Infectious Disease Flashcards
What type of vaccine is Rabies?
Inactivated vaccine
What type of vaccine is Haemophilus Influenzae B?
Subunit and conjugate vaccine
What type of vaccine is MMR?
Live attenuated vaccine
What type of vaccine is Influenzae? (injectable form)
Inactivated vaccine
What type of vaccine is HPV?
Subunit and conjugate vaccine
What type of vaccine is BCG?
Live attenuated vaccine
What type of vaccine is the Polio Injection?
Inactivated vaccine
What type of vaccine is Shingles?
Subunit and conjugate vaccine
What type of vaccine is Chickenpox?
Live attenuated vaccine
What type of vaccine is Hepatitis A?
Inactivated vaccine
What type of vaccine is Pertussis?
Subunit and conjugate vaccine
What type of vaccine is Nasal Influenzae vaccine?
Live attenuated vaccine
What type of vaccine is Meningococcus?
Subunit and conjugate vaccine
What type of vaccine is Rotavirus?
Live attenuated vaccine
What type of vaccine is Hepatitis B?
Subunit and conjugate vaccine
What type of vaccine is Pneumococcus?
Subunit and conjugate vaccine
What classes of vaccines are safe to give to immunocompromised patients?
Inactivated vaccine
Subunit and conjugate vaccine
What is a Toxin vaccine?
It contains a toxin produced by a pathogen
What type of vaccine is Diptheria?
Toxin vaccine
What type of vaccine is Tetanus?
Toxin vaccine
What classes of vaccines are unsafe to give to immunocompromised patients?
Live attenuated vaccine
When is the BCG vaccine offered? To what populations?
- All infants living in areas of the UK where the annual incidence of TB is 40/100,000 or greater
- All infants with a parent / grandparent who was born in a country where the annual incidence of TB is 40/100,000 or greater. The same applies to older children but if they are 6 years old or older they require a tuberculin skin test first
- Healthcare workers
- Prison staff
- Staff of care home for the elderly
- Those who work with homeless people
When is the 6-in-1 vaccine offered?
At 2, 3, 4 months old
When is the oral rotavirus vaccine offered?
At 2, 3 months old
When is the Meningitis B vaccine offered?
At 2, 4, 12-13 months old
When is the pneumococcal vaccine offered?
At 3 months, 12-13 months old
When is the MMR vaccine offered?
At 12-13 months, at 4 years old
When is the Hib/Men C vaccine offered?
At 12-13 months old
When is the 4-in-1 vaccine offered?
At 3-4 years old
When is the annual flu vaccine (intranasal live) offered?
At 3-8 years old
When is the 3-in-1 vaccine offered?
At 13-18 years old
When is the MenACWY vaccine offered?
At 13-19 years old
When is the HPV vaccine offered?
At 12-13 years old
What type of vaccine is Oral Polio?
Live attenuated
When does Influenza season start?
When does the vaccinations begin each year?
Flu season: Mid-Nov
Vaccination: September - Early Nov
What are the three types of Influenza? Which ones cause illness?
A, B, C
A&B cause illness
What are the two types of Flu-vaccine and what groups of patients are they given to?
Live, intranasal vaccine (to children)
Inactivated, injectable (to at risk groups)
What are contraindications to giving the live, intranasal vaccine to children?
- If Immunocompromised
- If aged <2 years old
- Current febrile illness / blocked nose / rhinorrhoea
- Current wheeze or history of severe asthma
- Egg allergy
- If child is taking aspirin (e.g. for Kawasaki’s Disease) due to a risk of Reye’s syndrome
What does the Inactivated, injectable form of Influenza given to at risk groups consist of?
- Trivalent, consist of two subtypes of influenza A and one subtype of influenza B
What are the indications of giving the Inactivated, Injectable form of Influenza to at risk groups?
