An estimated 2 billion people in various parts of Asia and Africa could be at risk of Zika infection, according to a new study conducted by researchers in Canada and the United Kingdom.

Scientists from the University of Toronto, Oxford University and the London School of Hygiene and Tropical Medicine (LSHTM) examined data on travel, climate and mosquito patterns to find out where the Zika virus could strike next.

They found that as many as 2.6 billion people living in Asia and Africa are the most vulnerable to an outbreak of the infection, based on the number of individuals traveling from Zika-affected countries to these regions, the type of climate that they have and the presence of mosquitoes that can spread the disease.

Countries such as Bangladesh, Pakistan, Vietnam and the Philippines are the ones particularly at risk of widespread Zika transmission because of their limited resources to handle such a public health emergency.

Study co-author Dr. Kamran Khan from St. Michael's Hospital in Toronto explained that the impact of Zika on populations is also dependent on the ability of affected countries to effectively diagnose and respond to a potential outbreak.

He added that their findings could be used to help agencies make necessary public health decisions at local, national and international levels.

Zika Outbreaks

While the Zika virus was first identified in 1947, it wasn't considered a major public health threat until doctors detected a major outbreak of the infection in Brazil in 2015.

It was later discovered that the infection can cause severe developmental disorders in unborn children when their mothers contract the virus during pregnancy. One of the most well-known of these is microcephaly, a condition in which babies are born with unusually small heads.

So far, there are more than 65 countries and territories around the world with active Zika virus transmissions.

Khan and his colleagues, however, pointed out that there are still a number of unknown factors related to Zika and how it is spread from one area to another.

They want to find out more about the types of mosquitoes capable of transmitting the virus and whether certain populations developed some form of immunity to the infection following a previous Zika outbreak.

Experts on the disease said that the highest rates of Zika transmissions have been recorded during summer when a large number of people travel from the Americas to other parts of the world.

Zika-carrying mosquitoes are also known to survive for longer periods during summer because the warmer temperatures.

Oliver Brady, a researcher at LSHTM and one of the authors of the study, said Indonesia, India and Nigeria are just some of the countries that are most at risk of outbreaks because of the number of people arriving from Zika-affected territories.

He said that if the Zika virus were to arrive in these areas, it could deliver a severe blow to their public health systems.

The findings of the multi-organizational study are featured in the journal The Lancet Infectious Diseases.