Also Known As
Arthropod-borne Virus Testing
Arbovirus Serology
Formal Name
Arbovirus (name specific for each virus) IgM and IgG Antibodies and Nucleic Acid Amplification Tests
This article was last reviewed on
This article waslast modified on
29 March 2018.
At a Glance
Why Get Tested?

To determine the cause of meningitis or encephalitis, rash or illness causing a fever that occurs after exposure to insects such as mosquitoes and ticks, usually during travel to warmer countries; to investigate the source of epidemics and track their spread

When to Get Tested?

When you have symptoms suggesting an arbovirus infection, after insect bites or other exposure to these viral infections

Sample Required?

A blood sample drawn from a vein in your arm or cerebrospinal fluid collected from a lumbar puncture

Test Preparation Needed?

None

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you will be able to access your results online.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, gender, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

Arboviruses (arthropod-borne viruses) are transmitted between humans by mosquitoes and other blood-sucking insects, such as ticks. Arbovirus testing detects either antibodies produced by the body's immune system in response to a specific arbovirus infection or the virus's genetic material in blood, cerebrospinal fluid or other bodily fluid.

Found throughout the world, arboviruses are an important cause of viral meningitis and encephalitis. In temperate climates, they tend to cause occasional seasonal epidemics. In tropical climates, they may be found year-round, whenever mosquitoes are active.

These viruses are spread when a mosquito, or sometimes another insect carrier (vector) such as a tick or sandfly, bites an infected bird or animal and becomes infected, then bites a human and passes it on. Arbovirus infections are usually not directly passed from person-to-person. Sometimes, an infection may be transmitted through a blood transfusion, organ transplant, sexual contact, from a pregnant woman to her baby, or from a mother to child through breast milk.

Depending on the virus causing the infection, people infected by an arbovirus may have only mild to moderate flu-like symptoms that resolve within a few days to a few weeks. Many people report no symptoms at all but, in other  cases, a sudden onset of high fever may be accompanied by a rash, jaundice , or severe joint pain and debilitating symptoms. In a few cases, a person may develop severe symptoms that may be life-threatening and require hospitalisation.

There are hundreds of different arboviruses, but most are uncommon. Examples of arboviruses include:

Virus/Illness

Insect Carrier

Typically Found In:

Chikungunya (CHIKV)

Mosquito

Africa, Asia, Southern Europe and the Caribbean

Yellow Fever

Mosquito

South America, Africa

Dengue Fever

Mosquito

South America, Asia, tropical tourist destinations, Caribbean

Zika Virus

Mosquito

Caribbean, South America, Africa, Asia

Japanese Encephalitis

Mosquito

Asia

West Nile Virus

Mosquito

U.S., Africa, parts of Europe, Middle East, West Asia and Australia

LaCrosse Virus

Mosquito

South and Central America, Asia, parts of U.S.

Rift Valley Fever

Mosquito, Tick, Sandfly

Africa and Middle East

Crimean-Congo Haemorrhagic Fever

Tick

Asia, Africa, Europe

Tick borne encephalitis

Tick

parts of Europe, Asia

Ross River Virus

Mosquito

Australia

How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein and/or cerebrospinal fluid is collected from a lumbar puncture.

Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.

Accordion Title
Common Questions
  • How is it used?

    Arbovirus testing is used to determine whether a person with signs and symptoms, plus a recent history of potential exposure to a specific arbovirus, has been infected. Testing can be important to distinguish an arbovirus infection from other conditions causing similar symptoms, such as bacterial meningitis, and can help guide treatment.

    Typically, the individual test requested is specific for a particular arbovirus, such as West Nile Virus (WNV) or dengue fever, depending on the person's symptoms and likely exposure. Individual test selection depends on a person’s symptoms and where they have been living or travelling. Sometimes, a panel of tests may be carried out to determine which arbovirus is causing the infection.

    Two types of tests are available:

    Antibody Tests
    Antibody testing detects antibodies produced in response to a specific arbovirus infection. There are two classes of antibodies that may be detected:

    • IgM antibodies are produced first and are present within a week or two after the start of symptoms. Levels rise for a few weeks, then taper off, becoming undetectable after a few months. IgM antibody testing is the primary test performed on the blood or cerebrospinal fluid of symptomatic people.
    • IgG antibodies are produced after IgM antibodies. Typically, the level rises with an acute infection, stabilises and then persists long-term. IgG tests may be ordered along with IgM testing to help diagnose a recent or previous arbovirus infection. Sometimes testing is done by collecting two samples, 2 to 4 weeks apart (acute and convalescent samples), and measuring the IgG level (titre). This may help determine whether antibodies are from a recent or past infection.

    Antibody tests may cross-react with viruses that are similar, so a second test that employs a different method may be used to confirm positive results.

    Nucleic Acid Amplification Test
    A nucleic acid amplification test (NAAT) amplifies and measures the arbovirus's genetic material to detect the presence of a specific virus. It can detect a current infection with the virus, often before antibodies to the virus are detectable, but there must be a certain amount of virus present in the sample in order to detect it. For most arboviruses, virus levels in humans are usually low and do not persist for very long.

  • When is it requested?

    Testing is primarily requested when a person has signs and symptoms suggesting a current arbovirus infection, especially if the person lives in or has recently travelled to an area where a specific arbovirus is endemic.

    In temperate areas an arbovirus infection may be suspected when symptoms arise during mid to late summer. In warmer areas, infections may occur year-round.

