ID Flashcards
HACEK organisms cause…
Name them
Subacute endocarditis
Haemophilus, Acinetobacillus, Cardiobacterium, Eikenella, Kingella
ESCAPPM organisms are…
Name them
Extended beta-lactamase activity
Enterobacter, Serratia, Citrobacter, Acinetobacter, Proteus, Providencia, Morganella
What to use for ESCAPPM organisms
Carbapenem, Aminoglycoside
Clinicla features meningitis
Headache, fever, neck stiffness, photophobia, confusion
Spreading, non-blanching petechial rash in Meningococcal
Kernig’s sign
when hip is flexed, inability to extend knee
Brudzinski’s sign
When lifting head of patient lying flat, knees rise involuntarily
DDx meningitis
malaria, encephalitis, septicaemia, sub-arachnoid, dengue, tetanus
2 Commonest cause meningitis adults
Neisseria, Streptococcus
Most common cause meningitis non-vaccinated kids
HIB
Common causes vaccinated kids <3 of meningitis
Strep Agalacticae, E.Coli
Immunocompromised meningitis causes
Listeria, Cryptococcus
Rx cryptococcus
amphotericin B and fluconazole
Viral meningitis causes
Enteroviruses (echo and cocksackie), herpes, varicella, measles, mumps, arboviruses
Ix meningitis
Blood culture, Gram stain/NAT of skin swabs if present. CSF gram stain and NAT
LP if CT shows no evidence increased ICP
Viral vs bacterial meningitis CSF
Both have high protein. Bacterial has low glucose and polymorphonucleocytes dominating. Viral has mononuclear cells and normal glucose
empirical meningitis Rx
Dexamethasone + ceftriaxone
Benzylpen to cover listeria, consider vanc if strep pneumo
Neisseria meningiditis Rx
Benzylpenicillin
Meningitis prophylaxis pregnant women
Ceftriaxone
Meningitis prophylaxis adults
cipro
Meningitis prophylaxis kids
rifampcin
What drugs don’t penetrate CSF
aminoglycosides, early gen cephalosporins, clindamycin, erythromycin
Neisseria culture media
chocolate
Meningococcal rash means…
septicaemia caused by neisseria
Why is meningococcal dangerous
50% mortality, multi organ fail, DIC (endotoxin)
What is DIC?
Activation of coagulation mechanism results in small clots forming everywhere (affecting organs) and uses up clotting factors so bleeding occurs in skin
CAP common causes
Strep pneumo, Mycoplasma, chlamydophila, legionella (HIB only in kids/COPD)
Clinical features pneumonia
pleuritic chest pain, sudden onset, productive cough, fever, headache, dyspnoea
Ix pneumonia
CXR, FBC, UEC, LFT, O2 sats
Sputum gram stain and culture (before Abx)
Blood culture
Mycoplasma serology
Nose and throat swab NAT
Bronchoalveolar lavage consider in severly ill
Assessing pneumonia severity
PSI (assess for admission)
CORB- confusion, O230, BP2= admit
SMART-CRP for ICU
empirical Abx for moderate CAP
Benzylpen/amoxil (strep, HIB) + Azithro/Doxy (atypical)
In tropical regions empiral Abx moderate CAP
Ceftriaxone + gent
Outpatient Abx pneumonia
Amoxycillin
Severe CAP Abx
Ceftriaxone + Azithromycin
Aspiration pneumonia Rx
Benzylpen + Metronidazole
Nosocomial pneumonia organisms
MRSA, pseudomonas, strenotrophomonas maltophila
Rx Nosocomial pneumonia
Gent + benzylpen
Pneumocystis Abx
Trimethoprim, sulfamethoxazole
3 infections for the returned traveller
Malaria, Dengue, Enteric fever
pneumonia, meningitis, gastro
Mosquito for malaria
anopheles
Key features of dengue
short incubation (4-7 days), maculopapular rash, thrmobocytopenia, leukopenia
Places for malaria
West Africa, nigeria, solomon islands, papua new guinea
Sx of malaria
fever, chills, sweats, headache, myalgia
Complications of malaria
anaemia, thrombocytopenia, splenomegaly
Complications from falciparum
cerebral, blackwater fever, pulmonary oedema, anemia, bleeding
Incubation fo falciparum
8-25 days. Presents within 6 weeks of infection
Mortality for falciparum
48 hours, .5-3.5%
Which forms can have liver relapse in malaria
vivax, ovale
Parasitemia levels in falciparum vs others
falciparum up to 60%, others <1%
Dx of malaria
thick and thin blood films, antigen detection, PCR
Rx non-falciparum
chloroquine, primaquine (eradicate liver phase)
Rx falciparum (non-severe)
