Expert Opinion: Dr. Helge Kampen

What If…? Tropical Diseases Spread Across Europe

The Isle of Riems, a small island in the Baltic Sea, is home to the Friedrich Loeffler Institut (FLI), one of the most modern animal health research facilities in Europe. FLI lab leader Dr. Helge Kampen explains how he and his team are investigating which non-native mosquito species are migrating to Germany, and which pathogens they might transmit. Their question: What risks do these invasive mosquitoes pose to the European population?

 

 

Most people in a Western European country like Germany, and Europe in general, feel safe from dangerous tropical diseases. Since the eradication of malaria in the middle of the last century, Germany has not had to face mosquito-borne diseases. However, this could easily shift. Along with climate change, mass tourism and globalization, various mosquito species are heading from tropical countries to Europe. Within our project “Mueckenatlas” (mosquito atlas), we identified seven non-native mosquito species in Germany. Among them were some species which could eventually transmit the viral agents of diseases like West Nile fever, dengue or chikungunya. This is a situation that could become critical because few experts here know how to control and manage eventual outbreaks.


Dr. Helge Kampen, Lab Leader at the Institute for Infectious Diseases at the Friedrich-Loeffler-Institut (FLI) – the Federal Research Institute for Animal Health, Germany

 

Compared to malaria, viral diseases represent a more serious threat to the health of the population in Europe. Since the elimination of malaria in Europe, native parasites do not exist anymore, and tropical parasites cannot effectively infect native mosquitoes. However, Asian mosquito species, which could transmit viral pathogens, are quickly spreading throughout Germany. One example is the Asian Bush mosquito, which was first detected in 2008 near the German-Swiss border. This mosquito, a possible vector of the West Nile virus, expanded at a fierce pace into the southern part of Germany over the following years. Overall, it seems that this species will probably colonize the entire country in the next five to ten years. Another vector of arboviruses, the Asian Tiger mosquito, can cause even more serious problems, as shown by the chikungunya fever outbreaks in Italy and Southern France in recent years. At first, Tiger mosquitoes were not considered to be able to proliferate in Germany because of the unfavorable weather. However, in the last three years, we have found evidence of these mosquitoes surviving the winter in some areas. While we have not yet observed any case of viral disease transmitted by mosquitoes in Germany, the chances are increasing. 

 

It is highly unlikely that malaria could occur again. Malaria has no animal reservoirs, whereas viruses can infect animals and proliferate. Moreover, we can easily diagnose and treat malaria, yet viral infections are often asymptomatic, can spread quickly and there are often no therapeutic options. Although our German healthcare system is good, we do not have any regulations for fighting mosquitoes. There are also no European standards for invasive vector control. Public authorities and people should be aware of the risk posed by mosquitoes, and controlling measures for the elimination of breeding areas should be put in place to avoid, or at least control, the spread of vectors.

 

Distribution of Asian bush mosquitoes (Aedes japonicus) in Germany in 2012

Source: Data from Dr. Doreen Walther at ZALF and Dr. Helge Kampen at FLI
Distribution of Asian bush mosquitoes (Aedes japonicus) in Germany in 2016

Source: Data from Dr. Doreen Walther at ZALF and Dr. Helge Kampen at FLI