Some big names in Corporate America could get hurt by the Zika virus.

The World Health Organization declared Monday that Zika is a "public health emergency of international concern." And last week WHO's director-general, Margaret Chan, said the virus is "spreading explosively" through Latin America. The mosquito-borne virus is linked to a condition that causes newborn babies to have abnormally small heads.

Several airlines are already offering refunds to pregnant passengers who have booked flights to countries in central and south America caught up in outbreak.

The airline industry is the first casualty, but it isn't the only business that's threatened by the spread of the virus. Citigroup runs a network of bank branches in the region and both Coke and Pepsi have a huge presence there.

Zika virus: Airlines are refunding tickets to Latin America

Jetblue (JBLU)gets about 30% of its total revenue from Latin America since Mexico is its second biggest market, according to FactSet data. Brazil is Citigroup (C)'s second biggest market after the U.S., and the bank relies on the region for 25% of its sales.

American Airlines (AAL), Coca-Cola (KO) and Pepsi (PEP) each earn about 10% of their total revenue from Latin America.

Some other companies are even more exposed. Electric company AES (AES), based in Virginia, gets 66% of its earnings from the region. Railway company Kansas City Southern (KSU) earns nearly half its revenue from Mexico, while toothpaste giant Colgate-Palmolive (CL) relies on the region for nearly 30% of its sales.

So far, the stocks of these companies aren't taking a hit. But health risks are scary, and the big warnings are just the type of thing that might keep more people indoors.

"Maybe you won't go to an open soccer stadium, maybe you won't go to a public park on Sunday," said Alberto Ramos, co-head of Latin America research at Goldman Sachs. "If you're not able to contain it...the impact on activity could be a lot more significant."

These fear-induced changes to daily life spells trouble for many of these American companies and could hurt their results.

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Even though several companies stand to lose a lot, Latin America isn't a game changer for all of corporate America. The region only contributes 4% of total revenue by S&P 500 companies, according to FactSet.

American Airlines spoke about Zika on its earnings conference call last week. Executives said they haven't noticed an impact on travel yet but noted that it's still too early to know if the virus will affect earnings.

If Zika does impact these companies, we'll find out when the companies report their first quarter results in the spring.