Infectious diseases Flashcards
For soft/tissue & musculoskeletal & line infections , state the antibiotic of choice for:
1. Staphylococcus infection e.g. staph aureus
2. Streptococcus e.g. group A strep
Also:
- List antibiotic options if Penicillin allergy (3)
- List antibiotic of choice for MRSA
Staphylococcus: Penicillin (Flucloxacillin)
Streptococcus: Benzylpenicillin or Flucloxacillin
Penicillin allergy:
- Tetracycline (Doxycycline)
- Carbapenem (e.g. Meropenem)
- Cephalosporin (e.g. Ceftriaxone)
MRSA:
- Glycopeptide (e.g.Vancomycin or Teicoplanin)
For mixed diabetic foot infections (e.g. Pseudomonas and Enterobacteriacae), list the antibiotics of choice (2)
- Penicillin (e.g. Tazocin)
- Carbapenem
List the antibiotics of choice for streptococci pneumonia respiratory infection (2)
- Penicillin (Amoxicillin)
- Macrolide (e.g. Clarithromycin or Erythromycin)
List the antibiotic of choice for Haemophilus influenza respiratory infection
Co-Amoxiclav (Amoxicillin and Clavulinic Acid)
List the antibiotic of choice for atypical respiratory infections e.g. Legionella or Mycoplasma
Tetracycline (Doxycycline)
List the anti-microbial treatment of choice for Influenza infection
- Oseltamivir
List the antibiotics of choice for severe Enterobacteriacae gastrointestinal infection (2)
- Fluroquinonlones (e.g. Ciprofloxacin)
- Macrolide (e.g. Clarithyromycin or Azithromycin)
List the antibiotics of choice for (typhoid) salmonella gastrointestinal infection (2)
- Macrolide (Azithromycin)
List the antibiotics of choice for Clostridium difficile gastrointestinal infection (2)
- Metronidazole
- Glycopeptide (Vancomycin)
List the antibiotics of choice for peritonitis / visceral infection (3)
Give another option if severe infection or penicillin allergy
- Co-amoxiclav
- Fluroquinolone (Ciprofloxacin)
- Aminoglycoside (e.g. Gentamicin)
Other option:
- Carbapenem
List the antibiotic of choice for Enterobacteriacae infection of the genitourinal tract for:
- Mild infection
- Moderate/severe infection
Mild infection:
- Oral Trimethoprim
- Oral Nitrofurantoin
Moderate/severe infection:
- IV Co-Amoxiclav
- Oral Fluroquinolone (Ciprofloxacin)
List the antibiotic of choice for pseudomonas aerogenosa infection of the genitourinal tract (2)
List an alternative antibiotic if resistant for beta-lactamases
- Fluroquinolone (Ciprofloxacin)
- Aminoglycoside (Gentamicin)
- Penicillin (Tazocin)
Alternative:
- Carbapenem
List the antibiotic of choice for Gonorrhoea infection of the genitourinal tract:
IM / IV Cephalosporin (Ceftriaxone)
List the antibiotic of choice for Chlamydia infection of the genitourinal tract:
- Macrolide (Azithromycin)
List the antibiotic of choice for infection of the CNS with: Strep pneumoniae, Neisseria Meningitidis or H Influenzae
IV Cephalosporin (e.g. Ceftriaxone)
List the antibiotic of choice for endocarditis with the following infections:
- Streptococci (strep viridians)
- Enterococci (e.g. E. Faecalis)
- Staph aureus
- ‘Culture negative’ endocarditis
- If resistant
Streptococci (strep viridians):
- Penicillin (Benzylpenicillin)
- With or without Aminoglycoside (Gentamycin)
Enterococci (e.g. E. Faecalis):
- Penicillin (Amoxicillin)
- With or without Aminoglycoside (Gentamycin)
Staph aureus:
- Penicillin (Flucloxacillin)
- With or without Aminoglycoside (Gentamycin)
‘Culture negative’ endocarditis
- Cephalosporin (Ceftrioxone)
If resistant:
