The annual influenza epidemic in the winter of 2018-2019 was less severe than the year before. Approximately 400,000 people have had the flu. During the previous epidemic (2017-2018), some 900,000 people became ill from the flu virus. The number of patients with legionella was high in 2018. In recent years there has been a steady increase in legionella, for which the reason is still unknown. These are the conclusions of RIVMNational Institute for Public Health and the Environment ’s annual report on influenza and other respiratory infections in the Netherlands.

Influenza

Between October 2018 and May 2019, a total of approximately 400,000 people became ill due to the influenza virus. An estimated 165,000 people consulted a general practitioner with flu-like symptoms. This is shown by figures from Nivel, the Netherlands institute for health services research. A total of 11,000 people were admitted to a hospital with complaints caused by the influenza virus. That is much less than the year before, when 16,000 people were admitted to a hospital. The epidemic lasted 14 weeks. That is longer than the average of nine weeks in the past 20 years.

Legionella

In 2018, the number of reports of legionella (legionnaire's disease) rose to 584. In recent years we have seen an increase in the number of patients with legionella. In 2017, there were 561 patients and 454 in 2016. Both the number of patients who become infected in the Netherlands and the number of patients who become ill abroad are increasing. Patients with legionella are also increasing in other European countries. What causes this increase is still unclear, and several studies have been started to find the cause.

Surveillance

Each year, RIVMNational Institute for Public Health and the Environment publishes an overview of the number of patients with influenza and other respiratory infections. The report also indicates how often other pathogens that cause respiratory complaints are reported. For these pathogens (such as tuberculosis, Q fever and parrot disease) the number of reports remained the same.