Infectious disease Flashcards
1
Q
What are examples of inactivated vaccines?
A
Polio
Flu vaccine
Hep A
Rabies
2
Q
What are some examples of conjugate/ subunit vaccines?
A
Pneumococcus Meningococcus Hep B Pertussis HPV Shingles
3
Q
What are inactivated vaccines?
A
Patient given killed version of pathogen
4
Q
What are subunit and conjugate vaccines?
A
Patient given part of an organism in order to stimulate an immune response
5
Q
What are live attenuated vaccines?
A
Contain a weakened version of the pathogen
6
Q
Who should not be given live attenuated vaccines?
A
Immunocompromised patients as they can still cause infection
7
Q
Give examples of live atenuated vaccines:
A
MMR BCG Chickenpox Nasal influenza Rotavirus
8
Q
What are toxin vaccines?
A
Contain a toxin that is normally produced by a pathogen, and cause immunity to the toxin not that pathogen
9
Q
What are some examples of toxin vaccines?
A
Diptheria
Tetanus
10
Q
At what stages in development are vaccines given?
A
8 weeks 12 weeks 16 weeks 1 year 3 12-13 14
11
Q
What vaccines are given at 8 weeks?
A
6-in-1
Meningococcal B
Rotavirus
12
Q
What is included in the 6-in-1 vaccine?
A
Diptheria Tetanus Pertussis Polio Hib Hep B
13
Q
What is included in the 12 week vaccine?
A
6-in-1
Pneumococcal
Rotavirus
14
Q
What is given at the 16 week vaccines?
A
6-in-1
Meningococcal B
15
Q
What vaccines are given at 1 year?
A
2 in 1
Pneumococcal
MMR
Meningococcal B
16
Q
What is in the 2 in 1 vaccine?
A
HiB
Mening C
17
Q
What vaccines are given at 3 years 4 motntsh?
A
4 in 1
MMR
18
Q
What vaccines are in the 4 in 1 vaccine?
A
Diptheria
Tetanus
Pertussis
Polio
19
Q
What vaccine is given at 12-13 years?
A
HPV
20
Q
How many doses of the HPV vaccine are given?
A
2: 6-24 months apart
21
Q
What vaccines are given at 14?
A
3 in 1
Meningococcal A, C, W & Y
22
Q
What is included in the 3 in 1 vaccine?
A
Tetanus
Diptheria
Polio
23
Q
Why is the HPV vaccine given at 12-13?
A
Hopefully before they become sexually active
24
Q
What is the BCG vaccine and who gets it?
A
Offered from birth for babies who are at higher risk of tuberculosis
25
What white blood cells pay a key part in sepsis?
Macrophages
Lymphocytes
Mast cells
26
What do the WBC's release in response to the causative pathogen?
Cytokines (Interleukins, TNF)
27
What is the action of the cytokines?
Activate other parts of the immune system, leading to further release of chemicals
28
What is the action of nitrous oxide?
Released in an immune response to cause vasodilation
29
What do cytokines do to blood vessels?
Cause the endothelial lining to become more permeable
30
Why do you get oedema in sepsis?
The blood vessels become more permeable, causing fluid to leak out into the extracellular space
31
What is the effect of the oedema in sepsis?
It creates space between the blood and tissues, reducing the amount of oxygen that reaches the tissues
32
What system is also activated in sepsis?
The coagulation system
33
What does the activation of the coagulation system lead to in sepsis?
Deposition of fibrin throughout the circulation, compromising organ/ tissue perfusion
Thrombocytopenia
Haemorrhages
DIC
34
What is disseminated intravascular coagulopathy?
Small blood clots develop throughout bloodstream and block small blood vessels
35
Why does blood lactate rise in sepsis?
It is a waste product which forms as a result of anaerobic respiration in hypo-perfused tissues
36
Why are tissues hypo-perfused in sepsis?
Chemicals cause vasodilation
Oedema reduces amount of oxygen reaching tissues
Fibrin depositions compromise perfusion
Inflammation
37
When does sepsis become septic shock?
When sepsis has lead to cardiovascular dysfuntion
38
How should septic shock be treated?
IV fluid resuscitation
| Inotropes
39
What signs should you look out for that indicate sepsis?
```
Deranged obs
Prolonged CRT
Fever/ hypothermia
Deranged behaviour
Poor feeding
Incosolable
Reduced consciousness
Floppy
Skin colour changes
```
40
How are children assessed for sepsis?
Traffic light system:
Green= low risk
Amber= medium risk
Red= high risk
41
What features are children assessed on when looking for sepsis?