- Glycopeptide (Vancomycin)
State the antibiotic of choice for treating Sepsis (before blood cultures have been taken), including the method of administration and dose
Meropenem IV 1g stat
Type of Carbapenem
List some common travel-associated infections that may occur with the following time frames:
0-10 days
10-21 days
21+ days
0-10 days:
Dengue fever
Viral illnesses
Gastrointestinal infection
10-21 days:
Malaria
Typhoid
Primary HIV infection
21+ days:
Malaria
Chronic bacterial infections e.g. Endocarditis, Brucella, Coxiella
TB
Parasitic infections
List suspected diseases for the following skin changes (following recent travel)
- Maculopapular rash
- Rose spots
- Black necrotic tissue
- Petechiae / ecchymoses / haemorrhagic lesions
Maculopapular rash:
- Dengue
- Primary HIV infection
- Childhood viruses e.g. Rubella
Rose spots:
- Typhoid fever
Black necrotic tissue:
- Rickettsia
Petechiae / ecchymoses / haemorrhagic lesions:
- Dengue fever
- Meningococcemia
- Viral haemorrhagic fever
List some differentials for patients presenting with splenomegaly after recent travel
- Malaria
- Typhoid fever
- EBV (Infectious mononucleosis)
- Brucellosis
List some differentials for patients with altered mental state and fever in a recently returned traveller (what is the overarching medical emergency?)
Overarching medical emergency: meningo-encephalitis
Differentials:
- Japanese encephalitis
- West Nile viral encephalitis
- Cerebral malaria
But don’t forgot more common causes e.g. Neisseria Menigitidis or Strep pneumonia
(Respiratory infection)
Pneumonia / lower respiratory tract infection - state the following:
- Pathophysiology
- Common bacteria (2)
- Presentation
- Investigations
- Management
Pathophysiology:
- Simply an infection of the lung tissue
- Leads to inflammation and production of sputum that fills the airways and alveoli
- Divided into community acquired pneumonia (CAP) or hospital acquired pneumonia (HAP) or aspiration pneumonia
Common bacteria (2):
- Streptococcus pneumoniae (50%)
- Haemophilus influenzae (20%)
Presentation:
- Shortness of breath
- Productive cough (sputum production)
- Chest pain (sharp, worse on inspiration)
- Fever
- Haemoptysis
- Delirium associated with infection
- Sepsis
Investigations:
- Calculate CURB score (if 0 or 1, may not need investigations)
- Routine blood tests e.g. FBC, U&Es, CRP
- Chest x-ray
(If moderate-severe infection)
- Sputum cultures
- Blood cultures
Management:
- Mild 5 day course oral antibiotics of Amoxicillin (or Doxycycline)
- Moderate-severe 5 day course dual oral antibiotics (Amoxicillin AND Doxycycline)
List the 5 causes of atypical pneumonia (legions of psittaci MCQs)
Legionella pneumophila (Legionnaires’ disease)
Chlamydia psittaci
Mycoplasma pneumoniae
Chlamydia pneumoniae
Q fever (Coxiella Burnetii)
(Cardiac infection)
Endocarditis - state the following:
- Pathophysiology
- Risk factors
- Common bacteria (2)
- Presentation
- Investigations
- Management
Pathophysiology:
- Infection of the endocardium (inner lining of heart chambers and valves)
- Caused by bacteria/fungi in blood stream
- Must have damage to the endocardium for endocarditis to occur
- Mostly occurs on left side of the heart (80-90%)
Risk factors:
- Previous endocarditis
- IV drug use
- Heart valve replacement
- Congenital heart defects
- Heart valve disorders / hypertrophic cardiomyopathy
Common bacteria (2):
- Staphylococcus aureus
