First of all, how they (IEDCR and icddr,b) conducted the survey has not been detailed in the interim report; they will detail everything soon. If the survey was conducted randomly in a statistically sound method, then it would represent the whole Dhaka city. But if this survey was conducted only based on accessible sources, then it wouldn't represent the whole Dhaka city. This will be clear later when they conduct a seminar about the survey.
As far we know, through the survey 20 percent was found positive from the households with existing coronavirus patients where other members had Covid-19 symptoms; and 14 percent was found positive from the households where other family members didn't reveal symptoms.
Besides, eight percent was found positive from the families where there was no Covid-19 patient and no one of the family revealed any symptoms. But the scariest of all, the survey found that 48 percent Covid-19 patient didn't have any symptom at all. The overall survey found that nine percent of the people of Dhaka city are Covid positive.
In 2009 during the Swine Flu outbreak, epidemiologists found that there remained 10 times more positive patients beyond the patients who went through laboratory tests. Currently, more than 60,000 people in Dhaka have tested positive for Covid-19; consequently, this number would be more than six lakhs in light of the past findings.
Now, however, if we consider the latest IEDCR and icddr,b findings, the number is absolutely much higher.
Secondly, nearly half of the patients who have been found positive were asymptomatic. It means they didn't reveal any symptoms such as fever, coughing or sore throat. These scary asymptomatic patients have been a major concern worldwide. The difference between us and them was that we didn't have proper data before.
Now that we have data, consequently the importance of strictly following the health instructions has also increased. Even though possibly not every Upazila in Bangladesh has Covid-19 patients, but one third of them are certainly having community transmission.
So everyone should take it for granted that somebody around you is carrying coronavirus for sure. So, whenever you step out of your home, you must wear a mask; you must maintain a minimum three feet social distance; you must wash your hands after you touch anything with bare hands.
If we do not follow these basic health instructions, the transmission of the virus cannot be stopped. It will keep spreading rapidly.
Besides, we have public health workers in the villages. After the rapid community transmission in the towns and cities, it is now of paramount importance that we engage field level public health workers in the cities and towns as well, who will go door to door to look after public health situations.
There should be more research like this. We should focus on serosurveillance next time which could provide us with more appropriate data regarding the coronavirus situation in the future.
Dr M Mushtuq Husain is former Principal Scientific Officer, IEDCR