Rapid Diagnostic Tests for Infectious Diseases

Rapid Diagnostic Tests for Infectious Diseases is a topic covered in the CDC Yellow Book.

To view the entire topic, please or .

Relief Central with Coronavirus COVID-19 Guidelnes is a free App with a companion website developed by the staff and friends of Unbound Medicine to assist relief workers, healthcare providers, first responders, and others called to serve in disaster relief situations around the world. Explore these free sample topics:

-- The first section of this topic is shown below --

Rapid Diagnostic Tests for Infectious Diseases

In the context of infectious diseases, the term rapid diagnostic test (RDT) most commonly refers to lateral-flow, immunochromatographic tests used to detect certain infections. More generally, such assays may be described as point-of-care (POC) tests. Although there are no accepted criteria for what constitutes an RDT or POC test, published definitions frequently focus on performance time and simplicity. Pathogen-specific or syndrome-based tests are considered RDTs if they meet either or both of the following criteria:

  • The test can be incorporated into a POC testing protocol for a given infection or clinical syndrome. Such assays have relatively short performance times, yield results that will affect clinical decision making, and allow management decisions to be made during the same encounter.
  • The test can be performed under a certificate of waiver under the Clinical Laboratory Improvement Amendments of 1988, so-called “waived” tests (Table 11-5).

Certain tests that meet this definition may not be used in a manner compatible with POC testing. For instance, an increasing number of waived, sample-to-answer molecular diagnostics (nucleic acid amplification tests, such as PCR or RT-PCR) are becoming available. At a given institution, though, such assays might only be performed in a central laboratory at specific times, thereby limiting their utility in a POC testing protocol. These assays typically require dedicated, bench-top equipment for performance. As such, adding capacity at individual clinical sites may not be feasible.

Table 11-5. Selected rapid diagnostic tests for pathogens in the returning traveler

Syndrome

Pathogen

Specimen

Additional information

Lateral-flow immunochromatographic tests and small panels

Systemic febrile illness

Ebola virus 1

Whole blood

Received emergency use authorization by FDA and WHO. May not be appropriate for excluding illness in early infection.

Dengue virus 1

Serum

Not FDA-cleared. Highly variable diagnostic performance. Antibodies may cross-react with other flaviviruses.

Malaria 1

Whole blood

Best performance characteristics for Plasmodium falciparum infections. Many versions may be available in endemic areas.

Gastrointestinal infections

Norovirus, rotavirus, adenovirus 1

Stool sample

Available in the United States individually or in combination. Adenovirus rapid tests are approved for ocular specimens.

Respiratory infections

Group A Streptococcus

Throat swab

Rapid antigen and molecular tests 2 available; both are specific but molecular tests have improved sensitivity.

Influenza

NP or throat swab

Rapid test sensitivity 50%–70%; negative testing should not direct treatment.

Legionella pneumophila 1

Urine

Only detects serogroup 1. Recommended by IDSA for patients with more severe disease.

Respiratory syncytial virus

NP or throat swab

Accurate antigen assays, recommended if results will affect management.

Streptococcus pneumoniae

Urine

Recommended by IDSA for use in certain patient populations.

Sexually transmitted infections

Chlamydia trachomatis and Neisseria gonorrhea 1

Urine, vaginal swab

Molecular tests remain gold standard; a sample-to-answer molecular assay is available. 1, 2

HIV

Whole blood, oral fluids

Antibody and antibody/antigen kits available. Molecular testing preferred for acute infection.

Treponema pallidum

Whole blood

Antibody detection, may not be appropriate for acute infections.

Trichomonas vaginalis

Vaginal swab

Rapid antigen testing is specific with sensitivity approximately 90%.

BV pathogens

Vaginal swab

Identifies increased sialidase activity, an enzyme associated with BV pathogens.

Multiplex molecular panels

Gastrointestinal pathogens

Includes common viruses, bacteria, and parasites 1, 2

Stool sample

Sensitive, certain positive results may be unrelated to active infection.

Respiratory pathogens

Includes common viruses and atypical bacteria 2

NP swab

Pathogens may have prolonged shedding time; positive results may not rule out infection from other pathogens.

Abbreviations: BV, bacterial vaginosis; FDA, US Food and Drug Administration; IDSA, Infectious Disease Society of America; NP, nasopharyngeal; WHO, World Health Organization.

1 Not waived by Clinical Laboratory Improvement Amendments.

2 Not immunochromatographic assay.

Assays that characterize a host response (such as C-reactive protein and procalcitonin) show promise in limiting unnecessary antibiotic use in certain clinical settings. However, their use and interpretation are complicated and can be confusing in the setting of returning travelers with potentially severe, nonbacterial tropical infectious diseases such as malaria and dengue.

