Paediatric Viral Diseases Flashcards
(97 cards)
1
Q
Why are different strains of viruses important?
A
Immunity against one strain does not protect against other strains, e.g. rhinovirus
Viruses can continually evolve to form new strains, e.g. influenza
2
Q
How is measles transmitted?
A
Airborne
3
Q
How is diphtheria transmitted?
A
Saliva
4
Q
How is smallpox transmitted?
A
Airborne droplet
5
Q
How is polio transmitted?
A
Faecal-oral route
6
Q
How is rubella transmitted?
A
Airborne droplet
7
Q
How is mumps transmitted?
A
Airborne droplet
8
Q
How is HIV/AIDS transmitted?
A
Sexual contact
9
Q
How is pertussis transmitted?
A
Airborne droplet
10
Q
How is SARS transmitted?
A
Airborne droplet
11
Q
How is influenza transmitted?
A
Airborne droplet
12
Q
How is ebola transmitted?
A
Bodily fluids
13
Q
What are the different ways viruses are acquired and spread?
A
Respiratory
Faecal-oral
Close exposure/skin or mucous membrane contact
Contact with blood
Animal vectors
14
Q
How are viruses spread by respiratory pathways?
A
Droplets - contaminated environment, exposure to mucous membranes
Aerosol - breathed directly in
15
Q
How are viruses spread by faecal-oral route?
A
Food and water
Contaminated environment
e.g. norovirus, enterovirus, hepA, hepE
16
Q
What are examples of blood-borne viruses and how are they spread?
A
HIV, HepB, HepC
Contamination of cuts
Inoculation of mucous membranes
Through the skin - ‘needlestick injury’
17
Q
How can the risk of spreading blood-borne viruses be reduced?
A
Universal precautions
Testing of healthcare workers performing exposure prone procedures (EPPs)
Infection control especially important in dialysis
18
Q
What are some animal vectors that can spread viruses?
A
Arthropods - insects, ticks e.g. dengue
Warm-blooded animal - dog bite e.g. rabies
19
Q
How can viruses spread from close exposure?
A
Skin to skin/mucous membranes
e.g. HSV
20
Q
How are viruses spread by sexual transmission?
A
Virus in body fluids - semen, saliva e.g. HIV
Via mucous membranes
21
Q
How can viral infection be prevented pre exposure?
A
Hygiene
Avoidance
Pre-exposure vaccination
22
Q
How can viral infection be prevented post exposure?
A
Post-exposure prophylaxis - Immunoglobulin, vaccination
23
Q
What family does RSV belong to?
A
Paromyxoviridae
24
Q
What are the subtypes of RSV?
A
A and B
25
How is RSV transmitted?
Droplet
26
Describe respiratory syncytial virus (RSV)
ssRNA 15-19kb length
Most common cause of bronchiolitis and pneumonia in children < 1yo
By age 3-5yrs infection is universal
Seasonal - winter in temperate zones and rainy season in tropics
Can lead to death and closure of units
Serious infection is life threatening for people having BMT
27
What infection does RSV cause?
Upper and lower respiratory tract infection
28
What does RSV cause in young children?
Laryngotracheobronchitis (croup)
Barking cough and breathlessness
29
What does RSV cause in adults?
Common cold
Flu-like illness
30
How is RSV diagnosed?
PCR
31
How can RSV be prevented in babies?
Intramuscular injections of Palivizumab
32
How is RSV treated?
Hydration
Oxygen
General nursing care
Antibaterials if secondary infection suspected with/without Ribavirin - toxic so rarely used but may improve lung function
33
What type of virus is rubella?
RNA
Enveloped virus
34
What family does rubella belong to?
Matonaviridae
35
What are symptoms of rubella in children?
Fever
Runny nose
Red eyes
Fine pink maculopapular rash that starts on face then trunk then arms and legs
36
What else can occur in rubella infection?
Posterior auricular lymphadenopathy - enlarged lymph nodes behind the ear
37
What are symptoms of congenital rubella?
