Coronavirus: What is the Covid-19 IGM/IGG rapid test Indians in UAE have to take before repatriation?

Abu Dhabi - The test requires only a drop of blood, and results can be known in 10-15 minutes.

The Indian embassy, with its health protocol for evacuation flights, has added a new terminology, the IGM/IGG test, for everyone at airports before departure.

Passengers who will fly from Abu Dhabi to Kochi on Thursday have been asked to report at the airport by noon, more than four hours prior to their scheduled 4.15pm flight.

Khaleej Times has learnt this is being done to facilitate the conduct of such a test. The departure for Air India Express, which normally operates from Terminal 1, has been moved to Terminal 3 to accommodate for conducting the medical screening and IGM/IGG test.

"Only those cleared by the UAE health authorities and found to be asymptomatic will be allowed to board the plane," the Indian embassy said.

Test detects antibodies

Dr Sundar Elayaperumal, specialist, microbiology, Burjeel Hospital, Abu Dhabi, said the Covid-19 IGM/IGG is a rapid test for antibodies. "IgM are antibodies produced by the body early in the disease in response to the antigens like bacteria, viruses, fungi and parasites etc, whereas IgG are antibodies produced by the body later in the disease, the convalescent phase, when the patient is recovering or had previous disease which confers immunity."

The IgM/IgG test, the doctor said, detects antibodies, both IgM and IgG, in the blood against Covid-19 pathogen.

Two ways to conduct test

There are two ways this test can be done, one is ELISA and other is rapid immune chromatography. Under the present situation, it will be rapid test that will be performed on Thursday.

"The rapid immune chromatography can be done in whole blood, plasma or serum. Just a drop of blood is required for the test like blood glucose monitoring. This test may take 10-15 minutes. There will be three red bands. One is the control band, which should be positive, to see the test cassette is working properly. If it is negative, the test is considered invalid and another cassette should be used. The other two red bands -- IgM and IgG -- may be positive or negative."

What is positive and negative?

"If IgM and IgG both are negative, it means a person never had any virus and no treatment is needed. If IgM and IgG both are positive, the person is infected and may be symptomatic or asymptomatic carrier. He/she probably needs conservative symptomatic treatment. If IgM is only positive, the person is infected but is asymptomatic carrier. So reverse transcription polymerase chain reaction (RT-PCR) is needed to confirm and treat that person. However, if IgG is only positive, then the person has developed immunity and is in less need of treatment," Dr Elayaperumal said.

The PCR test, he said, detects the antigen virus and is now the gold standard for detecting most of the infections.

He underlined an asymptomatic carriers may harbour the virus but not suffer from it. However, he/she can transmit the infection to others.

Who can and can't take the flight?

Dr Elayaperumal added that as per the requirements of the Indian government and the regulations of the UAE heath authority, there are many probabilities on who can take the flight.

"Yes, the rapid antibody test can be done at the airport. Passengers who are both IgM and IgG negative may be cleared but shouldn't have typical symptoms of Covid-19. People who will test positive for IgG may be allowed to travel and shouldn't have typical symptoms of Covid-19. Passengers who are only IgM positive may not be allowed to travel in spite of no symptoms. And passengers who are both IgM and IgG positive may not be allowed to travel. However, there may be certain modifications to these criteria."

• Abu Dhabi
• India