The Epidemiological curve, or “epi-curve,” wasn’t designed to satisfy the public’s desire for instant understanding about the spread of COVID-19. Infections confirmed today were contracted days or even weeks earlier. (It takes time for symptoms to present, medical help to be obtained, tests to be taken and results confirmed.) In this visual, VPAP shows how information Virginia gathered during the week ending April 5 revealed the spread of COVID-19 in early March.
Antibody tests could help scientists understand the extent of COVID-19’s spread in populations. Because of limitations in testing accuracy and a plethora of unknowns about immunity itself, however, they are less informative about an individual’s past exposure or protection against future infection.
What COVID-19 Antibody Tests Can and Cannot Tell Us
Assays that detect prior novel coronavirus infections could reveal the extent of outbreaks. But they may give individuals false security
We know that the number of cases we have on record is an underrepresentation of the true burden for several reasons. Some underrepresentation is because testing for SARS-CoV-2 might not be available for the infected person… Another factor is that not everyone will need to see a doctor for COVID-19. The World Health Organization (WHO) published a very detailed report about the outbreak of COVID-19 in China and found that 80% of cases were mild or moderate. Since then, there have been studies that have identified infections in people who never develop symptoms. If someone gets infected and recovers on their own, then public health may never find out about the case.
Five Things to Remember When Interpreting Epidemiologic Data – Coronavirus
Data will change some overtime. VDH gets data on COVID-19 from a number of different sources. Laboratory results, morbidity reports, death certificates, medical records, and patient interviews are a few of the ways we collect data. Sometimes these different sources will disagree on something. For example, we may get a positive lab result that doesn’t have the patient’s address. To count this case, we use the address of the doctor who ordered the lab test. During the course of the interview, we may find out that the case-patient sought care from their doctor in one county, but actually lives in a different county. In another example, we may receive a report of a case-patient who has all of the symptoms of COVID-19 and meets the criteria for a ‘Probable’ case. If later laboratory testing comes back negative, then we won’t count that person as a case anymore. Every time that we report data, we are reporting the most up-to-date information we have, even if it’s different from what we reported before.