Cataracts, glaucoma
Heart defects
Deafness
Developmental delay
Low birth weight
38
How is rubella transmitted?
Respiratory spread and droplets
Highly infectious
Humans are the only host
May be infectious from one week before rash appears and remain infectious for another week after it appears
39
How is rubella diagnosed?
PCR
Detection of IgM by serology
40
How is rubella prevented pre-exposure?
MMR vaccine
41
How is rubella prevented post-exposure?
Post-exposure prophylaxis with MMR vaccination or human normal immunoglobulin (HNIG)
42
How is HNIG done for rubella?
HNIG from pooled plasma from donors outside the UK
Ideally administered within 72hrs of exposure but up to 6 days
43
Who is HNIG used for?
In pregnancy
Infants <6months
Immunosuppressed
In other groups MMR is used
44
What type of virus is measles?
Single stranded RNA
Enveloped helical
45
What family does the measles virus belong to?
Paramyxovirus
46
What genus does measles virus belong to?
Morbillivirus
47
What are some other paramyxoviruses?
Mumps
Parainfluenza
RSV
Metapneumovirus
48
What is the incubation period of measles?
Typically 10 days but can range from 7 to 18 days
May be prolonged in immunocompromised
Individuals are highly infectious from beginning of their illness
After recovery there is life long immunity
49
How is measles transmitted?
Droplet infection e.g. coughs and sneezes
50
What are symptoms of measles virus?
Start with high fever, conjunctivitis, cough, runny nose and sometimes diarrhoea before a maculopapular rash develops
Rash is often intense and blotchy and will last about a week starting on the face
51
What can be seen with measles infection?
Koplik spots - small white spots on inside of cheeks
52
What are some complications of measles infection?
Pneumonia
Ear infections
More rarely meningitis and encephalitis
53
What is subacute sclerosing panencephalitis (SSPE)?
A fatal neurodegenerative complication of measles
Occurs many years later (7-10yrs)
Characteristic changes in EEG
54
How does SSPE present?
Mood changes
Sleeplessness
Forgetfulness which rapidly progresses over 1-3 years
55
What happens if you get measles in pregnancy?
If infection occurs during pregnancy and individual is not immune may result in miscarriage, stillbirth or pre-term delivery
56
Who are the at risk groups for measles infection?
Immunocompromised patients - infection may be severe and possible fatal
Pregnant women - may cause miscarriage or premature labour
Infants < 1 year - infection may be very severe and possibly fatal
57
How is measles diagnosed?
PCR - oral swab, throat swab
Positive during prodrome (early signs and symptoms) and when rash is present
58
What family does mumps virus belong to?
Paramyxovirus
59
What is the incubation period for mumps?
16-18 days
60
Describe mumps infection
Highly contagious
Spread via respiratory secretions
Pain and swelling in parotid (salivary glands)
Prodrome - fever, headache, malaise
61
What are some rare serious complication of mumps in hcildren?
Orchitis (testicular swelling)
Meningitis
Encephalitis
Hearing loss
Pancreatitis
62
How is mumps prevented?
MMR vaccine
63
How is mumps diagnosed?
Saliva swap and serology for IgG/IgM
64
Describe chickenpox
Usually occurs in childhood <10yo
Caused by varicella zoster virus (VZV)
90% British adults are immune
Usually mild illness
More severe in adults with higher rates of complications
Mild prodrome
65
Who are the groups at risk of severe disease with chickenpox?
Pregnant women
Premature babies (<28weeks)
Neonates born to susceptible mothers
Immunocompromised patients
66
What is the incubation period of chickenpox?
10-21 days
67
What does VZV cause?
Chickenpox and shingles
68
What type of virus is VZV?
Herpes virus
69
Describe VZV
Chickenpox is primary systemic infection with lifelong immunity to chickenpox - travels from skin to root ganglion along sensory nerves
Shingles occurs due to reactivation from root ganglia, up sensory nerves, to the skin - usually in one dermatome
70
How is VZV transmitted?
Direct contact with lesions or by respiratory spread from someone with chickenpox
71
What are complications of VZV?
