Flu season in Czechia
Current flu, COVID-19 and RSV activity in Czechia — based on ECDC ERVISS weekly data from the State Health Institute (SZÚ). Rescaled into a consultation-equivalent signal for a qualitative low / moderate / high classification.
Current situation: Influenza
In week 15 of 2026, activity of influenza (seasonal flu) in Czechia is low. The trend — derived from clinical surveillance — is falling. Over a four-week comparison, a clear decline is visible.
The classification is based on the ECDC ERVISS weekly reports, drawing on data from the State Health Institute (SZÚ) via the sentinel ARI/ILI surveillance network. Seasonally, infection waves in Czechia typically peak between January and March; activity is usually markedly lower during the summer months. How severe a given season becomes depends on the circulating virus variant and the population's immune status, among other factors.
Data sources and methodology
The current picture for Czechia is built on the European Respiratory Virus Surveillance Summary (ERVISS), published weekly by the European Centre for Disease Prevention and Control (ECDC). the State Health Institute (SZÚ) via the sentinel ARI/ILI network is the national public-health authority that feeds ERVISS with sentinel primary care and virology data.
ECDC ERVISS
ERVISS is ECDC's weekly pan-European surveillance summary for influenza, SARS-CoV-2 and RSV. National authorities — in Czechia's case the State Health Institute (SZÚ) via the sentinel ARI/ILI network — submit harmonised indicators every week, which ECDC publishes in a standardised dataset on Thursdays. Using ERVISS rather than each country's native portal ensures cross-country comparability.
ILI / ARI consultation rates and positivity
the State Health Institute (SZÚ) via the sentinel ARI/ILI network operates a sentinel network of general practices that report weekly rates of patients consulting for influenza-like illness (ILI) or acute respiratory infection (ARI). A subset of patients is swabbed and tested by reference laboratories, producing pathogen-specific positivity rates for flu, SARS-CoV-2 and RSV.
Why this source
Combining consultation incidence with virological positivity yields a pathogen-specific weekly incidence signal (ILI × positivity / 100). This is the standard European methodology and provides a more robust view than either indicator alone — consultation rates capture illness burden, positivity confirms which pathogen is driving it.
Qualitative classification
The “low”, “moderate” and “high” categories follow seasonal reference values and epidemiological thresholds calibrated to match our classifications for other countries. The ILI × positivity / 100 product is scaled to comparable thresholds using a divisor of 3, which aligns European sentinel peaks with the consultation-equivalent scale used elsewhere. Data refreshes weekly when ECDC publishes the latest ERVISS update, typically on Thursdays.
Frequently asked questions
When is flu season in Czechia?
Czech flu activity usually starts rising in late December, peaks between January and March, and eases by April. The precise window shifts year to year with the dominant influenza subtypes and residual immunity. SZÚ — the State Health Institute (Státní zdravotní ústav) — publishes weekly influenza updates through its sentinel ARI/ILI network. Central European climates tend to produce peaks similar in timing to neighbouring Germany, Austria, and Slovakia.
How does SZÚ classify flu severity?
SZÚ describes influenza activity using an ARI/ILI consultation-rate band together with laboratory positivity and severity indicators from hospitals. The weekly picture is expressed qualitatively, from sporadic through regional to widespread, and is also reported to ECDC for the European Respiratory Virus Surveillance Summary (ERVISS). The qualitative framing lets clinicians and the public interpret whether the season is ordinary, elevated, or exceptional.
How is flu surveillance organised in Czechia?
Czechia's influenza surveillance combines a sentinel network of primary-care physicians reporting ARI and ILI consultations, virological confirmation at SZÚ's National Reference Laboratory for Influenza in Prague, and hospital notifications of severe cases. Weekly bulletins summarise the picture and feed ECDC ERVISS, which places Czechia's trajectory alongside Germany, Austria, Poland, and Slovakia.
Is the flu vaccine free in Czechia?
Czechia covers seasonal influenza vaccination through public health insurance for defined groups — adults aged 65 and above, residents of long-term-care facilities, people with chronic illnesses, and healthcare workers — with vaccines delivered by GPs and occupational-health services. Other adults can receive the vaccine at their own cost or through employer-sponsored programmes. SZÚ reports vaccine-uptake estimates alongside the weekly surveillance bulletin.
How does Czechia compare to its Central European neighbours?
Because Czechia reports into ECDC ERVISS with harmonised indicators, its weekly flu classification is directly comparable with Germany, Austria, Slovakia, Poland, and the rest of the EU/EEA. Central-European countries typically see broadly similar peak windows between January and March. Lead–lag patterns of a few weeks are common and are visible in ECDC's side-by-side dashboards.
Want the actual numbers?
You'll find them in the app.
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