Childhood Viral Infections Flashcards Preview

Clinical Pathology > Childhood Viral Infections > Flashcards

Flashcards in Childhood Viral Infections Deck (58):
1

What are the different types of childhood viral infections?

- Asymptomatic / Subclinical infection
- Fever and a rash
- Respiratory tract infections
- Gastro-intestinal infections
- Others – mumps
- meningitis/encephalitis
- EBV/CMV
- HIV and viral hepatitis

2

Which of the childhood viral diseases are notifiable?

- Acute meningitis
- Acute poliomyelitis
- Measles
- Mumps
- Rubella
- Smallpox

- Report must be made upon clinical diagnosis by diagnosing clinician

3

Which Ig is produced in acute infection?

IgM

4

Which Ig is produced long-term following an infection?

IgG (IgA in breast milk)

5

Which of the viral diseases cause rashes?

- Parvovirus
- Measles
- Chickenpox
- Rubella
- Non-polio enterovirus infection
- EBV (with ampicillin)
- (not forgetting bacterial causes such as Staphylococcus aureus, N. meningitidis)

6

To which family of viruses does measles belong?

Paramyxovirus

7

What type of virus is measles?

Enveloped single stranded RNA virus

8

What is the mode of transmission for measles?

Person to person
Droplet spread

9

What is the infectivity of measles?

From start of first symptoms (4 days before rash to 4 days after disappearance of rash.

10

What is the incubation period for measles?

7-18 days (average 10-12)

11

What are the clinical features of measles?

- Prodrome - Fever, malaise, conjunctivitis, coryza and cough (3’c’s)
- Rash - Erythematous, maculopapular, head – trunk,
- Koplik’s spots - 1-2 days before rash.
- Fever
- Infection in the immunocompromised
- Rash + fever + cough/coryza/conjunctivitis

12

What are Koplik's spots?

prodromic viral enanthem of measles manifesting two to three days before the measles rash itself. They are characterized as clustered, white lesions on the buccal mucosa (opposite the lower 1st & 2nd molars) and are pathognomonic for measles.

13

What is coryza?

Rhinitis

14

What are the complications of measles?

- Otitis media (7-9%)
- Pneumonia (1-6%)
- Diarrhoea (8%)
- Acute encephalitis – rare but fatal (1 in 2000)
- Rarer complications
- Subacute sclerosing panencephalitis (SSPE)
1/25000
- Rare, fatal, late (7-30 years after measles)
- Death – highest in

15

At what ages do most complications occur?

Under 5 years or over 20.

16

How may measles be diagnosed?

- Clinical
- Leukopenia
- Oral fluid sample
- Serology

17

What is the treatment for measles?

- Supportive
- Antibiotics for superinfection

18

How can measles be prevented?

- Vaccine – live MMR
- 1 year / pre-school

- Human normal immunoglobulin
- pregnant

19

Which virus causes chicken pox?

Varicella zoster

20

What kind of virus is the varicella zoster virus?

DNA virus

21

What is the route of transmission for the varicella zoster virus?

Respiratory spread/personal contact (face to face/15mins)

22

What is the incubation period for chicken pox?

14-15 days

23

What is the period of infectivity for chicken pox?

2 days before onset of rash until after vesicles dry up.

24

Does chicken pox have any animals hosts?

No - only humans

25

What are the clinical features of varicella?

Fever, malaise, anorexia
Rash – centripetal
macular > papular > vesicular > pustular

26

What are the possible complications of chicken pox?

- Pneumonitis (risk increased for smokers)
- Central nervous system (CNS) involvement
- Thrombocytopenic purpura
- Foetal varicella syndrome
- Congenital varicella
- Zoster

27

How is chicken pox diagnosed?

- Clinical
- PCR –vesicle fluid/CSF

28

How is serology used in chicken pox?

- Immunity testing
- IgG in pregnant women in contact with VZV and no history of chickenpox

29

How is chicken pox treated?

- Symptomatic adults and immunocompromised children

- Aciclovir oral, iv in severe disease or neonates.

- Chlorpheniramine can relieve itch (>1 yr olds)

30

How might chicken pox be prevented?

- Vaccine – live, 2 doses (USA/Japan)
- Health care workers
- Susceptible contacts of immunocompromised pts

- VZ Immunoglobulin (VZIG) given if:
- significant exposure
- a clinical condition that increases the risk of severe varicella e.g. immunosuppressed patients, neonates and pregnant women
- no antibodies to VZ virus
- Ig does not prevent infection in all, reduces severity

31

What kind of virus is rubella?

Togavirus, RNA virus

32

What is the route of transmission for rubella?

Droplet spread – air-borne

Less contagious

33

What is the incubation period for rubella?

14-21 days

34

What is the period of infectivity for rubella?

One week before rash to 4 days after.

35

What are the clinical features of rubella?

