Travellers to tropical and subtropical regions are at particular risk of contracting mosquito-borne diseases such as chikungunya, dengue, Zika or malaria. In view of this, it’s important to find out all about the precautions you can take both during and after any such trip to reduce the risk of infection.
With chikungunya, dengue and Zika, there’s the additional danger that the disease can be brought into Switzerland and then spread by the Asian tiger mosquito, which is already well established in some parts of the country.
How to protect yourself from mosquito bites
Wear bright long clothing.
Use insecticides and mosquito repellent.
Sleep under mosquito nets.
For country-specific information visit HealthyTravel.
How you can best protect yourself
During your trip: prevent mosquito bites
If you’re travelling to a region where mosquito-borne diseases such as chikungunya, dengue and Zika are known to occur, you should protect yourself from being bitten by mosquitoes as much as possible. The best ways to do this are:
- Wearing bright long clothing, preferably impregnated with insecticide.
- Applying insect repellent directly onto any exposed skin, by day and in the evenings.
Most insect repellents contain DEET (diethyltoluamide) or icaridin. Products which provide protection for up to four hours are approved by the Swiss Tropical and Public Health Institute.
- Sleeping under an insecticide-impregnated mosquito net and/or in an air-conditioned or well-ventilated room.
- Using mosquito coils and/or mosquito repeller plugs.
The above precautions against mosquito bites will also protect you from contracting other illnesses that occur in such regions, including malaria, yellow fever, Oropouche and further mosquito-borne diseases.
If you develop symptoms such as a fever, joint or muscle pain, a skin rash and/or a headache (see the overview below), see a doctor.
After your trip: stay alert to symptoms
If, after returning from your travels, you develop symptoms such as a fever, joint or muscle pain, a skin rash and/or a headache (see the overview below), see your GP or seek out a centre specialising in travel medicine.
You should also continue to protect yourself from mosquito bites for the first two weeks after your return to Switzerland, to help minimise the risk of local further infection (see ‘The infection chain’ below).
The infection chain
Human-to-human
Human-to-insect-to-human
Insect-to-insect
Zika can be passed directly from human to human. The virus can be transmitted from one person to another through sexual contact. Pregnant women who are infected can also pass the virus to the fetus.
When an infected mosquito bites a human, it transmits the virus via its saliva into the person’s bloodstream, where the virus then spreads. The infected person will then carry the virus in their blood for the next one to two weeks.
If this person is bitten by a further mosquito during this time, the virus will be transmitted to this mosquito, too, which can then pass it on to any further humans it bites. So the infection chain continues.
This is why it is so important to break this chain of infection and prevent the further spread of the virus – not least by continuing to protect yourself from mosquito bites after you return from your trip.
In a few rare cases, an infected mosquito may pass the virus on to its larvae. Such ‘vertical transmission’ is more common with dengue and Zika than with chikungunya.
The risk of infection in Switzerland
No case of local chikungunya, dengue or Zika infection in Switzerland has been reported to date. All the cases of such diseases which have been reported in Switzerland to date have been brought into the country following travel abroad. And although the Asian tiger mosquito is now well established in some parts of the country, the risk of local transmission of mosquito-borne diseases remains very low. In the parts of the country with no Asian tiger mosquitoes, there is no such risk at all.
Three types of invasive (i.e. non-endemic) mosquito have become established in Switzerland: the Asian tiger mosquito (Aedes albopictus), the Asian bush mosquito (Aedes japonicus) and the Korean bush mosquito (Aedes koreicus). The Confederation and the cantons are monitoring and combatting the spread of the Asian tiger mosquito: for further information on this (in German, French or Italian), visit the Federal Office for the Environment website. You can play your part in these endeavours, too, by reporting any sightings of any black-and-white-striped mosquitoes to the Swiss Mosquito Network.
Overview of the chikungunya, dengue and Zika mosquito-borne diseases
Chikungunya
- Symptoms: Fever, aching limbs, headache, joint pains, muscle pain, nausea, fatigue, skin rash.
- Incubation period: 4-8 days from bite
- Vaccination: Available, but not authorised in Switzerland.
- Treatment: No specific antiviral medicines are available. Symptomatic and supportive treatment: adequate fluid intake, analgesics and antipyretics (paracetamol).
Please note: Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen should not be taken to treat dengue, because they increase the risk of haemorrhaging. These drugs should also not be taken in cases of suspected Zika or chikungunya until dengue can be conclusively ruled out.
Dengue
- Symptoms: High fever, headache, aching limbs, nausea, skin rash. But around 50% of cases show no symptoms at all.
- Incubation period: 4-7 days from bite
- Vaccination: Available, but only recommended for persons who have already had a dengue infection more than six months ago.
- Persons who contract dengue a second time are at greater risk of developing a severe case of the disease.
Infection during pregnancy carries the risks of premature birth, low birth weight or foetal emergency.
- Treatment: No specific antiviral medicines are available. Symptomatic and supportive treatment: adequate fluid intake, analgesics and antipyretics (paracetamol).
Please note: Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen should not be taken to treat dengue, because they increase the risk of haemorrhaging. These drugs should also not be taken in cases of suspected Zika or chikungunya until dengue can be conclusively ruled out.
Zika
- Symptoms: Skin rash, fever, conjunctivitis, muscle and joint pains, headache. But some 80% of cases show no symptoms at all.
- Incubation period: 3-14 days from bite
- Vaccination: None available.
- Zika can also be transmitted through sexual contact.
Infection during pregnancy carries the risk to the foetus of severe neurological consequences. It can also lead to miscarriage or premature birth.
- Treatment: No specific antiviral medicines are available. Symptomatic and supportive treatment: adequate fluid intake, analgesics and antipyretics (paracetamol).
Please note: Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen should not be taken to treat dengue, because they increase the risk of haemorrhaging. These drugs should also not be taken in cases of suspected Zika or chikungunya until dengue can be conclusively ruled out.
Last modification 17.10.2024
Contact
Federal Office of Public Health FOPH
Prevention and Healthcare Provision Directorate
Communicable Diseases Division
Schwarzenburgstrasse 157
3003
Bern
Switzerland
Tel.
+41 58 463 87 06