There are significant knowledge gaps around Zika and a lack of historical data on its vectors, transmission dynamics, and geographical distribution, but despite these challenges, there is a need to describe the current status of local vectorborne transmission of Zika in a given place, in order to inform advice for travellers. On 10 March 2017, the WHO released a new Zika classification table that categorises countries according to the status of Zika virus transmission in that country. As of 29 September 2017, the Australian Government Department of Health no longer maintains a separate list of Zika affected countries. Advice to travellers is now based on the WHO Zika virus classification table.
In summary, the WHO categories are:
For more information about the categories, check the WHO website.
Evidence for categorisation may be reported by the country /territory/ area where infection occurred, or by another country following diagnosis of a returning traveller or by published scientific research.
In WHO Category 3 and 4 there is a possibility of Zika virus being present, along with other mosquito borne diseases. WHO Category 4 includes countries where there may be no evidence of Zika transmission because it has not been looked for. These countries may border countries considered WHO category 1 or 2 and this should be taken in to consideration when performing a risk assessment.
The mosquitoes that spread Zika virus usually do not live at elevations above 2,000 metres. The risk of mosquito borne transmission in such areas of high elevation within a country is minimal.
Countries in Category 2 may experience seasonal variations in transmission. These countries may experience outbreaks from time to time and may be moved to category 1.
| Category | Travel to a Zika affected country (WHO Category 1 and 2) | Travel to a country potentially affected by Zika (WHO Category 3 and 4) |
|---|---|---|
| * If prevention of sexual transmission is not important (partner not at risk of pregnancy, or does not reside in areas of Queensland with the vector) - based on the outcomes of a post-travel individual risk assessment, this measure may not be required. Some couples may choose to abstain for shorter or longer periods depending on this individual risk assessment and risk tolerance. ^Serological tests may be used to exclude infection in some circumstances | ||
| Pre - Travel advice for women who are pregnant or planning pregnancy | Consider deferring travel or defer pregnancy, based on individual risk assessment. | Advice based on Individual risk assessment. |
| All travellers | Individual Risk assessment |
Individual Risk assessment |
| Post exposure advice | Pregnant women should:
Women should avoid pregnancy while travelling and avoid pregnancy for at least 8 weeks after the last day of travel or for 8 weeks after diagnosis. Advice relating to a partner who has travelled also applies. Men with a pregnant partner should avoid unprotected sex for the duration of the pregnancy or for 6 months after the last day in a Zika affected country or 6 months after diagnosis, whichever is longer. Men with a partner who is planning pregnancy or at risk of pregnancy should avoid pregnancy for at least 6 months after the last day in Zika affected country or 6 months from time of diagnosis of infection. Anyone who is planning a pregnancy can be offered advice about the possibility of testing to help exclude Zika virus infection, including if there are concerns about the consequences of delaying pregnancy for the recommended time periods. To minimise the risk of sexual transmission for all other men and women: If a female partner has travelled or been potentially exposed, avoid unprotected sex for at least 8 weeks after the last day in a Zika affected country or for 8 weeks after diagnosis. If a male partner has travelled or been potentially exposed, avoid unprotected sex for at least 6 months after the last day in a Zika affected country if no symptoms appear, or 6 months from time of diagnosis of infection.* Travellers returning to areas of Queensland with suitable mosquitoes to transmit Zika should avoid mosquito bites for 4 weeks after return. |
Advice based on Individual Risk assessment. Elements from Zika affected country recommendations may apply.For further information, please refer to Zika Virus Factsheet - the Basics |
