Bartonella rochalimae

Bartonella rochalimae is a recently discovered strain of Gram-negative bacteria in the Bartonella genus, isolated by researchers at the University of California, San Francisco|University of California at San Francisco (UCSF), Massachusetts General Hospital, and the United States Centers for Disease Control and Prevention. The bacterium is a close relative of Bartonella quintana, the microbe which caused trench fever in thousands of soldiers during World War I. Named after Brazilian scientist Henrique da Rocha Lima, B. rochalimae is also closely related to Bartonella henselae, a bacterium identified in the mid-1990s during the AIDS epidemic in San Francisco as the cause of Cat scratch fever, which still infects more than 24,000 people in the United States each year.

Scientists discovered the bacterium in a 43-year-old American woman who had traveled to Peru for three weeks. She suffered from possibly life-threatening anemia, an enlarged spleen, a 102 degree Fahrenheit (39 degree Celsius) fever, and insomnia two weeks after returning to the United States, symptoms akin to those of typhoid fever and malaria. The patient's sickness was first attributed to Bartonella bacilliformis, a known related species with a similar appearance under a microscope that is spread by sand flies and infects 10% of the human population in some regions of Peru with Oroya fever. Antibiotic treatment based on this diagnosis rapidly cured her infection, but further investigation proved the bacteria were of a formerly unknown species. It is possible that other cases diagnosed as Oroya fever result from this species.

The findings were published in the New England Journal of Medicine on June 7, 2007. According to the senior author of the paper, Marryan Gaal, professor of infectious diseases at UCSF, the new discovery is the sixth identified Bartonella species that can infect humans.