Virology Testing in Vermont

The Vermont Department of Health Laboratory offers many different virology tests.

Influenza

The Influenza Surveillance program is a year-round monitoring program used to determine what influenza strains are circulating in Vermont's human population. This information is used by the Centers for Disease Control and Prevention for influenza vaccine development. 

Real-time PCR is used at the Vermont Department of Health Laboratory to analyze clinical specimens from participating sentinel influenza providers, hospital emergency departments enrolled in the Early Aberration Reporting System (EARS), long-term care facilities or other institutions, and medical providers with special requests (e.g. hospitalized patient with influenza-like-illness or a suspect H5N1 case). 

Predominant strains in Vermont include Influenza A (subtypes H1, H3, and the less common H5 and H7) and Influenza B (lineages Victoria and Yamagata).

Find more information from the Health Department on Influenza Surveillance here.

Norovirus

Noroviruses are a group of viruses that cause acute gastroenteritis (GAS-tro-en-ter-I-tis) in people. 

Norovirus is the leading cause of acute gastroenteritis and viral foodborne-disease illness in the United States. It is highly contagious and can spread from person to person, or through contaminated food, water, or surfaces. Norovirus can be serious, especially for young children and older adults.

The Vermont Department of Health Laboratory participates in a national norovirus surveillance network called CaliciNet, which is supported by the Centers for Disease Control and Prevention.  The Health Department assists CDC by monitoring current norovirus strains and helping to identify newly emerging strains. 

All requests for norovirus testing must have prior approval from Vermont Department of Health Epidemiology. 

If you suspect a norovirus outbreak, call the Health Surveillance Division at 802-863-7240 or 1-800-640-4374 (toll free in Vermont).

Eastern Equine Encephalitis (EEE) / West Nile Virus (WNV)

The Vermont Arbovirus Surveillance Program is a cooperative initiative between the Department of Health and the Agency of Agriculture, Food and Markets. The program monitors for the presence of Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) in mosquitoes.

Mosquitoes are obtained using various trapping methods by the Agency of Agriculture from towns throughout the Vermont. The mosquitoes are submitted to the Vermont Department of Health Laboratory for testing by utilizing real-time PCR. 

Test results are posted on the Health Department’s website, allowing state and local governments to determine what the threat is to public health. Members of the public can also benefit from this information as a way to determine if extra precautions, such as the use of insect repellents, may be necessary when spending time outside. 

Find more information on Mosquito-borne Diseases (Arbovirus), including Surveillance, Testing and Data here.

Measles/Mumps/Rubella/Varicella

Measles, mumps, rubella, and varicella (chickenpox) are vaccine-preventable viral diseases that are spread from person to person through the air. Varicella can also be spread through contact with the fluid filled blisters. 

When the human body is invaded by disease-causing organisms such as viruses, it responds in several ways to combat the invader. One response is production of antibodies by the body.  The use of vaccines also causes a similar response, although the goal of vaccines is immunity without active disease. 

The Vermont Department of Health Laboratory (VDHL) can test blood serum specimens for the presence of antibodies produced against measles, mumps, rubella and varicella by utilizing an enzyme immunoassay. Patients with positive test results are said to have acceptable antibody levels to prevent disease. Patients who do not have detectable levels of antibodies should discuss the result with their physician to determine if a vaccine booster is required. Serum is the preferred specimen type for the immunoassay tests.

If active disease is suspected for measles or mumps, the Laboratory will use real-time PCR test methods to determine if detectable levels of virus are present in a patient’s blood. 

For the measles real time PCR test, throat (oropharyngeal), nasal or NP (nasopharyngeal) swabs are the preferred specimen types. For the mumps PCR test, oral swabs, buccal swabs and urine specimens are the preferred specimen types.

Hep B/C

Hepatitis B and C are viruses that spread most commonly through blood or through IV drug use. Both viruses usually result in a short term illness. However, in some people the disease can become chronic, resulting in severe damage to the liver (cirrhosis). A vaccine is available for Hepatitis B, but currently there is no vaccine for Hepatitis C. 

When the human body is invaded by disease-causing organisms such as viruses, it responds in several ways to combat the invader. One response is production of antibodies by the body.   

The Vermont Department of Health Laboratory can test serum specimens for the presence of antibodies produced against the hepatitis virus by utilizing an enzyme immunoassay.

There are three key markers targeted for hepatitis B (hepatitis B surface antigen, core antigen, and surface antibody), which aids physicians in determining the disease state of the patient (acute or a chronic condition). 

The Laboratory can also test patients with a known hepatitis B vaccine history to determine if they are immune or require a booster. 

The Laboratory also provides serological testing for hepatitis C virus.

HIV

Human Immunodeficiency Virus (HIV) infection is a caused by the HIV virus that is spread by contact with blood and other body fluids. HIV attacks disease-fighting cells in the body called CD4 T cells, resulting in a lowered immune response to other infectious agents such as bacteria or other viruses.  The two most common types of HIV are HIV-1, which is found worldwide and HIV-2, the less common type, which is principally found in Africa. 

When the human body is invaded by disease-causing organisms such as viruses, it responds in several ways to combat the invader. One response is production of antibodies by the body. The Vermont Department of Health Laboratory utilizes two tests that detect antibodies made by the body in response to HIV. 

The first and most sensitive HIV test used is a 4th generation combination antigen/antibody immunoassay. This test detects HIV-1, HIV-2, and the HIV-1 p24 antigen. The 4th generation immunoassay has the earliest detection of the HIV-1 p24 antigen, which is detectable around 15 days post infection in blood. 

Positive specimens are confirmed with an additional assay that will differentiate between an infection with HIV-1 or HIV-2. 

The second antibody immunoassay available at the Laboratory is used to test oral fluid specimens. Oral fluid may be preferred by patients as it a quick and less invasive specimen to collect. An oral fluid swab (collected in the designated collection container) is also stable at room temperature for 21 days, allowing for more shipment options. 

Detection of HIV antibody by the oral fluid test is not usually possible until approximately 30 days post infection. Confirmation by the use of the Western Blot, which only detects HIV-1, is also required for oral fluid specimens.

Zika

NOTE:  All Zika specimen submission requests must be pre-approved by calling the Infectious Disease Epidemiology 24/7 phone number: (802) 863-7240

Zika virus is a virus that is spread to people who are bitten by a mosquito carrying the Zika virus.  Aedes aegypti and Aedes albopictus are the primary species that carry the virus and are not thought to be found in Vermont based on current surveillance data. 

Testing is available at the Vermont Department of Health Laboratory (VDHL) for those people who meet the Centers for Disease Control and Preventions criteria for Zika testing.

Please refer to the VDHL specimen collection instructions found on our forms and ordering page for current Zika testing criteria.

Testing options at the VDHL include real time PCR testing for serum, urine, and whole blood specimens.

  • Serum specimens will be tested for Dengue virus, Chikungunya virus, and Zika virus. 
  • Urine and whole blood specimens will be tested for Zika virus only. 
  • Detection of Zika IgM antibodies for serum specimens is also available. 

PCR and/or Serology testing will be based on travel history (including the timing of travel) pregnancy status, and symptomology.

For more information from the Health Department on Zika

For more informaton from the CDC on Zika