Covid measures keep tropical diseases at bay

Asian tiger mosquitoes, first seen in Switzerland in 2003, can carry tropical diseases such as dengue fever or chikungunya © Keystone / Ennio Leanza

Switzerland’s coronavirus-related travel restrictions have had at least one positive effect: this year the Federal Office of Public Health (FOPH) has received half as many reports of tropical diseases as last year.

The FOPH noted lower figures for “travel-related diseases” such as dengue fever, chikungunya fever and malaria, spokesman Jonas Montani said on Tuesday.

The decline is likely to be due “mainly” to the travel restrictions imposed in an attempt to curb the spread of Covid-19. The FOPH had expected this outcome, since the pathogens are acquired primarily on journeys to the tropics or subtropics. There has never been a recorded transmission of dengue fever or chikungunya virus in Switzerland.

Two cases of malaria infection have been recorded in Switzerland, both in the Zurich area: one in 1997 and one in 1999. The FOPH suspects this was due to mosquitoes that had arrived on a plane. This so-called airport malaria would also be affected by travel restrictions, Montani said.

He added that it could not be ruled out that people had decided not to go to the doctor after a trip, meaning the FOPH would not be aware of an infection.

According to FOPH figures published in its latest BulletinExternal link, the number of cases of the three diseases reported so far in the year under review was about half as high as in the same period last year. There have been 82 reported cases of malaria (down from 140), 60 cases of dengue fever (118) and ten cases of Chikungunya fever (23).