The parasitic disease known as bilharzia was endemic in Puerto Rico during the DIVEDCO era, and it was typically carried by common freshwater snails like the one featured in the upper left-hand corner of Carlos Raquel Rivera’s promotional poster for the film Sucedió en Piedras Blancas. With a title that calls to mind a low-budget horror film, this 1957 production underscored in dramatic fashion the particular dangers of bilharzia for children, who were prone to catching the disease while swimming in infected bodies of water. In Rivera’s poster, three shirtless boys who are getting ready to take a dip in a local swimming hole look on as a government scientist from San Juan tests the infected water. The film, and the subsequently published companion booklet titled Bilharzia (on display), also discuss other common means of contracting the disease, typical symptoms, and effective methods of preventing its transmission.