Chapter 25 Flashcards
risk of sequelae with some bacterial infections
Streptococcus pyogenes and rheumatic fever
Staphylococcus spp. and bacterial endocarditis
antimicrobial susceptibility should be known before antibiotics are prescribed
Empirical antibiotic treatment is often started before lab testing is completed.
Antibiotic resistance
epidemiological surveillance
Track spread of disease to identify source and stop further spreading
human body sites considered “sterile”
Blood
Cerebrospinal fluid
Pleural fluid (from space outside lungs)
Synovial fluid (joints)
Peritoneal fluid (abdomen)
Any tissues from internal organs
blood cultures
collected by venipuncture into bottles
bacterial growth induces fluorescence
cerebrospinal fluid (CSF)
collected by lumbar punture
direct microscopy and culture
pleural, synovial, and peritoneal fluid
collected by needle aspiration
direct microscopy and culture
quantitative reverse transcription-PCR (qRT-PCR)
is used routinely for the high-throughput diagnosis of viral pathogens such as WNV
RFLP analysis
restriction fragment length polymorphisms
if a patient has a disease, how often will the test be positive
a measure of sensitivity
if a patient does not have a disease, how often will the test be negative
specificity
Point-of-care (POC) tests
sensitivity may be sacrificed for rapid results (often need other confirmatory tests)
Advantages of POC tests
No culturing is required.
Clinicians can immediately prescribe the right antibiotic.
Patients can avoid taking unnecessary antibiotics.
Clinicians can quickly determine a chain of infection in patients with similar symptoms.
Clinicians can notify patients, who are hard to reach once they have left the clinician’s office, while they are still present.
disadvantage of POC tests
No data about pathogen antibiotic sensitivity
Increased risk of clinician becoming infected
Multiple infections may be overlooked if the initial test is positive.
