Seroprevalence is the level of a pathogen (e.g. the virus Covid-19) found in a particular population - a country, city or region for example. This is measured by administering blood test to as wide a sample of that population as is feasible.
Testing
The accuracy of seroprevalence is dependent on a number of factors including
- the size of the sample tested as a proportion of the general population
- the representative nature of that population in terms of age, sex, socio-economic conditions, ethnicity, size of household, number of social interactions, occupation etc.
- the accuracy of the tests, especially if these are physically difficult to administer. Covid-19 tests are quite physically intrusive as they require a throat swab.
- the accurate record keeping of the testers
- the potential for cross-contamination
- the estimated number of false positives and false negatives.