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
EKRM_Factsheet_Layperson_IT_Japanese_Encephalitis.pdf
EKRM_Factsheet_Layperson_EN_Dengue.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:
For further information, please refer to the factsheet on "Mosquito and tick bite protection".
Note on the dengue vaccine Qdenga®:
Consistent mosquito protection during the day (see above) is still considered the most important preventive measure against dengue!
Of note
Mpox has been commonly found in West and Central Africa for many years where the suspected reservoir - small mammals - is endemic. There are two types of Monkeypox virus called ‘clades’ that cause the disease mpox - clade I in Central Africa and clade II in West Africa. Since the end of smallpox vaccination campaigns in the early 1980’s, cases of mpox have increased, slowly at first and significantly in the last 5-10 years, especially in the Democratic Republic of Congo (DRC).
In 2022, a new emerging subclade of clade II was responsible for a global epidemic that spread mainly through sexual contact among men who have sex with men. It resulted in the first public health emergency of international concern (PHEIC) declared by the WHO until 2023. Although the clade II epidemic is now under control, it continues to circulate worldwide.
In 2024, the continued spread of mpox clade I in endemic regions of Central Africa, particularly in the DRC, and the emergence of a new subclade Ib in Eastern DRC and neighboring countries have raised global concern and prompted the WHO to declare a PHEIC for the second time in two years. The current geographical spread of the mpox clade Ib variant occurs via commercial routes through sexual contact (e.g. sex workers), followed by local transmission in households and other settings (which is becoming increasingly important).
Animal to human transmission
Mpox can spread from animal to human when they come into direct contact with an infected animal (rodents or primates).
Human to human transmission
Mpox can be spread from person to person through close physical contact (sexual and non-sexual contact) with someone who has symptoms of mpox. Skin and mucous membrane lesions, body fluids, and scabs are particularly infectious. A person can also become infected by touching or handling clothing, bedding, towels, or objects such as eating utensils/dishes that have been contaminated by contact with a person with symptoms. Household members, family caretakers, and sexual partners of a confirmed case of mpox are at higher risk for infection as are health care workers who treat a case without adequate personal protection.
The incubation period (time between infection and onset of symptoms) ranges from a few days up to 3 weeks. Mpox causes a rash / skin eruption that can be painful associated with swollen lymph nodes and fever. Fever may start already before the rash phase. Other symptoms include muscle aches, back pain, and fatigue. The rash may be localized or generalized, with few or hundreds of skin lesions. It mainly affects the face, the trunk and the palms of hand and soles of the feet. It can also be present in genital areas and on mucous membranes such as in the mouth and throat. Symptoms usually last 2 to 4 weeks and the person remains contagious until all lesions have healed (once the cabs have fallen off).
Complications include secondary bacterial infections, infections of the lung and brain and involvement of other organs, still birth and others. Children, pregnant women, and people with weak immune systems are at higher risk to develop a severe form of mpox.
The majority of person with mpox recovers spontaneously and do not need specific antiviral treatment. Care management consists of relieving pain and other symptoms and preventing complications (e.g., superinfection). Several antiviral treatments are studied in various countries and may be used in trials or in clinical situations according to the recommendations of national medical societies.
In case of symptoms:
General precautions:
Vaccination:
There are several vaccines against mpox (e.g. Jynneos®, manufacture Bavarian Nordic). The Bavarian Nordic vaccine was originally developed to fight against smallpox, but offers a cross-protection against mpox. In Switzerland, the Jynneos® vaccine has been licensed by Swissmedic since 2024. Groups at risk (e.g., men who have sex with men or transgender people with multiple sex partners) are eligible for vaccination since 2022 and this recommendation remains unchanged (see FOPH recommendations). In light of the epidemiological situation in Africa in 2024, the Swiss Expert Committee for Travel Medicine recommends vaccination against mpox for professionals who are / will be in contact with suspect mpox patients or animals in endemic/epidemic regions or who work in a laboratory with the virus (for updates, see news).
The risk to the general population and travelers (tourists) is considered extremely low if the above-mentioned general precautions are followed and vaccination is not recommended.
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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