Enterovirus 68 laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]

Patients with EV-D68 infection often have leukocytosis with lymphocyte predominance. Reverse transcription polymerase chain reaction (RT-PCR) assay of an oral or nasopharyngeal swab is usually positive. Viral culture is less likely to be ordered, but will often show positive results for the infective agent. Serology tests have a low sensitivity for the diagnosis of EV-D68 infection.

• Routine tests such as a complete blood count may not show any abnormalities.
• Leukocytosis with an increased number of lymphocytes can be observed among some patients. ^{[1] [2]}
• The serum C-reactive protein could be elevated among some patients with asthma. ^[3]

• Infection with non-polio enteroviruses can be confirmed by:^[4]

• Isolating or identifying the virus in cell culture
• Polymerase chain reaction (PCR) assay.

• Non-polio enteroviruses can be detected in respiratory specimens (including nasopharyngeal or oral swabs and bronchoalveolar lavage).

• ED-V68 is rarely present in cerebrospinal fluid (CSF). Nonetheless, it has been previously reported among 1 patient who had unusual neurological symptoms due to EV-D68.

• Enterovirus 68 is diagnosed by reverse transcription polymerase chain reaction (RT-PCR) testing.
• RT-PCR assay is conducted to target the 5′-nontranslated region, followed by partial sequencing of the structural protein genes, VP4–VP2, VP1, or both. RT-PCR provides definitive enterovirus type-specific information. ^[5]

• Detection of IgM levels or an increase in the IgG levels may also be performed to diagnose EV-D68 infection with a low sensitivity. Thus, this test is not routinely performed to diagnose EV-D68. ^[6]