ID and Micro

Question 1

give some causes of acquired immunodeficiency

Answer 1

Diabetes, Cirrhosis, renal failure, HIV or iatrogenic due to radiotherapy, cytotoxic chemotherapy, immunosuppressive medication or splenectomy.

Question 2

give some pathogens which usually don’t cause disease in an immunocompetent host and may indicate underlying immuocompromise

Answer 2

aspergillus spp, pneumocystis jiroveci, JC virus, CMV, BK virus.

Question 3

what are the different stages of a Haematopoietic stem cell transplant?

Answer 3

1. stem cells harvested (allogenic or autologous)
2. Conditioning regime (chemo+/- radiotherapy to eradicate cancer/bone marrow stem cells)
3. stem cells infused into patient
4. supportive medications given as stem cells graft
   5, monitor for late effects

Question 4

Who is at risk of neutropenia?

Answer 4

received chemotherapy in the past 6 weeks OR
received high dose chemotherapy or bone marrow transplant in the last year OR
have a haematological condition causing numeric (i.e. reduced numbers of white cells) or functional (normal numbers of white cells but not working properly) neutropenia e.g. myelodysplasia

Question 5

where can infections arise from in a neutropaenic patient?

Answer 5

Infections arise from patients’ own flora. Common sites are IV lines, oral cavity, sinuses, lungs, skin, perineal region and urinary tract. Bacteraemia is often associated with these or may result from translocation from the gut. CXR changes of pneumonia may often be absent due to the reduced neutrophil entry into the alveolar spaces

Question 6

what is a potentially life-threatening complication of chemotherapy and haematopoietic stem cell transplantation?

Answer 6

Neutropenic sepsis is a potentially life-threatening complication of chemotherapy and haematopoietic stem cell transplantation.

Question 7

How can neutropaenic sepsis present?

Answer 7

Any clinical deterioration, infective symptoms, or pyrexia in a patient at risk of neutropenia should be taken very seriously and cultures should be taken (IV lines, sputum / bronchoalveolar lavage, urine etc) and empirical antibiotic treatment started promptly. Neutropenic patients who have sepsis can present with minimal signs of infection and may NOT have pyrexia. Observe for pallor, mottled skin, tachycardia, altered mental state, anxiety, and increased respiration rate.

Question 8

what is the usual antimicrobial cover for someone suspected to have neutropaenic sepsis?

Answer 8

Local guidelines will recommend broad spectrum regimens that cover gram positive and gram negative organisms (including pseudomonas) and cover known circulating antimicrobial resistance patterns. Thus antipseudomonal penicillins (e.g. piperacillin-tazobactam ) or ceftazidime or carbapenems (Meropenem) +/- glycopeptides (vancomycin/teicoplanin) will be used. In the absence of a confirmed pathogen, failure to respond within 3-5 days often leads to inclusion of empirical antifungal therapy e.g. with an azole (e.g. voriconazole) or an echinocandin (e.g. anidulafungin).
**If line infection is suspected, add Vancomycin (prescribed as per Trust Vancomycin chart), unless the antibiotic regimen already contains Teicoplanin.

Question 9

In Solid Organ Transplant recipients, what infections are they at risk of post transplant and at what time intervals since SOT?

Answer 9

First month after SOT:- Nosocomial: wound infection, pneumonia, IV line infection. Reactivation of previous infection e.g. TB, strongyloidiasis.
1-6 months after SOT:- Viral Infections: CMV, EBV, HBV. Opportunistic PCP, Legionella, aspergillosis, Listeria
>6 months after SOT:- Progressive viral: CMV, HBV. Opportunistic: PCP, Cryptococcus, Listeria, Nocardia. Community Acquire: S pneumoniae, influenza

Question 10

what infection risk are anti-TNF drugs associated with?

Answer 10

anti-TNF drugs are associated with increased risk of reactivation of latent TB or HBV. Pre-treatment screening for these as well as herpes virus infection (VZV, CMV) is usually undertaken and prophylactic treatment given where deemed appropriate.

Question 11

genital herpes cause and presentation

Answer 11

Genital herpes is most often caused by the herpes simplex virus (HSV) type 2 (cold sores are usually due to HSV type 1). Primary attacks are often severe and associated with fever whilst subsequent attacks are generally less severe and localised to one site. There is typically multiple painful ulcers.

Question 12

chancroid? presentation?

Answer 12

Chancroid is a tropical STI caused by Haemophilus ducreyi. It causes painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement. The ulcers typically have a sharply defined, ragged, undermined border.

Question 13

Lymphogranuloma venereum cause and presentation? tx?

Answer 13

Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis. Typically infection comprises of three stages
stage 1: small painless pustule which later forms an ulcer
stage 2: painful unilateral tender inguinal lymphadenopathy
stage 3: proctocolitis
tx - doxycycline

Question 14

genital ulcers - painful vs painless?

Answer 14

painful - genital herpes, chancroid

painless - LGV (can also be painless papule but remember painful lymphadenopathy), syphilis (painless lymphadenopathy)

Question 15

what is the abx used for prophylaxis post dog/cat bites or for treatment of an infected dog or cat bite?

