Zika virus is a mosquito-transmitted infection related to dengue, yellow fever and West Nile virus. Zika is not a new disease, as it was first discovered in the Zika forest in Uganda in 1947. It is common in Africa and Asia, though it did not begin spreading widely in the Western Hemisphere until May of 2015, when an outbreak occurred in Brazil.
How is the virus transmitted?
Zika is spread through the bite of infected mosquitos, specifically the Aedes aegypti and Aedes albopictus species. These mosquitos are not native to Canada and the risk of local transmission is considered to be low. However, Canada has had, and will likely continue to see, travel-related cases of Zika virus.
The Pan American Health Organization (PAHO) expects we will see local transmission in all of the Americas with the exception of Canada and Chile. On February 1, 2016, the World Health Organization (WHO) declared the outbreak of Zika virus in the Americas to be a public health emergency of international concern. WHO continues to work with the countries affected as well as with other international partners to help better understand the disease and its risks. Canada has reported many lab-confirmed cases of Zika virus, including those among pregnant women, which were acquired through travel to infected areas. For up-to-date case counts, visit the federal government’s Surveillance of Zika Virus page.
Symptoms of Zika virus infection can include fever, rash, joint pain, conjunctivitis, muscle pain and headache. The incubation period is unknown, but is likely to be a few days to a week after exposure.
Only about 20% of individuals infected with the Zika virus become ill. The illness is usually mild and lasts 3-7 days.
Why the virus is a public health concern
Zika infection while pregnant can cause development of microcephaly in the fetus. Microcephaly is a congenital condition associated with incomplete brain development. In September 2015, a sharp increase in the number of children born with microcephaly was noted in Brazil in the area affected by the outbreak. The Public Health Agency of Canada (PHAC) has developed travel recommendations for pregnant women, as well as for those who plan to become pregnant in the near future and their partners (see the PHAC links below for the most current information and guidance on this emerging situation).
Emerging evidence indicates that sexual transmission of Zika virus can occur and is of concern during pregnancy. The government also offers guidance for the prevention of sexual transmission.
There has also been concern raised about increased rates of Guillain-Barré syndrome and other neurological and autoimmune syndromes in areas where the Zika virus is circulating.
While there is limited evidence to indicate if Zika can be transmitted through blood products, Health Canada, Héma-Québec and Canadian Blood Services are working to review the evidence and develop strategies for protecting Canada’s blood supply.
What you can do
As a nurse, it is important that you be current with your knowledge of this disease so that you can
- offer prevention information for patients and families who may be travelling
- understand the risk of disease for travellers who have returned to Canada
- protect yourself, your families and your patients and clients
The following resources include more detailed and up-to-date information on Zika virus, including the number and location of confirmed cases and symptoms.
WHO also provides an up-to-date list of countries affected.
Government of Canada
Public Health Notice — Zika Virus (Public Health Agency of Canada [PHAC])
Zika virus infection in the Americas: Travel Health Notice (PHAC)
World Health Organization (WHO)
Zika virus (WHO fact sheet, January 2016)
Zika virus infection (Disease Outbreak News)
Zika virus disease, frequently asked questions about Zika virus (WHO Emergencies Preparedness, Response)
Prevention of potential sexual transmission of Zika virus, interim guidance (February 18, 2016)
Guillain-Barré syndrome – El Salvador (Disease Outbreak News, January 21, 2016)
Zika virus outbreaks in the Americas (WHO Weekly Epidemiological Record, November 6, 2015)
Pan American Health Organization (PAHO)
Zika Virus Infection
PAHO statement on Zika virus transmission and prevention (January 24, 2016)
As the Zika virus spreads, PAHO advises countries to monitor and report birth anomalies and other suspected complications of the virus (January 18, 2016)
Epidemiological Update: Neurological syndrome, congenital malformations, and Zika virus infection(January 17, 2016)
Zika virus infection and Zika fever: Frequently asked questions (January 6, 2016)
Question and Answers: Zika and pregnancy (January 5, 2016)
Neurological syndrome, congenital malformations, and Zika virus infection. Implications for public health in the Americas – Epidemiological Alert (December 1, 2015)
U.S. Centers for Disease Control (CDC)
Interim guidelines for the evaluation and testing of infants with possible congenital Zika virus infection — United States, 2016 (MMWR, January 26, 2016)
Interim guidelines for pregnant women during a Zika virus outbreak — United States, 2016 (MMWR, January 22, 2016)
Interim guidelines for prevention of sexual transmission of Zika virus — United States, 2016 (February 12, 2016)
Recognizing, managing, and reporting Zika virus infections in travelers returning from Central America, South America, the Caribbean, and Mexico (Health Advisory, January 15, 2016)
Zika virus disease Q & A
Possible association between Zika virus infection and microcephaly — Brazil, 2015 (MMWR, January 22, 2016)
Facts about microcephaly
Question and Answers: Zika virus infection (Zika) and pregnancy
Questions and answers for pediatric healthcare providers: Infants and Zika virus infection
Updated diagnostic testing for Zika, chikungunya, and dengue viruses in US Public Health Laboratories (memo, Jan 13, 2016)
Zika virus spreads to new areas — region of the Americas, May 2015-January 2016 (MMWR, Jan 22, 2016)
Travel Health Notices
Surveillance and control of Aedes aegypti and Aedes albopictus in the United States
Etymologia: Zika virus (June 2014)
Photo of Aedes aegypti mosquito courtesy of CDC/ Prof. Frank Hadley Collins, Dir., Cntr. for Global Health and Infectious Diseases, Univ. of Notre Dame.