- All people over the age of 65 years old
- All people over the age of 6 months plus the following:
- Chronic respiratory disease, including asthmatics who use steroids
- Chronic heart disease (heart failure, ischaemic heart disease, including hypertension if associated with cardiac complications)
- Chronic kidney disease
- Chronic liver disease: cirrhosis, biliary atresia, chronic hepatitis
- Chronic neurological disease: (e.g. Stroke/TIAs)
- Diabetes mellitus (including diet controlled)
- Immunosuppression due to disease or treatment (e.g. HIV)
- Asplenia or splenic dysfunction
- Pregnant women
- Adults with a body mass index >40 kg/m²
- Health and social care staff directly involved in patient care
- Those living in long-stay residential care homes
- Carers of the elderly or disabled person whose welfare may be at risk if the carer becomes ill
What are the contraindications for the Inactivated, Injectactable Influenza vaccine?
Egg protein allergy
When is Tetanus offered to children?
At five points in their life:
- 2 months, 3 months, 4 months, 4-5 years, and 13-18 years
A patient has high risk wounds, give examples of such wounds?
What would you give?
- Wounds: Compound fractures, delayed surgical intervention, necrotic tissue
- Treatment: IM Human Tetanus Immunoglobulin
If patient has a high risk wound, and no vaccination history, what would you give?
A dose of tetanus vaccine plus intramuscular human tetanus immunoglobulin
What is Sepsis defined as?
A syndrome that occurs when an infection causes a patient to become systemically unwell due to a severe systemic inflammatory response (SIRS)
What is the pathophysiology of Sepsis?
- Pathogens recognised bymacrophages,lymphocytesandmast cells → Releaseof cytokines
- Cytokinesincrease blood vessel permeability → Fluid leakage intoextracellular space →Oedema + a reduction inintravascular volume. Oedema reduces oxygen to tissues
- Cytokines cause further release of chemicals i.e.NO→vasodilation
- Activation of coagulation system→ Fibrin deposition compromising organ and tissue perfusion. Platelet + clotting factor consumption as more blood clots form →Thrombocytopenia,haemorrhagesand an inability to form clots and stop bleeding → Disseminated Intravascular Coagulopathy(DIC)
- Anaerobic respirationin the hypo-perfused tissues → Increased lactate
What is Septic Shock?
When Sepsis → Cardiac dysfunction. Arterial BP falls → Hypoperfusion. This also causes anaerobic respiration and a rise in blood lactate
What things are assessed regarding the Traffic Light System for Sepsis?
Traffic Light System: Colour, Activity, Respiratory Rate, Circulation & Hydration, and Other
How is Septic Shock managed?
Manage as Sepsis plus:
- Aggressive IV Fluid therapy → Improves BP and tissue perfusion
- If IV Fluid fails → ITU/HDU admission, consider inotropes i.e. noradrenaline to stimulate CVD
How is Neonatal Sepsis Categorised?
- Early onset → First 72 hours of life
- Late onset → From Day 7-28 of life
What are common causes of Neonatal Sepsis in:
Early onset Sepsis
Late onset Sepsis
- Early onset: Group B Streptococcus
- Late onset: Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella and Enterobacter, and fungal species
What are risk factors for Neonatal Sepsis?
- Mother who has had a previous baby with GBS infection
- Mother who hascurrent GBS colonisationfrom prenatal screening, current bacteruria, intrapartum temperature ≥38ºC, membrane rupture ≥18 hours, or current infection throughout pregnancy
- Premature (<37 weeks)
- Low birth weight (<2.5kg)
- Evidence of maternal chorioamnionitis
What is the antibiotic of choice for Neonatal Sepsis according to NICE Guidelines?
Benzylpenicillin with Gentamicin
What is Meningitis?
Inflammation of the meninges, which are linings of the brain and spinal cord usually caused by a bacterial or viral infection
What is Neisseria Meningitis? What feature of Meningitis is unique to this?
A gram-negative diplococci, typically causes a non-blanching rash
What is Meningococcal Meningitis?
Refers to bacteria infecting the meninges and the cerebrospinal fluid around the brain and spinal cord
What is the most common cause(s) of Meningitis in Neonates - 3 months?