    Some signs and symptoms may include:

    • Fever
    • Headache
    • Muscle weakness and pain
    • Joint pain
    • Nausea
    • Skin rash

    A small percentage of people, especially the young, elderly, and immunocompromised, may have more serious symptoms associated with meningitis and encephalitis. These symptoms may include:

    • High fever
    • Severe headaches
    • Convulsions
    • Confusion
    • Stiff neck
    • Muscular paralysis

    Antibody tests may be requestetd within the first week or two of the onset of symptoms to detect an acute infection. An additional blood sample may be collected 2 to 4 weeks later to determine if the antibody level is rising. When an infection of the central nervous system is suspected, antibody testing may be performed on cerebrospinal fluid as well as blood.

  • What does the test result mean?

    Results of arbovirus testing require careful interpretation, taking into consideration the individual's signs and symptoms as well as risk of exposure to the insect vectors.

    Antibody Tests
    Antibody tests may be reported as positive or negative, or may be reported as less than or greater than a certain titre. For example, if the established threshold is a titre of 1:10, then a result less than this is considered negative while a titre greater than this is considered positive.

    If IgM or IgG antibody is detected in the cerebrospinal fluid (CSF), it suggests that an arbovirus infection is present in the central nervous system. If a CSF antibody test is negative, then it suggests that there is no central nervous system involvement or the level of antibody is too low to detect.

    If IgM and IgG arbovirus antibodies are detected in an initial blood sample, then it is likely that the person became infected with the arbovirus within the last few weeks. If the IgG is positive but the IgM is low or negative, then it is likely that the person had an arbovirus infection sometime in the past. If the arbovirus IgG antibody titer increases significantly between an initial sample and one taken 2 to 4 weeks later, then it is likely that a person has had a recent infection.

    Negative results for IgM and/or IgG antibodies may suggest that symptoms are due to a different cause, such as bacterial meningitis. However, the person may still have an arbovirus infection – it may just be that it is too soon after initial exposure to the virus and there has not been enough time to produce a detectable level of antibody. If suspicion of arbovirus remains high, antibody testing may be repeated at a later time or a NAAT test may be done as follow up.

    The following table summarises results that may be seen with antibody testing:

    IgM Result

    IgG Result

    Possible Interpretation

    Positive

    Negative

    Very recent infection or cross-reactivity

    Positive

    Positive

    Recent infection

    Low or negative or not tested

    Increasing in samples taken 2-4 weeks apart

    Recent infection

    Low or negative

    Positive but stable

    Past infection

    Negative

    Negative

    • Too soon after initial exposure for antibodies to develop
    • Symptoms due to another cause

    A positive result on an initial test for IgM arbovirus antibody in blood or CSF is considered a presumptive positive since antibodies to viruses in the same family may cross-react. It suggests a diagnosis, but it is not definitive. A positive result on a second test using a different method (NAAT or neutralization assay), or repeat testing on a later sample, confirms the diagnosis.

    Nucleic Acid Amplification Testing (NAAT)
    A positive NAAT for an arbovirus indicates infection with that specific virus.

    A negative NAAT means there is no virus present in the sample tested or the virus is present in very low (undetectable) numbers. A negative test cannot be used to definitely rule out the presence of an arbovirus.

  • Is there anything else I should know?

    The presence of arbovirus antibodies may indicate an infection but cannot be used to predict the severity of an individual's symptoms or the person's prognosis.

    Other tests, such as antigen tests for dengue fever and viral cultures, may be used in some instances. NAAT and viral cultures may be used in research settings and by the medical community at a national and international level to identify and study the strains of arboviruses causing infections. Different strains have been isolated and associated with regional epidemics.

    In the UK, the tests are often performed at a central national laboratory NAAT testing may be used to screen donated blood or organs, or to test the tissues of a person who has died (post mortem) to determine whether a specific arbovirus may have caused or contributed to the person's death.

    Arbovirus testing can also be performed on suspected host animals and insect pools to detect the presence and spread of an arbovirus in the community and region. This information can be used to help investigate outbreaks, identify and monitor infection sources, and to guide efforts to prevent the spread of the infection.

  • Should everyone be tested for arboviruses?

    In general, there is no need. Most people who become infected have few to mild symptoms and are only exposed to those arboviruses that are present in the areas where they live or travel. Testing is not usually done on asymptomatic people.

  • Are arboviruses something I should worry about when I travel?

    Every region in the world has its own health concerns, so it is prudent to read about the areas where you will be travelling and to talk to your healthcare provider about the risks for infection. There is an increased risk of an arbovirus infection when travelling to a tropical location or to an area that has seasonal outbreaks. A person's likelihood of exposure will be influenced by that person's planned activities and by the preventive measures that the person takes against insect bites. (For more on the specific diseases related to your travels, visit the Destinations page on the Centers for Disease Control and Prevention web site

  • What can I do to protect against arboviruses?

    Protection begins with preventing mosquito bites. Measures include wearing long-sleeved shirts and trousers when outdoors, using insect repellent and mosquito nets, and staying indoors at dawn and dusk when some mosquitoes are most active. Around your home, you can eliminate standing water sources that attract mosquitoes. Communities can take preventive measures by monitoring the seasonal risks and spraying for mosquitoes as warranted.

  • Are there vaccines for arboviruses?

    There are vaccines for Yellow Fever, Japanese Encephalitis and Tick-Borne Encephalitis for humans and there are several vaccines for the equine encephalitis viruses that have been developed for horses. Research in this area continues.

  • Who performs arbovirus testing?

    Most testing is performed by a reference laboratory.