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 IgM tells you the person currently has the 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?
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?
1) 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
What are the 3 possible complications in rubella?
1) Thrombocytopenia
2) Post infectious encephalitis
3) Arthritis
What percentage of children with rubella are asymptomatic?
50%
What are the 6 features of congenital rubella syndrome?
1) Cataracts and other eye defects
2) Deafness
3) Cardiac abnormalities
4) Microcephaly
5) Retardation of intra-uterine growth
6) Inflammatory lesions of the brain, liver, lungs and bone marrow
When is congenital rubella syndrome more severe?
When infection is contracted earlier in pregnancy
Foetal damage is rare after 16/40, only deafness reported up to 20/40
Risk less than 11 weeks transmission: 90%
Risk 11-16 weeks transmission: 20%
Risk 16-20 weeks: minimal, deafness only
Risk >20 weeks transmission: no increased risk
How is rubella diagnosed?
Oral fluid testing - IgM/G (PCR is within 7 days of rash)
When are Ab detectable in rubella infection?
IgM and IgG detectable
Ab detectable from time of rash
IgM positive for 1-3 months - implications in pregnancy
Is there any treatment for rubella?
No treatment available, immunoglobulin given to exposed pregnant women
Is rubella vaccinated against?
Yes - MMR
initially this was only for 11-14 year olds, 2-3% of women of child bearing age remain susceptible
What virus causes ‘slapped cheek’ or ‘fifth disease’ or parovirus B19, and what kind of virus is it?
B19 - a DNA virus
How is B19 virus transmitted?
Transmitted by respiratory secretions or from mother to child
What is the incubation period of parovirus B19?
4-14 days
In what percentage of people is parovirus B19 asymptomatic?
20%
What are the consequences of foetal parovirus B19? 2
Anaemia - can be treated with foetal transfusion
Hydrops (accumulation of fluid in 2 or more fetal compartments)
What are the consequences of parovirus B19 infection in pregnancy?
Risk of miscarriage in early pregnancy but this is low
What are the 5 clinical features of parovirus B19?
Minor respiratory illness Rash illness (looks like slapped cheeks) Arthralgia (joint pain) Aplastic anaemia (deficiency of all types of blood cells) Anaemia in the immunosuppressed - can be prolonged
What 3 factors aid diagnosis of parovirus B19?
1) Serology IgM/IgG - 90% have IgM at time of rash
2) Amniotic fluid sampling
3) PCR in immunocompromised
What is the treatment for Parovirus B19?
None if self limiting
Blood transfusion
Is their a vaccine for parovirus B19?
no
How can infections of Parovirus B19 be controlled?
Difficult as infectious prior to the arrival of the rash an significant number of cases are sub clinical
pregnant healthcare workers should avoid chronic cases
What are enteroviruses?
Viruses so named because they reproduce initially in the GI tract after infections
What 3 diseases can be caused by enteroviruses?
1) Hand, foot and mouth disease
2) Fever-rash syndromes
3) Meningitis - PCR of CSF to detect
What percentage of enteroviral infections are asymptomatic?
90%
How are enteroviral infections transmitted?
Faecal oral route and by skin contact
How are enteroviral infections treated?
Supportive management and good hygiene to prevent transmission
Give 6 viruses which commonly cause respiratory symptoms in children?
1) Respiratory syncytial virus
2) Parainfluenza
3) Influenza
4) Adenovirus
5) Metapneumovirus
6) Rhinovirus
Respiratory syncytial virus is from what genus and causes what disease?
Its a pneumovirus
Can cause bronchiolitis in under 1 year old which can be life threatening, reinfections are common
How is respiratory syncytial virus diagnosed?
PCR on secretions from nasopharyngeal aspirate
What is the therapy of respiratory syncytial virus?
O2, manage fever and fluid intake
Previously used treatment such as bronchodilators/steroids are no longer recommended
Immunoglobulin and monoclonal Ab - palivizumab
Metapneumovirus is from what genus and what sort of disease does it cause?
Paramyxovirus
Causes respiratory illness similar to RSV, ranges from mild upper respiratory tract infection to pneumonia
How is metapneumovirus diagnosed?
PCR
What is the therapy for metapneumovirus?
Supportive only
What percentage of childhood respiratory infection does adenovirus account for?
10%
What clinical features does adenovirus cause?