- Group B Streptococcus (GBS) commonly acquired from mother at birth. Also more common in those born prematurely and following PROM
- E. Coli and Listeria Monocytogenes
What are the most common causes of Meningitis in 1 month old - 6 years old?
- Neisseriameningitidis(meningococcus)
- Streptococcuspneumoniae(pneumococcus)
- Haemophilus influenzae
What are the most common causes of Meningitis in patients 6-60 years old?
- Neisseriameningitidis(meningococcus)
- Streptococcuspneumoniae(pneumococcus)
What are the most common causes of Meningitis in patients > 60 years old?
- Streptococcus pneumoniae (pneumococcus)
- Neisseria meningitidis (meningicoccus)
- Listeria monocytogenes
What is the most common cause of Meningitis in immunocompromised patients?
- Listeria monocytogenes
What is the first-line investigation NICE recommends for Meningitis?
Lumbar Puncture
At what level is the Lumbar Puncture performed?
L3-L4 vertebral level
What are the contraindications of a Lumbar Puncture if indicated for Meningitis?
Signs of raised ICP:
- Focal neurological signs
- Papilloedema
- Significant bulging of the fontanelle
- Disseminated intravascular coagulation
- Signs of cerebral herniation
If an LP cannot be performed for Meningitis, what investigation can be performed as second line?
- Blood cultures, PCR
What special tests can be performed for Meningeal Irritation? State the names of them
Kernig’s test
Brudzinski’s test
Outline what Kernig’s test is for Meningeal Irritation
Patient on their back, flexing one hip and knee to 90 degrees and then slowly straightening the knee whilst keeping the hip flexed at 90 degrees
Where there is meningitis it will produce spinal pain or resistance to movement
Outline what Brudzinki’s test is for Meningeal Irritation
Patient flat on their back and gently using your hands to lift their head and neck off the bed and flex their chin to their chest
In a positive test this causes the patient to involuntarily flex their hips and knees
What are is the most common complication of Meningitis? What are others?
- Hearing lossis a key complication - MOST COMMON
- Seizures and epilepsy
- Cognitive impairment and learning disability
- Memory loss
- Cerebral palsy, with focal neurological deficitssuch as limb weakness or spasticity
What are the Leptomeninges?
The two inner meninges of the brain (Pia and Arachnoid mater) between which the CSF circulates
How much CSF is there? How much is produced a day and by what?
There is 150ml of CSF however 500ml is produced by the the choroid plexus (70%) and blood vessels (30%)
What is the route in which CSF drains?
- Lateral ventricles (via foramen of Munro)
- 3rd ventricle
- Cerebral aqueduct (aqueduct of Sylvius)
- 4th ventricle (via foramina of Magendie and Luschka)
- Subarachnoid space
- Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus
What is the final location of drained CSF?
It is reabsorbed via arachnoid granulations into the venous system
What are the contents of CSF fluid?
- Glucose: 50-80mg/dl
- Protein: 15-40 mg/dl
- White blood cells: 0-5 cells/mm
- Red blood cells: Nil
What does Bacterial Meningitis CSF parameters look like?
Low glucose, high protein, high neutrophils
What does Viral Meningitis CSF parameters look like?
Normal glucose, normal/high protein, high lymphocytes
What are the five pillars of management for Bacterial Meningitis?
- Antibiotics
- Steroids
- Fluids
- Cerebral monitoring
- PHE Notification and PEP
What antibiotics are offered to children below <3 months of age for management of Meningitis?
IV Cefotaxime + IV Amoxicillin (Amoxicillin to cover Listeria in pregnancy)
What antibiotics are offered to children for meningitis above >3 months of age?
IV Cefotaxime
How does antibiotic choice change in bacterial meningitis if there is a pencillin-resistant pneumococcal cause?
Prescribe Vancomycin
What is the steroid of choice for Bacterial Meningitis? How often and for how long?
Dexamethasone, QDS, for 4 days
WHEN are steroids indicated for treatment of Meningitis?
