Contact tracing and diagnosis. These are the two actions that must be put on track to try to stop the coronavirus pandemic, in addition of course to compliance with the basic rules such as the use of masks always, social distancing and frequent hand washing. There are several tests available.
But what are the tests available to diagnose Covid?
The most common methods are essentially four, although the technology is constantly evolving and new kits may soon arrive. It must be said that the official method of diagnosis remains the oropharyngeal swab.
Available tests: the oropharyngeal swab
Unfortunately we have now learned to know him. It is the most reliable test out there and is also called a molecular test because it looks for coronavirus genes. A healthcare professional takes organic material from the cavity of the nose and mouth using a tool very similar to a cotton swab. Once this material has been collected, it is sent to a center that is able to analyze it, through a chemical reagent that amplifies the genes of the virus. The big limitation is that these swabs can only be analyzed by specialized laboratories that are present in a few Italian regions. This is due to the fact that very expensive machinery is needed to read them. The analysis takes from two to six hours, but the problem of the few laboratories means that sometimes you have to wait even days.
Available tests: the antigenic swab
It is the so-called fast buffer. The collection is very similar to that which occurs with the oropharyngeal swab. The difference is in the response times, which are extremely short. There is even talk of just 15 minutes. The price tag is that it offers less reliability. The rapid swab does not identify the genes of the coronavirus, but its proteins, which are also called antigens. This is why it is referred to as an antigenic buffer. This type of swab has recently been used in airports to check the positivity of passengers arriving from some countries. In case of positivity, a classic oropharyngeal swab was performed.
Salivary tests were also at the center of the discussion. As the name implies, these are tests that use saliva as a sample to be analyzed. There are two types, as is the case for tampons. They can be molecular if they identify coronavirus genes or antigenic if they look for virus proteins. They are very useful especially on large numbers, such as in the control of schools and companies. Also in this case, if there is a positive result, it is necessary to undergo the oropharyngeal swab to have a confirmation.
It is not considered a diagnostic tool, but only statistical. Basically it tells us if we have come into contact with the coronavirus, but not if we have an ongoing infection. Generally, a health worker takes a blood sample, and sends it to specialized laboratories, which in this case, unlike what happens for the traditional swab, are very numerous. There are also quick ones, commonly called lancing device.
A rapid antigenic swab is being tested in a Treviso hospital, which has already received the green light from the Food and Drug Administration, the American drug agency. A smaller cotton swab is used directly than that used for the traditional swab and can be managed directly by the patient. Those who have experienced it compared it to the act of picking the nose, which is therefore much less invasive than the oropharyngeal swab. The advantages include the rapidity of response that is obtained in ten minutes and the low cost of the machinery that analyzes it.