Tiger mosquito in Germany: How dangerous is your bite?

The Asian tiger mosquito has been native to Europe since the late 1970s. A specimen was first detected in Germany in 2007. The tiger mosquito bite can be dangerous because the insect can transmit potentially serious diseases. What is the real risk of infection, and when should you seek medical advice for a sting? How can you identify the tiger mosquito, and do you have to report your sighting? You can find out that and more in this article.

Asian tiger mosquito: origin and distribution

As the name suggests, the Asian tiger mosquito (Aedes albopictus) originally comes from Southeast Asia. The insect has now spread widely through trade in goods and tourism and can be found in Asia and Europe, as well as in North and South America and Africa.

A distinction is made between isolated evidence and a permanent establishment of the species. In Europe, the tiger mosquito has established itself in Italy, France and Spain, among other places, but larger populations are now also appearing in parts of Germany.

 

Where is the tiger mosquito found in Germany?

The first detection of a tiger mosquito in Germany was in 2007 in a parking lot on Autobahn 5 near the Swiss border. While there were initially only isolated reports of sightings until 2013, larger tiger mosquito populations have been established in Germany since 2014. Bavaria and Baden-Württemberg are particularly affected, but specimens have also been seen in Hesse, North Rhine-Westphalia and Thuringia.

How do you recognize tiger mosquitoes?

The Asian tiger mosquito has a relatively small body size. It is a maximum of 0.5 to 0.9 centimetres in size and is, therefore, smaller than a one-cent coin. For comparison, the common mosquito, particularly in Germany, can reach up to 1.5 centimetres in size.

The colouring is particularly striking: the tiger mosquito is black with characteristic, slightly broken white stripes. It also has a white line from the back of the head to the base of the wings. The wings bear no pattern and are transparent. The tiger mosquito has five white stripes on its long hind legs. If blood is in their stomach, their abdomen will appear dark red.

In contrast to other mosquito species, tiger mosquitoes are less active at night: they bite mainly at dusk and during the day.

 

Tiger mosquitoes: confusion possible

Despite its characteristic appearance, the tiger mosquito can also be confused with native and other invasive mosquito species, i.e., immigrated mosquito species. The most likely candidates for confusion are the ringworm and the bush mosquito.

The native ringworm,  also known as the ringworm, also has a striped pattern. However, it grows up to 1.3 centimetres in size, while the tiger mosquito reaches a maximum of 0.9 centimetres. In addition, their colouring is grey-brown and white, while that of the tiger mosquito is black and white.

The  Asian bush mosquito is very similar to the tiger mosquito. It also has black and white stripes. However, it has three white lines on its back instead of one. For example, mosquitoes can also transmit viruses that can cause meningitis or West Nile fever. Except in Saxony, Schleswig-Holstein and Mecklenburg-Western Pomerania, it is widespread throughout Germany.

What does the tiger mosquito bite look like?

The bite of the tiger mosquito does not differ optically from that of the common mosquito species in Germany. The bite injures the skin, and specific saliva proteins of the mosquito enter the body. The messenger substance histamine is released in response, and the affected area swells and turns red. The activation of certain nerve fibres also causes itching. Therefore, the symptoms caused by the bite are usually precisely the same as with other mosquito bites.

How dangerous is the tiger mosquito bite?

The bite of the tiger mosquito is annoying but not dangerous in itself. The fact that the Asian tiger mosquito still has a bad reputation is mainly because it can transmit pathogens in some instances. In Southeast Asia and other tropical regions, it significantly contributes to the spread of diseases.

The tiger mosquito can serve as a transmitter for the following diseases :

• Dengue fever
• Zika virus infection
• West Nile fever
• yellow fever
• Chikungunya fever

Transmission only occurs under certain conditions: the insect must first have bitten a person already infected with the pathogens of one of the abovementioned diseases. The tiger mosquito itself does not carry the virus.

In addition, the viruses must multiply in the mosquito’s body before transmission. Constantly higher outside temperatures accelerate this; with colder temperatures, it can take a few weeks. The lifespan of a tiger mosquito is a maximum of 30 days.

In rare cases, transmission between infected animals and humans can also occur if a tiger mosquito has previously bitten an animal that carries the pathogen. In Germany, for example, migratory birds come into question.

 

Risk of infection by tiger mosquitoes in Germany

Infections via a tiger mosquito with one of the virus diseases mentioned are currently sporadic in Germany, although they cannot be ruled out. If temperatures across Germany rise over the long term due to climate change, the risk of infection from tiger mosquitoes could also increase.

With a view to possible infections with the diseases mentioned abroad – and thus the “bringing” of diseases to Germany, which can be spread here by mosquitoes – the occurrence of the tiger mosquito is viewed by the Federal Environment Agency as a potential risk to health. An infection with one of the diseases mentioned through the bite of a tiger mosquito has not yet been proven in Germany. Such cases are known in Spain, Italy, France and Croatia.

Laboratory studies indicate that native mosquito species, such as the common mosquito, may also be potential vectors of the West Nile virus. So far, however, no infection with West Nile fever via the common mosquito has been detected in Germany. However, the conditions mentioned above for infection also apply here.

When should you seek medical advice?

Suppose symptoms such as fever and flu-like symptoms such as headaches, tiredness, chills or muscle and body aches co-occur as a mosquito bite. In that case, you should seek medical advice to be safe. Symptoms such as nausea, conjunctivitis or a skin rash can also be warning signs.

The diseases mentioned can heal without consequences but also take a severe course. Infections with the Zika virus during pregnancy can also lead to congenital disabilities in the unborn child.

If germs get into the wound through scratching or mosquito saliva, inflammation can also develop, which, in the worst case, can lead to sepsis (blood poisoning).

If in doubt, you should seek medical advice if you experience symptoms after a sting. The family doctor is the right contact person here.

Is there an obligation to report if a tiger mosquito is sighted?

 In Germany, there is no obligation to report if a tiger mosquito is sighted or caught. However, the environment and health ministries of the countries point out that reporting tiger mosquitoes can help to contain the spread of this species as much as possible – and thus also prevent the risk of possible transmission of diseases.

Suppose you have caught a mosquito and suspect it is a tiger mosquito. In that case, you can send the well-preserved, dead specimen or a corresponding photo to official registration offices, such as those in some federal states. In addition, the website “Mosquito Atlas” and the pan-European “Tiger Project” exist as nationwide reporting platforms.

 

Prevent the spread of the tiger mosquito and avoid bites.

Like other mosquito species, the tiger mosquito uses standing water to lay its eggs and as a breeding ground. MinorMinor water accumulations, such as bird baths, rain barrels, or water residue in flower pots or vases, are sufficient. Therefore, avoid leaving such containers uncovered for long periods and replace the water regularly, for example, in bird baths. Copper (about a copper coin) or clove oil in the water can kill the larvae. Depending on the other use of the water, these can be effective against the larvae of the tiger mosquito.

Mosquito larvae can also multiply in ponds, although natural predators such as dragonfly larvae or water beetles usually ensure the population is contained in natural waters.

Another biocide used to combat mosquito larvae is Bti (Bacillus thuringiensis israelensis). However, this insecticide is also deadly to other insects and should only be used as a last resort and only with expert guidance.

The usual protective measures such as long clothing, insect repellent sprays, or fly screens help prevent bites.