[Viral hemorrhagic fever].
Viral haemorrhagic fevers, such as Lassa fever and yellow fever, cause tens of thousands of deaths annually outside the Netherlands. The viruses are mostly transmitted by mosquitoes, ticks or via excreta of rodents. Important to travellers are yellow fever, dengue and Lassa and Ebola fever. For yellow fever there is an efficacious vaccine. Dengue is frequently observed in travellers; prevention consists in avoiding mosquito bites, the treatment is symptomatic. Lassa and Ebola fever are extremely rare among travellers; a management protocol can be obtained from the Netherlands Ministry of Health, Welfare and Sports. Diagnostics of a patient from the tropics with fever and haemorrhagic diathesis should be aimed at treatable disorders such as malaria, typhoid fever, rickettsiosis or bacterial sepsis, because the probability of such a disease is much higher than that of Lassa or Ebola fever.