Swabs chaos, what to do and when to do it: in Italy infectious diseases experts provide clarity
Swabs chaos: the Italian Society of Infectious and Tropical Diseases intervenes in the debate about swabs that has developed in recent days
Swabs chaos in Italy, what infectivologists say
The infectivologists of the Italian Society of Infectious and Tropical Diseases – SIMIT have intervened in the debate on tampons that has developed in recent days in Italy.
There is confusion and disorientation in the population that crowds pharmacies and diagnostic centres in search of reassurance, in the face of the spread of the variant Omicron, so Simit tries to clarify.
“An asymptomatic subject, if vaccinated with three doses or with two doses for less than 120 days, must put himself in self-monitoring and make a swab in case of suspected symptoms – said Prof. Claudio Mastroianni, President SIMIT -.
In symptomatic subjects, different types of swab can be performed, antigenic or molecular.
If a rapid swab in a subject with close contact symptoms is negative, an antigenic/molecular test should be repeated 5 days later if symptoms persist.
Ideally, a molecular swab should be done, but this depends on availability.
The antigenic tests available in pharmacies are qualitative (they reveal whether the subject is positive) and can give false negatives, as they have a lower sensitivity of around 70%.
Swabs chaos, what is the semi-quantitative test?
“There is also another test, among the latest generation of antigenic tests, called semi-quantitative, which are performed in reference laboratories and represent an alternative to molecular swabs.
There are therefore more reliable semi-quantitative rapid antigenic swabs,” concludes the clinician.
The unit of measurement is called the COI (Cut Off Index): if it exceeds 10, positivity is almost certain and there is no need for a molecular test to confirm it.
So far this test has been used in laboratories, but it will soon be available in pharmacies and can also be prescribed by GPs.