Purulent CSF
CSF WBC >1000 μL
Raised WBC + protein count >1g/L
Bacteria on gram stain
When are steroids contraindicated for treatment of Meningitis?
Children below the age of < 3 months
What is the consensus regarding PEP for close contacts of a patient diagnosed with Bacterial Meningitis?
Single dose of Ciprofloxacin within 24 hrs of diagnosis to those who have had contact in 7 days prior
What is the management for Viral Meningitis?
Mainly supportive, as it is milder over Bacterial Meningitis. Acyclovir may however be used
What is Encephalitis?
Inflammation of the brain, due to infective or non-infective causes
What are the broad terms for causes of infective Encephalitis?
- Viral encephalitis (most common)
- Bacterial encephalitis
- Fungus encephalitis
What are non-infective causes of Encephalitis?
Auto-immune causes
With viral encephalitis, what is the most common cause in neonates?
HSV-2 from genital warts
With viral encephalitis, what is the most common cause in children?
HSV-1 from cold sores
Aside from HSV, what are other causes of viral encephalitis?
VZV
EBV
CMV
What features are specific to Viral Encephalitis caused by the most common viral cause?
HSV:
- Affects focal lobe -> Aphasia
- Affects temporal lobe -> Seizure (motionless staring, confusion, disorientation, inability to respond to others, jamais vu)
What are the features of Encephalitis?
Headache, vomiting, fever, altered GCS, unusual behaviour, psychiatric symptoms, acute onset of focal neurological symptoms and focal seizures
What are the investigations for Encephalitis?
- Lumbar puncture → Lymphocytosis (high lymphocytes) send CSF for viral PCR testing
- CT scan / MRI - if a lumbar puncture is contraindicated
- EEG recording→ Lateralised periodic discharges at 2 Hz
- Swabs -Of areas can help establish the causative organism
- HIVtesting - recommended in all patients with encephalitis
What is the management of Encephalitis?
- For HSV/VZV Encephalitis → Acyclovir
- For CMV → Gancyclovir
What is Infectious Mononucleosis also known as?
Glandular fever
Kissing disease
Mono
What are the main causes of Infectious Mononucleosis?
- EBV (Epstein-Barr Virus), aka HHV4 (most common)
- CMV (Cytomegalovirus)
- HHV6
What is Epstein-Barr also known as?
HHV-4
How is Infectious Mononucleosis spread?
Is found in saliva, and is spread through kissing, sharing toothbrushes, drinking cups
What is the classic triad for Infectious Mononucleosis? In how many patients is this seen in?
In 90% of patients:
Pyrexia, lymphadenopathy, and sore throat
Where is the lympadenopathy in patients with Infectious Mononucleosis? How is this different to tonsilitis?
Anterior and posterior triangles of the neck
In tonsilitis, seen in upper anterior cervical chain
What are other features of Infectious Mononucleosis aside from the the triad of pyrexia, lympadenopathy and sore throat?
Splenomegaly Palatial petechiae Haemolytic anaemia Anorexia Hepatitis (rise in ALT)
Maculopapular, pruritic rash seen after taking amoxicillin
What marker is measured to help diagnose Infectious Mononucleosis?
Heterophile antibodies
How long does it take for Heterophile antibodies these to form?
Can take upto 6 weeks
What tests can be used to detect Heterophile antibodies for diagnosis of Infectious Mononucleosis?
Monospot Heterophile antibody test (Introduce patient’s blood to horses RBCs)
Paul Bunnell test (Introduce patient’s blood to sheep RBC)
Aside from Heterophile antibodies, what other tests can be used to diagnose Infectious Mononucleosis?
EBV antibodies (IgM for acute infection, and IgG for immunity)
According to NICE, when should the Heterophile antibody test be performed?
2 weeks from onset of illness
What is the specificity / sensitivity of the Heterophile test for diagnosis of Infectious Mononucleosis?
The heterophile test is 100% specific for Infectious Mononucleosis, but not all IM patients will produce heterophile antibodies
What is the management of Infectious Mononucleosis?
