Racing Against the Pandemic
President Joko Widodo ordered mass rapid testing to track the spreading of Covid-19. But a previous testing method is still needed to more accurately detect the virus.
PRESIDENT Joko Widodo needed 17 days to decide on using the rapid test kit in order to detect early those infected with the novel coronavirus. Since President Jokowi announced the first two confirmed Covid-19 cases in Indonesia on March 2, the disease has rapidly spread, infecting over 500 individuals in 20 provinces and causing 48 deaths. “I want to increase the number of rapid test kits,” said Jokowi before a meeting at the State Palace, Jakarta, on March 19.
One day after the decision, the government held the first mass rapid testing in South Jakarta. In a press conference on March 20, Jokowi said the rapid testing was performed in an area known to have had contact with confirmed Covid-19 patients. Testing was performed door to door. “There is indication that South Jakarta is the most vulnerable,” said Jokowi.
Before, Covid-19 testing relied on the polymerase chain reaction (PCR) method. The Health Research and Development Agency (Balitbangkes) was its primary motor. The health ministry stated that the Covid-19 sample testing at the institution was already conducted in line with World Health Organization (WHO) standards. Testing was performed at a Balitbangkes’ bio safety level 2 (BSL-2) laboratory. To ensure accuracy, the lab would test at least three specimens from each patient.
When the disease spread further, the government allowed 15 additional laboratories to help test for the coronavirus. These facilities are in Palembang (South Sumatra), Jakarta, Yogyakarta, Surabaya (East Java), Makassar (South Sulawesi), and Papua. Some are research laboratories, among others, the Eijkman Institute for Molecular Biology in Jakarta; Airlangga University Medical School in Surabaya, and University of Indonesia Medical School in Depok, West Java.
Government’s spokesperson for Covid-19 related affairs, Achmad Yurianto, says 700,000 people in Indonesia are at risk of being infected with the corona. The government will prepare around 1 million rapid test kits for mass testing, which will be performed on those at high risk of infection, based on their contact and travel histories.
Yurianto says the rapid testing method tests specimens using blood samples. The procedure is also easier to perform as it does not require a BSL-2 laboratory. “This test can be done at almost all hospitals in Indonesia,” he said.
TESTING methods have been controversial since Covid-19 began to spread in Indonesia over the past three weeks. PCR testing is seen as the most reliable method for detecting the coronavirus. But the procedure is believed to take too long, as much as three days, and requires a high safety level laboratory, which only a few exist in the country. “It takes too long to detect the spread of the disease,” said professor of biochemistry and molecular biology at the Airlangga University Veterinary School, Chairul Anwar Nidom.
According to Nidom, rapid testing can be used as an early filter for those suspected of carrying the virus. The method can also be used to map the distribution of the disease in a community. Additionally, rapid testing is good for use on a massive scale because of its quick and inexpensive procedure. A rapid test result can be obtained in less than an hour. The price of a rapid test kit for the coronavirus, said Nidom, is not so different from the price of a rapid test kit for the flu, at around Rp150,000-200,000. In the meantime, a PCR test costs around Rp1-2.5 million.
The PCR method tests a swab sample taken from the respiratory tract or from the feces of a person suspected of infection. Meanwhile, the rapid test is used to detect antibodies that can be discovered in a blood sample. These antibodies show whether someone has been or is currently infected with corona. “No need to wait until symptoms of the disease occur,” said Nidom on Thursday, March 19.
Rapid testing consists of two parts, to test for the immunoglobulin G (IgG) antibody and the immunoglobulin M (IgM) antibody for the coronavirus. If someone’s rapid test results show a positive IgG, the person has been infected by the coronavirus in the past. Meanwhile, the IgM indicator is used to detect whether the person tested is currently infected with corona.
Even so, rapid testing cannot read virus concentrations in detail. The virus can cause symptoms if the plaque-forming unit (PFU) or its concentration is at around 100,000-10,000,000 per milliliter. If the concentration is still under 1,000 PFU, antibodies can still eradicate the virus. But the virus would still be detected by the rapid test kit because of these antibodies. “Which is why PCR is still needed to finalize the diagnosis and proper handling,” said Nidom.
The Eijkman Institute for Molecular Biology also relies on PCR to detect the coronavirus. The institute was only appointed by Jokowi to help examine Covid-19 specimens on March 13. In fact, Eijkman had already received samples to be tested from several hospitals. “We have been ready from the start,” said Eijkman Institute Director Amin Soebandrio on March 18.
Amin says PCR testing is still the gold standard for detecting the coronavirus. Eijkman has five researches specially assigned to testing Covid-19 related samples. According to Amin, they only receive samples sent by hospitals and can only test up to 80 samples each day. “If the number of cases drastically increases, we must raise the capacity,” said Amin.
The PCR process can take up to five hours. The long process and limited capacity are why it is difficult to use the PCR method for mass testing. In one day, Eijkman only runs one PCR. If a sample arrives after the PCR procedure has already begun, the sample will be included in the next cluster. But if a sample is found to be Covid-19 positive, the sample is immediately retested on the same day, to make sure. “Which is why we said testing can take two-three days,” he said.
Achmad Yurianto says rapid testing must still be combined with the PCR method and genome sequencing to confirm detection of corona. The reason being, rapid testing has a lower accuracy rate as it can only detect the virus’ antibodies. Several countries have been overwhelmed by the false positive result of the rapid tests that indicated a spike in Covid-19 cases.