AssaHome: Test kit for Covid-19
Covid-19 is the first pandemic in my life. More than 4 million people have been infected and 380,000 people have died due to the pandemic. In Bangladesh, more than 55 thousand people have been infected, 746 people have died, and the numbers of new cases are increasing everyday.
Since data collection is not comprehensive, and many people with Covid-19 have been asymptomatic, actual numbers are likely much higher. Thousands of health care workers including nurses and doctors have tested positive for the virus. We don't know how many people will be infected and die until we see the flattening of the curve of coronavirus. We don't send soldiers to war without a gun and expect them to do their job.
As health care workers are testing positive, we should not send them without PPE and expect to do their best job. It is alarming for our health system. In is noteworthy to mention, about 80% cases were mild or asymptomatic but they can spread viruses among people.
Half of the populations in the world are locked-down due to the spread of the virus. School, office, factories and businesses are closed now. The world economy is devastated due to this pandemic. People are protesting to open the economy but the virus is in the air and it is still spreading.
There is no question about opening the nation, but we need to be smart to reopen the country safely, otherwise, we'll be in the same place in the circle. We have to track, monitor, and control the virus to reopen the economy.
To contain the pandemic it is imperative to increase the number of testing. The Harvard report calls to scale up the capacity 2 to 6% of the population per day to reopen the nation safely. Bangladesh conducts 900 tests against one million populations, ranks 148th in the world. Policy makers suggested for Covid-19 testing for millions of people per day. That is only possible by point of care test and decentralizing the system.
Scientists developed several types of tests (antibody, antigen and molecular diagnostic test/PCR) for Covid-19. Each type of test has a unique role to fight against a pandemic virus.
Large numbers of infected individuals are waiting to be tested. We need massive testing and the kind of testing that can be done not only in clinics and hospitals, but can be done at points of entry like factories, stations, airports, or even at home. A rapid, point -of -care molecular diagnostics for the Covid-19 is urgently needed.
An antibody test looks for the presence of antibodies in the blood, which is specific for SARS-CoV-2. This test determines how much of the population has been infected. This is important for policymakers to understand how the virus is spreading through the population.
This test cannot diagnose someone with an active SARS-CoV-2 (source CDC/USA) as it takes 1-3 weeks to develop antibodies after infection.
A new category test, Covid-19 antigen test, was approved last week by the FDA. These diagnostic tests quickly detect fragments of proteins found in the virus collected from nasal samples using a swab. The advantage of this test is speed; however, it can't detect active infections. This test is highly specific but not as sensitive as polymerase chain reaction (PCR). There is a higher chance to get false negative results. Negative results tests may need to be confirmed by PCR before taking treatment decisions or prevent the spread of the virus.
This is the gold standard method recommended by WHO and CDC for diagnosis of active infections. This test is incredibly accurate but running the test requires an expensive instrument, involves many steps, typically carried out by trained technicians and takes more than 1 day to get results after sample collection. Most people are not being tested due to scarcity of kit and testing facilities.
Therefore, the point of care (POC) of testing is inevitable. Scientists are working around the clock to develop POC tests.
Point of care tests:
Dr Zhang's team developed STOPCovid, figured out a lot of the reactions in a single tube, allowing the test to be faster and more cheaply. To see the presence of coronavirus, they stuck a piece of paper in the tube, lines appearing on the paper meant the presence of coronavirus similar to a pregnancy test. This test can be done to a point of care or at-home and cost will be $6.0/test. In the photo, test strips showing single line (left panel) indicate no infection; double lines (right panel) indicate presence of virus.
There are well equipped labs in Bangladesh that have the infrastructure to develop point of care tests for Coronavirus. Researchers at Child Health Research Foundation have successfully mapped the genome sequence of Covid-19. The genome sequence will help to develop molecular point of care tests. Many NRB (non- resident Bangladeshi) scientists are doing excellent researches in university, biotech and pharmaceuticals who are interested in developing POC tests to help their motherland.
I have no doubt that a country like Bangladesh can develop a home test kit for Covid19 for testing massive people. Bangladeshi scientists can collaborate for developing kit or technology transfer for testing millions of people with low cost at home and point of entry. It will be out of control if the second wave hits Bangladesh. We should not open the country without massive testing. We should reopen slowly and monitor aggressively to make our country safe.
The writer is principal scientist at 4Catalyzer, USA