Bangladesh scientists create $3 kit. Can it help detect COVID-19?
Dhaka, Bangladesh - A group of scientists in Bangladesh has developed a $3 testing kit they claim can detect coronavirus in less than 15 minutes.
The South Asian nation's pharmaceutical regulator - the
Directorate General of Drug Administration (DGDA) - gave its green light
for the mass production of the kit last Thursday, saying it would ease
the pressure on the pathology services struggling with coronavirus
detection.
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Bangladesh's largest vernacular daily Prothom Alo
reported last week that only 1,732 testing kits are available in a
country of nearly 180 million people.
Besides, according to a report of The Business Standard,
the Bangladesh government has so far prepared only 29 intensive care
unit (ICU) beds for COVID-19 patients in five Dhaka hospitals.
Most private hospitals that have ICU facilities are refusing to admit patients with even mild symptoms amid the COVID-19 scare.
Similar kit developed in China
The kit developed by Bangladesh's Gonoshasthaya-RNA
Biotech Limited is similar to one developed in January by scientists in
China as the coronavirus outbreak intensified in the Chinese province of
Hubei.
A report by The Guardian said the Australian regulatory
authority "urgently approved four Australian companies" to import the
testing kit developed by the Chinese scientists after those companies
sought to supply it into the Australian market.
Some experts say that because the kit looks for antibodies
produced by the white blood cells in response to the virus rather than
the virus itself, there is a margin of error where it could return a
false negative if used at the wrong time.
The standard laboratory test for coronavirus is known as
reverse transcription-polymerase chain reaction (RT-PCR), which detects
the virus's genome rather than antibodies produced to fight it.
Dr Bijon Kumar Sil, leader of the Bangladeshi research
team that invented the kit, told Al Jazeera that their test, known as
the 'dot blot test', looks for antibodies in the blood that are created
in response to a given virus.
"Coronavirus or any types of virus enter the body through
the nose, mouth or eyes, then attaches to cells in the
throat that produce a protein," said Sil.
He said viruses are made up of an outer shell of protein,
which carries the virus's DNA or RNA - the genetic code with the
instructions for making new copies of the virus.
'It's cheap to produce'
The infected cell reads the RNA and begins making proteins which eventually multiplies the virus, said Sil.
"But as the infection progresses inside the human cell,
the human immune system at one stage produces specific antibody in blood
to fight against the specific virus," he said.
"Antibodies are one of the key weapons against viruses in our immune system's arsenal," he said.
"Our dot blot test detects the specific antibody in the
blood created by the white blood cell in response to coronavirus," he
said adding that the antibody assays use blood serum, saliva and sputum
samples to provide the results within few minutes.
Dr Sil invented a similar kit for detecting the SARS
coronavirus while working in Singapore during the outbreak of the
respiratory disease in 2003. The Chinese government later bought the
patent of the kit he developed as it was proven to be effective in
detecting the SARS coronavirus "in most cases".
"The best part of this rapid kit is it's cheap
(approximately $3) to produce unlike the RT-PCR testing kit which one is
expensive," he said.
An RT-PCR kit costs about $120 to $130. A specialised
biosafety lab is also needed to house a PCR machine, each of which may
cost $15,000 to $90,000, Dr Mohibullah Khondoker, a member of Dr Sil's
research team said.
Khondoker said only a few pathological laboratories in
Bangladesh has the desired biosafety level to conduct RT-PCR tests,
"whereas our rapid dot blot test can be conducted by most of the
laboratories".
Limitations of the dot-blot kit
Dr Md Shajedur Rahman Shawon, researcher at Centre for Big
Data Research in Health, University of New South Wales in Australia,
however, said 'dot blot test' has its disadvantages.
Shawon said the rapid kit looks for antibodies in the
blood produced in response to infection by coronavirus, whereas the
RT-PCR looks for the virus itself (through RNA extraction) in
respiratory specimens.
"Since the rapid test relies on the presence of a
sufficient amount of antibodies in the blood, factors like timing of the
test, previous infections, immune status of a person, cross-reaction
with other antigens, can produce false results," he said.
The Australia-based researcher said the false results could take two forms: false-negative and false-positive.
The false-negative results will tell a person who is
actually infected with coronavirus that they are not, which could lead
to them spreading it further because they do not think they need to take
precautions.
On the other hand, a false-positive result tells a person
that they are infected when, in fact, they are not. This might be less
dangerous than false-negatives in the case of a highly contagious
virus-like coronavirus, said Dr Shawon.
"Several labs around the world are trying to develop such a
rapid kit, but none has received approval from public health
authorities because of lack of reliability and validity of these kits,"
he said.
"While rapid kits can be used as a screening tool, their
efficacy in detecting true-positive and true-negative cases need to be
assessed before any approval by the regulator can be made," he added.
A better option in current situation
When asked about the supposed disadvantages of the test
kit, Dr Sil said, "The rapid dot blot test could record false-negative
if used at a wrong time."
"Sometimes, it takes more than three days to develop
antibodies in the blood cell, so if a test is conducted before three
days, then it might come as false-negative," he said.
"Under normal circumstances, RT-PCR is the only 'gold
standard' test for detecting coronavirus, but the current situation is
anything but normal. Here, a rapid dot blot test can be given a shot as
countries like Bangladesh are suffering from acute coronavirus test kit
crisis," he added.
Dr Khondorker told Al Jazeera that Bangladesh has one of the most fragile healthcare systems in the world.
"There is no health insurance facility for most of the
people, and people can't afford even basic healthcare. So when we
developed our kit, we kept the cost in mind and tried to make it as
cheap as possible," he said.
Khondoker added that they are working day and night to increase the efficiency of the test kit.
"You understand this is no less than a war-like situation
now. There are possibilities of witnessing a boom of
coronavirus-affected patients in the next few weeks. It is impossible to
test them all with methods like RT-PCR as that method is not only
expensive but also time-consuming," he said.
"But our method gives result within 15 minutes and, at present, I would say it works in 90 percent of cases."
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