- Viridans alpha-hemolytic streptococci
Presentation:
- Fever
- Tachycardia
- Splinter haemorrhages / Janeway lesions / Osler nodes
- Fatigue / malaise
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Echocardiogram
- ECG
- Chest x-ray
- Blood cultures
Management:
- Antibiotics depending on infective microorganism
Staphylococcus e.g. aureus: IV Flucloxacillin plus oral Gentamicin
Streptococcus e.g. viridans: IV Benzylpenicillin plus Gentamicin
May consider surgery
(CNS infection)
Meningitis - state the following:
- Pathophysiology
- Common causative organisms (bacterial and viral)
- Presentation
- Investigations
- Management
Pathophysiology:
- Inflammation of the meninges
Common causative organisms:
- Can be bacterial or viral
Bacterial: Neisseria Meningitidis or Streptococcus Pneumoniae
Viral: Herpes Zoster, Varicella Zoster or Enterovirus
Presentation:
- Fever
- Neck stiffness
- Photophobia
- Headaches
- Vomiting
- Altered consciousness
- Seizures
- Non-blanching rash (if meningococcal septicaemia)
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Lumbar puncture
- Meningococcal PCR test (blood test)
- Blood cultures
- Bacterial throat swabs
Management:
(Bacterial)
- Give antibiotics within 1 hour: IV ceftriaxone 2g immediately (continued every 12-hours initially)
- IV Dexamethasone 10 mg every 6 hours
- Notify public health (notifiable disease) - may need to track close contacts within last 7 days
(Viral)
- Often milder, so supportive treatments
- Can use Aciclovir for Varicella Zoster infections
Outline 2 special tests for meningitis
- Kernig’s test
- Bend leg to flexion at 90 degrees
- Normal: no pain on straightening leg upwards
- Abnormal: pain on straightening leg upwards - Brudzinski’s test
- Normal: neck lifted, legs remain flat/straight
- Abnormal: neck lifted, hips and knees bend too
List some complications of meningitis
- Hearing loss (give steroids)
- Seizures and epilepsy
- Cognitive impairment and learning disability
- Memory loss
- FOcal neurological deficits e.g. limb weakness
Outline the results of a lumbar puncture in bacterial meningitis and viral meningitis
Appearance
Protein
Glucose
WCC
Culture
Appearance
Normal: clear
Bacterial: cloudy
Viral: clear
Protein
Bacterial: raised
Viral: normal or mildly raised
Glucose
Bacterial: reduced
Viral: normal
WCC
Bacterial: raised with neutrophils
Viral: raised with lymphocytes
Culture
Bacterial: positive for bacteria
Viral: negative
List some complications of meningitis
- Hearing loss
- Seizures and epilepsy
- Cognitive impairment and learning disability
- Memory loss
- FOcal neurological deficits e.g. limb weakness
(CNS infection)
Encephalitis - state the following:
- Pathophysiology
- Common causes
- Presentation
- Investigations
- Management
Pathophysiology:
- Inflammation of the brain parenchyma
Common causes:
Primary infection - most commonly viral:
- Herpes simplex
- Varicella zoster
- MMR (measles, mumps and rubella)
- Tick-borne encephalitis
- Japanese encephalitis
- Rabies
Secondary infection - immune system:
- Post-viral
- Tumour
- Post-vaccination
Presentation:
- Fever
- Headaches
- Vomiting
- Altered consciousness
- Focal neurological deficits
- Seizures
- Myalgia
May also develop meningitis symptoms: neck stiffness and photophobia
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- CT or MRI head
- Lumbar puncture
- EEG (electroencephalogram)
Management:
Treat the cause!
