What is the purpose of seroprevalence surveys during the COVID-19 pandemic?

By using seroprevalence surveys, CDC can learn about the total number of people that have been infected, including those infections that might have been missed. These surveys also can help estimate how much of the population has not yet been infected, helping public health officials plan for future healthcare needs.

What does seroprevalence mean?

Antibodies are proteins that can fight off infections. Investigations using serology testing are called seroprevalence surveys. CDC is collaborating with public health and private partners on a variety of seroprevalence surveys of different sizes, locations, populations studied, and purposes.

What are the CDC seroprevalence surveys?

The seroprevalence surveys CDC is conducting include large-scale geographic surveys, community level surveys, and smaller-scale surveys focusing on specific populations in order to learn information about COVID-19. The largest surveys that CDC is conducting are called “large-scale geographic seroprevalence surveys.”.These surveys are being conducted in locations across the United States and are first focusing on areas highly impacted by COVID-19, such as Washington State and New York State, including New York City.

What do the results of the third national serosurvey tell us?

The results of the third national serosurvey are broadly consistent with data on cases and deaths once we factor in some shift in spread from urban to rural settings. There is no very strong reason to believe that the current survey has greatly underestimated the extent of infection nationally, although this can’t be ruled out entirely.

How effective are ICMR serosurveys in Tamil Nadu?

Comparing the ICMR survey in three districts with the 38 district surveys of the Tamil Nadu Directorate of Public Health, shows that the ICMR serosurveys found a seropositivity of 43\%, 24\% and 31\% in the districts of Chennai, Coimbatore and Thiruvannamalai in the serosurvey in December 2020-January 2021.

What is the difference between Tamil Nadu and Delhi serosurveys?

Tamil Nadu used a chemiluminescence method for all its assays, while serosurveys in Delhi, Mumbai, Pune and other local serosurveys have used different methods — which means that some of the variations may be due to the testing methods which have varying sensitivity and specificity for antibodies directed against different viral antigens.