Infectious Diseases Flashcards
Brucellosis (organism, endemic areas, exposure)
Organism: Brucella bacteria
Areas: NSW and QLD
Exposure: Wild pigs (i.e. pig hunters) through cuts and wounds
Hepatitis A (incubation, prognosis, complications, clinical features)
Incubation period: 15-45 days
Prognosis: Recovery in 3-6 weeks
Complications: Fulminant hepatitis (rare)
Clinical features: Pre-icteric (prodromal) phase - Anorexia, nausea +/- vomiting - Malaise - Headache - Distaste for cigarette in smokes - Mild fever \+/- diarrhoea \+/- upper abdominal discomfort
Icteric phase
- Dark urine
- Pale stools
- Hepatomegaly
- Splenomegaly
Hepatitis C - key points
● Curable
● Direct-acting antiviral drug are highly effective and well tolerated
● Goals of treatment: prevent liver cirrhosis, prevent transmission
● Treatment can be prescribed by specialists, GPs, nurse practitioners
○ GPs can prescribe independently without specialist guidance one they are experienced in
managing hepatitis C
Hepatitis C - who to test
IVDU Prison Sexual partner with hep C HIV or hepatitis B infection Child of mother with Hep C Evidence of liver disease Needle stick injury Tattoos or body piercing
Hepatitis C - how to test
- Perform hepatitis C virus antibody
- If positive, test for HCV RNA +/- genotyping
● In practice 1 + 2 would be performed together
● Not necessary given antivirals target genotype 1-6 but useful for individuals at high risk of
re-infection
● MBS funded
Hepatitis C - pretreatment assessment
- Confirm current hepatitis C infection (HCV RNA)
- Assess whether treatment-naive or previously treated and not cured
- Assess for presence of cirrhosis
Risk factors
- Longer duration of infection
- Alcohol consumption
- Obesity
- Type 2 diabetes
- Co-infection with hepatitis B or HIV
Examination
- Spider naevi, palmar erythema, gynaecomastia, splenomegaly
Investigations
- Pathology: Thrombocytopaenia, low albumin, prolonged PT/INR, aspartate aminotransferase-to-platelet ratio index > 1.0
- Imaging: FibroScan
Significance
- Determines treatment regimen and duration
- Needing ongoing surveillance for hepatocellular carcinoma, oesophageal varices and
osteoporosis - Consider whether patient has hepatitis B or HIV co-infection
- Review medications for potential drug interactions with direct-acting antiviral drugs
● Drug interactions between hepatitis C and HIV can be challenging and specialist input is
recommended - Consider pregnancy
- Consider whether patient has decompensated liver disease
Hepatitis C - medications and monitoring post-treatment
Medications
Consists one of 3 tablets and taken daily for 8 to 12 weeks.
● Patients with cirrhosis are treated for 12 weeks.
Monitoring after hepatitis C treatment
All: HCV RNA test at least 12 weeks after completion of treatment to confirm cure.
Long-term: For those with persisting liver pathology and at risk of reinfection.
Re-infection: Perform annual hepatitis C virus RNA in people with risk factors for hepatitis C reinfection.
Hookworm (key point, clinical features, diagnosis, treatment, prevention)
Key point
● Common in humid tropic regions
● Acquired by walking barefoot on earth contaminated by faeces - larvae penetrates the skin, travels through
the lungs and settle in the small intestine
Clinical features: local irritation/eruption at point of entry, followed by 1-2 weeks of respiratory symptoms, iron/protein
deficiency anaemia.
Diagnosis: faecal microscopy.
Treatment: Albendazole 400mg STAT
Prevention: Wearing shoes and socks in endemic regions.
Influenza A - oseltamivir doses
Needs to be dosed according to eGFR CrCl >60 75mg PO BD CrCl >30-60 30mg PO BD CrCl >10-30 30mg PO daily ESRD Not recommended
Leptospirosis (exposure, treatment)
Exposure: Through urine of affected animals
Treatment: Doxycycline 100mg PO BD for 7 days
Listeriosis (organism, exposure, significant, treatment)
Organism: Listeria monocytogenes
Exposure: contaminated food, unwashed vegetables, unpasteurised foods
Significant: Stillborn in pregnancy
Treatment: amoxicillin 1g PO/IV 8 hourly for 10-14 days
Measles (epidemiology, characteristic, pathology, complications, treatment, DHHS)
Epidemiology: endemic, immunity lifelong.
Characteristics: Koplik spots (tiny white spots like grains of salt, opposite the molars).
Pathology: Measles IgM rising 3-5 days after the onset of the rash.
Clinical features:
- Prodromal, 3-4 days, The three Cs’: cough, coryza and conjunctivitis
- Exanthema, 4-5 days, Blotchy, bright red maculopapular eruption. May become confluent and blanches under pressure.
- Convalescent, 7-10 days, Recover period.
Complications: otitis media, pneumonia, diarrhoea, miscarriage/premature delivery, encephalitis.
Treatment: No cure. Rest, avoid bright lights and stay in bed until fever subsides.
Prevention: MMR vaccine. Consider normal immunoglobulin ASAP from exposure if under 12 months or MMR is contraindicated.
Department of health advice:
1. Isolate suspected cases
2. Notify DHHS
3. Measles serology +/- PCR (PCR requires approval)
4. Offer MMR vaccine to eligible individuals (born after 1966, <14 years of age) - generally given 12 months
and 18 months
5F presenting with fever and lethargy. Returned from a trip from Brazil 2/7. Current outbreak of measles. COVID-19 negative.
- What are the six important findings in history and physical examination that would make you more suspicious of measles?
- What are the 4 immediate actions you need to take to reduce the risk of transmission of possible infection to others?
What are the six important findings in history and physical examination that would make you more suspicious of
measles?
● Lack of complete/2 doses of immunisation against measles
● Contact with suspicious case
● Coryzal symptoms at the beginning
● Dry cough
● Red eyes/conjunctivitis
● Classic descending exanthema of measles
● Koplik spots in the mouth
What are the 4 immediate actions you need to take to reduce the risk of transmission of possible infection to others?
- Isolate Maya
- Contact communicable disease prevention section of Department of Health
- Take blood for measles serology
- Record the details of the people who have been exposed to the case within the practice
- Discuss nasal swab for measles PCR with Department of Health
Pertussis (testing, prevention, treatment, vaccination, school exclusion)
Testing:
● 2-4 weeks: sputum PCR
● >3-4 weeks: serology (should not be performed <2 weeks)
Infectiousness: Nil after 3 weeks and antibiotic therapy after this point is not indicated.
Prevention:
1. Identify contacts (individuals who have been within 1 m for more than 1 hour)
2. Prescribe pertussis prophylaxis if:
● Infant < 6 months
● Women in the last month of pregnancy
● Individuals who may transmit pertussis to infants younger than 6 months
3. Start antibiotic prophylaxis ASAP (more benefit than harm if commenced within 14 days of first contact) -
aimed at preventing spread to those <6 months
4. Seek advice from local public health authority if uncertain
Treatment: Azithromycin 500mg STAT followed by 250mg for 4 days (total 5 days)
Vaccination: Close contacts that are not up to date with pertussis should be given booster ASAP
School exclusion: Unimmunised < 7 years must be excluded from school or childcare for 14 days from last exposure to infection or until they have taken 5 days of effective antibiotics
Pinworm infection (treatment, recommendation)
AKA: Threadworm infection.
Treatment: Albendazole 400mg (child <10kg 200mg) PO as single dose.
Recommendation: Consider repeating dose after 2 weeks and treatment household contacts/carers at the same time
due to risk of reinfection.