- Prodrome – non-specific
- Lymphadenopathy – post-auricular, suboccipital
- Rash - very non specific transient, erythematous, behind ears and face and neck.
- Complications
- thrombocytopenia;
- post infectious encephalitis;
- arthritis
- 50% of infectious children are asymptomatic.

36

What are the features of congenital rubella syndrome?

Congenital rubella syndrome (CRS)
- cataracts and other eye defects
- deafness
- cardiac abnormalities
- microcephaly
- retardation of intra-uterine growth
- inflammatory lesions of brain, liver, lungs and bone marrow.

CRS more severe when infection contracted earlier in pregnancy.

Foetal damage rare after 16/40; only deafness reported up to 20/40

37

What are the risks of intra-uterine transmission during different stages of pregnancy?

Less than 11 weeks - 90%
11-16 weeks - 20%
16-20 weeks - minimal risk, deafness only
>20 weeks - no increased risk


38

How is rubella diagnosed?

- Oral fluid testing – IgM/G (PCR if within 7 days of rash).

- Serology – IgM and IgG. Antibodies detectable from time of rash.

- IgM positive for 1-3 months – implications in pregnancy.

39

What treatment is available for rubella?

- No treatment available – immunoglobulin given to exposed pregnant women.

- Vaccine - initially 11-14 year olds. Now part of MMR.

- 2-3% women of child bearing age remain susceptible.

40

What disease is caused by parvovirus B19?

'Slapped cheek' or 'fifth disease'.

41

What kind of virus is parvovirus B19?

DNA virus

42

How is parvovirus B19 transmitted?

Respiratory secretions or from mother to child.

43

What's the incubation period for parvovirus B19?

4 to 14 days

44

Why should pregnant women avoid parvovirus B19?

Risk of miscarriage in early pregnancy - but low

45

What are the symptoms of foetal parvovirus B19

- Anaemia
- Hydrops

46

What are the clinical features of parvovirus B19?

- Minor respiratory illness
- Rash illness ‘slapped cheek’
- Arthralgia
- Aplastic anaemia
- Anaemia in the immunosuppressed

47

How is parvovirus B19 diagnosed?

- Serology IgM/IgG – 90% have IgM at time of rash
- Amniotic fluid sampling
- PCR in immunocompromised

48

How is parvovirus B19 treated?

None if self limiting illness
Blood transfusion
No vaccine available

Infection control – difficult as infectious prior to arrival of the rash and significant number of cases are subclinical.

Pregnant HCWs should avoid chronic cases.

Not a notifiable disease

49

What are the features of enteroviral infections?

- Coxsackie, entero, echoviral infections.
- Worldwide, prevalent in under 5 year olds.
- 90% asymptomatic.
- Transmission is faecal-oral and by skin contact.
- Hand, foot and mouth disease.
- Fever-rash syndromes.
- Meningitis – PCR of CSF.
- Supportive management and good hygiene to prevent transmission.

50

Which viruses cause respiratory disease in children?

- Respiratory Syncytial Virus
- Parainfluenza
- Influenza
- Adenovirus
- Metapneumovirus
- Rhinovirus

51

What kind of virus is respiratory syncytial virus (RSV)?

Pneumovirus

52

What are the clinical features of RSV?

- Bronchiolitis
- Under 1 year olds (0-24 months)
- Annual winter epidemics, incubation 4-6 days.
- Can be life threatening
- Reinfections common

53

How is RSV diagnosed?

PCR on secretions from nasopharyngeal aspirate.

54

What is the treatment for RSV?

- O2, manage fever and fluid intake.
- Previously used treatment such as Bronchodilators/steroids are no longer recommended.
(immunoglobulin and monoclonal abs - Palivizumab)

55

What are the features of metapneumovirus?

- Recently discovered virus
- Paramyxovirus
- Nearly universal by aged 5.
- Causes respiratory illness similar to RSV – ranges from mild upper respiratory tract infection to pneumonia.
- Dx – PCR
- Rx – supportive only

56

What are the features of adenovirus?

- Accounts for 10% childhood respiratory infection.
- Clinical disease mild URTI (occ. Severe pneumonia)
conjunctivitis
(diarrhoea – serotypes 40/41)
- Dx Respiratory panel PCR
Eye swab PCR
Serology possible
- Rx None/ cidofovir in immunocompromised

57

What are the features of parainfluenza?

- Paramyxovirus
- 4 types 1-4 1 in winter
3 in summer
- Transmission - person to person; inhalational
- Clinical - croup/bronchiolitis/URTI
- Dx - Multiplexed PCR
- Rx - none (unlike influenza)

58

What are the features of rhinovirus?

- Member of picornaviridae
- ‘The common cold’
- Found in approximately 70% children with mild upper respiratory tract symptoms.
- Similar clinical features – coronavirus, human bocavirus, enterovirus, adenovirus

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