infectious diseases Flashcards
Retro-orbital headache, fever, facial flushing, rash, thrombocytopenia in returning traveller →
?dengue
Patients with an uncertain tetanus vaccination history should be given ____
for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin
Pneumonia, peripheral blood smear showing red blood cell agglutination →
mycoplasma pneumonia
prophlyactic abx for animL BITE?
co-amoxiclav
travel Hx, prolonged fever, abdominal pain, constipation, ‘rose’ spots, bradycardia →
?typhoid fever
Abx recommended for pyelonephritis?
cephalosporin
quinolone
Resp Abx
1. CAP
2. Atypical pneumonia
3. HAP
- CAP: amoxicillin
- Atypical pneumonia: clarithromycin
- HAP: co-amoxiclav if within 5 days of admission, piperacillin with tazobactam if after 5 days
UTIs Abx
1. LUTI
2. Pyelonephritis
3. Prostatitis
- LUTI: trimethoprim/nitrofurantoin/amoxicillin
- Pyelonephritis: ceftazidime/ciprofloxacin
- Prostatitis: quinolone/trimethoprim
Abx for cellulitis near eyes or nose?
Co-amoxiclav
Otitis media vs otitis externa - Abx?
media: amoxicillin
externa: flucloxacillin
erythromycin for both if penicillin allergic
Abx for throat infections/sinusitis
phenoxymethylpenicillin (PenV) (erythromycin if allergic to penicllin)
STI Abx
1. Gonorrhea
2. Chlamydia
3. PID
4. Syphilis
5. BV
- Gonorrhea: ceftriaxone
- Chlamydia: doxycycline
- PID: doxycycline + ceftriaxone + metronidazole
- Syphilis: benathine benzylpenicillin (doxy/erythromycin if allergic)
- BV: metronidazole
Campylobacter enteritis Tx?
clarithromycin
___________ is a mass-like fungal vall that colonises an existing lung cavity (like TB, lung cancer, cystic fibrosis). _____ sign on Xray.
aspergilloma
crescent sign
undercooked or reheated rice is most associated with ___________.
bacillus cereus
most common causative organism in cellulitis
strep pyogenes
classification system used for cellulitis
Eron system
painful genital ulcers with sharply defined, ragged borders + unilateral painful inguinal lymph node =
chancroid
tropical disease caused by haemophilus ducreyi
classifying bacteria
- Gram-positive cocci: all strep, staph
- Gram-negative cocci: neisseria meningitidis, gonorrhoeae
- Gram-positive rods: ABCDL
Acintomyces
Bacillus anthracis
Clostridium
Diptheria
Listeria - Everything else is gram-negative rod:
E.Coli
H.influenzae
Pseudomonas
Salmonella
Shigella
Campylobacter
‘ground glass’ hepatocytes on light microscopy is associated with
chronic hepatitis (secondary to hep B infection)
__________is the second line choice antibiotic for MRSA, after vancomycin or teicoplanin
Linezolid
Latent tuberculosis treatment options:
3 months of isoniazid (with pyridoxine) and rifampicin, or
6 months of isoniazid (with pyridoxine)
Pt tests positive for MRSA before elective surgery - Tx?
Nasal mupirocin + chlorhexidine for the skin
Positive non-treponemal test + negative treponemal test is consistent with a
false-positive syphilis result
HIV, neuro symptoms, single brain lesions with homogenous enhancement -
CNS lymphoma
Fever, rash, chills and headache occurs following antibiotic administration for syphilis - Tx?
Jarisch-Herxheimer reaction
JHR generally requires supportive management with antipyretics and resolves within 24 hours.
____________ - stains with India ink
Cryptococcus neoformans
Streptococcus pneumoniae would have a gram-positive stain while Neisseria meningitidis would have a gram-negative stain. Mycobacterium tuberculosis would have a Ziehl-Neelsen (acid-fast) stain. In toxoplasmosis, the head CT usually shows single or multiple ring enhancing lesions, and mass effect may be seen.
______________ is an alternative to metronidazole for patients with bacterial vaginosis
Topical clindamycin
If a combined HIV test is positive
it should be repeated to confirm the diagnosis
HIV testing
- HIV antibodies
- people develop HIV ab 4-6 week after expsoure
- comprises ELISA + confirmatory Western Blot assay - p24 Antigen
- poitive from 1-4 weeks after exposure - Combined test (p24 and HIV ab)
- gold standard
- if positive, repeat test
- you can test HIV RNA levels at the same time
Test for HIV in asymptomatic Pts 4 weeks after possible exposure.
If negative, repeat in 12 weeks.
Start post-exposure prophylaxis within 72h of exposure.
Disseminated gonococcal infection triad -
tenosynovitis, migratory polyarthritis, dermatitis
Neisseria gonorrhoea
HIV seroconversion occurs when?
from 3-12 weeks
Which abx is C/I in long QR syndrome?
Clarithryomycin
what can cause false positive syphillis VDRL/RPR?
‘SomeTimes Mistakes Happen’ (SLE, TB, malaria, HIV)
Tx for typhoid fever?
Ceftriaxone
Which Abx is ecoli sensitive to extended spectrum beta-lactamase (ESBL)-producing Escherichia coli
meropenem
ESBLs exhibit hydrolytic activity against both penicillins and cephalosporins.
HIV, neuro symptoms, widespread demyelination –>
progressive multifocal leukoencephalopathy
neuro complictions of HIV:
- behavioural changes and speech, motor and visual impairment. MRI is the imaging modality of choice, identifying multifocal non-enhancing lesions, which represent widespread demyelination.
2.cognitive decline, behavioural changes and motor impairment. CT shows cortical and subcortical atrophy.
- meningism, nausea/vomiting, seizures and focal neurological deficits. Lumbar puncture often shows a high opening pressure and cerebral oedema may be seen on CT.
- This is associated with the Epstein-Barr virus and presents with various symptoms depending on lesion location. CT often shows a single brain lesion with homogenous enhancement.
- This accounts for around 50% of cerebral lesions in patients with HIV and often presents with constitutional symptoms, headache and confusion. CT commonly shows multiple ring-enhancing lesions.
Progressive multifocal leukoencephalopathy (PML)
AIDS dementia
Cryptococcus infection
Primary CNS lymphoma
Toxoplasmosis
Mx of primary CNS lymphoma
Mx of toxoplasmosis
Treatment generally involves steroids (may reduce tumour size), chemotherapy (e.g. methotrexate) and whole-brain irradiation. Surgical may be considered for lower grade tumours.
Management is with sulfadiazine and pyrimethamine.
swimmers itch + eosinophilia
schistosomiasis
Immunocompromised patients with toxoplasmosis are treated with
pyrimethamine plus sulphadiazine
Cause of false negative Mantoux tests include and are not limited to:
TB
AIDS
Long-term steroid use
Lymphoma
Sarcoidosis
Extremes of age
Fever
Hypoalbuminaemia
Anaemia
If a patient has had 5 doses of tetanus vaccine, with the last dose < 10 years ago,
they don’t require a booster vaccine nor immunoglobulins, regardless of how severe the wound is
which abx lowers seizure threshold
Ciprofloxacin lowers the seizure threshold
Epstein-Barr virus may result in which blood test abnormality
neutropaenia
most common reason for recurrent tonsilitis in a young person
glandular fever
Ciclosporin side-effects:
everything is increased - fluid, BP, K+, hair, gums, glucose