-- To view the remaining sections of this topic, please or --

Rapid Diagnostic Tests for Infectious Diseases

In the context of infectious diseases, the term rapid diagnostic test (RDT) most commonly refers to lateral-flow, immunochromatographic tests used to detect certain infections. More generally, such assays may be described as point-of-care (POC) tests. Although there are no accepted criteria for what constitutes an RDT or POC test, published definitions frequently focus on performance time and simplicity. Pathogen-specific or syndrome-based tests are considered RDTs if they meet either or both of the following criteria:

  • The test can be incorporated into a POC testing protocol for a given infection or clinical syndrome. Such assays have relatively short performance times, yield results that will affect clinical decision making, and allow management decisions to be made during the same encounter.
  • The test can be performed under a certificate of waiver under the Clinical Laboratory Improvement Amendments of 1988, so-called “waived” tests (Table 11-5).

Certain tests that meet this definition may not be used in a manner compatible with POC testing. For instance, an increasing number of waived, sample-to-answer molecular diagnostics (nucleic acid amplification tests, such as PCR or RT-PCR) are becoming available. At a given institution, though, such assays might only be performed in a central laboratory at specific times, thereby limiting their utility in a POC testing protocol. These assays typically require dedicated, bench-top equipment for performance. As such, adding capacity at individual clinical sites may not be feasible.

Table 11-5. Selected rapid diagnostic tests for pathogens in the returning traveler

Syndrome

Pathogen

Specimen

Additional information

Lateral-flow immunochromatographic tests and small panels

Systemic febrile illness

Ebola virus 1

Whole blood

Received emergency use authorization by FDA and WHO. May not be appropriate for excluding illness in early infection.

Dengue virus 1

Serum

Not FDA-cleared. Highly variable diagnostic performance. Antibodies may cross-react with other flaviviruses.

Malaria 1

Whole blood

Best performance characteristics for Plasmodium falciparum infections. Many versions may be available in endemic areas.

Gastrointestinal infections

Norovirus, rotavirus, adenovirus 1

Stool sample

Available in the United States individually or in combination. Adenovirus rapid tests are approved for ocular specimens.

Respiratory infections

Group A Streptococcus

Throat swab

Rapid antigen and molecular tests 2 available; both are specific but molecular tests have improved sensitivity.

Influenza

NP or throat swab

Rapid test sensitivity 50%–70%; negative testing should not direct treatment.

Legionella pneumophila 1

Urine

Only detects serogroup 1. Recommended by IDSA for patients with more severe disease.

Respiratory syncytial virus

NP or throat swab

Accurate antigen assays, recommended if results will affect management.

Streptococcus pneumoniae

Urine

Recommended by IDSA for use in certain patient populations.

Sexually transmitted infections

Chlamydia trachomatis and Neisseria gonorrhea 1

Urine, vaginal swab

Molecular tests remain gold standard; a sample-to-answer molecular assay is available. 1, 2

HIV

Whole blood, oral fluids

Antibody and antibody/antigen kits available. Molecular testing preferred for acute infection.

Treponema pallidum

Whole blood

Antibody detection, may not be appropriate for acute infections.

Trichomonas vaginalis

Vaginal swab

Rapid antigen testing is specific with sensitivity approximately 90%.

BV pathogens

Vaginal swab

Identifies increased sialidase activity, an enzyme associated with BV pathogens.

Multiplex molecular panels

Gastrointestinal pathogens

Includes common viruses, bacteria, and parasites 1, 2

Stool sample

Sensitive, certain positive results may be unrelated to active infection.

Respiratory pathogens

Includes common viruses and atypical bacteria 2

NP swab

Pathogens may have prolonged shedding time; positive results may not rule out infection from other pathogens.

Abbreviations: BV, bacterial vaginosis; FDA, US Food and Drug Administration; IDSA, Infectious Disease Society of America; NP, nasopharyngeal; WHO, World Health Organization.

1 Not waived by Clinical Laboratory Improvement Amendments.

2 Not immunochromatographic assay.

Assays that characterize a host response (such as C-reactive protein and procalcitonin) show promise in limiting unnecessary antibiotic use in certain clinical settings. However, their use and interpretation are complicated and can be confusing in the setting of returning travelers with potentially severe, nonbacterial tropical infectious diseases such as malaria and dengue.

There's more to see -- the rest of this entry is available only to subscribers.