```
Colour
Activity
Respiration
Circulation
Other (fever, rash, seizures)
```
42
When would a child be treated immediately for sepsis?
All under 3 months with a temperature of >38
43
What is the immediate management of sepsis?
```
3 In:
- IV fluids
- Abx
- Oxygen
3 Out:
- Blood cultures
-Urine ouput/ dipstick
- Blood tests
```
44
What blood tests should be done when investigating sepsis?
```
FBC
U&E
CRP
INR
Blood gas: Lactate and acidosis
```
45
What additional investigations may be performed when diagnosing sepsis?
```
CXR
Abdo/ pelvic USS
LP
Meningococcal PCR
Serum cortisol
```
46
How long should antibiotics be continues if bacterial infection is the suspected cause of sepsis?
5-7 days
47
When would you consider stopping antibiotics in a suspected sepsis case?
When there is low suspicion of bacterial infection
Patient is well
Blood cultures and two CRP results are negative at 48 hours
48
What is the most common cause of fever in infants <3 months?
Bacterial
49
Why is it unlikely for an infant <3 months to have a viral infection?
Due to passive immunity from mother
50
What is meningitis?
Inflammation of the meninges
51
What are the meninges?
Lining of the brain and spinal cord
52
What meningococcal septicaemia?
Meningococcus bacterial infection in the bloodstream
53
What is meningococcus full name?
Niesseria meningitidis
54
What kind of bacteria is meningococcus?
Gram-negative diplococcus
55
What causes the classic 'non-blanching' rash in meningitis?
Meningococcal septicaemia causing DIC and subcutaneous haemorrhages
56
What is meningococcal meningitis?
When meningococcus infects the meninges and CSF
57
What are the most common causative organisms of meningitis?
```
Niesseria meningitidis (meningococus)
Strep pneumoniae (pneumococcus)
```
58
What is the most common cause of bacterial meningitis in neonates?
Group B strep (found in the mothers vagina)
59
What are the typical symptoms of meningitis?
```
Fever
Neck stiffness
Vomiting
Headache
Photophobia
Altered consciousness
Seizures
```
60
What is the characteristic symptoms of meningococcal septicaemia?
Non-blanching rash
61
How do neonates and babies present with meningitis?
```
Non-specific:
hypotonia
Poor feeding
Lethargy
Hypothermia
Bulging fontanelle
```
62
When is a lumbar puncture indicated in meningitis investigations?
< 1 months presenting with fever
1-3 months with fever and unwell
<1 year with unexplained fever and serious illness
63
What are the two special tests that can be performed to look for meningeal irritation?
Kernig's test
| Brudzinski's test
64
What is Kernig's test?
Lying the patient on their back, flexing one hip and knee to 90 degrees and then slowly straightening the knee to stretch the meninges
65
What is Brudzinski's test?
Lying patient flat on back and gently lifting head and neck off bed. Positive test is if patient involuntarily flexes hips and knees
66
How is bacterial meningitis managed in the community?
Stat Benzylpenicillin injection prior to transfer to hospital
67
What should be sent off prior to starting antibiotics in an ideal worlsd?
Blood culture and CSF
| Meningococcal PCR
68
How is bacterial meningitis treated in hospital?
Follow local guideline antibiotics
69
What are the typical antibiotics given to an infant <3 months to treat meningitis?
Cefotaxime + amoxicillin
70
What antibiotic is given to children >3months for meningitis?
Ceftriaxone
71
What should be added to antibiotic treatment if there is a risk of penicillin resistant pneumococcal infection?
Vancomycin
72
What is given to children with meningitis in addition to antibiotics and why?
Dexamethasone to reduce the frequency and severity of hearing loss and neurological damage
73
What must be done in all cases of bacterial meningitis and meningococcal infection?
Inform public health as they are notifiable diseases
74
What is given to people who have had significant exposure to a patient with meningococcal infection?
Post exposure prophylaxis: single dose of ciprofloxacin
75
What counts as significant exposure?
Prolonged contact with a patient with meningococcal infection within 7 days prior to onset of infection
76
What are the most common causes of viral meningitis?
HSV
Enterovirus
VZV
77
What must be done to differentiate between bacterial and viral meningitis?
LP for CSF
78
How is viral meningitis treated?
Tends to be milder so usually supportive
| Van use aciclovir
79
Where is the needle inserted in a lumbar puncture and why?
L3-L4, as the spinal cord ends at L1-L2
80
What are CSF samples tested for after an LP?
```
Bacterial culture
Viral PCR
Cell count
Protein
Glucose
```
81
What should be taken at the same time as an LP and why?
