different parts of the body, and has a viremic stage
How does Mumps spread?
By the respiratory route via saliva
What is the major defining characteristic of mumps?
-Parotitis (swelling of the parotid gland)
-Orchitis (testicular swelling) (Testicular swelling rarely leads to sterility but can lead to lower fertility
When is a person with Mumps infectious?
A few days before symptoms
Pre-vaccine mumps was a major cause of ______ and _______
encephalitis and meningitis
Mumps can also cause unilateral _________, either permanent or temporary
hearing loss
What type of vaccine is the vaccine we have for MMR?
attenuated live virus
Why have older adolescents or college-age students having MMR outbreaks recently, even if vaccinated?
Probably due to waning vaccine immunity and crowded living conditions
If someone who is vaccinated contracts mumps, there are fewer _________
complications
What type of infection is Measles?
-A paramyxovirus with a generalized/systemic infection
-Measles has a longer incubation time and a viremic stage
How is Measles spread?
Through the respiratory route and can be aerosolized (Measles aerosols can stay in the air for 2 hours)
Measles is (asymptomatic/symptomatic)
Symptomatic
-Very few are asymptomatically infected
People who are infected with Measles are infectious (before/after) the measles rash
Before
What percentage of susceptible people who come into contact with someone who has measles will become infected?
90%
What are the 3 C’s of measles with high fever?
Cough
Coryza
Conjunctivitis
What are Koplik spots?
Pathognomonic of measles - 1 to 2 days before the rash, Koplik spots appear
Where do Koplik spots appear?
On the buccal membrane, often opposite 2nd molars, and can cover the entire mucous membrane of the mouth
How are Koplik spots described?
As grains of sand or salt surrounded by a red halo, sometimes also described as having a bluish cast
What causes the measles rash?
Cytotoxic T cells killing measles-infected cells
When might the measles rash NOT be present?
In immunocompromised people
There is a very high measles death rate in the ________
immunocompromised
There is a high rate of _______ with measles
hospitalizations
-Many hospitalized patients have pneumonia, and most deaths are from pneumonia
_________ can occur with a moderate death rate. However, survivors can have permanent neurological complications
Encephalitis
___________ can occur many years after measles infection. ______ leads to coma and death. It is rare in measles and seems to happen more when infected before the age of 2.
Subacute sclerosing panencephalitis (SSPE); SSPE
What type of vaccine is the measles vaccine?
Live-attenuated
(part of MMR)
When does the measles vaccine need to be given?
At 1 year of age. If given earlier, maternal antibodies can interfere with vaccine efficacy
What is the post-exposure prophylaxis for measles
1) Vaccine, if given up to 72 hours after exposure, may prevent disease
2) Immune globulin (IG) may prevent or modify the disease if given up to 6 days after exposure.
Describe the structure of Rubella
Togavirus +ssRNA icosahedral virus, enveloped and inactivated the same was as paramyxoviruses
What does Rubella cause?
German measles/3-day measles
How is Rubella spread?
Respiratory droplets
What type of infection is Rubella?
Systemic infection/Not a local infection, with longer incubation times
Rubella infections are (asymptomatic/symptomatic)
Many infections are asymptomatic
When is a person with Rubella infectious?
A week before and a week after the rash
What are the symptoms of Rubella?
-Many of the same symptoms of Measles but milder and post-auricular lymphadenopathy occur before the rash
-The rash lasts only 3 days and again is milder than Measles
Some people who have rubella have _________ on the soft pallet
Forchheimer spots
(However, this is not pathognomonic of rubella. Other diseases also have petechia on the soft pallet)
Rubella causes __________ if infected during the first trimester of pregnancy up to 20 weeks
congenital rubella syndrome
What did the rubella outbreak in the 60s lead to?
-Large number of neonatal deaths
-Miscarriages
-Congenital rubella syndrome that included deafness, blindness, cognitive impairment, and cardiac problems
What type of vaccine is the vaccine for rubella?
Live-attenuated vaccine
(part of MMR)