1) mild URTI - occasionally severe pneumonia
2) Conjunctivitis
3) Diarrhoea
How is adenovirus diagnosed? 3
Respiratory panel PCR
Eye swab PCR
Serology possible
What is the therapy for adenovirus infection?
None or cidofovir in immunocompromised
What genus does parainfluenza virus belong to?
paramyxovirus
How many types of parainfluenza virus are there?
4
1 in winter
3 in summer
How is parainfluenza virus transmitted?
Person to person - inhalational
What are the 3 clinical features of parainfluenza virus?
1) Croup
2) Bronchiolitis
3) URTI
How is parainfluenza virus infection diagnosed?
Multiplexed PCR
What is the therapy for parainfluenza virus?
There is no therapy
Rhinovirus causes what?
Common cold
Which 4 viruses cause similar clinical features to rhinovirus?
1) Coronavirus
2) Human bocavirus
3) Enterovirus
4) Adenovirus
What genus does rhinovirus belong to?
Picornaviridae
Rhinovirus is found in what percentage of children with mild upper respiratory tract symptoms?
70%
What 2 viruses commonly cause diarrhoea in children?
Rotavirus
Norovirus
What type of virus is rotavirus?
RNA virus
How is rotavirus transmitted?
Faecal-oral route and occasionally respiratory - has a low infective dose
What is the incubation period of rotavirus?
1-2 days
What are the clinical features of rotavirus?
Diarrhoea and vomiting, shows seasonal variation, most common in 6/12-2years
Increased mortality in poorer countries
How is rotavirus diagnosed?
PCR
What is the treatment for rotavirus?
Rehydration
How Is rotavirus prevented?
Oral live vaccine, Given at 2 and 3 months of age
How is norovirus spread?
Food bourne virus - person to person spread
What are the clinical features of norovirus?
High incidence of vomiting, short course - 12-60 hours
How is norovirus diagnosed?
PCR
How is norovirus treated?
Rehydration
What family does the mumps virus belong to?
Paramyxoviridae family
How is the mumps virus transmitted?
Direct contact, droplet spread, fomites (objects or materials that are likely to carry infection)
What is the period of infectivity of the mumps virus?
Several days before parotid swelling to several days after
What is the incubation period of the mumps virus?
2-4 weeks (mostly 16-18 days)
What are the clinical manifestations of mumps?
Prodrome - non specific eg. low grade fever, anorexia, malaise and headache
Next 24 hours - earache, tenderness over ipsilateral parotid
Next 2-3 days - gradually enlarging parotid with severe pain (normally bilateral but can be unilateral in 25%)
Pyrexia up to 40 degrees
After peak swelling, pain, fever and tenderness rapidly resolve and the parotid gland returns to normal size within one week
What are the 7 rare manifestations of the mumps virus?
1) Submandibular and/or sublingual sialadenitis (inflammation of a salivary gland)
2) Epididymo-orchitis (inflammation or epididymis and/or testis)
3) Oophoritis (inflammation of an ovary)
4) Meningitis
5) Encephalitis
6) Renal function abnormalities (mild)
7) Pancreatitis
What is the most common extrasalivary gland manifestation of mumps?
CNS involvement
What is the most common extrasalivary manifestation of mumps in adults?
Epididymo-orchitis
What are the consequences of mumps infection in pregnancy?
Infection in first trimester - increased foetal death
What investigations aid diagnosis of mumps?
Have a normal white cell count Raised serum amylase - salivary or pancreatic Normally clinically diagnosed Serology IgM - blood and saliva PCR
What is the treatment for mumps?
Symptomatic treatment
Is there a vaccine for mumps?
Yes, MMR
Which 7 viruses can cause neonatal/congenital infection?
1) Varicella zoster virus
2) Rubella
3) Cytomegalovirus
4) Toxoplasma
5) Herpes simplex virus
6) Hepatitis B virus
7) HIV
What are the symptoms of congenital cytomegalovirus infection? 3
Growth retardation, deafness, blindness
What are the clinical features of toxoplasma congenital disease? 2
Chorioretinitis (inflammation of the choroid and retina of the eye)
Hydrocephaly
What is given to neonates born to mothers with hepatitis B infection?.
Hep B immunoglobulins/vaccine for neonate
What 3 parts of the history from parents are very important when a child presents with a possible viral infection?
1) Vaccination history
2) Travel history
3) Contact history
