Possible Clues:

• Rubella
• Disease and its cause, an ego like the French
• Rubella, by another name
• Illness caused by bug — one given various names by the French
• Bug set off a nameless illness
• A nameless germ spreading disease
• Virus leads to a development of lameness producing complaint
• Virus leads to a developing lameness, producing complaint
• Disease from microbe, a nameless disorder
• Viral illness associated with a rash