Travellers heading to Bali are being advised to take enhanced precautions following a new US Centres for Disease Control and Prevention (CDC) Level 2 Travel Health Notice relating to Zika virus.
The notice, issued on 7 August 2026, follows reports of Zika in travellers returning from Bali, Indonesia. The CDC is advising all travellers to Bali to take steps to prevent mosquito bites and sexual transmission of Zika during and after their trip.
For most people, Zika infection causes either no symptoms or a relatively mild illness. Symptoms can include fever, rash, joint pain and conjunctivitis. However, Zika infection can have serious consequences during pregnancy, as the virus can pass from a pregnant woman to her foetus and cause birth defects.
How is Zika spread?
Zika is primarily spread by the bite of an infected Aedes mosquito. These mosquitoes can also transmit other infections, including dengue and chikungunya.
Unlike many other mosquito-borne infections, however, Zika can also be transmitted sexually. This means that precautions may need to continue after returning home, even if the traveller has experienced no symptoms.
The fact that many Zika infections are asymptomatic is particularly important. A person may have been infected without realising it and may still need to consider the potential implications of their infection after returning from a risk area.
What precautions should travellers take?
The CDC recommends that travellers to Bali take measures to prevent mosquito bites during their stay. These include using an effective insect repellent, wearing clothing that covers the arms and legs where practical, and taking steps to reduce mosquito exposure in accommodation.
Travellers should also be aware of the possibility of sexual transmission and follow appropriate precautions during and after travel.
For anyone who is travelling while pregnant, planning a pregnancy, or travelling with a partner who is pregnant or planning a pregnancy, Zika requires particular consideration. The CDC recommends discussing the potential risks with a healthcare professional before travelling.
What about travellers who have already returned?
This is where awareness of Zika becomes particularly important.
Because infection can be asymptomatic, simply feeling well after returning from Bali (or other regions where this disease is prevalent) does not necessarily establish that a person has not been infected. Anyone who develops symptoms following travel to an area where Zika is a risk should tell their healthcare provider about their travel history.
For people who are concerned about a possible previous exposure, appropriate medical advice and testing can help determine what steps may be necessary.
TMB’s Zika Exposure Screening
Tropical Medical Bureau has an ongoing Zika Exposure Screening service for travellers who may have been exposed to Zika during previous travel.
Screening can be particularly relevant for people who have travelled to areas where Zika transmission occurs and subsequently have concerns about a possible exposure, and particularly for those who are pregnant or considering pregnancy within a few months of their travel.
The current situation in Bali is a useful reminder that travel health does not necessarily end when you arrive home. Some infections require consideration after a trip has finished, particularly when the infection can occur without obvious symptoms.
If you have recently travelled to Bali or another destination where Zika is a concern and would like to discuss possible exposure, speak to a travel health professional about whether Zika screening is appropriate for you.
Travel advice can change as new information becomes available, so travellers should check the latest guidance before departure and seek individual medical advice where appropriate.