Vroča poletja: Ali potrebujemo policijo proti komarjem?

In the heart of Berlin, near the Potsdamer Platz, a pond named Pianosee has become both a symbol of sustainable urban design and a growing concern for public health officials. Designed by architect Renzo Piano, this water feature collects rainwater, supports native vegetation such as reeds, and hosts colorful carp that feed on insects. The concept aligns with the broader goal of transforming cities into “sponge cities” capable of managing extreme weather conditions. However, recent developments suggest that these ecological efforts may inadvertently create new challenges, particularly with the spread of disease-carrying mosquitoes. The issue stems from climate change and globalization, which have expanded the range of mosquito species in Germany beyond their traditional roles as nuisance pests. Scientists and health experts warn that some once-harmless local mosquitoes could now act as vectors for pathogens. This shift is highlighted by the Mückenatlas, a citizen science project that has been collecting data on mosquito populations since nearly 15 years ago. Researchers from the Leibniz Centre for Agricultural Landscape Research and the Friedrich-Loeffler Institute (FLI) analyze samples sent in by participants. Additional monitoring occurs in areas such as the Rhine Valley, urban centers, and wetlands, tracking the distribution of over 50 species, including invasive ones like the tiger mosquito (Aedes albopictus) and the Japanese bush mosquito (Aedes japonicus). Dr. Helge Kampen, head of the laboratory for medical entomology at the FLI and leader of the national expert commission on mosquitoes as disease vectors, emphasizes how rising temperatures are altering mosquito behavior and pathogen dynamics. He explains that warmer conditions accelerate insect metabolism, leading to faster reproduction rates and increased population sizes. At the same time, pathogens within the mosquitoes can replicate more quickly under these conditions. “Insects are temperature-dependent,” he says. “As temperatures rise, their metabolic processes speed up. They reproduce more rapidly, and their populations grow larger. Meanwhile, the pathogens they carry can also multiply more efficiently.” This phenomenon is particularly concerning for certain species, such as the common house mosquito (Culex pipiens), which has a brownish, ringed body and gray-brown legs. These mosquitoes, once considered harmless, are now being observed carrying viruses that can infect humans and animals. In Berlin, researchers have documented the emergence of the West Nile virus, originally introduced through human activity. The virus spreads among birds, and when common house mosquitoes bite infected birds, they can pick up the virus. Within days, the virus replicates in the mosquito’s body, moving from its digestive system to its salivary glands. When the mosquito bites again, it can transmit the virus to other birds, mammals, or even humans. To better understand the risk of West Nile virus transmission in Berlin, Dr. Sandra Junglen, virologist and group leader at the Institute of Virology at Charité, conducted a three-year study. Her team captured approximately 24,000 mosquitoes in different locations across Berlin-Schöneberg during June, July, August, and September each year. These sites included a residential area, a cemetery, a backyard, a repurposed industrial site undergoing nature restoration, and a protected natural area. The results revealed 16 species of mosquitoes, with the common house mosquito making up 80% of the sample. The presence and prevalence of pathogens varied depending on location, underscoring the need for targeted surveillance and intervention strategies. As the summer heat intensifies, concerns over mosquito-borne diseases continue to mount. Public health authorities are increasingly called upon to develop proactive measures, potentially including enhanced monitoring systems, community education campaigns, and targeted interventions to reduce mosquito breeding grounds. Whether such initiatives will lead to the creation of a dedicated “mosquito police” remains uncertain, but one thing is clear: the intersection of climate change, urban planning, and public health demands a renewed approach to managing the growing threat posed by disease-carrying mosquitoes.