Blood glucose sample to compare to CSF glucose content
82
What are the characteristic features of CSF sample infected with bacteria?
```
Cloudy
High protein content
Low glucose content
High neutrophil count
Bacterial culture positive
```
83
What are the characteristic features of a viral CSF sample?
Clear appearance
Normal (or raised) protein
Normal glucose
High lymphocyte count
84
Why does the CSF contain high protein and low glucose with bacterial infection?
Bacteria release proteins and use up glucose
85
What are the key complications of meningitis?
```
Hearing loss
Seizures
Cognitive impairment
Learning disability
Memory loss
Cerebral palsy
```
86
What is encephalitis?
Inflammation of the brain
87
What are the non-infective causes of encephalitis?
Autoimmune
88
What is the most common cause of encephalitis?
Viral infection
89
What is the most common viral cause of encephalitis?
Herpes simplex virus (HSV)
90
Wha is the most common viral cause of encephalitis in children?
HSV-1 from cold sores
91
What is the most common viral cause of encephalitis in neonates?
HSV-2 from genital herpes contracted during birth
92
What are other viral causes of encephalitis?
```
VZV
Cytomegalovirus
EBV
Enterovirus
Adenovirus
Influenza
```
93
How does encephalitis present?
```
Altered consciousness
Altered cognition
Unusual behaviour
Acute onset of focal neurological symptoms and seizures
Fever
```
94
What key investigations are done into encephalitis?
```
LP
MRI
EEG
Swabs to find causative organism
HIV testing
```
95
When would an LP be contraindicated and what investigation should be done instead?
GCS < 9
Haemodynamically unstable
Active seizures or post-ictal
Do CT scan instead
96
How is suspected encephalitis managed?
IV antivirals
97
What antiviral is used to treat HSV or VZV?
Aciclovir
98
What antiviral is used to treat CMV?
Ganciclovir
99
What are the complications of encephalitis?
```
Lasting fatigue
Change in personality/ mood/ memory/ cognition
Learning disability
Headaches
Chronic pain
Movement disorders
Sensory disturbance
Seizures
Hormonal imbalance
```
100
What causes infectious mononucleosis?
Epstein Barr Virus (EBV)
101
What is infectious mononucleosis also known as?
Mono
Kissing disease
Glandular fever
102
How is EBV spread?
Saliva of infected individuals: kissing, sharing cups, toothbrushes act
103
When are most people infected with EBV?
As children when it causes few symptoms
104
When does EBV infection tend to cause more severe symptoms?
In teenagers or young adults
105
What is symptomatic infection with EBV called?
Infectious mononucleosis
106
What are the symptoms fo IM?
```
Fever
Sore throat
Fatigue
Lymphadenopathy
Enlarged tonsils
Splenomegaly
```
107
Why should cefalosporins and amoxicillin be avoided in glandular fever?
Cause itchy maculopapular rash
108
How is EBV diagnosed?
Antibody tests
109
What are heterophile antibodies?
Antibodies that are produces in infectious mononucleosis (and other things)
110
Up to how long does it take heterophile antibodies to be produced in IM?
Up to 6 weeks
111
How are heterophile antibodies tested for?
Monospot test
| Paul-Bunnel test
112
What is a monospot test?
Introduces patients blood to RBC's from horses. Antibodies will react to give a positive result
113
What antibodies is it possible to test for in EBV infection?
IgM
| IgG
114
How is IM managed?
Supportive
| Avoid alcohol and contact sports
115
What are the complications of IM?
```
Splenic rupture
Glomerulonephritis
Haemolytic anaemia
Thrombocytopenia
Chronic fatigue
```
116
What kind of infection is mumps?
Viral infection
117
How is mumps spread?
Respiratory droplets
118
What is the incubation period for mumps?
15-25 days
119
How long does mumps usually last?
1 week
120
How is mumps managed?
Supportively
121
What level of protection does the MMR vaccine offer against mumps?
80%
122
What is the symptoms course of mumps?
Prodrome (flu-like symptoms) followed by parotid swelling a few days later
Symptoms of complications (abdo pain, testicular pain, meningitis)
123
What is the characteristic feature of mumps?
Parotid gland swelling with associated pain
124
What are the complications of mumps?
Pancreatitis
Orchitis
Meningitis
Sensironeural hearing loss
125
How is mumps diagnosis confirmed?
PCR testing of saliva swab
126
What must be done in all mumps cases?
Notify public health
127
How can HIV be transmitted to children?
During pregnancy
During birth
Breastfeeding
Blood or bodily fluid exposure
128
How can you prevent transmission of HIV during birth?