- Antivirals
- Steroids
- Plasmapheresis
- Immunoglobulin therapy
- Surgery to remove any tumours
- Supportive therapy e.g. IV fluids, anti-epileptic medication, analgesia, oxygen
(GI infection)
Gastroenteritis - state the following:
- Pathophysiology
- Common causes
- Presentation
- Investigations
- Management
Pathophysiology:
- Inflammation of the stomach and intestines (gastro & enteritis)
Common causes:
Mostly viral
However, many bacteria can also cause gastroenteritis
Presentation:
- Nausea and vomiting
- Diarrhoea
- Fever
- Abdominal pain
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Stool culture with microscopy and sensitivties
Management:
Targeted towards underlying cause
- Isolation of patient
- Patient education regarding hygiene
- Rehydration solution or IV fluids
- 48 hrs away from school/work until symptoms have completely resolved
- Antibiotics not given unless patient is at high risk of complications and once organism has been identified
State some common causes of gastroenteritis - viral, bacterial and parasite
Viral:
- Norovirus
- Rotavirus
- Adenovirus
Bacteria:
- E Coli
- Campylobacter Jejuni
- Shigella
- Salmonella
- Bacillus Cereus
- Yersinia Enterocolitica
- Staphylococcus Aureus toxin
Parasite:
- Giardiasis
List some complications of gastroenteritis
- Lactose intolerance
- IBS
- Reactive arthritis
- Guillian-Barre syndrome
(GI infection)
Clostridioides Difficile - state the following:
- Pathophysiology
- Risk factors
- Presentation
- Investigations
- Management
Pathophysiology:
- Spore-forming anaerobic bacteria causing inflammation of the large colon
Risk factors:
- Recent antibiotic use (especially broad spectrum)
- Recent stay in hospital
- Immunosuppression
- Previous infection with C.Diff
- > 65 years
Presentation:
- Diarrhoea
- Fever
- Nausea and vomiting
- Abdominal pain
- Loss of appetite
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Stool culture, microscopy and sensitivities
Management:
- Antibiotics, specifically oral Metronidazole or oral Vancomycin
- Newer treatments: Faecal microbiota transplant
(Urinary infection)
Cystitis (lower UTI) - state the following:
- Pathophysiology
- Risk factors
- Presentation
- Investigations
- Management
Pathophysiology:
- Infection of the bladder
- Usually E Coli which ascends from the urinary tract
Risk factors:
- Young
- Sexually active
- Female
- Poor hygiene
Presentation:
- Urinary frequency
- Nocturia
- Suprapubic pain
- Dysuria
- Cloudy urine
- Urgency
- Fever
- Haematuria
Investigations:
May not need further investigations
- Urine dipstick
Management:
- Nitrofurantoin for 3 days (Trimethoprim second line)
- If complicated, for 7 days
(Urinary infection)
Pyelonephritis (upper UTI) - state the following:
- Pathophysiology
- Risk factors
- Presentation
- Investigations
- Management
Pathophysiology:
- Infection of the ureters and kidneys
- Usually from E Coli which ascends from the urinary tract, further up to the kidneys
Risk factors:
- Young
- Sexually active
- Female
- Poor hygiene
Presentation:
- Flank pain
- Vomiting
- High fever
(other cystitis symptoms)
- Haematuria
- Urinary frequency
- Nocturia
- Suprapubic pain
- Dysuria
- Cloudy urine
- Urgency
- Fever
Investigations:
- Urine dipstick
- Midstream urine sample for MCS
- Blood cultures and assess for Sepsis
Management:
- Oral Co-amoxiclav for 10 days
(Soft tissue and skin infections)
Cellulitis - state the following:
- Pathophysiology
- Presentation
- Classification system
- Investigations
- Management
Pathophysiology:
- Infection of the skin and underlying soft tissues
- Commonly caused by staph aureus
Presentation:
- Erythema (rubor)
- Calor
- Dolor
- Tubor
- Bullae (fluid filled blisters)
- Tight skin
- Gold-yellow crust (suggests staph aureus infection)
Classification system:
Eron classification
Class 1: no systemic toxicity
Class 2: systemic toxicity
Class 3: significant systemic toxicity
Class 4: sepsis / life threatening infection
Investigations:
- Bloods (FBC, U&Es, CRP)
- Blood cultures
Management:
- Oral or IV Flucloxacillin (IV if class 3 or 4 Eron classification)
(Soft tissue and skin infections)
Necrotising fasciitis - state the following:
