So far this season (2023), 6 cases of Murray Valley Encephalitis (MVE) have been recorded, two of which were fatal. The Kimberley region has been particularly affected. This has been the worst season for MVE since 2012. Other arboviruses are also transmitted in Western Australia: dengue virus, Ross River virus, Japanese encephalitis virus, Barmah Forest virus, Kunjin virus, etc.
Murray Valley encephalitis virus is transmitted by mosquitoes. The risk of contracting and becoming ill is low, but the illness caused by the virus can be severe and possibly fatal.
Initial symptoms include fever, drowsiness, headache, stiff neck, nausea and dizziness. People who experience these symptoms should seek medical attention as soon as possible.
In Queensland, the number of cases with Ross River Virus (RRV) infections is increasing, with over 150 people tested positive on the Sunshine Coast. Due to rainfall and the associated increase in the mosquito population, more people are expected to become ill in the coming weeks.
Ross River virus disease is the most common mosquito-borne infectious disease in Australia; it occurs throughout of the country but is found primarily in Queensland, Victoria, and Western Australia. Transmission occurs through Culex and Aedes mosquitoes. After an acute phase with fever, skin rash, and joint pain, RRV can sometimes cause long-lasting pain in various joints (polyarthritis).
Consequences for travelers
Optimal mosquito protection is recommended around the clock (24/7) (see factsheet mosquito and tick bite protection). There is neither a specific medication nor a vaccination.
References
All travellers should have completed a basic immunisation and boosters according to the Swiss vaccination schedule, LINK.
All travellers should have completed a basic immunisation and boosters according to the Swiss vaccination schedule, LINK.
Travellers should be immune to chickenpox. Persons between 13 months and 39 years of age who have not had chickenpox and who have not received 2 doses of chickenpox vaccine should receive a booster vaccination (2 doses with minimum interval of 4 weeks), see Swiss vaccination schedule, LINK.
For administrative reasons, there is the following entry regulation of the country:
Exempt from this entry requirement:
EKRM_Factsheet_Layperson_EN_Yellow-fever.pdf
EKRM_Factsheet_Layperson_EN_Mosquito-and-tick-bite-protection.pdf
For administrative reasons, there is the following entry regulation of the country:
Exempt from this entry requirement:
CDC Map: Yellow fever vaccine recommendations for the Americas
Footnotes
As against all mosquito-borne diseases, prevention from mosquito bites is during day and night (see “Insect and tick bite protection” factsheet). The available vaccine is highly efficacious and provides a long-term protection. It is recommended for people aged 9 months or older who are travelling to yellow fever endemic areas. In addition, providing proof of vaccination may be mandatory for entry into certain countries.
The vaccine is a live-attenuated form of the virus. In immunocompetent persons, protection starts about 10 days after the first vaccination. Reactions to yellow fever vaccine are generally mild and include headache, muscle aches, and low-grade fevers. Side effects can be treated with paracetamol but aspirin and other nonsteroidal anti-inflammatory drugs, for example ibuprofen or naproxen, should be avoided. On extremely rare occasions, people may develop severe, sometimes life-threatening reactions to the yellow fever vaccine – which is why this vaccine is used with caution in immunocompromised individuals, pregnant women and the elderly for safety reasons. Talk to your travel health advisor if you belong to this group.
EKRM_Factsheet_Layperson_EN_Japanese-Encephalitis.pdf
EKRM_Factsheet_Layperson_EN_Mosquito-and-tick-bite-protection.pdf
20231101_Factsheet_Layperson_EN_Dengue_CLEAN.pdf
EKRM_Factsheet_Layperson_EN_Mosquito-and-tick-bite-protection.pdf
CDC Map: Distribution of dengue
Dengue fever is the most common insect-borne infectious disease worldwide. There are 4 known serotypes of dengue virus, so it is possible to be infected with dengue more than once. Approximately 1 in 4 infected individuals develop symptoms of dengue, resulting in high fever, muscle and joint pain, and skin rash. In rare cases, most often after a second infection, life-threatening bleeding and shock (severe drop of blood pressure) may occur.
In 3 out of 4 cases, an infection with the virus remains asymptomatic. After a short incubation period (5-8 days), 1 out of 4 infected people present an abrupt onset of fever, headache, joint, limb and muscle pain, as well as nausea and vomiting. Eye movement pain is also typical. A rash usually appears on the 3rd or 4th day of illness. After 4 to 7 days, the fever finally subsides but fatigue may persist for several days or weeks.
In rare cases, severe dengue can occur. Particularly susceptible are local children and seniors as well as people who have experienced a prior dengue infection. Tourists extremely rarely present with severe dengue. In the first days, the disease resembles the course of classic dengue fever, but on the 4th/5th day, and usually after the fever has subsided, the condition worsens. Blood pressure drops, and patients complain of shortness of breath, abdominal discomfort, nosebleeds, and mild skin or mucosal hemorrhages. In the most severe cases, life-threatening shock may occur.
There is no specific treatment for dengue virus infection. Treatment is limited to mitigation and monitoring of symptoms: fever reduction, relief of eye, back, muscle and joint pain, and monitoring of blood clotting and blood volume. Patients with severe symptoms must be hospitalised.
For treatment of fever or pain, paracetamol or acetaminophen are recommended (e.g. Acetalgin® Dafalgan®). Drugs containing the active ingredient acetylsalicylic acid (e.g. Aspirin®, Alcacyl®, Aspégic®) must be avoided.
Effective mosquito protection during the day and especially during twilight hours (i.e. sunset) is the best preventive measure:
Note on dengue vaccines:
two vaccines against dengue are on the market: Qdenga®and Dengvaxia®. The Qdenga® vaccine was approved by the European Union in December 2022.
However, due to the data available, many European countries, as well as the Swiss Expert Committee for Travel Medicine (ECTM), currently recommend vaccination with Qdenga® only for certain travelers and in special situations. Consultation with a specialist in tropical and travel medicine is therefore recommended.
Of note:
Consistent mosquito protection during the day (see above) is still considered the most important preventive measure against dengue!
Wichtig: Eine STI kann auch ohne oder mit nur leichten Symptomen auftreten. Auch wenn Sie sich dessen nicht bewusst sind, können Sie andere anstecken. Deshalb ist es wichtig sich testen zu lassen.
Durch Bakterien oder Parasiten hervorgerufen
Alle diese Krankheiten können geheilt werden. Wichtig ist dabei, frühzeitig zu testen und umgehend zu therapieren, um Komplikationen und v.a. weitere Übertragungen zu vermeiden.
Durch Viren hervorgerufen
There is a risk of arthropod-borne diseases other than malaria, dengue, chikungunya or zika in sub-/tropical regions, and some areas of Southern Europe. These include the following diseases [and their vectors]:
EKRM_Factsheet_Layperson_EN_Mosquito-and-tick-bite-protection.pdf
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