The cross-sectional epidemiological survey conducted in Dhaka jointly by the government's IEDCR and Icddr,b have brought out some surprising revelations about the coronavirus situation in the country. It shows that around 45 percent of those surveyed in the capital were carrying Covid-19 antibody, a majority of them asymptomatic; the presence of such antibodies among slum-dwellers was much higher (about 74 percent). If extrapolated to the roughly two crore population in Dhaka, it means nearly one crore may have already been infected. This is marginally good news, scientists agree, as it means people might be on the way to develop herd immunity, provided the immunity against the virus lasts long. But scientists are unsure of how long the protection works, and whether if someone's antibody test comes out positive, they may still be re-infected by Covid-19 and unknowingly spread the disease to others. This is especially risky for those with underlying health conditions.
However, these are still conjectures based on a survey done about three months ago and involving a relatively small sample size (3,227 households) compared to the large population of Dhaka. We still don't know how immunity to Covid-19 works or how accurately such seroprevalence surveys can project the situation. So there is little room for complacency—which, unfortunately, continues to underpin our official response. We have seen how officials and ministers often suffered from misguided optimism over Bangladesh's preparedness in the last seven months, resulting in devastating consequences. The official figures of infection hover around only 380,000, in stark contrast to the projected figures. Officials failed to explain this gap, nor did they tell us how the survey findings will factor into their response plan—both for those at risk of infection and those who recovered from the disease but still risk health complications and productivity loss as a result of their exposure. The fact is, although they assured us of "necessary preparedness" to deal with a possible second wave of coronavirus during winter, precious little has been done to improve our test, trace and isolate regime.
All this points to the fact that although antibody prevalence is vital to tackle the virus, the bigger concerns of a massive, silent outbreak and associated risks to both health and economy remain. Unless such surveys are done from time to time to understand the movement of the virus and relevant policy efforts are remodeled in light of their findings, such efforts are but wasted opportunities. We must continue to ensure the public wear face masks, along with maintaining physical distancing and hand hygiene. The IEDCR survey has shown how profound the threat is and how big a task we have at hand, so the government must respond by revitalising public health institutions and allowing scientific evidence to dictate its policy interventions to contain the virus.