Internal medicine - Infectiology Flashcards
Define FUO
Higher then 38C without any etiologic findings
Classification of FUO
Classical
Nosocomial
Neutropenic
HIV associated
Define Classical FUO
▪ > 38.3 C periodically
▪ Duration > 3 weeks
▪ No clear etiology despite investigation:
o 3 outpatient visits
o 3 days in the hospital
o 1 week of invasive ambulatory investigation
Define Nosocomial FUO
▪ > 38.3 C periodically
▪ Hospitalized for > 24h
▪ No fever at admission
▪ Evaluation for at least 3 days
Define neutropenic FUO
▪ > 38.3 C periodically
▪ Neutropenic count > 500
▪ Evaluation for at least 3 days
Define HIV ass FUO
▪ > 38.3 C periodically
▪ Duration > 4 weeks for OP
▪ Duration > 3 days for IP
▪ Confirmed HIV disorder
Large groups of etiology for FUO
Local pyogenic infection
IV infections
Mycobacterium
Immunological
Thermoregulatory
Other
Name 5 drugs ass with FUO
Allopurinol
Heparin
Erythromycin
Isoniazid
Penicillin
what is the MINIMUN diagnostic workup you have to do in FOU
Laboratory studies:
CBC with differential
Liver chemistries
Serum electrolytes
LDH
Creatine kinase
Urinalysis and urine culture
Blood culture (three sets) if bacteremia is suspected
Imaging:
X-ray or CT chest
Ultrasound or CT abdomen and pelvis
Treatment in FUO
do NOT gibe AB, antipyretics or steroids unless:
Steroids in temporal arthritis
AB in neutropenia, tuberculosis or culture neg endocarditis
Define URTI
Upper respiratory tract infection is any infection involving the paranasal sinuses, nasal cavity, pharynx or larynx, and is often caused by a virus.
Classified based on location involved
Nasal sinuses?
maxillary sinus
ethmoidal sinus
sphenoidal sinus
frontal sinus
lymphoid tissue as first line of defense?
Tonsils
List the URTI and pathogen
Common cold - rhinovirus
Influenza - influenza virus
Covid - SARS covid
Sinusitis - rhinovirus, pneumonia, hemofilus
Tonsilitis/pharyngitis - Rhinovirus, s. pyogenes
Laryngitis - rhinovirus, pneumonia, hemofilus
Epiglottitis - Pyogenes, hemofilus, rhinovirus
Croup - parainfluenza virus
Pathogen in mononucleosis?
Epstein-Barr virus (EBV) HSV-4
mononucleosis transmission?
body secretions especially salvia - hence kissing disease
what cells does EBV infect?
B-cells
EBV incubation period?
6w
signs and symptoms of mononucleosis
→ Splenomegaly, fever, fatigue, malaise
→ Pharyngitis and/or tonsillitis
→ Bilateral cervical lymphadenopathy
→ Abdominal pain
→ Possibly hepatomegaly and jaundice
→ Maculopapular rash (similar to measles): The rash is caused by the infection itself in about 5% of cases but is most commonly associated with the administration of aminopenicillin
Diagnosis of mononucleosis
Monospot test with sheep RBC - agglutination is positive
Labs: liver transaminase and LDH
Peripheral smear 10-90% atypical B-lymphocytes
Serology Anti-VCA IgM- only 3 months/ IgG lifetime
treatment of mononucleosis
Supportive only
No contact sport
Define pneumonia
Pneumonia is a respiratory infection characterized by inflammation of the alveolar space and/or the interstitial tissue of the
lungs Pneumonia is most transmitted via aspiration of
airborne pathogens (primarily bacteria, but also viruses and fungi) but may also result from the aspiration of stomach
contents.
3 groups of pneumonia
Community-acquired pneumonia
Hospital-acquired pneumonia (HAP)
Ventilator-associated pneumonia (VAP)
typical pathogens causing pneumonia
Streptococcus pneumoniae (most common)
Hemophilus influenzae
Moraxella catarrhalis
Klebsiella pneumoniae
Staphylococcus aureus
atypical pathogens causing pneumonia
▪ Mycoplasma pneumoniae
▪ Chlamydophila pneumoniae
▪ Chlamydophila psittaci
▪ Legionella pneumophila
▪ Coxiella burnetiid → Q fever
▪ Francisella tularensis → tularemia
Virus causing pneumonia
▪ RSV
▪ Influenza viruses, Parainfluenza viruses
▪ CMV
▪ Adenovirus
▪ Coronaviridae (SARS-CoV-2)
Symptoms of pneumonia
Severe malaise, high fever and chills
Productive cough with purulent sputum (yellow-greenish)
Crackles and bronchial breath sound on auscultation
Dullness on percussion
Tachypnea and dyspnea (nasal flaring, thoracic retractions)
Pleuritic chest pain when breathing, often accompanying pleural effusion
what can PCT tell us?
Levels > 0.25ug indicates bacterial infection
Continue or discontinue AB
CURB65 stands for
Confusion
Urea > 7 mmol/L
RR: < 30
BP: SBP <90
Age > 65
If 2 or more then inpatient
what desides ICU or not in pneumonia patient?
