How has Bangladesh remained immune to COVID-19?
COVID-19 has been detected more in developed countries, compared to developing ones. The reason why there are no reported cases in some countries may be because they have a poor detection system
One of my professors recently asked me, "How many people have been infected with the new coronavirus in your country?" When I told him no cases have been reported yet, he was surprised. "How is it possible that your country is still not affected? If the outbreak in Japan is still going on, you must return to Bangladesh to save your life!"
I know he was speaking in jest, but it is true that if the outbreak of COVID-19 intensifies, several Bangladeshi migrants might return to Bangladesh for their safety.
There has been much speculation and conjecture about how Bangladesh has remained immune to coronavirus that has already affected more than sixty nations.
Even though the World Health Organisation (WHO) declared coronavirus a 'global health emergency', they said it has not met the criteria yet of being described a pandemic. As COVID-19 virus spread at an alarming rate in some regions, WHO said it has the potential of becoming a pandemic.
Many countries have been affected by the novel virus and there is a high risk of a worldwide outbreak.
India, Nepal, and Sri Lanka have reported a number of confirmed cases of COVID-19. Additionally, many other developing countries also have detected patients with this life-threatening virus.
Even though closely connected to China, Bangladesh is still safe from coronavirus – or so it is said. But is that really true?
Recently, preprint journal MedrXiv published a couple of reports where they stated COVID-19 has been detected more in developed countries compared to developing ones.
The reason why there are less reported cases, particularly in Southeast Asia and Africa, may be because they have a poor detection system or perhaps are unable to detect COVID-19, researchers predicted based on flight data.
How does one detect coronavirus?
The scientific name of coronavirus is Coronaviridae. It belongs to the ribonucleic acid (RNA) virus family which is known to be responsible for common colds and other upper respiratory tract infections.
The typical pathological detection system of Bangladesh is not marked for detecting viruses such as influenza. It requires a special test that only the Institute of Epidemiology Disease Control and Research (IEDCR) in Bangladesh does in their lab.
However, there is a guideline and sophisticated way to test for the virus. If you find the symptom in patients, first collect blood samples or swab them.
A laboratory test called real-time reverse transcriptase PCR or RT-PCR is then carried out. The PCR needs specialised personnel to handle it.
When the RNA is processed as complementary DNA or cDNA sequence, the specialists confirm the presence or absence of the virus genome. This is the way to determine whether one has been exposed to coronavirus and has the possibility to develop COVID-19.
The process is costly and complicated, but some countries such as Japan are observing patients for four days – recording their body temperature and other symptoms, such as breathing problems. If those symptoms do not go away in that time period, they go for an RT-PCR.
Given the complexity of the diagnosis and the lack of availability in Bangladesh, there is a possibility that there might be undetected patients of coronavirus silently spreading it among others. The earlier we diagnose the patients, the faster we can treat them.
However, the intensity of infection is still unclear in Bangladesh. We have limited numbers of healthcare workers, hospital beds, support staff, ventilators, and other equipment – and would struggle to respond to a surge in cases of the virus.
It is however also possible that we may not have to deal with a surge in the virus.
I believe the outbreak of novel coronavirus depends on environmental factors such as air temperature, pH – a measurement of the potential activity of hydrogen ions – and relative humidity.
Even though some African countries and even India have reported cases, majority of the infected countries have a lower temperature than that of ours. There is a speculation that high temperature perturbs the conjugation of COVID-19. Our average high temperature might be an advantage for us.
Generally, the viral infectivity is completely lost after a 14-day incubation period at 22, 33, or 37 degrees Celsius and the virus may remain stable at four to 10 degrees.
In a study in 1989, a group of researchers also found that the chances of survival of the virus in low temperature is high.
Many scientists still believe that the coronavirus will not survive long in warmer environments. Hence, we may consider COVID-19 as a temperature-sensitive virus like the other variants of the coronavirus family, including SARS and MERS.
How does temperature kill coronavirus? Most of the viruses are made up of a nucleic acid molecule inside a protein shell called 'capsid' and covered with an external membrane outside the shell which is sensitive to high temperatures.
If the temperature increases, it is believed that coronavirus might float in the air. There it can survive for only a short time and our bodies might not be infected.
Another possible reason for low or no prevalence in Bangladesh is that our immune system is boosted. Bangladeshis can easily adapt elsewhere in the world when they travel, without catching any major illness. If a Japanese individual visits Bangladesh for a couple of months, they feel uncomfortable due to the humidity and hot temperature, albeit, that is not true for everyone.
Although there is no reported case in Bangladesh, we must take preventive measures beforehand. We should not forget how many lives we lost to dengue.
The march of COVID-19 reminds us how helpless we are against nature. If we do not pay attention to epidemics at our doorsteps, we may face a difficult situation in handling deadly viruses or bacteria in future.
The author is a PhD candidate at Osaka University, Japan. He can be reached at [email protected]