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. Currently, homeless people in the United States are sometimes diagnosed with this illness. The bacteria are sometimes passed through the bite of an infected tick.

The first clinical description occurred during World War I (WWI), but the condition has probably caused human infection for centuries. Trench fever was considered the most prevalent disease among Allied troops serving in the trenches during WWI. After WWI, trench fever became dormant, until it reemerged as an epidemic on the eastern European front during World War II. Since WWII, classic trench fever has almost disappeared as a clinical entity.

Trench Fever attacked all armies and until the final year of the war baffled doctors and researchers. Chief symptoms of the disease were headaches, skin rashes, inflamed eyes and leg pains.

Despite such wide-ranging symptoms the condition was not itself particularly serious, with patients recovering after some five or six days although prolonged hospitalisation amounting to several weeks was common.

Trench fever is a louse-borne disease. The lice do not become infectious at once after feeding on a trench-fever patient; there is a latent period of some 8-12 days before they are dangerous to other people. Thereafter the excreta of the lice, rather than their bites, are infective. If these infective excreta be rubbed into a scratch or scarification trench fever develops in about eight days. The importance of this discovery about the excreta lies in the fact that persons may contract the condition who have never had lice upon them. The excreta is a dry powder, easily blown about, and so apt to reach the clothes. It remains infective for long periods and even when exposed to sunlight. Water on the other hand seems to diminish its infectivity quickly.

The blood of trench-fever patients is infective to other patients when injected into their veins. Thus the parasite circulates in the blood. The parasite is also in the louse excreta.

Cause of trench fever:

The cause of trench fever is Bartonella quintana (also called Rochalimaea quintana), an unusual rickettsial organism that multiplies in the gut of the body louse. Transmission of the rickettsia to people can occur by rubbing infected louse feces into abraded (scuffed) skin or into the conjunctivae (whites of the eyes).

The vector for Trench Fever was, of course the body louse, pediculus corporis which became infected by feeding on the blood of infected soldiers; spread was by migration of the louse and infection of the new host by the insect bite or by scratching the skin which was contaminated by the louse excreta. The excreta remained infective for long periods, weeks or months.

The disease is classically a 5-day fever. The onset of symptoms is sudden with high fever, severe headache, back pain and leg pain and a fleeting rash.

Recovery takes a month or more. Relapses are common.