The Institute of Physics and the Prague Public Transit Company have recently agreed on mutual cooperation aimed at testing the Prague public transportation network for the presence of the SARS-CoV-2 virus that causes Covid-19.
During April researchers from the Institute of Physics of the Czech Academy of Sciences will collect around 500 surface and air samples on board buses, trams, trains and in metro stations operated by the Prague Public Transit Company using ad hoc biosensors and air sampling systems. Their analysis will take a month, the results should be available at the end of May, beginning of June.
Air sampling system
The presence of the SARS-CoV-2 virus will be tested using swabs from surfaces that people regularly touch such as poles, grips, seats, push-buttons, contact-free ticket terminals as well as control buttons in elevators, escalator handrails, escalator retaining system in metro stations or street furniture on platforms such as benches or infopanels. To detect airborne virus on board vehicles and in metro stations, experts will use an air sampling device with the 80-160 l/min. capacity, developed for this purpose by the researchers from the Institute of Physics of the Czech Academy of Sciences in collaboration with the MATCA National Competence Centre.
To capture viral particles we will use a similar technology like the one used on London tube network by experts from the Imperial College whom we have been consulting on the procedure.
“To capture viral particles we will use a similar technology like the one used on London tube network by experts from the Imperial College whom we have been consulting on the procedure,” Alexandr Dejneka, the head of research at the Institute of Physics, explained. The samples from air and contact surfaces inside the vehicles will be tested using biosensors developed by Hana Lísalová and her team from the Institute of Physics. “They are based on a specially designed polymer nanobrush that selectively captures coronavirus particles in a liquefied sample, ignoring everything else in it, “Alexandr Dejneka added.
The researchers from the Institute of Physics will perform the collection during April, taking a total of 150 swabs on buses, 150 swabs on trams, 100 swabs on trains and 50 swabs in metro entrance halls and station platforms. In addition, they will take 50 air samples, 10 for each of the following places: buses, trams, trains, metro entrance halls and station platforms. Each air sampling session on vehicles will take 20-30 minutes, depending on the type of the vehicle, and around 1 hour in metro entrance halls and station platforms; the device’s long-lasting batteries will allow sampling in full traffic with passengers. The swabs in metro carriages will be taken immediately after passengers get off and the train is taken to the metro depot, because the time a train spends in the terminal station navigating to the opposite travel direction is not long enough for the researchers to take the samples. The swabs on buses and trams will be taken at turning loops, samples from metro entrance halls and station platforms will be taken in full traffic.
The Prague Public Transit Company has selected metro routes and stations that run or are located near a hospital. The selected locations will include places such as the Březiněveská turning loop, which is the terminal station for tram lines 3 and 24 providing transportation service for the area around the University Hospital “Na Bulovce” and the General University Hospital in Karlovo náměstí, and other similar facilities located along the transit route through Prague. For buses, the collection spots will include the Želivského terminal and bus lines 124, 139, 150, 199 and 213 running near the “Královské Vinohrady” University Hospital and going as far as the Thomayer University Hospital and several other “polyclinics” and medical facilities in Modřany, Vršovice or Jižní Město. Samples from trains will be taken at the Kačerov and Hostivař train depots, the sampling from entrance halls and train platforms is also planned for stations near hospitals such as “Karlovo náměstí”, “Budějovická” or “Kačerov”.
Subsequently, researchers from the Institute of Physics of the Czech Academy of Sciences will analyse the samples at the Biological Centre of the Czech Academy of Sciences and the Faculty of Natural Sciences of the University of South Bohemia in České Budějovice. In cooperation with the above research facilities, the researchers will run tests using biochips and, simultaneously, a PCR method test analysis and cultivation to determine infectiousness of suspected samples. The testing results should be made available at the end of May, beginning of June.
The experts from the Institute of Physics of the Czech Academy of Sciences took pilot swabs and air samples at the beginning of February 2021. During the pilots, they were verifying the proposed methodology, including the methodology for sample analysis.