The most notable infectious disease outbreak in 2015 was the flu epidemic in the winter of 2014-2015, which at 21 weeks was the longest ever recorded in the Netherlands. This was concluded in the RIVM National Institute for Public Health and the Environment report ‘State of Infectious Diseases in The Netherlands 2015’.

The report is published every year by the Dutch National Institute for Public Health and the Environment (RIVM National Institute for Public Health and the Environment ), and provides insight into infectious disease trends in the Dutch population. The report also covers relevant developments abroad. Another important development in 2015, besides the flu epidemic, was the influx of refugees from Syria and Eritrea. As a result, reception centres were especially vigilant in detecting infectious diseases among asylum seekers. The most common notifiable infectious diseases among asylum seekers were tuberculosis, malaria, and chronic hepatitis B. There is no evidence of significant transmission of TB and chronic HBV to the Dutch population.

Surveillance of infectious diseases

The theme of this year’s report is the surveillance of infectious diseases in the Netherlands, based on data about disease incidence and distribution. These data are collected in order to detect an outbreak of an infectious disease, to monitor trends in infectious diseases, and to determine the effectiveness of vaccination programmes, for instance. By combining and analysing surveillance data from the many data sources available, insight into the epidemiology of infectious diseases is enhanced.

Burden of disease estimates

In this edition, the disease burden has been re-estimated for 35 infectious diseases in the Netherlands in the 2012-2014 period. The disease burden provides an indication of the number of years that people suffer poor health due to an infectious disease. Some infectious diseases, such as gastroenteric infections, occur frequently in the population, but do not generally cause serious symptoms. Other infections, such as tetanus, are rare but cause relatively high numbers of fatalities. One health indicator that combines both aspects is the Disability Adjusted Life Year (DALY). The average annual disease burden for the entire Dutch population was the highest for flu (8,653 DALYs per year). Diphtheria was estimated to have the lowest disease burden (0.6 DALY per year). The low disease burden for diphtheria is the result of the Dutch National Immunisation Programme.