The Department of Public Heath is one of the departments of the Maricopa County, Ariz. It provides various health services for the more than 3 million residents of Maricopa County by diagnosing and treating infectious diseases. The department offer programs to prevent the spread of disease and also provides health education. It public health clinical services include tests of sexually transmitted diseases and tuberculosis, and health care for the homeless individuals. The department provides disease control and prevention services, such counseling and testing, and community health nursing and immunizations. It additionally offers public health emergency management programs. The department is headquartered in Phoenix.