The information on this webpage is provided for health professionals in north Queensland. Information is correct as at 13 December 2016. Information provided does not replace clinical judgement. Please contact your local public health unit for further information.

North Queensland is vulnerable to dengue and Zika outbreaks because Aedes aegypti mosquitoes, which transmit dengue and Zika, are common in north Queensland towns.

There have been 38 cases of Zika imported into Queensland, with no local transmission recorded to date.

Zika transmission

Zika virus is primarily spread through the bite of an infected Aedes aegypti mosquito, as with dengue. Zika virus can also be transmitted in-utero and perinatally. Sexual transmission of Zika virus also occurs, and has been reported from male to female, male to male and (rarely) female to male. RNA of Zika virus has been detected in semen 188 days after symptom onset and from vaginal swabs for up to 11 days after symptoms develop.

Clinical effects

Most people (up to 80%) with Zika virus will have no symptoms. If symptoms do occur, they are usually mild and include rash, fever, arthralgia, myalgia and non-purulent conjunctivitis. Symptoms last 5-7 days. In adults, Zika can cause Guillain-Barré syndrome, as can other flaviviruses.

Zika virus causes a range of birth defects including microcephaly, fetal death and placental insufficiency. These may occur in up to 29% of symptomatic women and can occur at any gestation. Birth defects have also been recorded in asymptomatic cases.

Treatment

There is no treatment for Zika virus. Advise patients to avoid aspirin and NSAIDs and to use paracetamol for symptom relief. If your patient is diagnosed with Zika virus, they should spray their home with long-acting surface spray and use insect repellent to prevent transmission to mosquitoes.

Notification

Please remember if you suspect Dengue or Zika virus clinically, you must notify without waiting for test results. Please notify suspected cases of dengue or Zika immediately to your local public health unit (TPHS, Cairns on 4226 5555 or Townsville PHU on 4433 6900).

Testing for Zika

The incubation period for Zika virus is 3 to 12 days. The viraemia is usually less than one week (although may be prolonged in pregnant women). Zika virus can be detected in urine by PCR for longer than in serum. Before testing for Zika, take a travel and sexual history. Test for the virus by PCR blood and urine early in the illness. It is far more reliable than antibody tests, which can cross-react with previous flavivirus exposure (eg. dengue) or vaccination (Japanese encephalitis or Yellow fever).

TestSymptomaticNo Symptoms
Zika PCR serumFirst 7 days of illnessUp to 19 days following travel exposure
Zika PCR urineFirst 14 days of illnessUp to 26 days following travel exposure
Zika serologyFrom day 4 of illness onwardsFrom day 9 of travel exposure onwards
Prevention

The area where known Zika virus transmission has occurred is rapidly expanding. See the Australian Government Department of Health website www.health.gov.au/zika for the most up-to-date information. Current areas of concern include Singapore, southeast Asia and the Pacific Islands. Any country with dengue transmission also has the potential for Zika transmission. Pregnant women should delay travelling to a country that has Zika transmission. Females who have travelled to a Zika virus affected country should abstain from intercourse or use condoms and delay plans for pregnancy for 8 weeks after they return. Men who have travelled should abstain or use condoms for 6 months after their return.

To prevent mosquito-borne transmission, residents in north Queensland should use long-acting crawling-insect surface spray every month in and around the home, especially in dark hiding places. It is also important to prevent breeding by tipping out anything holding water in and around the home. Please see the Queensland Health Zika website www.health.qld.gov.au/zika for more information including a video on how to spray your home.

The Eliminate Dengue releases in Cairns and Townsville will help control the spread of Zika as Wolbachia carrying Aedes aegypti mosquitos have been shown to block flaviviruses in the mosquito.

Public Health unit contacts

TPHS, Cairns Office Phone Fax
Level 7, 5b Sheridan St, Cairns 4870 (07) 4226 5555 (07) 4226 3095
Townsville PHU Office Phone Fax
242 Walker St, Townsville 4810 (07) 4433 6900 (Townsville), (07) 4744 9100 (Mt Isa) (07) 4433 6956

Resources

For patients

You can find out more information and download patient resources including a general Zika brochure, Zika and pregnancy brochure, posters, and a video on how to spray your home via the Queensland Government Zika Health Advice here.

View or download the Fact Sheet Zika June 2017 here.

View or download the TPHS News Issue 7 – June 2017 here.

How to do DIY residual insect spray in the home