A Frankfurt Airport worker has died of malaria after a rare outbreak led to six employees contracting the serious infection spread by mosquitoes.

It is believed the mosquitoes arrived at Germany’s busiest airport on a plane, according to German public health officials.

The remaining five infected individuals are receiving medical treatment, a spokesperson for airport operator Fraport said.

Traps have been installed at the airport and mosquitoes captured will be analysed in a laboratory to determine their species and origin.

“Sadly, we must confirm that one employee has died as a result of the infection,” the Fraport spokesperson told the BBC.

“We have provided comprehensive information to all employees and encourage them to consult a doctor if they experience any symptoms.”

The outbreak is being investigated by the Frankfurt Public Health Department.

The BBC understands that six male airport workers in different jobs and different areas of the airport were infected, and officials are analysing blood samples to determine if they were infected by one mosquito or six different mosquitoes.

It was reported in July that the outbreak involved four infected workers.

The Robert Koch Institute – a German federal government agency and research institute for disease control and public health – previously said the four employees fell ill between 4 and 6 July and the mosquitoes were brought in by plane.

The institute said malaria in Germany almost exclusively affects long-haul travellers who were infected in malaria-endemic areas, and that malaria transmitted within a German airport is rare.

“The lack of a travel history can lead to a delayed diagnosis. A delayed diagnosis increases the risk of a severe course of the diseases,” the institute said in its epidemiological bulletin.

The last case of airport malaria was in 2023 also at Frankfurt Airport, it added.

Malaria is a disease spread by some types of mosquitoes biting humans, and is mostly found in tropical countries, according to the World Health Organization (WHO).

The infection, which is preventable and curable, is caused by a parasite and does not spread from person to person. However symptoms can be mild or life-threatening.