The survey, which ran from Apr 18 to Jul 5, was conducted by the Institute of Epidemiology, Disease Control and Research and the International Centre for Diarrheal Disease Research, Bangladesh in collaboration with USAID and the Bill & Melinda Gates Foundation.
The IEDCR released a summary of the survey on Monday.
The households surveyed were classified as ‘symptomatic’ and ‘asymptomatic’ on the basis of coronavirus tests. If a COVID-19 symptom was identified in a family member on the day of the survey or in the previous seven days, the family would deemed 'symptomatic' and vice versa.
According to the IEDCR, the survey covered 3,277 families.
Six slums, comprising 720 families, were also included in the survey.
About 6 percent of slum-dwellers in the city have been found to be infected with the virus.
Among those with symptoms, 53 percent suffered from fever, 36 percent cold, 17 percent sore throats while 5 percent experiences a shortness of breath.
Fifteen percent of symptomatic patients were hospitalised, one of whom had died.
“The tests conducted by the health directorate are identifying about 22 percent of COVID-19 patients. The number is relatively low. But the results of the survey are important,” Dr ASM Alamgir, principal scientific officer of IEDCR, said.
Among the 263,000 COVID-19 cases confirmed by the government, over 67,000 are in Dhaka. The city houses around 15 million people.
A large part of the city’s population have not undergone the coronavirus test fearing sufferings at queues or delay in results, making it difficult for the authorities to understand the scale of the epidemic.
The survey has finally given a glimpse into the real picture, believes public health expert Mushtuq Husain, who has been advising the government over the outbreak.
The study has proven that the actual number of people infected with the virus in the capital was much higher than those confirmed by the government, the former chief scientific officer of the IEDCR told bdnews24.com.
The number of patients with mild symptoms who have undergone test should be 10 times as many the number of confirmed cases, according to him.
Out of the households surveyed in the study, 5 percent were symptomatic while the rate is 2 percent of the city’s total population.
As much as 30 percent of the symptomatic individuals, 14 percent of the asymptomatic individuals from symptomatic households and 8 percent of the asymptomatic individuals from asymptomatic households had COVID-19, according to the survey.
Overall, 9 percent among all individuals in Dhaka on the day of the visit was estimated as RT-PCR +ve.
The prevalence of COVID-19 cases was the highest among people aged 40 years and above (13 percent), and adolescents aged 15-19 years (12 percent).
The prevalence was 6 percent among children aged less than 10 years.