Respiratory infections Flashcards
What are parameters of CURB65 score?
Confusion Urea >7 RR >30 BP - systolic <90 or diastolic <60 Age >65
not validated for use in immunocompromsied patientd
What is risk of mortality for these CURB65 score?
0 or 1
2
3-5
0 or 1 - low risk, community treatment
2 - intermediate 3-15% risk mortality. Consider hospital care
3-5 - high risk. >15% mortality. May need ITU support
How long can legionella urinary antigen test remain positive?
Can remain positive for few weeks, even after being antibiotics. So can still be useful as diagnostic tool
only detects serotype 01
When should we suspect atypical pathogens?
in outbreak settings
infections in otherwise healthy individuals
atypicals - legionella, mycoplasma, chlamydia spp
Patients with COPD.
What are indications for long term antibiotic prophylaxis?
frequent exacerbations with sputum production
prolonged exacerbations
exacerbations requiring hospitalization
What are risks of influenza in pregnancy?
miscarriage
small-for-gestational age
increased risk of severe infection requiring ITU support
risk of secondary bacterial infection
21 year old returns from Saudia Arabia, with fever, cough, SOB.
CXR shows bilateral pulmonary infiltrates
What are potential diagnoses?
MERS-CoV
SARS-CoV
Hanta virus pulmonary syndrome
influenza - including avian influenza
Legionella
Mycoplasma
Coxiella burnetti
Chlamydia spp
Cryptococcus
Histoplasma
Tularaemia
Melioidosis
21 year old returns from Saudia Arabia, with fever, cough, SOB.
CXR shows bilateral pulmonary infiltrates
Tests positive for influenza. What are next steps?
Continue respiratory precautions
send for flu typing - assess for H5N1 or H7N9
treat with oseltamivir 75mg BD 5 days
in TB treatment, when is it considered
MDR-TB
XDR-TB
MDR-TB - if resistant to both isoniazid and rifampicin
XDR-TB - resistant to above, plus fluoroquinolone, plus injectable e.g amikacin
What are quick tests which can give idea about TB resistance in sample?
Gene Xpert (Cepheid) firstly confirms M. TB present
sputum processed to detect major mutation in rpoB, which accounts for 98% resistance against rifampicin
42 year old man with 18 weeks history of cough. CXR normal
Suspect pertussis.
Patient has had all vaccinatons in childhood
Wife is 36 weeks pregnant
How to diagnose pertussis?
Nasopharyngeal culture/ PCR
Pertussis IgG - if raised can suggest recent infection, as long as not immunised in past year
Clinical diagnosis - “whoop” cough or paroxysms of cough, for >14 days
42 year old man with 18 weeks history of cough. CXR normal
Suspect pertussis.
Patient has had all vaccinatons in childhood
Wife is 36 weeks pregnant
What is treatment?
Antibiotics reduce transmission, and so mostly used as public health measure
azithromycin 5 days
co-trimoxazole 14 days
no benefit is started after 21 days of symptoms
42 year old man with 18 weeks history of cough. CXR normal
Suspect pertussis.
Patient has had all vaccinatons in childhood
Wife is 36 weeks pregnant
Children aged 6 + 8 at home
What prophylaxis is recommended for family?
Prophylaxis for all household contacts, who have had contact within 21 days of patient, and at risk e.g health conditions, pregnant, unvaccinated. Combination of antibiotics and vaccination
Do not need prophylaxis if had vaccine booster within past 5 years
- Children vaccinated ages 2, 3, 4 months - would not require antibiotic prophylaxis, as vaccinated
- Unvaccinated, or no recent vaccination - give antibiotics, and vaccinate
- Pregnant mother - erythromycin safer in pregnancy. Mother should have had pertussis booster during pregnancy
Patient with pertussis
What are treatment options with someone with protracted cough?
Very little evidence, but these have been tried -
corticosteroids
b-eta agonists
antihistamines
pertussis immunoglobulin
What are benefits of using Taz/ gent in neutropenic sepsis?
Normally neutropenic as on chemotherapy, so at risk of certain organisms
Antibiotics will cover most organisms including pseudomonas
Patient with AML. Presents SOB - treated for neutropenic sepsis
CT chest shows patchy consolidation bilaterally, nodules, and halo sign
What are possible diagnoses?
Non-infective -
pulmonary oedema
leukaemic infiltration
drug toxicity
Viral - Influenza RSV parainfluenza adenovirus CMV
Chlamydia
Mycoplasma
Legionella
PCP
Cryptococcal
Nocardia
Aspergillus - nodules, halo sign, air crescent, all suggest angioinvasive aspergillus infection
How to diagnose pulmonary aspergillus infection?
BAL
culture for fungi
Beta-2-glucan
galactomannan
aspergillus PCR
PCP PCR
What is treatment of choice for pulmonary aspergillus?
Voriconazole
Ambisome
capsofungin
23 year old with CF.
Increase SOB.
Known colonised with pseudomonas and staph aureus
Recent sputum grew Stenotrophomonas maltophilia
What is the significance of this?
Stenotrophomonas maltophilia was originally classified as a pseudomonas, and is an environmental bacteria found in soil. Gram negative, non-fermenter
Resistant to beta-lactams and carbapenems
recognised as opportunistic pathogen in immunocompromised
Patient with CF, what bacteria do we need to look for in sputum?
These species require special testing
pseudomonas
S maltophilia
Haemophilus influenzae
Staph aureus
Burkholderia
Aspergillus
TB
Fungi
If sputum culture psoitive, difficult to know if this organism is colonising airway, or causing infection