Chikungunya - IGM

Chikungunya (chik-un-GUN-yuh) is a mosquito-borne viral infection that causes a quick onset of fever and severe joint pain. Chikungunya signs and symptoms often show two to seven days after being bitten by an infected mosquito.

Chikungunya is a virus spread by mosquitoes. This mosquito was first identified in 1952 after an outbreak in southern Tanzania. It is an RNA virus that belongs to the Togaviridae family alphavirus genus. The name chikungunya means to become distorted and depicts the stooping appearance of joint pain sufferers (arthralgia).

Chikungunya virus can infect a new, uninfected host faster than other mosquito-borne viruses. The mosquito, once infected, is thought to be capable of transmitting the virus for the remainder of its life.

Virus, viral nucleic acid or virus-specific immunoglobulin (Ig) M and neutralising antibodies are formed in serum or plasma during laboratory diagnosis. In the first three days of illness, viral culture may detect the virus.

Chikungunya virus RNA can commonly be detected in serum during the first eight days of sickness. Antibodies to the chikungunya virus usually emerge at the end of the first week of disease. In some acute phases, samples test negative for chikungunya test. In that case, to rule out the diagnosis, convalescent-phase samples should be taken.

The chikungunya test includes testing of IgM and IgG antibodies. IgM antibodies indicate recent or ongoing infection, while IgG antibodies indicate past infection. The chikungunya test helps detect the presence of antibodies against the chikungunya virus in the individual. If you have not tested positive on a diagnostic test for chikungunya test done to confirm exposure to the virus.

Studies show that chikungunya is a huge concern for public health in India. Close to twenty-four Indian states and about six union territories are endemic to the disease.

Many patients feel better in around seven days, although joint pain might continue for months in some people. The symptoms are similar to diseases caused by the same mosquitoes, dengue fever.

Complications include inflammation of the heart, liver, brain, skin, kidneys and nerves.

The elderly (>65 years) and newborns, particularly those with significant medical issues, are at the greatest risk of severe disease and consequences. Death is uncommon and affects the elderly.

Chikungunya fever

The chikungunya test chart detects antibodies produced against the chikungunya virus in the blood sample. Patients with an acute start of fever, especially those who recently returned from places where the virus is prevalent, should be evaluated for chikungunya virus infection.

Chikungunya test chart is advised on people who are at high risk of chikungunya infection. It includes:

• People who have symptoms of chikungunya fever and live in high-risk areas of chikungunya.
• People who have symptoms of chikungunya fever after a recent travel history to a chikungunya-prone locality.

The chikungunya test values are indicated if a person is experiencing the following symptoms:

• Sensation of moderate illness
• Sudden high fever (104°F or 40°C)
• Flu-like symptoms
• Severe headaches
• Severe Joint pain
• Crippling pain in joints
• Bone pain
• Muscle discomfort
• Myalgia
• Arthritis
• Conjunctivitis
• Nausea
• Vomiting
• Maculopapular rash
• The flat red area on the skin covered with elevated bumps
• Hyperpigmentation
• Mouth ulcers
• Diarrhoea
• Dehydration
• Sleeplessness

When the chikungunya test value is positive, the doctor will start the treatment. Treatment for chikungunya, like most acute conditions, needs 15-20 days.

Below are the reasons why a doctor would prescribe a chikungunya test second time:

• If the symptoms do not disappear or new ones arise, the doctor will order another chikungunya test procedure.
• After 15 days, the chikungunya test repetition helps to understand if the patient has healed. If the doctor suspects the previous report was false-negative or false-positive, he may ask for a repetition of the chikungunya test report after seven days.
• In case of acute chikungunya, if the chikungunya test results are negative, the test needs a repetition within ten days with another sample.

Before the Test

Typically, your doctor will not ask you to take special measures for a chikungunya test. However, if you are scheduled for this test along with another one, your healthcare provider may recommend fasting or avoiding certain foods. Always consult a doctor before the test for guidance.

During the Test

When the phlebotomist arrives for the chikungunya test, a blood sample will be drawn from a vein in your arm. Here's what you can expect during the test:

• The area where the needle will be inserted will be cleaned with antiseptic.
• A tourniquet will be tied to your upper arm to make your veins visible.
• A needle will be inserted into the vein to draw the blood. This process may cause a brief pinch lasting a few seconds.
• The blood will be collected in a vial or small test tube, and a label will be filled with your details.

After the Test

Following the blood collection:

• A bandaid will be placed over the insertion site to stop any bleeding.
• Bruising is a common after effect. Some people also feel dizzy. You may be advised to rest for a few minutes.
• If bleeding, pain, or rashes at the puncture site persist, it's important to contact your healthcare provider.

The chikungunya test reports include only two parameters. IgM and IgG antibody tests detect antibodies produced by the immune system as a response to the chikungunya virus.

The chikungunya IgG and IgM normal ranges are in the table below.

Note: If the chikungunya report values are normal range, it does not rule out chikungunya completely. The chikungunya test chart is interpreted by a healthcare provider.

The normal values and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

For interpretation of chikungunya, test results should be used in correlation with clinical presentation and including exposure history.

The chikungunya test results may be in two forms:

• Chikungunya positive
• Chikungunya negative

This interpretation is based on IgG and IgM antibodies formed in response to the chikungunya virus.

• IgM and IgG Negative - There is no sign of chikungunya virus infection. If clinical suspicion continues, testing on a fresh specimen taken after 5 to 10 days is indicated.

• IgM and IgG Positive - Antibodies to the chikungunya virus (IgM and IgG) are present, indicating a recent or previous infection. Chikungunya virus IgM antibodies may be present for 3 to 4 months after infection.

• IgM Positive, IgG Negative - Chikungunya virus IgM antibodies are present, indicating recent infection. To confirm, repeat testing in the next 5 to 10 days to detect anti-chikungunya virus IgG seroconversion.

• IgM Negative, IgG Positive - Antibodies to the chikungunya virus are present, indicating past infection.

• IgM and/or IgG Borderline - The test needs repetition in 10 to 14 days.