Chikungunya detection & Viral Load
Chikungunya Virus :

Chikungunya fever is a viral disease transmitted to humans by the bite of infected Aedes Aegypti mosquitoes. Chikungunya virus (CHIKV) is a member of the genus Alphavirus, in the family Togaviridae. CHIKV was first isolated from the blood of a febrile patient in Tanzania in 1953. Chikungunya virus is a small (about 60–70 nm-diameter), spherical, enveloped, positive-strand RNA virus Symptoms of Chikungunya includes fever, debilitating arthralgia (joint pain), swelling of joints, stiffness of joints, myalgia (muscular pain), headache, fatigue (weakness), nausea, vomiting and rash.The incubation period (time from infection to illness) can be 2-12 days, but is usually 3-7 days. "Silent" CHIKV infections (infections without illness) do occur; but how commonly this happens is not yet known.

Acute chikungunya fever typically lasts a few days to a couple of weeks, but some patients have prolonged fatigue lasting several weeks. Additionally, some patients have reported incapacitating joint pain, or arthritis which may last for weeks or months. No deaths, neuro-invasive cases, or a hemorrhagic case related to CHIKV infection has been conclusively documented in the scientific literature. Aedes mosquitoes, which are highly domestic in the rural, urban and periurban areas are vectors of this disease. They bite during the day and are easily recognized by the black and white stripes/spot markings on their bodies and legs. They breed easily in anything which can hold clean water including tyres,coconut shells, flower pots, storage jars and cooling systems. The eggs become adults within a span of 7-10 days. The mosquito can rest inside, outside and around the house, school and other areas in towns and villages where it is dark, cool and shaded. Prevention Since specific drug treatment and vaccines are not available; all central efforts should be directed against mosquitoes. It is important to eliminate their breeding grounds in order to control the disease. However,efforts should be intensified before the transmission season especially during and after the rainy season and at the time of the epidemic.

Methodology:

Taqman Real time PCR assay.

Clinical Use:

• Detect acute infection prior to seroconversion (ie, within 1-2 weeks post-exposure).
• Assess viral measured by changes in the Chikungunya levels.
• Assess prognosis and early diagnosis for better patient cure.
• Confirm active Chikungunya virus infection In patient

Prevention:

• Draining water from coolers, tanks, barrels, drums and buckets, etc.
• Emptying coolers when not in use.
• Removing from the house all objects, e.g. plant saucers, etc. which have water collected in them.
• Use mosquito repellent on exposed skin.
• Wear long sleeves shirts and pants.
• Have secure screens on windows and doors to keep mosquitoes out.
• Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water
   in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out.
• Additionally, a person with chikungunya fever should limit their exposure to mosquito bites in order to avoid further
   spreading the infection. The person should stay indoors or under a mosquito net.

Performed:

Every day.

Reported:

3-4 days.

Specimen Required:

Blood, serum, plasma, Collect in: Lavender (EDTA), pink (K2EDTA), or serum separator tube. Stability collection to initiation of testing On Cells: Ambient: 4 hours; after separation from cells: Refrigerated: 48 hours; Frozen at -20°C: 72 hours; Frozen at -70°C: 4 months. Do not thaw avoid repeated freezing and thawing.

Specimen Preparation:

Separate serum or plasma from cells within 24 hours.

Storage/Transport Temperature:

Refrigerate specimen's at 2°C-4°C.

Unacceptable Conditions:

Heparinized specimens, Hemolysis sample, Quantity not sufficient for analysis, specimen grossly contaminated, specimen too old, frozen whole blood specimen, specimen leaky or tube broken.

Interpretation:

This test can quantitate/detect Chikungunya virus RNA over the linear range 70-108 copies/mL. However this does not mean that lower copies or higher copies cannot be detected. The lower copies can be detected in some cases. This is a limitation of the currently available extraction systems. A negative result does not preclude the presence of Chikungunya virus infection because results depend on adequate/proper patient sample storage and transportation as RNA is fragile and thermo labile, absence of inhibitors and sufficient RNA to be detected. A negative test cannot be used to definitely rule out the presence of Chikungunya. A RT-PCR may detect Chikungunya as long as the virus is actively replicating in the person.

The result of this test must always be correlated with clinical status and history of the patient and other relevant data and should not be used alone for the interpretation.

Note:

The test is intended for use in conjunction with clinical presentation and other laboratory markers as an indicator of disease prognosis.