AHMEDABAD: About 29% of the family members of Covid-19 patients were found to have seroprevalence – a phenomenon where pathogens for a specific disease or infection are found in the bloodstream – in Ahmedabad. The number was higher compared to the general population where the figure was 26%.
The analysis, based on the data of sero survey carried out by the AMC in October last year, was published in the recent edition of Journal of Health Science & Medical Research. The sero survey included 17,000 citizens, whereas analysis of its impact on immediate contacts had at least 10% or over 1,700 samples.
The samples processed by AMC-run hospitals — AMCMET, Maninagar, and NHL MMC, Ellisbridge — indicated that for other contacts, seroprevalence was 24.4%. Moreover, the study indicated that females had slightly higher seropositivity among family and other contacts. It was 29% and 26.8% compared to 28.6% and 22.4% respectively among males.
“It is quite possible that the second wave during April-May that recorded a very high number of cases, also gave higher seropositivity to families and society at large,” said an epidemiologist. ‘It can be said that about a fourth of total contacts had already acquired an immune response without being identified as a confirmed case,’ mentioned the study. The researchers also stressed on contact tracing and isolation as an effective strategy based on the evidence. The study added that there was a rise in seropositivity as the age of citizens increased, but reduced steadily after 60 years.
Experts said the dynamics of immunity and infectivity would decide how the potential third wave would unleash. “If there is high seroprevalence as indicated by recent sero survey, the chances of widespread infection may be minimised. At least there could be lower mortality. In the first wave, the infectivity was comparatively lower, which according to Delta variant increased manifold this year,” said the epidemiologist.
