What action is critical in the case of a person infected with smallpox arriving at an emergency department?

Isolating the person from all other patients is the critical action when a suspected case of smallpox arrives at an emergency department. Smallpox is a highly contagious infectious disease caused by the variola virus, and it poses significant risks to public health through airborne transmission and contact with contaminated materials.

By isolating the patient, healthcare providers can effectively prevent the spread of the virus to other individuals in the emergency department, including both patients and staff members. This isolation can be achieved by moving the patient to a designated area that is equipped to handle cases of highly infectious diseases, ensuring that strict infection control measures are in place.

While vaccination can be effective in certain contexts, it is not an immediate priority once a patient presents with symptoms, as the vaccine is most effective when given before exposure or shortly after exposure. Administering fluids is generally important in managing patient care but is not specific to the immediate infectious risk posed by smallpox. Wearing a mask can help reduce transmission for some respiratory diseases, but in the case of smallpox, the primary focus must remain on isolation to contain the outbreak and protect the broader community.