Mefloquine (neuropsychiatric) , malarone (expensive)
Rx severe falciparum
artemisin derivatives (not widely available)
Quinine (tolerance issue)
Doxycyline (last resort)
Prophylaxis for malaria
doxy, chloroquine, mefloquine, malarone
Dengue causing mozzie
aedes aegypti
Features of dengue
severe myalgia, fever, retro-orbital headache, rash on trunk, THROMBOCYTOPENIA
Major complication dengue
haemorrhagic fever
Dx of dengue
PCR, serology
Typhoid causative agents
Salmonella typhi and paratyphi
Typhoid pathyphys
bacteraemic illness that causes inflammatory destruction of intestine and other organs. mainly ingested in food/water in sub-continent
Typical rash of typhoid
rose spots
Dx of typhoid
blood cultures, urine and stool cultures (usually not positive till second week though)
Clinical features of typhoid
progress from week to week. 1st week quite non-specific, leading to diarrhoea and fever in second week. 3rd week septic shock, intestinal bleeding etc
Rx Typhoid
Ciprofloxacin
Abx chlamydia
Azithromycin
Abx Neisseria gonnorhoea
Ceftriaxone
Complications of chlamydia
PID, infertility,
Tests for STIs
NAT on first void urine, discharge culture, PCR, genital swab MCS and PCR
Urethra, cervix, vagina MCS and PCR
HIV screening blood test
ELISA to detect antibodies
Syphillis investigation
dark ground microscopy
HIV testing window period
6 months
Vaginal discharge causes
bacterial vaginosis, candidiasis, trichomoniases
Cervical discharge causes
chlamydia, gonorrhoea, carcinoma
Bacterial vaginosis caused by… and symptoms and Rx
Trichomonas, grey white discharge, metronidazole
UTI likely organisms
E.coli, Staph saprophyticus
Rx UTI mild
Trimethoprim, cephalexin
Rx UTI severe
gentamicin, amoxil
Osteomyelitis DDx
gout, septic arthritis
Causes of Osteomyelitis
S.aureus (80%), think TB and malignancy too. E.coli/pseudomonas in vertebral osteomyelitis in adults
Sx osteomyelitis
pain, tender, warm, erythema, systemic infection
RFs for osteomyelitis
diabetes, vascular disease, impaired immunity, surgery, open fractures
Radiology bad for osteomyelitis why?
10-14 days to show changes
Management approach OM
Drain abscess and give IV Fluclox (vanc if MRSA)
RF septic arthritis
pre-existing joint disease (RA), diabetes, immunosupression, prosthetic joints
Ix Septic arthritis
joint aspiration for synovial fluid microscopy and culture, blood cultures
What level of CD4 cells do opporutnistic infecitons appear in HIV
<200
Name some opportunistic infections
Pneumocystis, toxoplasmosis, cryptococcus, CMV, MAI
Name infections 200-500 CD4 counts
TB, HSV, VZV, oesophageal candida, Kaposi sarcoma
TB treatment
Rifampcin, Isoniazid, Pyrazinamide, Ethanbutol
Kaposi’s sarcoma= HHV?
8
Neutrophil defects in HIV cause what infections…
bacteria and fungi
CMI defects cause what type of infection…
parasite, virus, intracellular
Febrile neutropenia dangeours bacterial organism and empirical therapy
Pseudomonas
Broad spectrum, meropenem+ aminoglycoside
Common HAI
Staph Aureus, pseudomonas, klebsiella
Precautions in hospital
hand hygeine, moment of hand washing, waste disposal, sterile environment, catheter and cannula management, infection control team
HIV, Hep C and Hep B risk from needle stick
.3, 3, 30
Immune complex deposition signs of IE
Roth spots, osler nodes, glomerulonephritis
Spetic emboli signs of IE
Janeway lesion, splinter haemorrhage, renal/splenic infarct
Causative organisms of IE
Acute- Staph Aureus
Subacute- viridans strep, enterococcal
Rare- HACEK, fungal, coxiella (Q-fever)
RFs for IE
IV injection, dental, operation, immunocompromised, Rheumatic fever
Dukes criteria number required
2 major, 1 major 3 minor, 5 minor
Major Dukes criteria
Vegetations/abscess on echo
Multiple positive blood cultures with endo suspective organisms
Minor Dukes criteria
Fever, Janeway, Osler, Splinter, Roth spots, other emboli, pre-existing heart condition, blood culture or echo stuff that doesn’t meet major criteria
Ix for IE
CXR, ECG, Blood culture, Echo
Empirical treatment for IE
Benzylpen + fluclox + gent