Emiliana Rodriguez remembers being a small child and witnessing friends play soccer at night when one of the players unexpectedly passed away on the field.

Rodriguez, a Bolivian native, was told that the “monster”—the silent killer known as Chagas—only appears at night, thus she became afraid of the dark after learning what had happened.

An uncommon kind of infection called Chagas disease is carried by nocturnal insects. The “silent and silenced disease” is another name for it; it can infect up to 8 million individuals a year, killing 12,000 of them on average.

When Emiliana Rodriguez, 42, moved to Barcelona from Bolivia 27 years ago, she found out she had to live with Chagas, a “monster.”

“The fear usually struck at night. She said, “I didn’t always sleep well. “I feared that I wouldn’t awaken from my slumber.”