Infectious Disease (CHOCOLATES ID)
Country of Birth: Which country were you from/born in?
Housing: What is your housing environment like?
Occupation: What is your occupation? Are you exposed to any types of bacteria/pathogens?
(abbatoir = q fever caused by coxiella burnetti)
Contacts: Have you recently had contact with someone with an infectious disease/sick
person?
Other drugs: Are you on any drugs that weaken your immune system?
Leisure: What do you do during your leisure time?
Animals: Do you have pets at home or come into contact with animals regularly?
Travel: Have you travelled overseas recently? Where to? When? How long? Did you fall
sick?
Eat and drinks: Have you eaten or drank anything unusual/special or bad?
Sexual activity: Have you been sexually active recently? How many partners do you have?
When? 5P for STI: Sex partners, protection, PHx STIs, Pregnancy, Partners/MSM,
Practices/positions
Immunocomprised/immunizations: Are you taking any immunosuppressive therapy? Are your
immunizations up to date?
Drugs: OTC, IVDU, Chemotherapy, alcoholism, new medicatiosn, illicit dugs (cocaine)
Systems review is focused on 2 aspects:
1. Exposure history: identify microorganisms with which patient may have come into
contact
2. Host specific hactors: predisposing factors to infection development
3. Site of infection also narrows down causative micoorganisms given nature of tropism.
Microorganisms have a preference on where they grow
For ALL febrile patients:
• Give 1g paracetamol stat for discomfort and fever
• Give 500mg bolus if hypotensive
o Fever with and sBP <90mmHg that is NOT responsive to fluid bolus of
at least 30ml/kg indicates a serious degree of hypovolaemia with septic
shock
• Due to Bohr effect, increased temp reduces affinity of Hb with O2 and hence
will need O2 support to maintain sats >94%
• Give regular 250-500ml/h infusion to restore or maintain normotension, replace
insensible losses and cover maintenance fluids
• May need inotropic support and aggressive fluid resuscitation for very sick
patients
• Broad spectrum antibiotics for: ceftriazone, cefepime or tazocin
o Septic shock patients
o Febrile neutropeia
o Febrile unwell patients with no localizing source
o Anaerobic cover (metronidazole 500mg IV) needed for deep tissue, GIT
and female pelvic infections
VERY COMMON CAUSE OF OVERWARFARINISATION (HIGH INR) IS DUE TO
ANTIBIOTICS BEING STARTED, ESPECIALLY PENICILLINS AND CEPHALOSPORINS
Handy tips for FEVER:
• High spiking fever 5-7 days afte surgery may indicate abscess formation
• Fever is a sign of transplant rejection
• Steroids elevate WCC (usually increased by 4, but reports of 20 possible) and
suppress fever response, regardless of cause. Usually upon their initiation, but does
not cause the usual left shift. The immunosuppression is due to reduced ability of
neutrophil to migrate to tissues/sites of inflammation and hence most are
sequestered in the blood stream shown by the raised WCC.
o Raised WCC (mainly neutrophil) caused by:
§ Demargination of neutrophils from endothelial surface of blood
vessles (predominan effect)
, § Delayed transmigration of neutrophils into tissue
Delayed poptosis
§ Increase in release of neutrophils from bone marrow
• Other casues of raised WCC In absenece of infection are vomiting, haemorrhage,
seizures, marrow dysplasia including leukaemia
• Adminstering antipyretic for fever caused by infection only treats symptom. Fever is a
positive adaptive mechanism that inhibits bacterial replication and enhances ability of
macrophages to kill bacteria. Hence, if fever not oo high (<40) and patient is
comfortable, not necessary to give antipyretic
Significant or non significant?
• External body fluids (urine, sputum, feces): presence of bugs sometimes may not
mean any infection, unless there is a foreign body etc
• Internal body fluids (Blood, surgical specimen, drains): ALWAYS significant and
MUST treat
More likely to be contaminant than true infection?
• Type of commensal organism of skin flora are grown, unless foreign lines/joints are
present, then true infection may be more likely
• When only 1 blood cultures positive out of 2 or more sets
• Antibiotic susceptibility pattern of one organism isolated from blood cultures is
different from subsequent cultures, or different organism altogether.
Deep seated Infection present?
