Which of the following diseases is caused by rickettsia bacteria?

Ehrlichiosis is the disease caused by rickettsia bacteria, specifically belonging to the genus Ehrlichia. These bacteria are typically transmitted through tick bites and can infect white blood cells, leading to a variety of symptoms such as fever, headache, fatigue, and more severe complications if left untreated. Effective identification and treatment of Ehrlichiosis are crucial, as it can resemble other conditions and may be mistaken for more common ailments.

The other diseases listed are caused by different pathogens. Leptospirosis is caused by Leptospira bacteria, Hantavirus Pulmonary Syndrome is caused by hantaviruses associated with rodent excretions, and Giardiasis is caused by the protozoan parasite Giardia lamblia. Understanding the specific causative agents of these diseases helps in the appropriate management and control of transmission risks.