Bartonella rochalimae is a recently discovered strain of Gram-negative bacteria in the Bartonella genus, isolated by researchers at the 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.