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PALO ALTO / CALIFORNIA – US researchers have developed polymerase chain reaction (PCR) tests that detect the RNA of 15 different respiratory disease viruses. In the first study in Lancet Microbe (2023; DOI: 10.1016 / S2666-5247 (22) 00386-X) High agreement was found with the results of the local control laboratories. According to the authors, regular checks of wastewater in the future could, in a similar way to a pollen report, show which diseases doctors should currently expect.
The pandemic has shown that wastewater surveys can be used for surveillance. US Centers for Disease Control and Prevention (Center for Disease Control) is already using the opportunity to monitor the spread of new variants of SARS-CoV-2. in Europe with Esi-Cora Similar systematic monitoring is planned. Since PCR test results are available within 24 hours, the course of the epidemic can be followed live, so to speak.
researchers Stanford University In Palo Alto, the tests now also want to be used for other viral diseases. Together with “Verily Life Sciences” (formerly “Google Life Sciences”), the researchers have developed 13 polymerase chain reaction (PCR) tests for the most common viral pathogens. This is relatively easy to do, since pathogens have long been genetically decoded and genetic sequences published. Alexandria Boehm’s team selected so-called conserved sequences for PCR testing. These are sections of the genome that are immutable for viruses, because any mutation will lead to the formation of defective viruses.
Besides the two already known tests, the PCR test includes influenza A and influenza B viruses, respiratory syncytial viruses RSV A and RSV B, 5 different influenza paraviruses, 4 seasonal coronaviruses, human rhinovirus and metavirus.
In a pilot study, researchers tested 216 samples collected three times a week for 17 months at a Santa Clara County wastewater treatment plant. The results were compared with reports from microbiological laboratories in the same area, where samples sent by doctors and clinics are examined.
As reported by Boehm and colleagues, the highest virus concentrations are found in human rhinoviruses and human seasonal viruses. According to the study, the concentration of these and other viruses was associated with the rates of positivity in the laboratories that the authorities have used for monitoring so far. The only exceptions were influenza B and RSV A, which can rarely be detected in sewage.
The researchers were able to follow various cold and flu outbreaks over a 17-month period. For example, there has been a wave of colds caused by the OC43 coronavirus and an increase in parainfluenza diseases caused by parainfluenza virus 3.
An interesting observation was that as omicron BA.1 increased, levels of other viral RNA decreased significantly, which the researchers attributed to changes in human behavior during the epidemic.
Boehm imagines the constant monitoring of sewage. Individual municipalities can then identify seasonal epidemics at an early stage with reasonable financial means. Doctors can be warned of an increase in respiratory diseases. In principle, results can be communicated daily like a weather report. This would give the population the opportunity to protect themselves from infection. © rme/aerzteblatt.de