The 4 kidnapped Americans are part of a large wave of U.S. medical tourism in Mexico

A Red Cross worker closes the door of an ambulance carrying two Americans found alive after they were abducted in Matamoros, Mexico, last week. Two of four Americans have been found dead, after they were caught in a cartel shootout, officials said Tuesday. (AP)

The four Americans who were shot at and abducted in Mexico were reportedly visiting for medical tourism — making them part of a booming industry that is vital to Mexico's economy.

"Pre-pandemic, some 1.2 million American citizens traveled to Mexico for elective medical treatment," Josef Woodman, CEO of Patients Beyond Borders, told NPR. His firm publishes a guide to international medical travel.