lab

• Microbiology and Parasitology and Epidemiology are important to the nursing discipline
• Proper diagnosis of an infectious disease requires:

  • Complete patient history
  • Thorough physical examination
  • Evaluation of signs and symptoms
  • Proper selection, collection, transport, and processing of appropriate specimens
• Nurses rely on assessment and critical thinking since some infectious diseases are diagnosed based on presenting signs and symptoms of the patient
• Tests are done if the healthcare team suspects other illnesses or to confirm the disease
• Tests done depending on signs and symptoms of the client:

  • Urine analysis for pelvic pain
  • Urine pregnancy test for ectopic pregnancy
  • Complete blood count for other infections
• Characteristics of a good screening test:

  • Simple
  • Rapid
  • Inexpensive
  • Safe
  • Acceptable
• Circumstances favoring screening:

  • Disease constitutes a significant public health problem
  • Disease is contagious
  • Treatment before symptoms occur is more effective
  • No benefit to early treatment
• Consequences of false-negative or false-positives are unsure

  • Screening test is inexpensive, easy to administer, not harmful, and not reliable
• Mechanism for follow-up of subjects with positive screening results is necessary
• Diagnostic Test:

  • Clinical or laboratory procedure to identify a diagnosis or detect a disease
  • Used to measure progress or recovery and confirm the patient is free from the disease
• Types of Diagnostic Tests:

  • Non-invasive
  • Minimally-invasive
  • Invasive
• Gold standard test is a definitive diagnostic test

  • Gold standard test may be invasive, unpleasant, too late, expensive, or impractical for screening
• Common Screening and Diagnostic Tests:

  • Urinary Tract Infection:
  • Screening: Urine microscopy
  • Diagnostic: Urine culture
  • Tuberculosis:
  • Screening: Tuberculin Skin Test, Interferon Gamma Release Assays
  • Diagnostic: Chest X-ray, sputum detection of Mycobacterium tuberculosis
  • Chlamydia, Trichomoniasis:
  • Screening: Tissue culture from a single cervical swab
  • Diagnostic: Direct Immunofluorescence, ELISA Test, PCR, serology tests
  • Meningitis:
  • No screening test
  • Diagnostic: Spinal Tap
  • Malaria:
  • Screening: Rapid Diagnostic Test
• • Diagnostic: Malaria antigens detection
• Direct Immunofluorescence, Enzyme Link Immunoassay (ELISA) Test, PCR, and serology tests are used for diagnosing various diseases
• Meningitis:

  • Diagnosed through a Spinal Tap
• Malaria:

  • Rapid Diagnostic Test detects Malaria antigens from sexual and asexual forms
  • Peripheral smear detects and differentiates all plasmodia at different stages
• Dengue:

  • IgM and IgG Rapid Test is an immunochromatographic assay for the simultaneous detection of IgG and IgM antibodies to dengue virus
  • Dengue NS1 test
  • Dengue RT-PCR Test
• Pinworm infestation:

  • Diagnosed through a Cellophane scotch tape test
• Amoebiasis, Ascariasis, Beef/Pork Tapeworms:

  • None
  • Diagnosed through stool examination by microscopy, serology, and ELISA test
• COVID-19:

  • RDT (Rapid Diagnostic Test) is a screening test for COVID-19
  • RT-PCR is a diagnostic test for the qualitative detection of nucleic acid from SARS-CoV-2
• Hepatitis B:

  • Hepatitis B surface antigen test determines current infection
  • Hepatitis B core antibody test determines past infection
  • Hepatitis B surface antibody test determines immunity status
  • HBsAg - Quantitative Assay assesses the amount of Hepatitis B surface antigen
• Syphilis:

  • Rapid plasma reagin (RPR) and Venereal Disease Research Laboratory test (VDRL) are blood tests for syphilis
• Hematology Test:

  • Determines specific blood levels useful in diagnosing infection
  • Red Blood Cells (RBC) levels vary with age and sex
  • White Blood Cells (WBC) levels are useful in diagnosing infection
  • Platelet count is useful in screening platelet function
  • Erythrocyte Sedimentation Rate (ESR) measures erythrocyte settling
• Difference of sensitivity and specificity:

  • Sensitivity identifies patients with the disease
  • Specificity identifies patients without the disease
  • Western Blot Analysis is the confirmatory test for HIV
• Nurses' responsibilities in screening and diagnostic tests:

  • Explain procedures clearly
  • Ensure handwashing and privacy
  • Proper collaboration among healthcare team members
  • Obtain appropriate clinical specimens and request appropriate tests
  • Adhere to safety policies and standard precautions
• Reasons why people avoid check-ups:

  • Expense
  • Fear of disease knowledge
  • Fear of misdiagnosis or mistreatment
  • Fear of separation from family
• Advocacy in nursing:

  • Clarifying indications for tests to avoid unnecessary procedures