Key points
- Tissue tests for dengue virus are most commonly used in forensic settings.
- Tissue tests for dengue virus may be performed on biopsy or autopsy specimens.
- A positive result confirms the presence of dengue virus in tissue.
- A negative result does not rule out dengue infection.
Appropriate specimens for testing
Fixed liver, kidney, spleen, and lung tissue are optimal for dengue virus tissue testing.
Keep in mind
In the instance of unexplained, potentially infectious deaths with multisystem involvement, submission of specimens from all major organs is recommended, specifically those with any significant pathologic findings.
Nucleic Acid Amplification Test (NAAT) for fixed tissue specimen
What the test is
NAATs detect dengue virus RNA. NAATs include real-time reverse transcription polymerase chain reaction (rRT-PCR) and in situ hybridization.
How and when NAAT should be used during infection
- Fixed tissue samples can be tested using NAAT.
- NAATs are most sensitive during the first 7 days of illness.
- However, these tests may be used to evaluate dengue as the cause of death at later times after illness onset.
- However, these tests may be used to evaluate dengue as the cause of death at later times after illness onset.
Immunohistochemical (IHC) analysis for fixed tissue specimens
What the test is
- Pathologists use immunohistochemical (IHC) analysis to identify dengue virus in tissues.
- The technique uses specific antibodies, which localize to the antigens of the etiologic agent of interest.
- Because the technique uses formalin-fixed tissues, specimen transport is simplified, allowing retrospective studies and minimizing laboratory worker exposure to infectious agents.
- CDC's Infectious Diseases Pathology Branch offers additional information on diagnostic techniques.
When IHC is useful
This test can be useful in evaluating dengue as a possible cause of death.
Interpretation of results
The interpretation of both NAAT and IHC for fixed tissue samples is as follows:
- A positive result confirms the presence of dengue virus in tissue.
- However, other causes of death should be taken into consideration.
- However, other causes of death should be taken into consideration.
- A negative result does not rule out dengue infection as a cause of death.
Reminder
Diagnosis should be interpreted within the context of histopathologic findings, clinical and epidemiologic history, and other laboratory studies.
Availability
Both IHC and NAAT tissue testing is only available in reference laboratories such as those from the CDC as part of forensic examination to evaluate dengue as a possible cause of death.
Keep in mind
Pre-approval is required prior to submission of any tissue specimens. For pre-approval, please contact pathology@cdc.gov.
To access information about tissue test orders (including specimen submission guidelines), click here.