More infectious diseases due to climate change

This is shown by the new report “Climate Change and Health” by the RKI.

Rising temperatures increase the risk of infectious diseases. A new report by the Robert Koch Institute (RKI) on the subject of climate change and health warns of this. Pathogenic bacteria can multiply better in Germany under warmer climatic conditions. Virus carriers such as ticks and mosquitoes also spread more when temperatures rise and tropical species become native to us.

The publication is the first part of the three-part status report on climate change and health coordinated by the RKI and was published in the Journal of Health Monitoring. The remaining two parts are scheduled to be released later this year.

Asian tiger mosquito becomes native

The influence of climate change can be shown very well using the example of the Asian tiger mosquito. It is already native to south-west Germany, but also to Berlin, Jena and Bavaria. The distribution area is increasing. The problem is that the tiger mosquito can transmit dangerous viruses such as the dengue virus, the chikungunya virus and the Zika virus.

These viruses multiply in the mosquito. And the higher the temperatures in summer, the faster they can multiply and the better they can then be transmitted. Of course, this assumes that people are first bitten by these mosquitoes that have the virus in their blood, who brought it with them from foreign tropical countries.

Increased monitoring needed

According to the authors, increased monitoring is therefore now required in order to have an overview of where the mosquitoes are spreading. And to be able to intervene when populations get too large.

Klaus Stark is one of the 60 authors of the report. The RKI epidemiologist emphasizes that climate change and rising temperatures in Germany are also increasing the spread of ticks. Here it is becoming more and more important to inform the population well – on the one hand how to protect oneself against ticks, but also how to deal with them, which treatments are possible and of course information about the TBE vaccination.

Newly immigrated tick species

The researchers report that climate change is also making new species of ticks native to us. “So-called hyalomma ticks, which were actually not found in Germany until a few years ago, are now present. Not very many yet, but they can transmit types of typhus through bacteria. That can be a problem,” says Stark.

It is now important that, for example, doctors are made aware that when they have a fever they sometimes think of dengue fever or the World Nile Virus – at least in areas where the Asian tiger mosquito occurs. Or in the case of tick bites, also consider spotted fever.

Heat waves promote climate-sensitive pathogens

In addition to mosquitoes and ticks, there is a whole range of other infections that will occur more frequently as a result of climate change. This is because around two-thirds of the infectious disease pathogens found in Europe are considered climate-sensitive. Increased heat waves or floods favor their development and spread.

An example of this is the Hanta virus. They reproduce more when there are more host animals. Hanta viruses have their reservoir in bank voles that feed on beechnuts. And beech trees produce significantly more fruit at higher temperatures, which then leads to an increase in the bank vole population – and to an increase in the risk of transmission.

Warning of vibrios in the Baltic Sea

Another example of so-called climate-sensitive pathogens are vibrios. This type of bacteria, which actually occurs naturally, multiplies at an above-average rate in the Baltic Sea, which is becoming ever warmer. Vibrios can penetrate the skin through the smallest of wounds.

In people with a weakened immune system, this can lead to serious infections. Therefore, people who want to swim in the Baltic Sea should be informed. Because people with previous illnesses and/or with a certain immune deficiency should not go into the water there.

Health risk heat

According to the report, heat waves could also pose a serious health risk in the future. According to Elke Hertig, older people and people with previous illnesses are particularly at risk. She researches climate change and health at the University of Augsburg and co-wrote the RKI report. There are currently two to three heat waves a year in Germany. Depending on how global warming progresses, there could be up to four or even six heat waves per year by the end of the century. According to the Robert Koch Institute, heat waves caused around 4,500 deaths in Germany last year.

Prepare health system

The researchers are therefore calling for the healthcare system to be prepared for the increase in such cases of infection. The current few cases could quickly become hundreds or thousands as a result of climate change.

Hertig emphasizes: “We are facing a really big challenge here.” There are a number of changes caused by climate change, not only in the area of infectious diseases, but also in terms of air pollutants. And: “Mental health is also something we have to consider. These are really significant challenges that the healthcare system is facing.”

The authors of the report agree that our healthcare system must be better adapted to the consequences of climate change. In particular, it must be taken into account that society in Germany is aging and that many older people live here with many previous illnesses, who are particularly vulnerable.