Answer 15

co-amoxiclav. certain conditions need to be met to require this abx. assess tetanus and rabies risk.

Question 16

classical features of dengue fever and cause

Answer 16

Retro-orbital headache, fever, facial flushing, rash, thrombocytopenia in returning traveller. caused by dengue virus

Question 17

complication of dengue fever

Answer 17

disseminated intravascular coagulation known as dengue haemorrhagic fever may develop

Question 18

management of dengue fever

Answer 18

Treatment is solely supportive such as fluid resuscitation, blood transfusion etc.

Question 19

what is Amsel’s criteria?

Answer 19

Amsel’s criteria is used for diagnosis of BV - 3 of the following 4 points should be present

1. thin, white homogenous discharge
2. clue cells on microscopy: stippled vaginal epithelial cells
3. vaginal pH > 4.5
4. positive whiff test (addition of potassium hydroxide results in fishy odour)

Question 20

Name the live attenuated vaccines currently in use in UK

Answer 20

MI BOOTY - 
MMR
Influenza
BCG
Oral typhoid
Oral rota virus
Varicella vaccine
Shingles vaccine
Yellow fever

Question 21

what is salmonella

Answer 21

bacteria. gram -ve rods.

Question 22

what is enteric fever and what is the cause? how is it transmitted

Answer 22

Typhoid and paratyphoid are caused by Salmonella typhi and Salmonella paratyphi. hey are often termed enteric fevers. typhoid is transmitted via the faecal-oral route

Question 23

what are the features of enteric fever?

Answer 23

initially systemic upset such as headache, fever, arthralgia.
relative bradycardia
abdominal pain, distension
constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid
rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid

Question 24

complications of enteric fever

Answer 24

osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens)
GI bleed/perforation
meningitis
cholecystitis
chronic carriage

Question 25

management of genital herpes?

Answer 25

Oral antivirals

Question 26

person with cellulitis who has been admitted and is on IV abx complains of extreme limb pain out of keeping with physical features. what are we worried about?

Answer 26

necrotising fasciitis. requires urgent surgical referral debridement

Question 27

person with headache, fever, lethargy and neck stiffness/pain on flexion. evaluation of cerebrospinal fluid obtained by lumbar puncture reveals encapsulated organisms visible by India ink.

What is the most likely causative organism?

Answer 27

Cryptococcus neoformans - stains with India ink

Question 28

most common cause of viral meningitis?

Answer 28

non-polio enteroviruses e.g. coxsackie virus, echovirus

Question 29

signs and symptoms of covid 19

Answer 29

most ppl have - fever, cough, fatigue, myalgia, anorexia, SOB. Other non-specific symptoms,
such as sore throat, nasal congestion, headache, diarrhoea, nausea and vomiting, have also been reported. sometimes neurological manifestations have also been reported.

Question 30

common prodrome of covid?

Answer 30

Loss of smell (anosmia) or loss of taste (ageusia) preceding the onset of respiratory symptoms have also been reported.

Question 31

what do older ppl or ppl who are immunocompromised present with if they have covid?

Answer 31

Older people and people who are immunosuppressed in particular may present with atypical symptoms such as reduced alertness, reduced mobility, diarrhoea, loss of appetite, confusion and absence of fever.

Question 32

what are the different Definitions of disease severities in covid-19 in adults?

Answer 32

1. mild - Patients with symptoms meeting the case definition for COVID-19 without evidence of viral pneumonia or hypoxia
2. moderate (covid 19 pneumonia)- Adolescents or adults with clinical signs of pneumonia (fever, cough, dyspnoea, fast breathing) but no signs of severe pneumonia, including SpO2 90% or more on room air.

3.severe (severe covid 19 pneumonia) - Adolescents or adults with clinical signs of pneumonia (fever, cough,
dyspnoea, fast breathing) plus 1 of the following: respiratory rate more than 30 breaths per minute; severe respiratory distress; or SpO2 less than 90% on room air

4. critical disease - can be either ARDS, sepsis or septic shock

Question 33

give some signs of sepsis related organ dysfunction

Answer 33

altered mental status, difficult or fast breathing, low oxygen saturation, reduced urine output, fast heart rate,
weak pulse, cold extremities or low blood pressure, skin mottling, laboratory evidence of coagulopathy, thrombocytopaenia, acidosis, high lactate and hyperbilirubinaemia.

Question 34

management of covid in the community?

Answer 34

cough:
- Encourage people with cough to avoid lying on their backs, if possible, because this may make
coughing less effective.
- people over 1 year with cough to take 1 teaspoon of honey
- only if cough is distressing: codeine linctus, codeine phosphate tablets or morphine sulfate oral solution in over 17s

fever:

• drink fluids regularly to avoid dehydration
• paracetamol or ibuprofen

breathlessness:
- Identify and treat reversible causes of breathlessness (eg PE, pulmonary oedema, etc.)
- keeping the room cool
- encouraging relaxation and breathing techniques, and changing body positioning
- opening windows and/doors
- if hypoxia is likely cause of SOB: consider a trial of oxygen therapy and discuss with the person, their family or carer possible transfer to and evaluation in secondary
care.