Coronavirus antigen testing
Coronavirus antigen testing Image Credit: Freepik

Islamabad: Pakistan is set to initiate faster and cheaper tests to quickly diagnose and trace infected people in an attempt to contain the second wave of coronavirus. A national policy has been formed to launch rapid antigen testing, according to the officials of the National Command and Operation Centre (NCOC), which is leading the country’s fight against the pandemic. Necessary arrangements are being made at all major hospitals to conduct antigen tests.

Unified strategy for antigen testing

The new testing has been announced based on recommendations of the World Health Organisation (WHO), says National Institute of Health (NIH) Executive Director Maj Gen Aamer Ikram. Briefing the forum, Ikram said the provinces have been taken on board to devise a “unified strategy” to conduct antigen testing as per international standards. Initially, all government-authorised public sector laboratories could perform the tests. Only those private labs will be allowed to conduct antigen tests which are already performing the PCR test, endorsing data in the national and provincial hub and are officially authorised to conduct the tests. The provincial authorities will regulate the testing at private labs.

Highest number of deaths reported in 4 months

Pakistan saw the highest COVID-19 daily death toll in more than four months on December 1 with at least 75 fatalities. The number of coronavirus cases in the country has crossed 400,000, with 2,829 cases reported during the last 24 hours. The total count of active cases is now 49,780, according to the latest official data. Most of the cases are being reported from high-density urban areas. Five cities including Islamabad, Karachi, Lahore, Rawalpindi and Peshawar were contributing 70 per cent to the spread of the virus in the country, the NCOC data showed.

Why antigen tests?

Rapid antigen tests are faster, cheaper and easier to determine whether someone is infectious. The tests detect specific proteins (called antigens) on the surface of the virus, and can identify people at the peak of infection. It can give results in less than 30 minutes and is considered “a game changer” as it can ramp up the COVID-19 testing capacity and help reduce transmission through early detection. However, the downside is that they can be less accurate. PCR test remains the gold standard and antigen test is recommended if PCR is not possible, health experts say.

Types of COVID-19 tests and how they work

Tests for COVID-19 fall into two categories - diagnostic tests such as PCR and antigen assays, and antibody tests. Three types of COVID tests are:

1. Molecular test (RNA or PCR test)

PCR test results are considered to be highly accurate but analysing the results can take time as it must be examined by lab technicians. It is most sensitive for detecting an active infection and to diagnose people who are currently sick with COVID-19. The test uses a sample of mucus taken from a person’s nose or throat.

2. Antigen test (rapid test)

The antigen test is called a rapid test as it can provide the results within minutes. This type of diagnostic test is inexpensive, efficient and fast but considered less accurate. Antigen tests may not detect all active infections, as it is not as sensitive as molecular PCR tests.

3. Antibody test

The antibody test is a blood test that looks for antibodies, which are produced in the body in response to an infectious agent such as a virus. A COVID-19 antibody test cannot diagnose active coronavirus infection. It can only tell whether a person has been infected at some point in the past.