The antibody testing at Atlantic Clinic is currently using the Acro Biotech kit.
The American supplier quotes an accuracy rate for the 2 types of antibodies:
IgM: 92.9% IgG: 98.6%*
However, there are some uncertainties at the moment:
- These figures are based on current information. New data is coming in all the time and may refine them.
- The usefulness of the test depends to a certain extent on the proportion of people within a given population that has the virus, which is at present unknown. No one knows how many people may have been infected but show no symptoms.
- Antibodies take at least 7 days after infection (or after 4 days of symptoms) to show up on the test, so it is not useful in the very early stages of an infection. In these circumstances, where active Covid-19 is suspected, the PCR test is better, which in Spain is normally done in hospitals.
Antibody testing is used to identify those who have been infected for at least 7 days, or have recovered from a previous illness (either with symptoms, or a “silent infection” which went unnoticed).
*For the technically minded, accuracy is a function of:
Relative specificity IgM 96%
Relative sensitivity IgM 85%
Relative specificity IgG 98%
Relative sensitivity IgG 100%
Dr. Anthony Crichton-Smith- GP
