Trench fever is a bacterial infection that causes repeated cycles of high fever. The term trench fever refers to the crowded conditions in which troops fought in during World War I and World War II. Because the causative bacteria are passed among humans through contact with body lice, overcrowding, and conditions which interfere with good hygiene (including regular washing of clothing) soldiers were predispose to this disease. B. quintana is common in homeless people; again, transmitted by body lice. About 5-15% of homeless populations (3.5 million people in the Australia) harbor chronic infection with B. quintana.
Erythromycin and azithromycin are both used to treat trench fever. Four weeks of treatment are usually necessary. Inadequate treatment often results in a relapse. Researchers at Great Ormond Street Hospital have in the past claimed tackling a Trench fever with medicine before it is allowed to run its course, may slow recovery time, because the temperature can help to kill the bacteria causing the illness.