A great collaborative effort led to this important study in Argentina now in medRxiv
Community-level SARS-CoV-2 Survey in One of the Largest Urban Slum of Buenos Aires City Reveals 53% Seroprevalence.
Let’s see what we found …
Follow this
Community-level SARS-CoV-2 Survey in One of the Largest Urban Slum of Buenos Aires City Reveals 53% Seroprevalence.
Let’s see what we found …
Follow this
1) From May 5th to June 10th, a search for COVID19 symptoms in Barrio Mugica showed 2949 qPCR positive (5.9% of the population). The seroprevalence study was initiated when the basic rep number (R0) decreased from 3.24 to 0.6 so when viral spread dropped drastically (June 10th)
2) From 854 people tested by a highly specific ELISA, 423 were IgG positive. Prevalence was 53.4%, very high!! unprecedented BUT this is in agreement with higher circulation in vulnerable populations (limited water supply and sanitation)
3) We found evidence of within-household clustering effect (rho=0.52; 95% IC 0.36-0.67). Living with a PCR-confirmed case doubled the chance of being SARS-CoV2 IgG positive.
4) Among the IgG positive, only 15% reported compatible symptoms, suggesting 85 % of asymptomatic. Remember DetectAR in this slum showed 2949 qPCR positive (5.9%) and the seroprevalence study showed 53.4% IgG positive. So also suggest near 9 to 1 asymptomatic to symptomatic ratio
5)The IgG was measured by a very robust and specific ELISA assay. Thanks @florian_krammer for the help in the COVIDAR IgG test, which uses only one step ELISA, BUT the plates are coated with both RBD and S ectodomain trimer.
6) We used a SeroKit for finger prick blood sampling at the front door of the houses for ELISA in whole blood, method validated by @GamarnikLab
