CDC issues a Level 2 travel alert for Bali

The United States CDC has issued a health alert for Zika viral disease to travellers planning a visit to Bali. Cases of the disease in returned travellers to Europe from Bali have likely changed the level of concern in the last 6 months.

It has been 10 years since a similar warning (Level 2 alert) was issued for travel to Brazil.

In January 2016, CDC advised women who were pregnant to postpone travel to Brazil. This came after WHO and the Pan American Health Organisation (PAHO) had been advised of an increase in the number of cases of microcephaly attributed to Zika virus disease.

WHO declared it a public health emergency in 2016.

What does this mean for Australian travellers in 2026?

How do we interpret this concern in 2026? Bali is a very popular destination for Australian travellers.

CDC defines a Level 2 Alert as "Practice Enhanced Precautions". The key points are covered in the CDC travel notice for Zika in Indonesia. The US Embassy in Jakarta has since issued its own health alert for Bali reinforcing the same advice.

Advice for pregnancy and babymoons

Travel risk is mostly focussed on whether the individual is pregnant, intending to be pregnant or having a partner who is pregnant. Those in these categories must decide on whether they still want to take the risk and travel.

Having a babymoon during early pregnancy may not be sensible in a Zika prone location like Bali, particularly given the recent cases. If you have been to Bali and are now considering pregnancy, wait at least 3 months after returning home before trying.

The World Health Organisation has also provided an excellent recent update on the epidemiology of Zika virus disease.

What is Zika Viral Disease?

Zika is a vector-borne disease. It is a viral disease transmitted from animals (ducks, goats, bats, horses, cows, water buffalo) and humans to humans. Only humans and non-human primates are known to be affected by the virus.

Contrary to common belief, it is not a new disease. Zika was first identified in the Zika Forest, Uganda in the 1940s. A very large outbreak of Zika disease in 2015 in Brazil raised international concerns.

More than 80 countries have now reported Zika infection. Sporadic outbreaks had been noted in Asia and the Pacific between 2008 and 2015.

How Zika spreads

The Zika virus is mostly transmitted by the bite of a female Aedes mosquito. This is the same species responsible for transmission of both dengue fever and Chikungunya. These mosquitoes mostly bite during the day but can also bite at night. Their habitat relates strongly to urbanisation with eggs being laid in small vessels containing water: bowls, buckets, dishes, and vases. Water in canoes and small ponds also provides good breeding sites. Breeding sites are found inside and outside dwellings.

While most infected people have few if any symptoms, there can be serious complications with infections prior to or during pregnancy. Zika can also be transmitted by sex from an infected partner. The partner may have been exposed overseas and be asymptomatic on return. Only 20% of infected people have any symptoms!

In a study of pregnant women with Zika infection, 5% resulted in birth defects. Approximately 1% of all Zika infections are likely to be sexually transmitted.

Vaccination and cases in Australia

There isn't a vaccine currently available.

The disease is notifiable in Australia. Very few cases are reported annually.