Need vasopresser - ICU
Need ventilatory support - ICU
What divides the treatment approach in an outpatient pneumonia?
Comorbidities yes or no
Yes: Combination therapy
No: monotherapy
Inpatient treatment in pneumonia
ONE IV B-lactam (Ampicillin-tazobactam or ceftriaxone)
ONE PO DAC (doxycycline, azithromycin, Clarithromycin)
Etiology of Nosocomial pneumonia
Pseudomonas aeruginosa
Enterobacteriaceae
Acinetobacter spp
Staphylococci (Staphylococcus aureus)
Streptococcus pneumoniae
risk factors of nosocomial pneumonia
- Old age and immobility of any cause
- Chronic disease: (bronchial asthma, COPD, heart failure)
- Immunosuppression: HIV, diabetes, immunosuppression, alcoholism
- Environmental factors: crowded living conditions
- Specific medications (e.g., amiodarone, bleomycin)
- Surgical procedures: upper abdominal surgery, chest surgery
Define UTI
Urinary tract infections (UTIs) are infections of the bladder, urethra, ureters, or kidneys that are most commonly caused by bacteria, especially E. coli.
Define upper and lower UTI
Upper UTI: kidney + ureter
Lower: bladder and urethra
Bacterial etiology of UTI
o Escherichia coli: leading cause of UTI (approx. 80%)
o Staphylococcus saprophyticus: 2nd leading cause of UTI in sexually
o Klebsiella pneumoniae: 3rd leading cause of UTI
o Proteus mirabilis
o Nosocomial bacteria: Serratia marcescens, Enterococci spp., and Pseudomonas aeruginosa are associated with increased drug resistance.
o Enterobacter species
o Ureaplasma urealyticum
Viral etiology of UTI
Only in immunocompromised and children
- Adenovirus
- CMV
- BK virus
These cause hemorrhagic cystitis!!!
Classification of UTI
By clinical presentation
By location
By severity
By source
BY frequency
What is urosepsis?
UTI with a dysregulated immune response that can lead to MOF sepsis
Define complicated UTI
Men
Pregnancy
Postmenopausal
Children with atypical UTI
Immunosuppressed
Renal failure
what is healthcare ass UTI
UTI due to catheter CAUTI
Clinical signs of an upper UTI
→ Symptoms of lower UTI
→ Fever
→ Flank pain
→ Fatigue/malaise
→ Nausea and vomiting
Diagnosis of UTI
o Positive urinalysis (proof of pyuria and bacteriuria): Initiate treatment.
o Negative urinalysis but persisting suspicion: Obtain urine culture.
urinalysis findings
Pyuria: presence of WBC - Positive leukocyte esterase ≥ 5 WBC/HPF
Bacteriuria: presence of bacteria in the urine
Leukocyte casts may indicate pyelonephritis
Presence of squamous epithelial cells can be a sign of contamination
treatment of UTI
First-line treatment
❖ Nitrofurantoin for 5 days
❖ Fosfomycin (single dose)
Second-line treatment: beta-lactam antibiotics for 5–7 days
❖ Amoxicillin/clavulanic acid
treatment of UTI in men
UTIs in men can involve the prostate, AB should be able to penetrate prostate (fluoroq)
Drug that can cause cystitis
cyclophosphamide
Define Pyelonephritis
Pyelonephritis is an infection of the renal pelvis and parenchyma that is usually associated with an ascending bacterial infection of the bladder
Risk factors for pyelonephritis
Pregnancy
Urinary obstruction
cystitis (most common cause)
Recent AB use
Immunosuppression
Renal transplant
Classification of pyelonephritis?
Uncomplicated: Immunocompetent, non-pregnant, normal anatomy
Complicated
Complicated pyelonephritis when
o Failure of outpatient therapy
o Sepsis
o Male sex
o Age > 60 years
o Urinary tract abnormalities (e.g., obstruction, indwelling catheter)
o History of surgery to the urinary tract or kidneys
o Hospital-acquired infection
o Renal impairment
o History of nephrolithiasis
o Immunosuppression
o Pregnancy
pH in UTI pyelonephritis
> 7.5-8.0
when to take blood cultures in UTI
Blood cultures (2 sets): Should be performed in all patients with suspected complicated pyelonephritis
can complicated pyelonephritis be outpatient
never, always to hospital
Indications for imaging in pyelonephritis
What type of imaging?
New GFR decrease to < 40
known or suspected urolithiasis
recurrent pyelonephritis
CT abdomen
Define Sepsis
Sepsis is an acute life-threatening condition characterized by organ dysfunction due to a dysregulated immune response to infection
Diagnostic criteria for sepsis
→ Persistent hypotension: Vasopressors are required to maintain MAP ≥ 65 mm Hg.
→ Persistent lactic acidosis: lactate > 2 mmol/L (18 mg/dL) despite adequate fluid resuscitation
qSOFA to predict sepsis
o Altered mental status
o Systolic BP < 100 mmHg
o Respiratory rate > 22/min