• Higher chance for deep seated infection with every day of blood cultures +ve when
on antibiotics (means strong infection)
• Protracted fever after antibiotic commencement
o More likely to have deep seated infection, OR pyelonephritis (just protracted
fever, but inflammatory markers getting better)
o Investigatiosn to do depends on the organism grown and its likely place to
stick at:
§ MSSA: do TTE as most concerning is IE
§ GNB: do CT AP since bowel collections likely
§ Enterococcus: CT Brain for mycotic aneurysm
§ Listeria: LP for meningitis
§ All gut bugs bacteraemia: screen for bowel cancer (Colonoscopy or
CTAP)
Types of fever:
• Sustained: septicaemi, drug fever
• Intermittent: urinary, Biliary tract, malaria, lymphoma, abscess
Upper VS lower GI:
• Upper: cover for strep mostly
• Lower: cover for enterococcus
Random facts:
• Adequate Vitamin C will reduce transmission of infections
• Adequate Vitamin D levels will allow for better immunity to fight against TB
Prophylaxis VS treatment only:
• Clostridium difficile:
o NOT tested unless diarrhoea present
o ONLY IF C. diff toxin present then treat patient.
o No prophylaxis should be given (inadvertently may worsen it)
• Pseudomonas: prophylaxis with Ciprofloxacin
Empirical treament:
, • GPC:
o Staph aureus: Since worried about MRSA, use Vancomycin / daptomycin
first then change to flucloxacillin/nafcillin/oxacilin/cephazolin
o Coagulase –ve staph: penicllins (nafcillin, oxacillin) / cephazolin, if strain is
resistant, start vancomycin / daptomycin
o Strep: flucloxacillin, cephazolin. For allergies, vancomycin/clindamycin
can be used. If allergies are not anaphylaxis, can use ceftriaxone
§ Always worried about strep pyogenes (Benzylpenicillin)
§ Strep pneumo can use urinary antigen to assist diagnosis
o Enterococcus: Ampicillin (not flucloxacillin), carbapenem (not ertapenam),
Vancomycin, Quinupristin/dalfopristin
• GPB: benzylpenicillin or Vancomycin, unless clostridium diff.
o Bacillus: vancomycin, clindamycin, penicillins (Bacillus cereus
implicated if endocarditis or ocular infection)
o Propionibacterium: penicillins, tetracyclines, macrolides (skin and
shoulder PJI)
o Corynebacterium: penicillins, vancomycin, erythromycin, clindamycin
o Lactobacillus: penicllins (Intrinsically resistant to vancomycin)
o Actinomyces: pencillins, amoxicillin, 3rd generation ceftraixone
o Clostridium Difficile: Metronidazole, tinidazole, vancomycin, teicoplanin,
tigecycline
• GNC/GNB: 1st line Ceftriaxone, but must think of the source. If it is form urine, then
it would be alright, but if possibly from intraabdominal or cancer cause, triple cover of
Ampicillin, gentamicin and metronidazole is more likely to work better.
o GNB usually very acute and severe course
o Can use antibiotics that cover pseudomonas as well:
§ Tazobactam/meropenem/cefepime +
aminoglycoside/ciprofloxacin
o Acinetobacter (usually in debilitated patients): meropenem or oral
ciprofloxacin
o Stenotrophomonas (ventilation associated infection): meropenem, bactrim
• Anaerobes: Pencillins, tazibactam, metronidazole
o Often need surgery to drain abscess, or debride non-viable tissues
• Candida: anidulafungin, caspofungin (1st line as they can be resistant to
fluconazole, especially candida glabrata) or fluconazole
o Posaconazole (used more for prophylaxis), voriconazole, amphotericin (in
order of potency and spectrum)
o Note that amphoterin can cause Mg and K wasting and hence must be
monitored
• Invasive aspergillosis: voriconazole (1st line)
Know your playground:
• Skn: Strep pyogenes, Staphylococcus aureus, streptococcal species
o Flucloxacillin
o Cephazolin
• Chest (CAP): Strep pneumoniae, Haemophilus influenza, klebsiella pneumonia,
influenza, atypical (legionella, mycoplasma, Chlamydia)
o Benzylpenicillin + doxycycline
o Ceftriaxone + Azithromycin
• GIT: polymicrobial (GN: E coli, klebsiella, proteus, enterobacter), (GP:streptococci,
enterococci), anaerobes
o Ampicillin, Gentamicin, Metronidazole
o Tazocin
• Biliary infection: GNB (E. coli, Klebsiella), Anaerobes
o Ampicillin, Gentamicin, Metronidazole
o Tazocin
• UTI: E. coli, Staph saprophyticus, proteus, klebsiella, Enterococcus
o Augmentin
o Cephalexin
o Trimehoprim
, o Ampicillin + gentamicin (IV)
Note:
• Swabs of ealing ulcers will still grow bugs
• If there’s pus, you need to GET IT OUT
• Is patient sick enough to warrat fluids, inotropes, steroids?
