Malaria is caused by
Plasmodium parasites and is transmitted to humans through the bites of infected female mosquitoes. Most malaria cases and deaths occur in sub-Saharan Africa. Other regions at risk are in Asia, Latin America and the Middle East. In 2015, 95 countries and territories had ongoing malaria transmission [
1]. The World Health Organization (WHO) has declared the Netherlands malaria free since 1970. Nowadays malaria in the Netherlands occurs only as an imported disease in returning travellers or in visitors from endemic countries. Malaria is a mandatory notifiable disease in the Netherlands. Surveillance of imported malaria is used to monitor trends and as a feedback tool on the effectiveness of pretravel health consultation and indications for malaria chemoprophylaxis. The national coordination centre for traveller’s health (LCR) is responsible for the national travel medicine guidelines for the Netherlands. An earlier study found a decreasing trend of incidence of imported malaria in the Netherlands during the time-period 2000–2007 [
2]. The annual number of imported malaria infections fell from 535 in 2000 to 197 in 2007. Most recorded infections were caused by
Plasmodium falciparum (2131/2847; 75%), and most cases had recorded Africa as the most likely continent of infection (2068/2847; 82%). Almost half of all 2847 cases were travellers visiting friends and relatives (VFR) in Middle and West Africa. During this time period, malaria notifications among VFR had decreased as well (from 210 in 2000 to 77 in 2007) [
2]. A decline in malaria incidence is seen globally; the WHO estimates a fall of 37% among populations at risk between 2000 and 2015 [
1]. The risk of imported malaria, however, depends on several factors: malaria endemicity at the destination, the season of travel to the destination, the number of travellers to risk areas, the behavior of the traveller and adherence to personal protective measures like insect repellents, adequate use of chemoprophylaxis, and efforts for vector control around the accommodation. The aim of this study is to analyse trends in malaria notifications in the Netherlands, to assess whether the decline has persisted since 2007 and to identify risk groups. In recent years, the number of Dutch travellers to malaria endemic countries has increased [
3] and since 2014 large numbers of asylum seekers from the Horn of Africa have arrived in the Netherlands. Although the incidence among asylum seekers was not studied separately in the previous study [
2], in light of the recent increase in refugees seeking asylum in the Netherlands, the additional aim is to quantify the incidence of imported malaria in asylum seekers.