- Pathophysiology
- Presentation
- Investigation / Management
Pathophysiology:
- Bacterial infection of the skin, soft tissue and fascia
Presentation:
- Generally features of sepsis
- Pain out of proportion to site of injury
- Fever
Investigation / Management:
- Immediate referral to surgical team for inspection, exploration and debridement of infected tissue (can use finger test)
- Blood culture
- Tissue culture
- May need CT if unsure
(Soft tissue and skin infections)
Diabetic foot infection - state the following:
- Risk factors
- Presentation
- Investigations
- Management
Risk factors:
- Abnormal distribution of pressures due to structural abnormalities (e.g. bunions, hammer or mallet toes) or gait abnormalities
- Impaired protective mechanisms (e.g. dry skin, immune system abnormalities, peripheral artery disease)
- Impaired recognition due to sensory neuropathy and/or visual impairments
Presentation:
- Local swelling
- Erythema (>0.5 cm around the wound)
- Localised pain
- Localised warmth
- Purulent discharge
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Blood glucose measurement (consider HbA1c)
- Pedal pulse examination or Doppler assessment
- X-ray of foot
- Tissue biopsy / sample
Management:
- Wound debridement and dressings
- Offloading of foot (casts)
- Antibiotics based off tissue sample, generally Flucloxacillin if mild infection (no abx if no evidence of infection)
- Control of ischaemia e.g. angioplasty
(MSK infection)
Septic arthritis - state the following:
- Pathophysiology
- Presentation
- Common causative organisms
- Investigations
- Management
Pathophysiology:
- Infection within a joint itself
- Can be in natural joint or as a complication of joint replacement
Presentation:
- Erythema
- Swelling
- Pain within joint
- Hot joint
- Reduced ROM and stiffness
- Systemic symptoms: fever, fatigue and sepsis features
Common causative organisms:
- Staphylococcus aureus (most)
- Neisseria gonorrhoea
- Group A streptococcus
- Haemophilus influenzae
- E Coli
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Joint aspiration and send for: gram staining, crystal microscopy, culture and sensitivities
Management:
- Treat as presumed septic arthritis until this has been disproved
- IV empirical antibiotics until microorganism is known from joint aspiration
- Flucloxacillin plus Rifampicin (first line)
- Usually for 3-6 weeks
*Consider joint washout and joint replacement if infection occurs in a prosthetic joint
List some differential diagnoses for a hot, swollen joint
- Gout
- Pseudogout
- Reactive arthritis
- Haemarthrosis
(MSK infection)
Osteomyelitis - state the following:
- Pathophysiology
- Risk factors
- Presentation
- Common causative organism
- Investigations
- Management
Pathophysiology:
- Infection of the bone (acute or chronic)
- Children: generally in long bones of arms or legs
- Adults: generally in hips, spine or feet
- Primarily from bacteria in bloodstream, but can also be from nearby cellulitis or direct trauma (especially in DFI)
Risk factors:
- Recent open fracture or orthopaedic surgery
- Poorly controlled diabetes
- Immunosuppression e.g. chemotherapy
- IV drug use
- Peripheral arterial disease
Presentation:
- Erythema
- Swelling
- Pain in affected area
- Hot joint
Common causative organism:
- Staphylococcus aureus (most)
Investigations:
- Routine bloods (FBC, U&Es, CRP)
- Blood culture
- Bone biopsy and sinus swab specimens
- Plain x-ray of affected area (including joints above and below) or CT or MRI
Management:
- IV Flucloxacillin for 6 weeks (1st line)
- If foreign body in place e.g. fixation metal, this is likely to be removed as a source of infection
State some changes that could be seen on imaging of osteomyelitis
- Oedema
- Periosteal thickening
- Osteopenia / bony lysis
- Scalloped bone edges
Suggest some questions you may want to ask a returning traveller with symptoms
Where did they travel?
How long have the symptoms been present for?
What symptoms do they have (which system is affected)?
What activities did they do whilst travelling?
Is anyone else in their travelling party affected?
Did they have any healthcare treatment whilst travelling?
