Louse-borne (epidemic) typhus

This code represents louse-borne epidemic typhus, a severe infectious disease caused by the bacterium Rickettsia prowazekii. It is characterized by high fever, headache, rash, and often neurological symptoms, transmitted to humans through the bite of infected body lice. The disease can be fatal if untreated.

Use this code when documentation clearly indicates a diagnosis of louse-borne (epidemic) typhus. This typically occurs in settings with poor sanitation and overcrowding, often following natural disasters or during wartime. Physician documentation of a confirmed diagnosis, including laboratory findings if available, supports its use.

• Differentiate from other forms of typhus (e.g., murine typhus, scrub typhus) which have distinct ICD-9-CM codes.
• Ensure the documentation specifies "louse-borne" or "epidemic" to accurately assign this code.
• Code any associated complications, such as pneumonia or neurological sequelae, in addition to the primary diagnosis.