Bacterial superinfection with Staph and Strep
Encephalitis
Pneumonia
72
Describe chickenpox rash
Prodrome of malaise, fever, headache 1-2 days before rash appears
Vesicular rash starts on trunk or face - papules, vesicles, pustules
Successive crops over days - croping is characteristic of chickenpox
Lesions of different stages of development
73
Describe the pathogenesis of varicella
Day 0 - infection of conjunctivae and/or mucosa of upper resp tract
Day 2 - viral replication in regional lymph nodes
Day 4-6 - primary viraemia
Day 8-10 - viral replication in liver, spleen and possibly other organs
Day 11-12 - secondary viraemia
Day 14 - infection of skin and appearance of vesicular rash
74
How is VZV diagnosed?
Usually clinically
Detection of VZV DNA by PCR from green topped virology swab
Assay also detects HSV1/2 as another common cause of vesicular rash
Serology for detection of VZV IgM
75
How is VZV treated?
Acyclovir advised for patients at risk of severe disease, not routinely recommended for chickenpox in children
Acyclovir available as oral or IV formulation
76
How can VZV be prevented?
Live attenuated vaccine pre-exposure
Hygiene
Avoidance of people with chickenpox/exposed shingles
Post exposure prophylaxis with acyclovir/VZIG (varicella zoster immunoglobulin) for immunocompromised/pregnant
77
What type of virus is enterovirus?
Non enveloped RNA viruses
Many serotypes
78
What family do enteroviruses belong to?
Picornaviridae
79
How are enteroviruses spread?
Faecal/oral route and respiratory droplets
80
What is the clinical presentation of enterovirus?
Febrile (with fever) illness often with rash
Aseptic meningitis usually in <1yo
Vesicular lesions in mouth, feet, buttocks, genitals
Herpangina - ulcers and lesions in mouth, sore throat, fever
Polio
81
What type of virus is Epstein Barr virus (EBV)?
ds DNA virus
One of the Herpes viruses
82
Describe EBV
Often asymptomatic in children
Mononucleosis - lymphadenopathy, malaise, fever
Splenic rupture
Often become infected in childhood and adolescence
Rash if ampicillin given
Prevention - hygeine
83
How is EBV diagnosed?
Serology for VCA IgG, EBNA IgG and IgM by ELISA
PCR from whole lood
Heterophile Ab - Abs produced against poorly defined Ags; in adolescents, heterophile Abs have high specificity and sensitivity in diagnosis of primary EBV infection
Often negative in children
84
What type of virus is cytomegalovirus (CMV)?
ds DNA enveloped virus
One of the Herpes viruses
85
Describe infection with CMV
Primary infection often asymptomatic in children or similar to glandular fever
Can cause congenital infection if susceptible pregnant women infected during pregnancy - deafness, developmental delay, low birth weight
86
How is CMV transmitted?
Via close contact with secretions
87
How is CMV treated?
Antiviral treatment not indicated in most children
Usually self limiting
In immunocompromised children or congenital infection can use ganciclovir/vaganciclovir
88
What type of virus is rotavirus?
ds DNA non-enveloped virus
89
Describe rotavirus infection
Can cause viral gastroenteritis in <5yo especially diarrhoea causing dehydration, requiring intravenous fluids
High mortality
90
How is rotavirus spread?
Faecal/oral route
91
How is rotavirus diagnosed?
Antigen detection or PCR
92
How is rotavirus prevented?
Hygiene
Infant vaccination Rotarix in UK routine schedule - given at 8 and 12 weeks of age
93
What type of virus is adneovirus?
ds DNA non-enveloped virus
94
What family does adenovirus belong to?
Arenaviridae
95
How is adenovirus transmitted?
Respiratory and faecal/oral route
96
How many serotypes of adenovirus are there?
88 in humans causing different illnesses - respiratory infection, conjunctivitis, gastroenteritis, severe disease in immunocompromised
97
How is adenovirus diagnosed?
Clinically
PCR from respiratory swab or blood
No antivirals required unless immunocompromised then cidofovir
Currently no licensed vaccine