Did they have any pre-travel vaccinations or prevention treatments
In a returning traveller with a fever, suggest some investigations that might be appropriate
Routine bloods (FBC, LFTs, U&Es)
Blood cultures
Malaria films or rapid diagnostic test
HIV test
Urine and stool culture
Chest x-ray or ultrasound of liver and spleen
Serology / PCR for specific diseases (e.g. dengue or other arboviruses)
Suggest some differentials for patients returning from travel, with jaundice
- Malaria
- Viral hepatitis
- Leptospirosis
Suggest some differentials for patients returning from travel, with a maculopapular rash
- Dengue
- HIV
- Syphilis
- Typhus
Suggest some differentials for patients returning from travel, with a urticarial rash
- Schistosomiasis
- Strongyloides (threadworm)
Suggest some differentials for patients returning from travel, with bloody diarrhoea
- Shigella
- Salmonella
- Ameobiasis (Entamoeba histolytica)
Suggest some differentials for patients returning from travel, with hepatomegaly
- Malaria
- Viral Hepatitis
- Leptospirosis
- Typhoid Fever
Suggest some differentials for patients returning from travel, with splenomegaly
- Malaria
- Visceral Leishmaniasis
Malaria - state the following:
- Pathophysiology and mechanism of spread
- Countries with high risk
- Presentation
- Investigations
- Management
Pathophysiology and mechanism of spread:
- Infectious disease caused by parasites (plasmodium family)
- Spread by bites of female anopheles mosquitoes, usually at night
Countries with high risk:
- Sub Saharan Africa
- South-east asia
Presentation:
- Recent travel to country with high incidence of malaria
- Jaundice / pruritus (from haemolytic anaemia)
- Fever
- Rigors
- Headache
- Myalgia
- Nausea and vomiting
(also hepatosplenomegaly)
Investigations:
- Routine bloods (FBC, U&Es, LFTs, CRP)
- Malaria blood film (EDTA bottle) over 3 consecutive days
- CT/ultrasound of liver
- Serology to look for viral hepatitis and other diseases
- Blood cultures (exclude other causes)
Management:
- Anti-malarial treatment once confirmed on blood film
Uncomplicated malaria with Falciparum: Artemisinin based combination therapies (ACTs) = oral Riamet®
Severe malaria: IV Quinine and Artesunate
- Monitor blood films until parasite cleared
List the 4 main types of malaria parasite (highlight the most severe type)
Plasmodium Falciparum (most severe type)
Plasmodium Vivax
Plasmodium Ovale
Plasmodium Malariae
List some complications of malaria infection with Plasmodium Falciparum (most severe type)
AKI / Renal failure
Seizures
Reduced consciousness
Pulmonary oedema
DIC
Severe haemolytic anaemia
Multiorgan failure and death
List the 3 types of anti-malaria prophylaxis tablets
Malarone (Atovaquone/Proguanil):
- Expensive
- Best side effect profile
Mefloquine:
- Can cause bad dream and rarely, seizures or psychotic disorders
Doxycycline:
- Side effects of photosensitivity, diarrhoea and thrush
Describe the principle of ‘pyrexia of unknown origin’ and the 4 types of categories that can be used
Describes a fever of above 38.3 degrees, lasting for > 3 weeks, that evades diagnosis
Pyrexia of unknown origin can be considered in four categories:
- Infective
- Inflammatory / autoimmune
- Malignancy
- Miscellaneous
Suggest baseline primary investigations that can be performed for ‘pyrexia of unknown origin’
Bloods:
- FBC
- U&Es
- LFTs
- CRP
- Erythrocyte sedimentation rate (ESR) as a marker of inflammation
- Clotting screen
- Creatine kinase
- 2 or more blood cultures
- HIV test.
