Measles Virus: Measles, also known as morbilli, is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, single-stranded, negative-sense RNA viruses. Measles is a highly contagious viral disease, which affects mostly children. It is transmitted via droplets from the nose, mouth or throat of infected persons. Initial symptoms, which usually appear 10–12 days after infection, include high fever, runny nose, bloodshot eyes, and tiny white spots on the inside of the mouth. Several days later, a rash develops, starting on the face and upper neck and gradually spreading downwards.

There is no specific treatment for measles and most people recover within 2–3 weeks. However, particularly in malnourished children and people with reduced immunity; measles can cause serious complications, including blindness, encephalitis, severe diarrhoea, ear infection and pneumonia. Measles can be prevented by immunization. Measles is spread through droplet transmission from the nose, throat, and mouth of someone who is infected with the virus. These droplets are sprayed out when the infected person coughs or sneezes. Among unimmunized people exposed to the virus, over 90% will contract the disease. The infected person is highly contagious for four days before the rash appears until four days after the rash appears. The measles virus can remain in the air (and still be able to cause disease) for up to two hours after an infected person has left a room. Several days later, a rash develops, starting on the face and upper neck and gradually spreading downwards. Severe measles is more likely among poorly nourished young children, especially those with insufficient vitamin A, or whose immune systems have been weakened by HIV/AIDS or other diseases. The most serious complications include blindness, encephalitis (an infection that causes brain swelling), severe diarrhoea and related dehydration, and severe respiratory infections such as pneumonia. Measles is one of the leading causes of death among young children even though a safe and cost-effective vaccine is available.

 

 

Methodology: Taqman Real time PCR assay

Clinical Use:

  • RT-PCR method detects Measles virus very early after the onset of symptoms
  • Assess viral measured by changes in the Measles virus RNA levels
  • To provide epidemiologic information for surveillance of circulating Measles
  • To confirm the clinical diagnosis in the early stages of an outbreak
  • Assess prognosis and early diagnosis for clinical management of patient and better cure
  • Confirm active Measles virus infection In patient

Screening:

  • people who have not received the proper vaccination series
  • whose immune systems have been weakened by HIV/AIDS
  •  residing in areas where extended community outbreaks exist
  • Children with immunodeficiency due to HIV or AIDS, leukemia, alkylating agents, or

Corticosteroid therapy, regardless of immunization status

 

Performed:  Every day
Reported: 2-3 days

Specimen Required: Oral Swabs, Bronchial Swabs, urine. 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.

NOTE: Throat or nasopharyngeal swabs are generally the preferred sample for virus isolation or RT-PCR detection

Specimen Preparation: Separate serum or plasma from cells within 24 hours.

 

Storage/Transport Temperature: Frozen-20 0C. Refrigerate specimens 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 Dengue Virus RNA Virus over the linear range 90-108 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 Dengue 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. The samples should be collected at the first contact with a suspected case of measles when the serum sample for diagnosis is drawn. Measles virus isolation is most successful when samples are collected on the first day of rash through 3 days following onset of rash; however, it is possible to detect virus up to day 7 following rash onset.

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.

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