• Label specimens appropriately, the more info, the more lab can help
• Ensure adequate cultures are taken
• Take a proper allergy history (if previous anaphylaxis, AVOID)
• Always review Abx and switch to narrower spectrum or orals and less is MORE!
• Cease when you can!
• Continue abx is withot risk
o Promote resistance
o Cannula associated infections
o C. Diff
Note:
• Necrosis will not have membrane bound vesicles (apoptotic bodies)
Control of microorganisms:
• Sterilisation: removal or killing or destruction of ALL viable organisms
o Physical or chemical
• Disinfection: removal or killing or destruction of MOST viable organisms
o Physicla or chemical
• Antiepsis: removing microbes from skin
• Moist heat:
o Killing spores need temperature >100
o Boiling (100) only kills some organisms but not all
• Autoclave: pressure and moist heat
o 121 degrees: 15 minutes
o 134 degress: 3.5 minutes
• Dry heat:
o 170 degrees: 1 hour
o 160 degrees: 2 hours
Examination:
• General inspection: assess how sick and potential causes and sources
o Anything prosthetic: valve, protheses, pacemakers, shunts, grafts
o IV lines, portacaths, PICC, CVC
o Drain tubes/IDC (oliguria)
o Dressing/bandages
o Track marks from IVDU
o Tattoos
o Rash
• Vitals: tachycardia, tachypnoea, hypotension, Hypoxemia, febrile
• Hands:
o Splinter hemorrhages
o Clubbing
• Eyes:
o Sclera icterus
o Injected conjunctiva (adenocirus/dengue/leptospirosis)
• Mouth:
o Dentition (IE)
o Ulcers
o Tongue (candidiasis)
o Tonsils (infection, abscess)
• Cardio: any murmurs
• Respiratory
o Crackles
Country of Birth: Which country were you from/born in?
Housing: What is your housing environment like?
Occupation: What is your occupation? Are you exposed to any types of bacteria/pathogens?
(abbatoir = q fever caused by coxiella burnetti)
Contacts: Have you recently had contact with someone with an infectious disease/sick
person?
Other drugs: Are you on any drugs that weaken your immune system?
Leisure: What do you do during your leisure time?
Animals: Do you have pets at home or come into contact with animals regularly?
Travel: Have you travelled overseas recently? Where to? When? How long? Did you fall
sick?
Eat and drinks: Have you eaten or drank anything unusual/special or bad?
Sexual activity: Have you been sexually active recently? How many partners do you have?
When? 5P for STI: Sex partners, protection, PHx STIs, Pregnancy, Partners/MSM,
Practices/positions
Immunocomprised/immunizations: Are you taking any immunosuppressive therapy? Are your
immunizations up to date?
Drugs: OTC, IVDU, Chemotherapy, alcoholism, new medicatiosn, illicit dugs (cocaine)
Systems review is focused on 2 aspects:
1. Exposure history: identify microorganisms with which patient may have come into
contact
2. Host specific hactors: predisposing factors to infection development
3. Site of infection also narrows down causative micoorganisms given nature of tropism.
Microorganisms have a preference on where they grow
For ALL febrile patients:
• Give 1g paracetamol stat for discomfort and fever
• Give 500mg bolus if hypotensive
o Fever with and sBP <90mmHg that is NOT responsive to fluid bolus of
at least 30ml/kg indicates a serious degree of hypovolaemia with septic
shock
• Due to Bohr effect, increased temp reduces affinity of Hb with O2 and hence
will need O2 support to maintain sats >94%
• Give regular 250-500ml/h infusion to restore or maintain normotension, replace
insensible losses and cover maintenance fluids
• May need inotropic support and aggressive fluid resuscitation for very sick
patients
• Broad spectrum antibiotics for: ceftriazone, cefepime or tazocin
o Septic shock patients
o Febrile neutropeia
o Febrile unwell patients with no localizing source
o Anaerobic cover (metronidazole 500mg IV) needed for deep tissue, GIT
and female pelvic infections
VERY COMMON CAUSE OF OVERWARFARINISATION (HIGH INR) IS DUE TO
ANTIBIOTICS BEING STARTED, ESPECIALLY PENICILLINS AND CEPHALOSPORINS
Handy tips for FEVER:
• High spiking fever 5-7 days afte surgery may indicate abscess formation
• Fever is a sign of transplant rejection
• Steroids elevate WCC (usually increased by 4, but reports of 20 possible) and
suppress fever response, regardless of cause. Usually upon their initiation, but does
not cause the usual left shift. The immunosuppression is due to reduced ability of
neutrophil to migrate to tissues/sites of inflammation and hence most are
sequestered in the blood stream shown by the raised WCC.
