Childhood viral infections Flashcards
Give 6 notifiable diseases which must be reported to public health England?
1) Acute meningitis
2) Acute poliomyelitis
3) Measles
4) Mumps
5) Rubella
6) Small pox
What is the difference in productions of IgM and IgG in response to infection?
IgM is produced in acute infection - will rise in acute infection
IgG provides long term immunity - will be raised following infection and last for longer
How can measurements of immunoglobulins be used in identifying infection?
Detection of IgG tells you the person has had the infection in the past
NB. some early acute infections will have negative serology and pts may need to be tested a few days later to see if their is any rise if IgM
Which kind of Ab is found in breast milk?
IgA
Name 7 possible causes of a rash in a child?
1) Parovirus
2) Measles
3) Chickenpox
4) Rubella
5) Non-polio enterovirus infection
6) Epstein Barr Virus (with ampicillin)
7) Bacterial causes such as staphylococcus aureus, N. meningitidis
When can Epstein Barr virus present with a rash?
When patients are given penicillin based Abx
Nb. if patients tell you they get a rash with penicillin it is important to note if that was because they had EBV
Which virus causes measles and what kind is it?
Paramyxovirus
Enveloped single stranded RNA virus
How is the measles virus spread?
Person to person, droplet spread
When is a person with measles infectious?
From start of the first symptoms (4 days before rash to 4 days after disappearance of rash)
What is meant by viral incubation?
The amount of time it takes for symptoms of a disease to appear after an individual is infected
What is the incubation period of the measles virus?
7-18 days (average 10-12)
Are humans the only natural host of the measles virus?
No
What are the clinical features of measles?
Fever Malaise 3C's: Conjunctivitis, cough and coryza Rash Koplik's spots 1-2 days before the rash
Define coryza?
Catarrhal inflammation of the mucous membranes in the nose (runny nose)
What are Koplik’s spots?
Small white spots seen on the tongue 1-2 days before a rash appears in a measles infection, only seen in measles
What kind of rash is seen in measles?
Erythematous, maculopapular, head to trunk
Define erythematous rash?
red rash
Define maculopapular rash?
Type of rash characterised by a flat, red area on the skin that is covered in small confluent bumps
What are the 4 less rare possible complications of measles?
1) Otitis media (inflammation of the middle ear)
2) Pneumonia (unlike bacterial pneumonia cant be cured by Abx)
3) Diarrhoea
4) Acute encephalitis - rare but fatal
Name 1 very rare and fatal complication of measles?
Subacute sclerosing panencephalitis, 1/25000, occurs 7-30 years after measles
What is the severity of measles infection in pregnancy?
Severe - up to 20% foetal losses
In which groups is death from measles highest?
-add-
What 4 factors can play a role in the diagnosis of measles?
1) Clinical
2) Leukopenia
3) Oral fluid sample
4) Serology
What is the treatment for measles?
Supportive
Abx for superinfection
What measures are put into place for prevention of measles?
MMR vaccine
Human normal immunoglobulin can be given to people who are immune compromised and at risk of infection
What kind of vaccine is the MMR vaccine, when is it given?
Live vaccine
Given 1 year and a booster at pre school
What virus causes chicken pox and what kind is it?
Varicella zoster virus
Herpes virus - DNA virus
How is chicken pox virus transmitted?
Respiratory spread/ personal contact (face to face/ 15 mins)
What is the incubation period of the chicken pox virus?
14-15 days
What is the infectivity period of the chicken pox virus?
2 days before the onset of rash until after vesicles dry up
Are humans the only host for the chicken pox virus?
Yes
How can chicken pox lead to shingles?
Both caused by the varicella zoster virus
Chicken pox infection tends to occur in childhood, the virus remains dormant in the dorsal root ganglion
In some people the virus can re-present as shingles which is a rash confined to one dermatome, which is painful.
What kind of rash occurs in Varicella zoster virus infection (chicken pox)?
Macular - popular - vesicular - pustular
What is meant by a vesicular rash?
A rash featuring small blisters on the skin
What are the 4 main clinical features of varicella zoster virus infection?
1) Fever
2) Malaise
3) Anorexia
4) Rash
What are the 6 possible complications of varicella zoster virus infection?
1) Pneumonitis (risk increased for smokers)
2) Central nervous system involvement
3) Thrombocytopenic purpura (rare blood disorder, blood clots form in small vessels)
4) Foetal varicella syndrome (child born with cutaneous scars and limb defects etc. due to intrauterine infection)
5) Congenital varicella (child with abnormalities at birth due to pregnant mother infection)
6) Zoster (another name for shingles)
6) Zoster
What 2 factors can play a role in diagnosis of varicella zoster virus?
1) Clinical diagnosis
2) PCR - vesicle fluid/CSF
How are non-immune pregnant women protected against varicella zoster virus infection?
IgG given to pregnant women in contact with VZV and no history of chicken pox
Which groups of people are given treatment for varicella zoster infection and what is that treatment?
Symptomatic adults and immunocompromised children given treatment:
1) Aciclovir oral, IV in severe disease or neonates
2) Chlorpheniramine can relieve itch (>1 year olds)
Who is given a vaccine for varicella zoster virus and what kind is it?
Live vaccine, given in 2 doses
Given to everyone in US and Japan
In UK given to healthcare workers and susceptible contacts of immunocompromised patients
For what 3 possible reasons could varicella zoster virus immunoglobulin be given, what should be noted about its use?
) Significant exposure
2) A clinical condition that increases the risk of severe varicella eg. immunosuppressed patients, neonates and pregnant women
3) No Abs to varicella zoster virus
Ig does not prevent infection in all, reduces severity
Which virus causes rubella and what kind is it?
Togavirus, an RNA virus
How is rubella transmitted?
Droplet spread - air-bourne
Less contagious than VZV and measles
What is the incubation period of rubella?
14-21 days
What is the period of infectivity of rubella?
One week before rash to 4 days after
Define prodrome?
An early symptom indicating the onset of illness
What are the clinical features of rubella? 3
Prodrome - non specific
Lymphadenopathy - post-auricular, suboccipital
Rash
What kind of rash occurs in rubella?
Very non specific, transient, erythematous, behind ears and face and neck