Imaging:
- Chest X-ray
- Ultrasound abdomen
Other:
- Urine dipstick
Can do more specialised secondary tests once PUO is better understood / idea of category of PUO
List some common causes of immunosuppression (disease and medication induced)
Disease:
- HIV infection
- Haematological cancers / malignancies e.g. lymphoma or leukaemia
- Autoimmune conditions e.g. RA, lupus, T1DM
- Immunodeficiency conditions
- Sickle cell disease (affects spleen)
Medication:
- Post-organ transplantation e.g. Mycophenolate Mofetil
- Corticosteroids e.g. Hydrocortisone
- Chemotherapy agents
List some diseases that immunosuppressed patients are more at risk of:
Bacterial
Viral
Fungal
Parasitic
Bacterial:
- TB (pulmonary and extrapulmonary)
- Mycobacterial infections
- Encapsulated bacteria: streptococcus pneumoniae, haemophilus influenzae, Neisseria meningitidis
- Non-typhoidal salmonellosis
- Melioidosis
- Syphilis
Viral:
- Arboviruses
- Coxsackie virus, cytomegalovirus (CMV)
- Epstein–Barr virus (EBV)
- Parvovirus
Fungal:
- Aspergillosis
- Candidiasis
- Cryptococcosis
- Endemic mycoses
- Histoplasmosis
- Pneumocystis jirovecii
Parasitic:
- Visceral leishmaniasis
Outline general management for pyrexia of unknown origin
Management should be supportive until the cause of pyrexia has been determined
Therapeutic trials of antimicrobials or steroids are not recommended (can mask signs/symptoms of underlying disease process)
Mortality of patients with PUO is generally low, especially patients that are seen as outpatients. Undiagnosed patients may be reassured that their prognosis is likely to be good, despite possible continuation of symptoms.
Outline how infections affect immunocompromised patients differently, compared to patients with normal immune systems
- Infections can be atypical and opportunistic (commensal bacteria can cause infection)
- Infections can progress more rapidly
- Infections can take longer to clear
- Usual symptoms may be absent
List some infections that individuals with HIV can be at higher risk of
- Oral candidiasis
- Kaposi’s sarcoma
- Hairy leukoplakia
- Pneumocystis jirovecii
- Reactivation of TB
List some clinical features and clinical findings that suggests a Malaria infection is SEVERE
- Clinical features (symptoms)
- Clinical findings (signs)
Clinical features (symptoms)
- Reduced GCS / consciousness
- Weakness meaning inability to walk without assistance
- > 2 convulsions in 24 hrs
- Very low blood pressure (< 80mmHg systolic)
- Spontaneous bleeding
Clinical findings (signs)
- AKI
- Hyperlactaemia / metabolic acidosis
- Pulmonary oedema / sats < 92% / resp rate > 30
- Hypoglycaemia
- Haemoglobinuria (Hb in urine)
- Anaemia (severe and normocytic)
List some factors that increase the risk of an individual coming into contact / acquiring TB
- Birth in a TB high prevalence country (Indian sub-continent and Sub-saharan Africa)
- Prison
- Drug and alcohol consumption
- Poor/crowded housing or homelessness
- Known contact with active TB
- Previous TB disease
Outline the meaning of antimicrobial stewardship
Interventions to improve and measure the appropriate use of antibiotics by promoting the optimal antimicrobial therapy e.g. dose, route, type
- Minimise toxicity and other adverse events
- Reduce cost of infections
- Limit selectivity for resistant strains
List the side effects of the 4 TB medications
Rifampicin (red-an-orange pissin)
- Orange urine/tears
- Hepatitis +
Isoniazid (I’m so numb-a-zoid)
- Peripheral neuropathy
- Hepatitis ++
GIVEN WITH PYRIDOXINE (B6) to prevent peripheral neuropathy
Ethambutol (eye-thambutanol)
- Optic neuropathy / reduced visual acuity
Pyrazinamide
- Hepatitis +++ (most severe)
- Hyperuricaemia / gout
(Gastrointestinal infection)
Hepatitis B - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Hepatitis B virus causes acute inflammation of liver, most don’t progress to chronic inflammation
- Transmission: blood/sex/vertical
Presentation:
Acute infection
- Abdominal pain
- Intrahepatic jaundice
- Nausea and vomiting
- Arthralgia
- Fatigue
- Deranged LFTs
Investigations:
- Hepatitis B serology
Management:
- No cure
- Can use lifelong anti-retrovirals
- Vaccination available for prevention
(Gastrointestinal infection)
Hepatitis C - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Hepatitis C virus causes acute inflammation of liver, which mostly progresses to chronic inflammation
- Transmission: blood/sex/vertical
Presentation:
- Most people have no symptoms in acute or chronic phase
Investigations:
- Hepatitis C serology (just anti-Hep C antibody)
Management:
- Cured with anti-viral drug combination
- No vaccination available
Tuberculosis - state the following:
- Pathophysiology
- Common extrapulmonary colonisation sites
- Presentation
- Investigations
- Management
Pathophysiology:
- Mycobacterium tuberculosis bacteria
- Inhaled through droplets of an actively infected individual
- Spreads through the lymphatics and blood
- TB can be active or latent
Common extrapulmonary colonisation sites:
- Lymph nodes
- Pleura
- Pericardium
- GI system
- Genitourinary system
- Subcutaneous
- CNS
- Bones and joints
Presentation:
- Weight loss
- Night sweats
- Cough +/- haemoptysis
- Lethargy
- Erythema nodosum
- Lymphadenopathy
- Spinal pain (if spinal TB)
Investigations:
- Mantoux test or QuantiFERON gamma
- Sputum cultures (if suspect active disease)
- Chest x-ray (if suspect active disease)
Management:
Acute pulmonary TB: RIPE
- Rifampicin
- Isoniazid (plus Pyridoxine)
- Pyrazinamide
- Ethambutol
Latent TB (at risk groups): 3 months of Rifampicin and Isoniazid OR 6 months of Isoniazid
Other:
- Test for other infectious disease e.g. HIV, Hepatitis
- Notify Public Health
- Contact tracing
- Isolation in -ve pressure rooms
Explain when you would use a Mantoux test vs QuantiFERON test in suspected TB (briefly explain each test)
Mantoux test:
- Looks for previous immune response to TB
- Inject Tuberculin (protein from TB)
- Positive result (bleb under skin) indicates previous exposure to TB
- This includes active TB, latent TB or previous BCG vaccination
QuantiFERON:
- Mix blood sample with TB antigens
- Positive result is release of interferon gamma by white cells (indicates previous exposure)
QuantiFERON can be used to confirm latent TB, in someone with a positive Mantoux test but no active disease
HIV - state the following:
- Pathophysiology
- Transmission
- Presentation
- Investigations
- Management including monitoring
Pathophysiology:
- Human immunodeficiency virus (HIV-1 most common), RNA retrovirus
- Virus enters and destroys CD4 cells
- Initial seroconversion, then asymptomatic until further along and immunocompromised
Transmission:
- Unprotected sex (oral, vaginal, anal)
- Vertical transmission
- Exposure to infected blood e.g. needlestick, blood splash in eye
Presentation:
- Initial flu-like symptoms (seroconversion)
- Generally asymptomatic for a period of years
- Symptomatic with atypical or opportunistic infections e.g. PCP or candidiasis
Investigations:
- Antibody blood test
- Can also do a PCR test
Management:
- Anti-retroviral treatment (ART)
- Single tablet once daily
- Recommended 2 NRTI and 1 other agent
- Aim of treatment: undetectable viral load and normal CD4 count
Monitor disease with CD4 count (<200 is end-stage HIV/AIDS) and viral load
Outline some AIDS-defining illnesses
Occurs when CD4 count has dropped significantly
- Kaposi’s sarcoma
- PCP (pneumocystis jirovecii pneumonia)
- TB
- Candidiasis (oesophageal or bronchial)
- Cytomegalovirus infection
- Lymphomas
List some highly active anti-retroviral therapy (HAART) medications for HIV
- Nucleoside reverse transcriptase inhibitors (NRTI)
- Integrase inhibitors (II)
- Protease inhibitors (PI)
- NON-nucleoside reverse transcriptase inhibitors (N-NRTI)
- Entry inhibitors (EI)
List some additional measures to prevent complications of HIV in patients
Prophylactic Septrin - prevent pneumocystis jirovecii pneumonia (PCP) if CD4 < 200
Yearly cervical smears - increased risk of HPV and cervical cancer
Up to date vaccinations, including:
- Flu
- Pneumococcal
- Hepatitis A and B
- Tetanus
- Diphtheria
- Polio
