Last weekend, the National Institute for Public Health and the Environment confirmed after reports from French and Dutch media that a Dutch tourist has contracted dengue fever in the South of France. She most likely contracted the infection from the Asian tiger mosquito.
Dengue fever is a tropical disease caused by the dengue virus. An estimated 400 million people contract this infection every year. The vast majority of this is caused by the tropical mosquito Aedes aegypti. Like all female mosquitoes, the Aedes ladies also need proteins and minerals to allow her eggs to mature. She gets the nutrients from blood.
Sneaky biting girl
Mrs. aegypti, also known as the yellow fever mosquito, lives in areas along the equator and is very efficient in transmitting viruses such as yellow fever virus, zika virus and therefore also the dengue virus. What makes her so efficient is that she is a sneaky biting girl who likes to live around people. A real city mosquito with a preference for human blood. During the day she inconspicuously stalks her prey, both indoors and outdoors. For her eggs to mature, she needs several blood meals per egg cycle. The aegypti ladies have expanded their habitat quite a bit in recent years. Yet she is not responsible for the infection of the Dutch tourist in the South of France.
The slightly friendlier niece
Mrs. aegypti's niece is Mrs. albopictus, or the Asian tiger mosquito. Mrs. albopictus prefers a temperate climate and has settled in the south of France, among other places. She occurs sporadically in the Netherlands when her eggs travel along through the trade in old car tires. We know that Mrs. albopictus also transmits the aforementioned viruses. A little less efficient, but she is able to do it. She is a little less picky than her tropical cousin. She likes any blood she gets under her suction mouth. She is therefore less dependent on people for the ripening of the eggs and mainly camps at the edges of cities in the adjacent forest or land. She is a bit less sneaky than her tropical cousin, so we notice her sooner. Also, she only needs one blood meal per egg cycle.
Don't panic, alertness is important
There is no immediate cause for panic, but it is a clear signal. A tourist can take the virus home. If he or she happens to be stung by a stray tiger mosquito in the Netherlands, we could be dealing with a local outbreak of the dengue virus.
BPRC has been researching the dengue virus for quite some time. More information can be found on our research areas page.