o Raised WCC (mainly neutrophil) caused by:
§ Demargination of neutrophils from endothelial surface of blood
vessles (predominan effect)
, § Delayed transmigration of neutrophils into tissue
Delayed poptosis
§ Increase in release of neutrophils from bone marrow
• Other casues of raised WCC In absenece of infection are vomiting, haemorrhage,
seizures, marrow dysplasia including leukaemia
• Adminstering antipyretic for fever caused by infection only treats symptom. Fever is a
positive adaptive mechanism that inhibits bacterial replication and enhances ability of
macrophages to kill bacteria. Hence, if fever not oo high (<40) and patient is
comfortable, not necessary to give antipyretic
Significant or non significant?
• External body fluids (urine, sputum, feces): presence of bugs sometimes may not
mean any infection, unless there is a foreign body etc
• Internal body fluids (Blood, surgical specimen, drains): ALWAYS significant and
MUST treat
More likely to be contaminant than true infection?
• Type of commensal organism of skin flora are grown, unless foreign lines/joints are
present, then true infection may be more likely
• When only 1 blood cultures positive out of 2 or more sets
• Antibiotic susceptibility pattern of one organism isolated from blood cultures is
different from subsequent cultures, or different organism altogether.
Deep seated Infection present?
• Higher chance for deep seated infection with every day of blood cultures +ve when
on antibiotics (means strong infection)
• Protracted fever after antibiotic commencement
o More likely to have deep seated infection, OR pyelonephritis (just protracted
fever, but inflammatory markers getting better)
o Investigatiosn to do depends on the organism grown and its likely place to
stick at:
§ MSSA: do TTE as most concerning is IE
§ GNB: do CT AP since bowel collections likely
§ Enterococcus: CT Brain for mycotic aneurysm
§ Listeria: LP for meningitis
§ All gut bugs bacteraemia: screen for bowel cancer (Colonoscopy or
CTAP)
Types of fever:
• Sustained: septicaemi, drug fever
• Intermittent: urinary, Biliary tract, malaria, lymphoma, abscess
Upper VS lower GI:
• Upper: cover for strep mostly
• Lower: cover for enterococcus
Random facts:
• Adequate Vitamin C will reduce transmission of infections
• Adequate Vitamin D levels will allow for better immunity to fight against TB
Prophylaxis VS treatment only:
• Clostridium difficile:
o NOT tested unless diarrhoea present
o ONLY IF C. diff toxin present then treat patient.
o No prophylaxis should be given (inadvertently may worsen it)
• Pseudomonas: prophylaxis with Ciprofloxacin
Empirical treament:
, • GPC:
o Staph aureus: Since worried about MRSA, use Vancomycin / daptomycin
first then change to flucloxacillin/nafcillin/oxacilin/cephazolin
o Coagulase –ve staph: penicllins (nafcillin, oxacillin) / cephazolin, if strain is
resistant, start vancomycin / daptomycin
o Strep: flucloxacillin, cephazolin. For allergies, vancomycin/clindamycin
can be used. If allergies are not anaphylaxis, can use ceftriaxone
§ Always worried about strep pyogenes (Benzylpenicillin)
§ Strep pneumo can use urinary antigen to assist diagnosis
o Enterococcus: Ampicillin (not flucloxacillin), carbapenem (not ertapenam),
Vancomycin, Quinupristin/dalfopristin
• GPB: benzylpenicillin or Vancomycin, unless clostridium diff.
