Above: Image © AlexLMX, iStockphoto.com

Why have Colombia, Ecuador, El Salvador and Jamaica all advised women to avoid getting pregnant at this time? Because of the surge in the number of babies in Brazil born with microcephaly, a condition that causes abnormal smallness of the head.

Zika virus is a suspected cause of this recent increase. Microcephaly is rare. Babies who have it are usually born with it. However, it can also occur after birth because of brain injury or infection. Researchers have found a link between mothers infected with Zika virus during pregnancy and cases of microcephaly in their babies.

World map of the Zika virus
Map showing Uganda, where Zika virus was first discovered (in red), and the countries in the Western Hemisphere where it has spread since 2014 (in purple).

Zika virus only recently began making headlines. However, Zika infections are not new. The virus was first discovered in infected monkeys from Uganda’s Zika Forest in 1947. Soon afterwards, in 1954, cases of Zika infection were reported in humans.

At first, reports of Zika outbreaks came only from equatorial Africa and Asia. Then, in 2007, the first case of Zika infection was diagnosed in the South Pacific. In 2014, a Zika case was reported on Chile’s Easter Island. This was the first reported case in the Western Hemisphere. Since then, the virus has spread to at least twenty countries in the Americas. Right now, there are also outbreaks in Samoa (in the South Pacific) and Cape Verde (off the west coast of Africa).

Zika virus is known as a flavivirus. It is similar to the viruses that cause other infections such as dengue, yellow fever, and West Nile virus. Most people who get Zika virus get it from the bite of an infected Aedes mosquito. Researchers are also exploring whether the virus can be transmitted through sexual contact.

Only 20-25% of people infected with the Zika virus show any symptoms. These symptoms include mild fever, skin rash and pink eye. These symptoms typically last between 2-7 days. However, in more recent outbreaks, Zika virus has been linked to infant microcephaly. It also might cause a rare nervous system disorder called Guillain-Barré syndrome.

As Zika virus spreads, some countries--including Canada and the United States--have issued travel advisories for places with Zika virus outbreaks. These advisories urge pregnant women not to visit these places.


CurioCity articles related to viruses:

Outbreak: The Ebola virus (2014)
K. Resmer, CurioCity

What causes a common cold? (2012)
C. Webb, CurioCity

Giant viruses (2014)
G. Rajan, CurioCity

Bacteriophages and the mystery of the ganges (2013)
G. Rajan, CurioCity

CurioCity videos related to the Zika virus:

Media reports:

Government/NGO/Hospital reports:

Zika virus infection in the Americas (2016)
Public Health Agency of Canada

Zika virus infection (2016)
Panamerican Health Organization

Zika virus (2016)
World Health Organization

Zika virus infection (2016)
European Centre for Disease Prevention and Control

Zika virus (2016)
Centres for Disease Control and Prevention

Explainer: The Zika virus in latin America (2016)
R. Glickhouse, Americas Society/ Council of the Americas

Microcephaly symptoms and causes (2016)
Boston’s Children’s Hospital

World Health Organization

Yellow Fever
World Health Organization

West Nile virus (2015)
Government of Canada

West Nile virus (2015)
Centre for Disease Control and Prevention

Scientific articles:

Zika Virus (I). Isolations and serological specificity (1952)
G.W.A. Dick, S.F. Kitchen, A.J. Haddow, Transactions of the Royal Society of Tropical Disease and Hygiene, 46

Zika virus in the Americas — yet another arbovirus threat (2016)
A.S. Fauci, D.M. Morens, The New England Journal of Medicine

Zika virus outbreak, Bahia, Brazil (2015)
G. S. Campos, A. C. Bandeira, S. I. Sardi, Emerging Infectious Diseases, 21

Probable non–vector-borne transmission of Zika virus, Colorado, USA (2011)
B. D. Foy, K. C. Kobylinski, J. L. Chilson Foy, B. J. Blitvich, A. Travassos da Rosa, A. D. Haddow, R. S. Lanciotti, R. B. Tesh, Emerging Infectious Diseases, 17

Potential sexual transmission of Zika virus (2015)
D. Musso, C. Roche, E. Robin, T. Nhan, A. Teissier, V.-M. Cao-Lormeau, Emerging Infectious Diseases, 21

Heather Auld


My name is Heather, and I am a PhD student in the Biology Department at Carleton University in Ottawa, Canada where I study how an individual's environment influences their behaviour. Most of my research is done in Trinidad, The West Indies, but I love to travel to all different kinds of ecosystems.

I also work on CurioCity as a Science Editor and to help bring you the most interesting stories and breakthroughs happening in science! I volunteer with Let's Talk Science as an outreach volunteer in Ottawa and rural Ontario. 

I love to observe and photograph the amazing animals and landscapes from around the world. 

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