CNBC reports that stocks are down for numerous travel companies who operate heavily in the Caribbean and Latin America, where there’s a significant presence of the Zika virus.

Among the companies listed with decreased stock values are cruise lines Carnival Corporation, Royal Caribbean International, and Norwegian Cruise Line, as well as airlines American Airlines, United Airlines, JetBlue, and Southwest. Pregnant women bear the highest Zika risk, as the mosquito-borne virus may cause microcephaly or other birth defects. As a result, some companies fear that family-oriented travelers may cancel their summer vacation plans.

Americans’ fears revolve largely around international travel, though ten new cases of Zika were recently found stateside in Miami.

While brands like JetBlue and Hilton Worldwide have prepared publicly for Zika fallout, by relaxing some of their booking policies to affected destinations, many travel companies have expressed little to no anxiety about the virus.

The travel industry has always been directly affected by fears of communicable disease, for example the Ebola epidemic in West Africa that began in 2013 and significantly reduced travel not only to the region but to parts of Africa thousands of miles from infected areas.

Watch CNBC’s segment here.

Photo Credit: CNBC discusses Zika's negative effect on travel to the Caribbean and Latin America.