Test ID HRTVS Heartland Virus, RNA, Molecular Detection, PCR, Serum
Ordering Guidance
Patients with a history of symptoms for more than 1 week may be negative by molecular tests (ie, real-time polymerase chain reaction) and may require serologic testing, which is available through the Centers for Disease Control and Prevention.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container: Sterile container
Specimen Volume: 0.5 mL
Collection Instructions:
1. Within 2 hours of collection centrifuge and aliquot serum into a sterile container.
2. Serum specimens not aliquoted from the serum gel collection tube into a sterile container will be rejected.
Useful For
Aiding in the diagnosis of central nervous system infection caused by Heartland virus using serum specimens
Testing Algorithm
For more information see Meningitis/Encephalitis Panel Algorithm.
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reporting Name
Heartland Virus, PCR, SerumSpecimen Type
SerumSpecimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 14 days | ||
Ambient | 24 hours |
Reject Due To
Gross hemolysis | Reject |
Heat-inactivated specimen | Reject |
Clinical Information
Heartland virus (HRTV) disease is an emerging zoonosis, transmitted to humans through the bite of infected Amblyomma americanum (Lone Star) ticks. HRTV possesses a single-stranded negative-sense RNA genome encoded on small, medium, and large segments. HRTV is a member of the Bandavirus genus, which includes other arthropod-borne viruses (arboviruses), such as severe fever with thrombocytopenia syndrome virus (SFTSV). Reports of human HRTV disease are relatively rare, with fewer than 100 cases reported to date, most from the Central, Southern, and Northeastern United States. Symptoms generally occur within 2 weeks of a tick bite and may include non-specific symptoms such as headache, fever, fatigue, anorexia, nausea, diarrhea, and muscle or joint pain. Leukopenia, thrombocytopenia, and elevation of liver transaminases are also common laboratory findings. Rarely, multisystem organ failure and death occur. While there is no targeted antiviral therapy and treatment is entirely supportive care, diagnosis is important for several reasons, including the ability to discontinue empiric antibiotics and to provide prognostic information for patients and families.
Detection of HRTV nucleic acid in serum is a marker for acute infection caused by this virus. Importantly, the period of time that the virus can be detected in serum and cerebrospinal fluid is brief. Therefore, molecular testing should be performed within the first week following onset of symptoms. After this time, serologic testing is the preferred method for diagnosis of HRTV infection. Serologic testing is currently only available through the Centers for Disease Control and Prevention.
Reference Values
Negative
Interpretation
Positive:
The detection of Heartland virus (HRTV) nucleic acid in serum is consistent with acute-phase infection. HRTV nucleic acid may be detectable during the first week following the onset of symptoms.
Negative:
The absence of HRTV nucleic acid is consistent with the lack of acute-phase infection but does not rule out infection. Additional serologic testing may be indicated.
Cautions
Results should be used in conjunction with clinical presentation and exposure history.
Negative Heartland virus (HRTV) polymerase chain reaction results may occur if the specimen was collected more than 7 days following symptom onset. Serologic testing for the presence of antibodies to HRTV may be recommended in such cases.
Clinical Reference
1. Savage HM, Godsey MS, Lambert A, et al. First detection of heartland virus (Bunyaviridae: Phlebovirus) from field collected arthropods. Am J Trop Med Hyg. 2013;89(3):445-452. doi:10.4269/ajtmh.13-0209
2. Brault AC, Savage HM, Duggal NK, Eisen RJ, Staples JE. Heartland virus epidemiology, vector association, and disease potential. Viruses. 2018;10(9):498. doi:10.3390/v10090498
3. Staples JE, Pastula DM, Panella AJ, et al. Investigation of Heartland virus disease throughout the United States, 2013–2017. Open Forum Infect Dis. 2020;7(5):ofaa125. Published 2020 Apr 11. doi:10.1093/ofid/ofaa125
Method Description
This Heartland virus (HRTV) real-time reverse transcription polymerase chain reaction (RT-PCR) laboratory-developed test is based on primer and probe sequences reported by Savage et al.(CDC assay, 1). It provides qualitative detection of HRTV RNA from serum and CSF of patients with suspected infection. HRTV RNA in clinical specimens is first extracted using the Roche MagNA Pure 96 instrument. RT-PCR testing is then performed on the Roche LightCycler 480 II (LC480).
This RT-PCR assay employs oligonucleotide forward and reverse primers and a TaqMan hydrolysis probe specific to the small segment of the non-structural protein region of Heartland virus. A reverse transcription step is first performed to convert RNA to complementary DNA (cDNA). The primers then bind to the target cDNA sequence and facilitate amplification of an 86 base pair amplicon product during PCR. Using the LC480 software, analysis of the resultant amplification curves is performed to allow for detection of HRTV RNA. Generation of an amplification curve and a crossing point (Cp) value indicates the presence of HRTV RNA in the specimen and may be used to support the diagnosis of acute HRTV infection in the appropriate clinical and epidemiologic setting.(Unpublished Mayo method)
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 5 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
87798
NY State Approved
YesForms
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.