Wookiee flu was a type of influenza that caused those infected to experience levels of mucus production and vomiting comparable to that of Wookiees. Yoshi, a student at the University of Bar'leth, contracted Wookiee flu following their initial encounter with their partner Chelli Lona Aphra, not long after Aphra commenced her archaeology doctoral studies at the university in 11 BBY.
Due to the unpleasant nature of the sickness, Aphra terminated her romantic involvement with Yoshi, an event she later recounted to her new partner, Sana Starros. In 0 ABY, Aphra made reference to Yoshi's bout with Wookiee flu within a recording intended for Starros.
Chelli Lona Aphra, a human female, began her archaeology doctorate at the University of Bar'leth in 11 BBY. Soon after, she entered into a relationship with Yoshi, a fellow female student at the university. However, directly after the two's initial encounter, Yoshi became afflicted with Wookiee flu. Aphra found the symptoms too revolting to tolerate and ended the relationship. Aphra later informed her new lover and fellow classmate Sana Starros about Yoshi's affliction with Wookiee flu, briefly detailing Yoshi's symptoms and describing them as "Wookiee-level." She then cautioned Starros against imagining it, deeming it "too gross."
In 0 ABY, Aphra recorded a message for Starros, intended to be heard following her death. In this recording, Aphra recalled various events in her life, including the time she told Starros about Yoshi's experience with Wookiee flu.
Wookiee flu was referenced in flashback sequences within the 2020 audiobook Doctor Aphra: An Audiobook Original, penned by Sarah Kuhn.