Mainly supportive:
- Adequate fluid intake
- Avoidance of alcohol
- Analgesia for pain
What activity should be avoided in patients with Infectious Mononucleosis and why?
Avoid contact sports for 8 weeks after due to risk of splenic rupture
What is the prognosis for Infectious Mononucleosis?
The majority will recover from acute infection within 2-3 weeks, however may feel fatigued for several months later
What are the complications of Infectious Mononucleosis?
- Splenic rupture
- Chronic fatigue
- Glomerulonephritis
- Haemolytic anaemia
- Thrombocytopenia
What cancer is associated with Infectious Mononucleosis?
Burkitt’s Lymphoma
What is Mumps?
A viral infection caused by RNA paramyxovirus
What time of year does Mumps occur?
Winter and spring
What is the incubation period of Mumps?
14-21 days
When do patients become infective with Mumps?
7 days before and upto 9 days after parotid gland swelling
How does Mumps spread? What does it infect?
By droplet infection
Respiratory tract epithelial cells -> Parotid gland -> Other tissues
What is the presentation of Mumps?
Fever, malaise, muscle pain, parotitis (ear ache, pain on eating, can be unilateral -> bilateral), trismus
How is Mumps prevented?
MMR vaccine
How is Mumps diagnosed?
Saliva swab -> PCR
How is Mumps treated?
Notify PHE
Supportive management: fluids, rest, analgesia
What are complications of Mumps?
Sensorineural hearing loss, orchitis, pancreatitis, encephalitis, meningitis
How common is Orchitis in those with Mumps?
Doesn’t affect pre-pubescent boys much, but it is the most common complication in post-pubescent males
Is MMR safe to administer to pregnant women or those attempting to become pregnant?
No
Is a pregnant woman with mumps at an increased risk of having a baby with congenital defects?
No
What type of virus is HIV? What types are there and which is most common?
HIV is a retrovirus. HIV-1 is the most common type, and HIV-2 rarely seen outside West Africa
How is HIV spread?
- Via unprotected oral, vaginal, anal sex
- Via mother-to-child during pregnancy, or birth, or delivery (vertical transmission)
- Via mucous membranes, blood, open wound exposure
How can HIV transmission be reduced during delivery of baby?
- Normal vaginal delivery → If woman has viral load < 50 copies / ml
- Caesarean section → Considered if load > 50 copies, but given to all > 400 copies / ml
- IV Zidovudine → If load unknown, or greater than 1000 copies / ml
How can HIV transmission be reduced after delivery of baby?
- Low risk baby → < 50 copies / ml → Zidovudine for 4 weeks to baby
- High risk baby → > 50 copies / ml → Zidovudine, Lamivudine, Nevirapine for 4 weeks to baby (Triple ART)
What is the consensus of a HIV mother breastfeeding her child?
Not recommended under any circumstances. If viral load is low, and mother is adamant, may be done rarely under close supervision of doctors
What circumstances might require a child to be tested for HIV?
- Babies to HIV positive parents
- When immunodeficiency is suspected, i.e. unusual, severe or frequent
- Young people who are sexually active can be offered testing if there are concerns
- Risk factors i.e. needle stick injuries, sexual injuries or IV drug use
How are babies who have HIV positive parents tested?
- HIV viral load testat 3 months. If this is negative, the child has not contracted HIV during birth and will not develop HIV unless they have further exposure
- HIV antibody testat 24 months. This is to assess whether they have contracted HIV since their 3 month viral load, for example through breast feeding. If the 3 month test is negative and they are not breastfed, this should be negative
What is Vertical Transmission?
When a condition is passed from mother to child during pregnancy or delivery
What are the absolute contraindications to having the MMR vaccine?
- Severe immunosuppression
- Allergy to neomycin
- Children who have received another live vaccine by injection within 4 weeks
- Pregnancy should be avoided for at least 1 month following vaccination
- Immunoglobulin therapy within the past 3 months (there may be no immune response to the measles vaccine if antibodies are present)