In a very serious health crisis, under what specific legal power can public health officials make a sick person stay isolated from others against their will, even if they don't want to?

Public health officials can make a sick person stay isolated from others against their will under the specific legal power known as police power. In the United States, police power refers to the inherent authority of state governments to enact laws and regulations to protect the health, safety, morals, and general welfare of their citizens. This power is reserved to the states by the Tenth Amendment of the U.S. Constitution, which states that powers not delegated to the federal government, nor prohibited to the states, are reserved to the states respectively, or to the people. During a serious health crisis, states use their police power to implement public health measures such as isolation and quarantine to prevent the spread of communicable diseases. Isolation is the separation of sick people with a contagious disease from people who are not sick. Quarantine is the separation and restriction of movement of people who were exposed to a contagious disease to see if they become sick. States establish specific public health statutes and regulations, which delegate this authority to state and local public health departments. These statutes outline the conditions under which isolation or quarantine can be imposed. When exercising police power to compel isolation or quarantine, public health officials must adhere to constitutional due process requirements, primarily from the Fifth and Fourteenth Amendments. Due process ensures that the government respects an individual's legal rights and typically requires providing the individual with clear notice of the isolation or quarantine order, an opportunity for a hearing to challenge the necessity and duration of the measure before a neutral party (often a court or administrative body), and ensuring the action is based on clear scientific evidence that the individual poses a risk of transmitting a serious communicable disease. The measure must also be the least restrictive option necessary to protect public health and must only last as long as necessary. For example, if a person is diagnosed with an active, highly contagious infectious disease, such as certain forms of tuberculosis, and refuses to comply with medical advice to self-isolate, public health authorities, armed with state-specific statutes derived from police power, can legally compel that individual to remain in a specified isolation facility until they are no longer infectious, always under judicial or administrative oversight to ensure constitutional rights are protected.