o Bacillus: vancomycin, clindamycin, penicillins (Bacillus cereus
implicated if endocarditis or ocular infection)
o Propionibacterium: penicillins, tetracyclines, macrolides (skin and
shoulder PJI)
o Corynebacterium: penicillins, vancomycin, erythromycin, clindamycin
o Lactobacillus: penicllins (Intrinsically resistant to vancomycin)
o Actinomyces: pencillins, amoxicillin, 3rd generation ceftraixone
o Clostridium Difficile: Metronidazole, tinidazole, vancomycin, teicoplanin,
tigecycline
• GNC/GNB: 1st line Ceftriaxone, but must think of the source. If it is form urine, then
it would be alright, but if possibly from intraabdominal or cancer cause, triple cover of
Ampicillin, gentamicin and metronidazole is more likely to work better.
o GNB usually very acute and severe course
o Can use antibiotics that cover pseudomonas as well:
§ Tazobactam/meropenem/cefepime +
aminoglycoside/ciprofloxacin
o Acinetobacter (usually in debilitated patients): meropenem or oral
ciprofloxacin
o Stenotrophomonas (ventilation associated infection): meropenem, bactrim
• Anaerobes: Pencillins, tazibactam, metronidazole
o Often need surgery to drain abscess, or debride non-viable tissues
• Candida: anidulafungin, caspofungin (1st line as they can be resistant to
fluconazole, especially candida glabrata) or fluconazole
o Posaconazole (used more for prophylaxis), voriconazole, amphotericin (in
order of potency and spectrum)
o Note that amphoterin can cause Mg and K wasting and hence must be
monitored
• Invasive aspergillosis: voriconazole (1st line)
Know your playground:
• Skn: Strep pyogenes, Staphylococcus aureus, streptococcal species
o Flucloxacillin
o Cephazolin
• Chest (CAP): Strep pneumoniae, Haemophilus influenza, klebsiella pneumonia,
influenza, atypical (legionella, mycoplasma, Chlamydia)
o Benzylpenicillin + doxycycline
o Ceftriaxone + Azithromycin
• GIT: polymicrobial (GN: E coli, klebsiella, proteus, enterobacter), (GP:streptococci,
enterococci), anaerobes
o Ampicillin, Gentamicin, Metronidazole
o Tazocin
• Biliary infection: GNB (E. coli, Klebsiella), Anaerobes
o Ampicillin, Gentamicin, Metronidazole
o Tazocin
• UTI: E. coli, Staph saprophyticus, proteus, klebsiella, Enterococcus
o Augmentin
o Cephalexin
o Trimehoprim
, o Ampicillin + gentamicin (IV)
Note:
• Swabs of ealing ulcers will still grow bugs
• If there’s pus, you need to GET IT OUT
• Is patient sick enough to warrat fluids, inotropes, steroids?
• Label specimens appropriately, the more info, the more lab can help
• Ensure adequate cultures are taken
• Take a proper allergy history (if previous anaphylaxis, AVOID)
• Always review Abx and switch to narrower spectrum or orals and less is MORE!
• Cease when you can!
• Continue abx is withot risk
o Promote resistance
o Cannula associated infections
o C. Diff
Note:
• Necrosis will not have membrane bound vesicles (apoptotic bodies)
Control of microorganisms:
• Sterilisation: removal or killing or destruction of ALL viable organisms
o Physical or chemical
• Disinfection: removal or killing or destruction of MOST viable organisms
o Physicla or chemical
• Antiepsis: removing microbes from skin
• Moist heat:
o Killing spores need temperature >100
o Boiling (100) only kills some organisms but not all
• Autoclave: pressure and moist heat
o 121 degrees: 15 minutes
o 134 degress: 3.5 minutes
• Dry heat:
o 170 degrees: 1 hour
o 160 degrees: 2 hours
Examination:
• General inspection: assess how sick and potential causes and sources
o Anything prosthetic: valve, protheses, pacemakers, shunts, grafts
o IV lines, portacaths, PICC, CVC
o Drain tubes/IDC (oliguria)
o Dressing/bandages
o Track marks from IVDU
o Tattoos
o Rash
• Vitals: tachycardia, tachypnoea, hypotension, Hypoxemia, febrile
• Hands:
o Splinter hemorrhages
o Clubbing
• Eyes:
o Sclera icterus
o Injected conjunctiva (adenocirus/dengue/leptospirosis)
• Mouth:
o Dentition (IE)
o Ulcers
o Tongue (candidiasis)
o Tonsils (infection, abscess)
• Cardio: any murmurs
• Respiratory
o Crackles
