The World Health Organization (WHO) recently announced that clusters of microcephaly that are possibly linked to the Zika virus constitute a “public health emergency of international concern.” This virus has captured the attention of the international community because thousands of babies are being born with underdeveloped brains to women who were infected with Zika during their pregnancy.Should Canadians be worried? For now, WHO says no, because our country doesn't harbour the mosquito types that spread the disease, aedes aegypti and albopictus. But Canadians shouldn't be too complacent about the spread of the virus. Here's why.For starters, Canadians are not entirely off the hook within Canada. Mosquitoes carrying Zika could in the future spread here too. Aedes albopictus is an invasive species and increasingly warm climates could allow them to migrate farther north. Researchers are also investigating the possibility that a mosquito native to Canada, the Aedes culex which already transmits viruses of the same family as the Zika virus, could be a cause for concern.And then there's travel. The Canadian government has advised Canadians to “exercise a high degree of caution” in most South American travel destinations, and some travel doctors are advising pregnant women to avoid travel to affected countries altogether. Ontario's Chief Medical Officer, when confirming the province's first case of Zika recently, went so far as to advise all travelers heading to affected areas to first consult their healthcare providers. Without bringing the disease under control as swiftly as possible, this situation may endure for a long time.The truth is there is still much to learn about the Zika virus. While mosquitoes are thought to be the main vectors of Zika, there are also two known cases of sexual transmission, one in Senegal in 2008 and another in Dallas in 2016. In fact, the Zika virus can be present in the semen, blood and breast milk of infected individuals even after they return to health.As a member of the international community, the Canadian government's response to Zika will affect how quickly the virus is resolved globally, as well as how Canada is remembered in the aftermath of the outbreak.We should start by learning from mistakes made with Ebola. Canada illegally closed our borders to Ebola-affected countries even though there was no scientific justification for this action. This measure unlikely had any effect on the number of Ebola cases within Canada and it surely hindered Canadians' humanitarian efforts in the affected countries. This measure was criticized by the WHO, it undermined international laws that aim to prevent the spread of disease, and it tarnished Canada's international reputation as a global health leader.This time, with Zika, the Canadian government must react differently, and do so while upholding its international legal obligations.There are at least three ways Canada can help stem the spread of the Zika outbreak.First, one of the key barriers to thwarting Zika is the dearth of knowledge about it. Canada is uniquely positioned to contribute its excellent researchers and research facilities to these efforts, as exemplified by research we did for the Ebola vaccine. This research capacity can be put to good use in this crisis.Second, many countries currently affected by Zika are among the poorest in the world. These countries have extremely low surveillance, laboratory and epidemiological response capacities, while Canada has great strength in these fields. This expertise could be dispatched to help foreign governments better tackle the spread of the virus in their territory. This effort could be done in a way that strengthens these capacities for the long term.Third, Canada must support the only organization that has the authority and will to lead the fight against Zika – WHO. In the past our governments have advocated a policy of “zero nominal growth” to WHO's budget, which means no increases except for inflation. This has resulted in budget cuts to the organization's pandemic response capacity as the world has simultaneously requested greater WHO attention and resource-shifting to non-communicable diseases.Canada helped WHO get itself into its current mess; Canada can help WHO get itself out. Greater Canadian support will be a necessary part of the rehabilitation of the WHO, especially when it comes to fighting global pandemics which affect us all.Canada could and should play a leading role in the fight against Zika. We need to ensure our country remains an international leader in global health – lest the effects of Zika come back to bite us.Gaëlle Groux (@GaelleGroux) is a Post-Bachelor Fellow with the Global Strategy Lab at the University of Ottawa's Centre for Health Law, Policy & Ethics.Steven J. Hoffman (@shoffmania) is an Associate Professor of Law and Director of the Global Strategy Lab at the University of Ottawa's Centre for Health Law, Policy & Ethics and an Adjunct Associate Professor of Global Health & Population at Harvard University.