Covid-19 – Who are the protagonists of this pandemic? From the swab to the result

by Giuseppe Scarlata, Antonino Napoleone, Domenico Gangemi | May 1, 2020.

On April 3, 2020, Italy has announced by an official document issued by the Ministry of Health that the number of swabs to be performed for detecting COVID-19 should be limited to individuals who are included in priority categories, including health care workers, hospitalized patients and those categories considered at high risk according to the recommendations of the World Health Organization (WHO) and the European Commission (EUCOMM). This strategy aims at ensuring optimal use of resources and relieving the pressure on the laboratories designated for diagnostic testing for COVID-19. Despite the fact that the Italian health and research system is constantly under many controversies and contradictions due to staff cutbacks, poor funding, and not optimal management of the COVID-19 emergency, on 29 April 2020 the number of swabs performed amounted to 1,910,761. In one month only the number of diagnostics tests carried out in Italy was quadrupled to cover the quota of 31,603 tests per million inhabitants. That means, Italy carries out 3.1 tests for every 100 people, Germany carries out 2.4 tests for every 100 people. This rapid growth reflects the results of optimal management and reorganization locally of the hospitals and certified laboratories, the rapid supply chain of chemical reagents and the hard work of a great team made up of medical doctors, nurses, social-health operators, biologists and biotechnologists, laboratory technicians and all the technical-health workers. 

Which path does the biological sample follow, how is a swab performed and analyzed and who are the protagonists of this “Italian health model”?

According to the guidelines of the Department of Infectious Diseases of the “Istituto Superiore di Sanità” (ISS, the higher national health institution), the biological sample should come from the lower airways (broncho-alveolar wash, endotracheal aspirate, sputum) or alternatively from the upper airways (pharyngeal swab, nasal swab/pharyngeal swab), which is easier to sample. The qualified personnel responsible for performing swabs is made up of physicians and nurses (figure 2a), who should wear appropriate personal protective equipment (long sleeve waterproof disposable gown, disposable gloves, FFP2/FFP3 filter mask, protective goggles, and disposable hair cap) and collect the biological sample in a sterile and hermetically sealed container. Since the nasopharyngeal swab is very practical to perform, is considered as the reference way of sampling: the pharyngeal swab is rubbed between the tonsillar areas (avoiding contamination with saliva or teeth), while the nasal swab is pushed and rotated to the back of the nasopharynx to have it covered with nasal secretions. At the end of the sampling process, the swab is left at room temperature and collected in a test tube (containing a virus transport medium), labeled with the patient’s name and surname, date of collection and type of sample, and then immediately sent to a certified laboratory; this task is usually carried out by Social-Health Operators (SHO) on duty at hospitals in support of health workers (figure 2b). If the sample cannot be immediately sent to the reference laboratory, it must be stored in the fridge at +4°C (if analyzed within 48h) or -80°C (if analyzed after 48h). Once arrived in the laboratory, the biological sample is processed in the shortest possible time by highly qualified Biologists, Biotechnologists and Laboratory Technicians (figure 2c), according to standardized working procedures that involve extraction and purification of the viral RNA through commercial molecular kits and subsequent amplification of SARS-CoV-2 specific genes by Real-Time Polymerase Chain Reaction (RT-PCR) technology. This technique represents the gold standard in the diagnosis of the new human coronavirus.

According to the Ministry of Health directives on April 3, 2020, if a too large number of swabs have to be analyzed, a priority line must be followed as recommended on the guidelines provided by the WHO. The priority line has to follow this order:

1. Hospitalized patients with a severe acute respiratory infection (SARI);
2. Patients with acute respiratory infection hospitalized or placed in nursing homes or other long-term care facilities;
3. Healthcare workers at higher risk;
4. People at risk of developing a severe form of the disease;
5. First symptomatic individuals within closed communities;

After the laboratory diagnosis, evaluated and validated by a Medical Director or Biologist (figure 2d), a representative number of clinical samples is sent to the National Reference Laboratory of the Istituto Superiore di Sanità (ISS), after an agreement, in order to provide epidemiological surveillance and to update the statistical data; whereas clinical samples of patients who have died from COVID-19 must be frozen at -80°C at the facility that carries out the sampling or at the certified laboratory that makes the diagnosis, and then sent to the National Reference Laboratory of the ISS if required.

This is what has been happening every day for the past three months in Italy, where the importance and dedication of all these health workers are not sufficiently highlighted. They manage in a well-coordinated and indefatigable way to provide the results of the diagnosis of thousands of patients in the shortest possible time.
During the International Labour Day, we praise health workers and researchers and their dedication to fighting against this pandemic. Share and have faith in medical sciences, to stop all of this, the protagonists of this pandemic are in action.

References:

1. Xie C. et al., Int J Infect Dis 2020 Feb 27. doi: 10.1016/j.ijid.2020.02.050. 
2. Raccomandazioni per raccolta, trasporto e conservazione dei campioni biologici COVID-19. Gruppo di lavoro ISS Ricerca traslazionale COVID-19. 14 Aprile 2020.
3. Corman VM. et al. Euro Surveill. 2020 Jan;25. doi: 10.2807/1560-7917.ES.2020.25.3.2000045.
4. Pandemia di COVID-19 – Aggiornamento delle indicazioni sui test diagnostici e sui criteri da adottare nella determinazione delle priorità. Aggiornamento delle indicazioni relative alla diagnosi di laboratorio. Ministero della Salute, 03-04-2020.
5. Kralik P. et al., Front Microbiol 2017 Feb 2.  doi: 10.3389/fmicb.2017.00108.
6. https://www.worldometers.info/coronavirus/covid-19-testing/
7. https://www.cdc.gov/coronavirus/2019-nCoV/lab/guidelines-clinical-specimens.html