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Diagnostic Virology Laboratory (DVL)

The USGS National Wildlife Health Center's Diagnostic Virology Laboratory (DVL) detects existing and identifies emerging pathogens of wildlife.


The DVL uses molecular testing including next generation sequencing (NGS) for rapid test turn around and is particularly skilled in virus isolation of novel pathogens. The laboratory is part of a nation-wide passive wildlife mortality surveillance program and regularly participates in large-scale active surveillance for specific diseases. This laboratory detected the introductions of West Nile Virus, highly pathogenic avian influenza virus, and spring viremia of carp virus into North America. The laboratory is currently testing for SARS-CoV-2, which causes COVID-19 in people, and rabbit hemorrhagic disease virus 2 in suitable animals. The DVL participates in the Federal Select Agent Program and is a member of the National Animal Health Laboratory Network and conducts research on viral phylogenetics, pathology, and disease ecology.


Virology Laboratory Capabilities

Scientist putting on PPE including respirator, tyvek suit, gloves, and shoe coverings in a laboratory.
Biological Sciences Laboratory Technician donning protective gear for SARS-CoV-2 testing.

Facility Capabilities

  • Biological Safety Level 3 (BSL-3) laboratory with dedicated isolation rooms
  • Restricted access for Select Agents
  • Dedicated extraction, molecular assay set up, and results analysis areas
  • High-capacity sequence analysis workstation and access to high performance computing clusters
  • Extensive archive of wildlife tissues and virus isolates

Molecular Diagnostic Capabilities

  • Multiple manual and robotic nucleic extraction platforms
  • Conventional and real time thermal cyclers for PCR and RT-PCR tests
  • Access to overnight Sanger sequencing service
  • Third generation next generation sequencing platforms
  • Agent-specific diagnostic tests (see table) and broad-spectrum survey tests

Virus Isolation Capabilities

  • Amphibian, reptilian, avian, and mammalian tissue culture systems available
  • Commonly used cell lines include Zebrafish (ZF4), Muscovy duck embryo fibroblast (MSDEF), African green monkey kidney (Vero) plus a library of specialty cell lines appropriate to different host species
  • Embryonated eggs are used to isolate avian influenza and Newcastle Disease viruses as well as avian poxviruses
  • Isolated viruses are identified by morphological (electron microscope), antigenic, and molecular characteristics
  • Isolated viruses are used for detailed genomic characterization as well as in experimental animal trials to characterize disease pathology, virus transmission, and host range determination

Serological Capabilities

Lab technician sitting at lab hood pipetting into vials.
NWHC technician preparing avian samples for avian influenza testing.
  • Crane Herpesvirus (Inclusion Body Disease of Cranes-IBDC)
  • West Nile Virus (WNV), St Louis Encephalitis (SLE) Virus, and Japanese Encephalitis Virus
  • Wellfleet Bay Virus (Common eider orthomyxovirus)
  • Plaque assay for determination of viral titer
  • Virus neutralization and microneutralization assays


Virology Diagnostic Tests

The following is a reference guide to commonly requested tests. It is not a full list of testing capabilities of the laboratories. Determination of which test will be run on any given submission will be based on case history, gross findings at necropsy, and the scientific judgment of the case pathologist.

Virology Diagnostic Tests
Test Test Method
Adenovirus PCR
African Swine Fever Virus (ASFV) qRT-PCR
Aleutian Mink Disease PCR
Alphaviruses including Togaviruses RT-PCR
Avian Influenza Virus (AIV) qRT-PCR, isolation in allantoic sac of embryonating eggs
Avian Avulavirus  (AAvV, multiple serotypes, previously Avian Paramyxovirus, APMV) RT-PCR,  isolation in allantoic sac of embryonating eggs
Bunyavirus RT-PCR
Calicivirus RT-PCR
Canine Distemper Virus (CDV) ELISA
Classical Swine Fever Virus (CSFV) qRT-PCR
Coronavirus RT-PCR
Duck Viral Enteritis (DVE) PCR, isolation in MSDEF
Eastern Equine Encephalitis Virus (EEEV) RT-PCR, isolation in VERO
Flavivirus RT-PCR, isolation in VERO
Foot and Mouth Disease Virus (FMDV) RT-PCR
Herpesvirus PCR, isolation in MSDEF
Highland J Virus RT-PCR, isolation in VERO
Inclusion Body Disease of Crane Virus (IBDCV) Serum neutralization
Morbillivirus RT-PCR
Newcastle Disease Virus (NDV, AAvV-1) qRT-PCR,  isolation in allantoic sac of embryonating eggs
Parvovirus, including CPV PCR, CPV ELISA
Poecivirus associated with beak deformation RT-PCR
Poxvirus PCR, isolation in chorioallantoic membrane, MSDEF
Rabies Sent out
Rabbit Hemorrhagic Disease Virus 2 (RHDV2) rRT-PCR
Ranavirus, including FV3 qPCR, isolation in ZF4
Rhabdovirus RT-PCR
Reovirus PCR, isolate in VERO
Reticuloendotheliosis Virus (REV) PCR, Isolate in VERO
SARS-CoV-2 qRT-PCR, isolate in VERO
Turtle Fraservirus 1 (TFV1) PCR
Viral Hemorrhagic Septicemia Virus (VHSV) RT-PCR, isolate in VERO
West Nile Virus (WNV) qRT-PCR, PRNT
The inside a a refrigerator full of sample vials in trays.
Samples awaiting testing in the NWHC Diagnostic Virology Laboratory.
Staff members in the laboratory with black streamers and balloon decorations.
Staff celebrating Halloween in the NWHC Diagnostic Virology Laboratory.