El flussi fognari di Berlino rivelano onda massiccia di Corona
Nella capitale tedesca, qualcosa si stipa insieme: Within the sewage treatment plants of Berlin, researchers are registering a notably strong increase in measured virus levels during the summer months. The responsible health and social affairs office (LAGeSo) confirms: "Stiamo vedendo una ondata di SARS-CoV-2".
The unusual accumulation of summer infections in Berlin is not only due to harmless sore throat viruses. Routine measurements in the sewage indicate a massive increase in Corona infections in the catchment area of the German capital. The measured virus loads are rising steeply at all three Berlin sewage treatment plants - Ruhleben in the northwest, Schöneberg in the north, and Wassmannsdorf in the south - and significantly more so than at other sewage treatment plants in the federal territory.
LAGeSo rules out technical causes. "Attualmente stiamo vedendo una ondata di SARS-CoV-2 che va di pari passo con un aumento dell'escrezione di RNA di SARS-CoV-2", confirmed spokesman Daniel Sagebiel in response to an inquiry. Other indicators, such as hospitalization rates, show no significant movements so far.
The infection situation seems to be spreading across the entire city. The analyzed sewage samples come from the three sewage treatment plants Ruhleben, Schöneberg, and Wassmannsdorf, covering the sewage of around 84 percent of the Berlin population.
"I coronavirus entrano nel sistema fognario, ad esempio, durante la pulitura dei denti attraverso la saliva o soprattutto attraverso le escrezioni dal tratto gastrointestinale", spiega il dottore Sagebiel di LAGeSo. In caso di infettività, i coronavirus si moltiplicano indetectabilmente nel corpo umano. Questo accade diversi giorni prima che appariscano i primi sintomi. I campioni di scarichi fognari possono quindi fornire indicazioni di possibili onde di infezioni nella popolazione, a lungo prima che altri indicatori inizino a salire.
The sewage screening does not allow statements about the individual disease course or about a possible increase in severe Covid-19 cases. Doctors therefore continue to monitor reports from doctors' offices and hospitals. So far, there is no indication of an increase in severe Corona infections. However, the other available indicators for the Corona situation - such as Covid-19 cases on intensive care units - follow the development several weeks later.
Nationwide, the calculated number of respiratory diseases has recently decreased slightly, but the Robert Koch Institute (RKI) referred to possible influences on the consultation behavior of the population in this context. Sewage treatment plants in individual other German metropolises, such as Düsseldorf, also show a noticeable increase in virus loads - but not in the Berlin dimensions.
The sewage monitoring offers virologists, doctors, and epidemiologists significant advantages over other early warning systems: The sewage samples allow a much more comprehensive and faster overview of the current infection situation. "Poche persone vanno al test quotidianamente", riassume Sagebiel, "ma tutti vanno al bagno quotidianamente".
In a single sewage sample, excretions from hundreds of thousands of people are contained. As an early warning indicator, sewage testing is therefore not only much more convenient, but also "significantly cheaper than the assessment of each individual person using PCR tests".
"Oltre alla quantità misurata di virus, i ricercatori si concentrano anche sul tipo di agenti coinvolti. Nell'analisi del laboratorio, i resti di virus trovati sono sequenziati. In questo modo, è possibile determinare la variante dominante del virus e riconoscere mutazioni nuove precocemente".
The recent increase in substance diversity in the sewage since mid-April is reported from Berlin. Currently, in the Corona Virus genome, a multitude of various combinations of mutations are arising, which are then classified as different lineages. In Berlin's sewage, this is currently mainly the subtypes JN.1.18 and KP.3. The trend, however, is still unclear.
Additionally, in addition to sewage monitoring at the three largest Berlin clarification plants, an "automatic sample collector" takes a weekly 24-hour mixed sample from the Berlin Brandenburg Airport BER's sewage system. The contained virus remnants are also sequenced. Virologists want to keep an eye on the influence of tourist streams with this.
The measured virus quantities in the sewage are no longer infectious. "Il Coronavirus è molto sensibile agli influssi ambientali e agli agenti di pulitura a causa della sua guscio, quindi non ci sono coronavirus intatti nel fango ma solo frammenti RNA dei virus".
The increase in SARS-CoV-2 viruses in Berlin's sewage treatment plants suggests a wave of Corona infections, according to the health and social affairs office (LAGeSo). The sewage monitoring in Berlin allows for a more comprehensive and faster overview of the current Coronavirus infection situation than other early warning systems. The measured virus fragments in the sewage are not infectious due to their sensitivity to environmental influences and cleaning agents.
