General Micro Flashcards
(42 cards)
Pregnant woman with no previous antenatal care.
What test would need to be done?
URGENT - HIV, syphillis, hep B
- urgent if presenting later than 20/40
Gay man presents with inguinal lymphadenopathy and maculopapular rash on his trunk, palms and soles.
10 weeks ago had unprotected sex.
What test would need to be done?
- clotted blood for HIV and syphillis
- urine and swabs for chlamydia/ gonorrhoea testing.
Hepatitis viruses not part of routine sexual health screening.
33M brought in by ambulance. Found unresponsive in street - injecting legal highs
What test would need to be done?
- clotted blood for HIV, hep B core Ab, Hep C Ab testing
22F attends family planning clinic for long acting reversible contraceptive as she has a new partner. Asymptomatic
What test would need to be done?
- clotted blood for HIV and syphillis testing
Describe antibiotic prescribing decisions likely to induce C diff infection?
4 C’s - clindamycin, cephalosporin, co-amoxiclav, ciprofloxacin
Unnecessary, broad spectrum, against gram -ve
excess duration
inappropriate route/ dose
What cleaning agent would be needed in C diff isolated rooms?
HCl
What tests are required to assess the severity of c diff?
Temp >38.5C CT scan /xray - severe colitis WBC Creatinine lactate
What drugs are risk factors for c diff?
PPI and histamine inhibitors
- always review indication and see if can be stopped
C diff infection - what treatment should be given in mild or severe cases?
no severity markers - metronidazole
1 or more severity markers - vancomycin
What should you use in initial assessment of pneumonia?
CURB 65
- confused (AMT score of 8 or less; new disorientation in person, place, time)
- urea - greater or equal to 7 mmol/L
- RR - greater or equal to 30/minute
- BP - systolic <90 or diastolic less than or equal to 60
65 - age 65 or older
Antibiotic treatments in community-acquired pneumonia
CURB 0-1
CURB 2
CURB 3-5
CURB 0-1
Amoxicillin or doxycycline (if penicillin allergy)
CURB 2
Amoxicillin plus clarithromycin
- if penicillin allergy - doxycycline or clarithromycin
CURB 3-5
Co-amoxiclav plus clarithromcyin
- if penicillin allergy - ciprofloxacin plus vancomycin
What should you recommend to everyone who has had a pneumococcus infection?
pneumococcal vaccine
What additional test should you do in someone presenting with pneumococcal sepsis?
HIV test
What test should you do in a pregnant lady suspected of having a UTI?
What is a complication of pyelonephrititis in pregnancy?
MSU culture
premature rupture of membranes
What is the treatment in asymptomatic bacteria?
dont treat unless pregnant or going for surgery of urinary tract
Infections that Staph aureus causes
SOFT PAINS
S - SSTI (cellulitis)/ surgical site infections
O - osteomyelitis and septic arthritis
F - food posioning
T - Toxic shock syndrome
P - pneumonia A - abscesses (psoas amongst others) I - infective endocarditis N - nec. fas. S - scalded skin syndrome
Staph aureus lab investigations
Gram stain = gram +ve, grape like clusters
Blood agar - aureus = golden (techoic acid)
Coagulase - converts fibrinogen to fibrin
positive = s. aureus
Staph aureus screening
swab throat, nose, groin, axilla
Where is s. aureus carried?
upper resp. tract 20-30% population
normal vaginal flora in some women
skin
Pathophysiology of s aureus
toxin production
- recurrent SSTI and necrotizing pneumonia
- enterotoxins = gastroenteritis
- TSST1 = toxic shock syndrome
- Epidermolytic toxin (A and B) = scalded skin syndrome (severe infection in babies with shedding of skin)
- Exfoliative toxin = allows it to disrupt skin barrier
DNAse
Adhesion = techoic acid allows it to adhere to skin/upper resp. tract
Evasion of immune system
- anti-opsonizing protein and protein A = anti-phagocytic
- leukotoxins - PVL - kills WBC (recurrent SSTI and necrotizing pneumonia)
- superantigens - subvert normal immune system by inducing strong polyclonal stimulation and expansion of T cells
- Biofilms - can produce bio-films on damaged skin, medical devices, heart valves - protection against immune cells
Risk factors for s aureus infection
Loss of skin barrier
Immunocompromised
Prosthetic material
Management for staph. aureus cellulitis
mark around border of erythema and limb elevation
IV flucloxacillin
if penicillin allergy or MRSA = IV vancomycin
Dont forget to US leg if might have DVT (swelling not going down while on antibiotics)
S aureus bacteremia
- mortality rate
- what might make patient at greater risk of relapse?
- management
- deep source infections
mortality rate = 26%
at greater risk of relapse if on short course of antibiotic
Guidance
- minimum of 2 week IV therapy - need longer course if have complication or deep site infection
- review blood culture 48-72 hours to ensure bacteremia resolving
- check for deep source infections - osteomyelitis, septic arthritis, disci tis, endocarditis, stroke, prosthetics?
Deep source infections
- endocarditis = do ECHO;
- if septic - check clotting as may bleed out = DIC
- rule out = psoas abscess (back/hip pain); discitis (palpate down spine); prosthetic related infection (graft infection, prosthetic joint)
MRSA
- what causes resistance to methicillin
- risk factors
- management
- mec
RF: history of MRSA; nursing home resident; family member with MRSA; prolonged hospitalization
Treatment = Vancomycin
If MRSA +ve isolate in single room and offered decolonization.
