Which ectoparasite serves as a vector for Bartonella quintana, the cause of trench fever?

Which ectoparasite serves as a vector for Bartonella quintana, the cause of trench fever?

• A. Fleas
• B. Ticks
• C. Lice
• D. Mites

Answer: (C)

Bartonella quintana causes trench fever and is transmitted to humans by the human body louse, Pediculus humanus corporis. The bacteria live in the louse and are passed to people when the louse feeds and its feces are rubbed into the skin, often through scratching. This mode of transmission fits the historical association of trench fever with crowded, unsanitary conditions where body lice proliferate. Fleas transmit other pathogens such as Yersinia pestis (plague) and certain Rickettsia, ticks transmit diseases like Rocky Mountain spotted fever and Lyme disease, and mites (chiggers) transmit Orientia tsutsugamushi (scrub typhus). None of those are Bartonella quintana, so the ectoparasite linked to trench fever is the body louse.

Bartonella quintana causes trench fever and is transmitted to humans by the human body louse, Pediculus humanus corporis. The bacteria live in the louse and are passed to people when the louse feeds and its feces are rubbed into the skin, often through scratching. This mode of transmission fits the historical association of trench fever with crowded, unsanitary conditions where body lice proliferate.

Fleas transmit other pathogens such as Yersinia pestis (plague) and certain Rickettsia, ticks transmit diseases like Rocky Mountain spotted fever and Lyme disease, and mites (chiggers) transmit Orientia tsutsugamushi (scrub typhus). None of those are Bartonella quintana, so the ectoparasite linked to trench fever is the body louse.