Infection Flashcards
Malaria
- Sx
- Investigations
- Mx
Presentation:
* Fever, sweating, rigors
* Headache, fatigue, lethargy, weakness
* Myalgia, arthralgia
* Nausea and vomiting, abdominal pain, diarrhoea
* Hepatosplenomegaly, pallor, jaundice
Investigations:
* Thick and thin blood films indicate trophozoites (Figure 16.1).
* Rapid diagnostic tests (RDTs) for malarial antigens
* Full blood count (FBC), as anaemia is common, and thrombocytopaenia suggests P. falciparum.
* Clotting screen for prolonged PT
Management:
* Uncomplicated P. falciparum malaria can be treated with oral artemether/lumefantrine.
* IV artesunate is first-line treatment for severe or complicated P. falciparum malaria.
* Non-falciparum malaria is usually treated with oral chloroquine (+ primaquine for vivax or ovale)
TB
- presentation
- investigation
- screening
- Mx
- SEs of TB drugs
Presentation: Active TB presents with cough ± haemoptysis, dyspnoea, and systemic symptoms such as low-grade fever, malaise, drenching night sweats, anorexia, and weight loss.
Examination may reveal lymphadenopathy and finger clubbing if longstanding. Auscultation is often normal or may reveal crackles.
Investigations:
* Chest X-ray for upper-zone consolidation (see Figure 16.2) ± cavitation, lymphadenopathy, and pleural effusion
* Sputum for Ziehl–Neelsen stain, culture
* Nucleic-acid amplification test (NAAT)
* HIV test
Asymptomatic screening: Mantoux test or interferon-gamma release assay (IGRA) is used to detect latent TB.
Management:
* Initially rifampicin, isoniazid, pyrazinamide, and ethambutol (RIPE) for 2 months, then rifampicin and isoniazid are continued for an additional 4 months.
* TB is a notifiable disease in the UK.
Rifampicin SEs:
Hepatitis
Red/orange urine, sweat, tears
Flu-like symptoms
Isoniazid SEs:
Hepatitis
Peripheral neuropathy, hence given with prophylactic pyridoxine (vitamin B6)
Agranulocytosis
Pyrazinamide SEs:
Hepatitis
Gout, arthralgia, myalgia
Ethambutol:
Optic neuritis
Tetanus
- Cause
- Incubation
- Presentation
- Mx
Tetanus is caused by tetanospasmin, an exotoxin released by Clostridium tetani, an anaerobic rod-shaped Gram-positive bacterium commonly found in the soil.
Incubation period: 3 to 21 days (average, 10 days)
Presentation:
* History of compound fracture or wound contaminated with soil, manure, or foreign bodies or caused by rusted metal
* Prodrome of fever, malaise, and headache
* Muscular spasms and rigidity, opisthotonus
* Trismus (lock jaw), dysphagia, risus sardonicus
Management of tetanus:
* Wound debridement, tetanus booster
* IV tetanus immunoglobulin
* Benzodiazepine to treat muscle spasm
* Metronidazole is the antibiotic of choice.
* Supportive care with sedation and intubation
HIV:
- seroconversion & diagnosis
- testing
- management
Seroconversion occurs 3-12 weeks after infection with a glandular fever type illness
Diagnosis:
- HIV antbodies 4-6 weeks to 3 months post infection (ELISA and western blot)
- p24 antigen: 1-2 weeks post infection
- combo test GOLD STANDARD
- testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure
- after an initial negative result when testing for HIV in an asymptomatic patient, offer a repeat test at 12 weeks
Measles
- Cause
- Sx
- Mx
- Complications
RNA virus
Sx:
- prodromal phase - irritable, conjunctivitis, fever
- koplik spots on buccal mucosa
- rash: behind ears then whole body
- diarrhoea
Mx: supportive
Complications: otitis media, pneumonia, encephalitis
Otitis externa
- causes
- management
- malignant otitis externa cause, investigation & Mx
Cause: staph.aureus, pseudomonas aeruginosa
Management:
1st line: topical ABX or combine w steroid
2nd line: oral ABX e.g. flucloxacillin
If a patient fails to respond to topical antibiotics then the patient should be referred to ENT.
Malignant otitis externa:
Malignant otitis externa is more common in elderly diabetics.
Cause: pseudomonas aerginosa
Diagnosis: CT
Mx: IV ABX
Mastitis
- features
- Mx
Features
- painful red hot breast
- fever & malaise may be present
Mx:
1st line: continue breast feeding
simple measures: analgesia & warm compress
2nd line: flucloxacillin 10-14 days as staph.aureus is most common cause
CONTINUE BREAST FEEDING
Pneumonia:
- diagnosis in community
- diagnosis in hospital
Community:
CRB-65
C- confusion
R - resp >=30
B - BO sys<=90, dias<=60
65 >65
- 0: low risk
- 1-2: intermediate risk (consider hospital assessment)
- 3-4: urgent hosp admission
Hospital:
CRB-65
C- confusion
U - urea >7
R - resp >=30
B - BO sys<=90, dias<=60
65 >65
0-1: home-based care
2+: hospital based care
3+: ITU
Necrotising fasciitis
- cause
- features
- mx
- mortality
Subtypes:
1. type 1 - anaerobes/aerobes (post-surgical diabetics)
2. type 2 - strep pyogens
Sx: worsening cellulitis, fever, tachy
Mx: urgent surgical debridement + IV ABX
Mortality: 20%
