(See also Overview of Bartonella Infections.)
Humans are the only reservoir of this Bartonella infection. B. quintana is transmitted to humans when feces from infected lice are rubbed into abraded skin or the conjunctiva.
Trench fever is endemic in Mexico, Tunisia, Eritrea, Poland, and the former Soviet Union and is reappearing in the homeless population in the US.
After a 14- to 30-day incubation period, onset of trench fever is sudden, with fever, weakness, dizziness, headache (with pain behind the eyes), conjunctival injection, and severe back and leg (shin) pains.
Fever may reach 40.5° C and persist for 5 to 6 days. In about half the cases, fever recurs 1 to 8 times at 5- to 6-day intervals.
A transient macular or papular rash and, occasionally, hepatomegaly and splenomegaly occur. Endocarditis may complicate some cases.
Relapses are common and have occurred up to 10 years after the initial attack.
Trench fever should be suspected in people living where louse infestation is heavy.
The organism is identified by blood culture, although growth may take 1 to 4 weeks. The disease is marked by persistent bacteremia during the initial attack, during relapses, throughout the asymptomatic periods between relapses, and in patients with endocarditis.
Serologic testing is available and can provide support for the diagnosis. High titers of IgG antibodies should trigger evaluation for endocarditis. PCR testing of blood or tissue samples can be done.
Although recovery is usually complete in 1 to 2 months and mortality is negligible, bacteremia may persist for months after clinical recovery, and prolonged (> 1 month) doxycycline or macrolide treatment may be needed. Patients are given doxycycline 100 mg orally 2 times a day for 4 to 6 weeks, plus, if endocarditis is suspected, gentamicin 3 mg/kg/day IV for the initial 2 weeks. Combination therapy is given for serious or complicated infections.
Body lice must be controlled.
Patients with chronic bacteremia should be monitored for signs of endocarditis.