Rickettsioses (A75-A79)
ICD-10 codes A75 through A79 classify various rickettsial infections, which include several types of typhus, spotted fevers, ehrlichiosis, Q fever, and other less common rickettsioses. These codes help identify infections caused by bacteria from the Rickettsia genus and related organisms transmitted primarily by arthropods like ticks and lice.
This range covers typhus fevers such as epidemic louse-borne typhus (A75.0), murine typhus (A75.2), and scrub typhus (A75.3). It includes spotted fevers like Rocky Mountain spotted fever (A77.0), African tick bite fever (A77.1), and other tick-borne illnesses. Ehrlichiosis, a bacterial infection spread by ticks affecting white blood cells, is coded under A77.4 and its variations like ehrlichiosis chaffeensis (A77.41). The chapter also incorporates Q fever (A78), a disease caused by Coxiella burnetii, which can lead to pneumonia, hepatitis, and endocarditis.
Additionally, other rickettsial diseases such as trench fever (A79.0) and rickettsialpox (A79.1) are covered, along with specific infections like anaplasmosis (A79.82) and Sennetsu fever (A79.81). These codes are critical for accurately documenting infections caused by various rickettsiae, facilitating appropriate diagnosis and treatment. Common synonyms like Rocky Mountain spotted fever, Brill-Zinsser disease, and Q fever myocarditis align with specific codes, aiding coders interpreting clinical notes mentioning these alternate names.
Certain infectious and parasitic diseases (A00–B99)
Rickettsioses (A75-A79)
A77 Spotted fever [tick-borne rickettsioses]
- A77.0 Spotted fever due to Rickettsia rickettsii
- A77.1 Spotted fever due to Rickettsia conorii
- A77.2 Spotted fever due to Rickettsia siberica
- A77.3 Spotted fever due to Rickettsia australis
A77.4 Ehrlichiosis
- A77.40 Ehrlichiosis, unspecified
- A77.41 Ehrlichiosis chaffeensis [E. chaffeensis] UPDATED CODE
- A77.49 Other ehrlichiosis
- A77.8 Other spotted fevers
- A77.9 Spotted fever, unspecified
Spotted fever [tick-borne rickettsioses] (A77)
- A78 Q fever
Q fever (A78)
A79 Other rickettsioses
- A79.0 Trench fever
- A79.1 Rickettsialpox due to Rickettsia akari
A79.8 Other specified rickettsioses
- A79.81 Rickettsiosis due to Ehrlichia sennetsu
- A79.82 Anaplasmosis [A. phagocytophilum]
- A79.89 Other specified rickettsioses
- A79.9 Rickettsiosis, unspecified
Other rickettsioses (A79)