Alter mode of delivery
| Prophylactic treatment
129
When can normal vaginal delivery be performed when the mother has HIV?
If she has a viral load <50
130
When should C-section be considered in a HIV +ve mother?
Should be considered >50
| Definitely performed if viral load >400
131
When should IV Zidovudine be given during C-section?
If the viral load is unknown or there are >10000 copies/ ml
132
What prophylactic treatment should low risk babies be give?
Zidovudine for 4 weeks
133
What prophylactic should high risk babies be given?
Zidovudine, lamivudine and nevirapine for 4 weeks
134
What makes a baby high risk in terms of prophylaxis treatment offered?
Mums viral load is >50 copies/ ml
135
Can HIV mothers breast feed?
Not recommended no matter how low the viral loaf
136
Why might a child under 18 months test positive for HIV despite not having the virus?
Due to maternal antibodies
137
When should you test children for HIV?
Babies to HIV positive parents
If immunodeficiency is suspected
Young people who are sexually active or there are other risk factors
138
What are the two options for HIV testing?
HIV antibody screen
| HIV viral load
139
How and when are babies to HIV positive parents tested?
HIV viral load test at 3 months
| HIV antibody test at 24 months
140
What are the key principles in managing HIV?
Antiretroviral therapy
Normal childhood vaccines
Prophylactic Septrin with low C4 counts
Treatment of opportunistic infections
141
What kind of infection is hepatitis B?
DNA virus
142
How is Hep B transmitted?
Direct contact with blood or bodily fluids
| Vertical transmission
143
How quickly do most children recover from Hep B infection?
Within 2 months
144
What happens to a small proportion of people with Hep B infection?
Become chronic hep B carriers0 Virus DNA integrates into their own DNA
145
What is the risk of developing chronic hepatitis B after exposure in a neonate?
90%
146
What is the risk of developing chronic hepatitis B after exposure in a child <5?
30%
147
What is the risk of developing chronic hepatitis B after exposure in an adolescent?
<10%
148
Are chronic hep B carriers symptomatic?
No have normal growth and development and liver function tests
149
What happens to <5% of chronic hep B carriers?
Develop liver cirrhosis
150
What are the different antigens and antibodies you can look for in Hep B infection?
```
HBsAg
HBeAg
HBcAb
HBsAb
HBV DNA
```
151
What is HBsAg and what does it signify?
Surface antigen
| Indicates active Hep B infection
152
What is HBeAg and what does it signify?
E antigen
| Marker of viral replication and implies high infectivity
153
What is HBcAb and what does it indiate?
Core antibodies
| Implies past or current infection
154
What is HBsAb and what does it indicate?
Surface antibody
| Implies vaccination or past/ current infection
155
What is HBV DNA and what does it indicate?
Direct count of viral load
156
When screening for hep B, what is initially looked for?
HBcAb and HBsAg for previous and active infection
157
If HBcAb and HBsAg are positive, what is then looked for?
HBeAg and HBV DNA (Viral load)
158
What can HBcAb help distinguish between?
Acute, chronic and past infection
159
What does the level of HBeAg correlate with?
The infectivity
160
Which children should be tested for hep B?
Those with hep B positive mums
Migrants from endemic areas
Close contacts of patients with hep B
161
What should neonates with hep B positive mothers be given within 24 hours of birth?
Hep B vaccine
| Hep B immunoglobulin infusion
162
What additional measures to babies born to hep B positive mothers recieve?
Hep B vaccine and Ig infusion at birth
Addition vaccine at 1 and 12 months
Test for HBsAg at 1
163
Is it safe for a hep B positive mother to breastfeed?
Yes if baby has been properly vaccinated
164
What does the hep B vaccine involve?
Injecting hep B surface antigen
| 3 doses at different intervals
165
How is Hep B managed?
Supportive
| Regular follow up with chronic cases
166
What kind of virus is Hep C?
RNA virus
167
How is hep C spread?
By blood and bodily fluids
168
Is there a vaccine for hep C?
No
169
What is the disease course of Hep C in adults?
1 in 4 make full recovery
| 3 in 4 develop chronic hep C
170
What are the complications of hep C?
Liver cirrhosis
| Hepatocellular carcinoma
171
What percentage of babies the Hep C infected mothers develop the virus?
5-15%
172
Do babies and children get affected by hep C?
No symptoms or pathology associated
173
How is Hep C tested for?
Hep C antibody
| Hep C RNA testing
174
How is Hep C managed in adults?
Curable using direct acting antivirals
175
How is Hep C managed in children?
Test babies at 18 months with positive mothers
Often clear is spontaneously
Treatment typically delayed until adulthood
