What is the specific agent responsible for Giardiasis?

Giardiasis is caused by a protozoan parasite known as Giardia lamblia. This microorganism inhabits the intestines of infected individuals and can be transmitted through contaminated water, food, or surfaces that have been contaminated with feces from an infected person or animal. Once ingested, Giardia lamblia can cause a range of gastrointestinal symptoms, such as diarrhea, abdominal cramps, and nausea.

Understanding the causative agent is crucial in managing and preventing the disease; specifically, identifying Giardia lamblia allows health officials to implement effective water treatment practices, educate the public about hygiene, and promote measures to prevent contamination. In contrast, the other options listed are bacterial pathogens responsible for different gastrointestinal illnesses, but they do not cause Giardiasis. Each of these bacteria is associated with distinct types of infections and would require different approaches for diagnosis, treatment, and prevention.