It is October, marking the start of the respiratory infection season. In autumn and winter, there is an increase in people who are coughing and sneezing. Various pathogens can cause a respiratory infection. That includes the influenza virus (flu), the respiratory syncytial virus (RSV) and the coronavirus SARS-CoV-2 (COVID-19). We are currently seeing an increase in people with respiratory symptoms and people with SARS-CoV-2.
A respiratory infection can range from mild cold symptoms to severe pneumonia. The most common symptoms are: coughing, sneezing, sore throat and nasal cold. This is sometimes accompanied by fever, muscle pain, headache or tiredness.
Some people are more at risk
A person who has a respiratory infection can pass it on to others, for example through coughing and sneezing. Although most people get better on their own after a few days, some may become seriously ill. For example, RSV is especially dangerous in very young children. COVID-19 and flu cause an additional risk of serious respiratory infection for older people and people who have chronic illnesses. A few simple recommendations can help limit the spread of respiratory infections and protect people who could become seriously ill from such infections.
Many cases of RSV and flu last winter
Working with various partners, including the Netherlands Institute for Health Services Research (Nivel), laboratories, hospitals and nursing homes, RIVM constantly monitors trends in respiratory infections in the Netherlands. During the previous season (in 2024–2025), the number of people with acute respiratory symptoms peaked during various time periods. Among children under five years old, the number of GP visits for acute respiratory infections peaked just before and just after New Year’s. In the same period, there was a peak in GP visits for an infection of the small airways (bronchiolitis) among children in this age group. RSV was also circulating widely during that time.
The seasonal flu epidemic lasted for nine weeks, from mid-January to mid-March 2025. By early March, the number of people who went to visit their GP with flu-like symptoms was no longer elevated, although laboratories were still detecting many cases involving the influenza virus. During the flu epidemic, there were elevated numbers of people who had respiratory infections that were so severe that ICU admission was needed.
Coronavirus SARS-CoV-2 in summer and autumn
In contrast to flu and RSV, which primarily circulate in winter, the coronavirus SARS-CoV-2 does not (yet) have a stable seasonal pattern. The virus was mainly observed in summer and autumn of 2024. During these periods, the weekly number of patients admitted to hospital with a SARS-CoV-2 infection was lower than in the same periods in previous years when SARS-CoV-2 was circulating widely.
Staying alert to symptoms together
RIVM closely monitors the development and spread of respiratory infections. This takes place in part through the Infection Radar survey, which RIVM uses to determine how many people in the Netherlands have symptoms that could indicate a respiratory infection. Every week, survey participants report whether they have symptoms such as fever, nasal cold, coughing, sneezing and sore throat. By mapping out the symptoms, it is possible to rapidly identify a possible surge in respiratory infections. You can help monitor viruses by signing up for the Infection Radar survey.