Prevention and Prophylaxis

Isolation

Preventing the transmission of infectious microorganisms from infected or colonized patients to other patients and health care workers must be a priority in the ED. The Centers for Disease Control and Prevention, post exposure prophylaxis and Hospital Control Practices Advisory Committee�s recommendations for isolation are reviewed below.

• Standard Precautions have replaced "universal precautions" and apply to all patients. Standard precautions stipulate that gloves should be worn when touching blood, bloody fluids, secretion (other than sweat), mucous membranes, or nonimpact skin. Hands should always be washed after touching a patient and after removing gloves. (Of note are observational studies demonstrating compliance with hand washing by health care workers to be < 50%.) Chorhexidine and isopropyl alcohol are superior to soap and water in removing transient flora from the hands. Chlorhexidine additionally provides a residual antibacterial effect. Gowns, face shields, and/or eye protection are recommended for procedures or activities that are likely to generate a splash of blood, bloody fluids, secretions, or excretions.

  

  Table: Isolation guidelines for selected conditions
  Standard Precautions	To be used for all patients
  Airborne Precautions	Tuberculosis - pulmonary, laryngeal (suspected or confirmed) Varicella/Zoster virus - chickenpox      Herpes zoster - disseminated      Herpes zoster - immunocompromised patient Rubeola (measles)
  Droplet Precautions	Adenovirus Epiglottitis (H. influenzae in children) Diphtheria Influenza Meningitis (suspected bacterial) Menigococcal disease Mumps Mycoplasma pneumoniae Parvovirus B 19 Pertussis Plague (pneumonic) Rubella Streptococcal (group A) pneumonia, pharyngitis, scarlet fever
  Contact Precautions	Abscesses Encephalitis Gatroenteritis (including C. difficile) Herpes simplex Impetigo Lice or scabies Multidrug resistant organism (including VRE) Respiratory syncytial virus Rubeola Varicella/Zoster virus - Herpes zoster - localized Wound infections
  Vancomycin resistant Enterococci

• Airborne precautions, in addition to standard precautions, are required for all patients known or suspected to be infected with a pathogen that is transmitted by the airborne route. Droplet nuclei (particles =5 �m) or dust particles containing the infectious agent are produced when an infected patient coughs, sneezes, or speaks. These particles may remain suspended in the air and travel long distances. Airborne precautions mandate a private room with negative pressure and a closed door. All visitors must wear an approved respirator mask (N95) that is fit tested. Transporting the patient out of a negative pressure room should be minimized and the patients must wear a standard surgical mask when outside of the room. Patients infected with the human immunodeficiency virus presenting with pneumonia, i.e., cough, fever, and pulmonary infiltrates on chest radiographs, should be placed in respiratory isolation until pulmonary tuberculosis can safely be excluded.
• Droplet precautions, in addition to standard precautions, are implemented for all patients known or suspected of having an infectious illness transmitted by droplets, i.e., large particles that do not remain suspended in the air. Droplets are produced when infected patients talk, cough, or sneeze. The droplets generally travel no farther than 3 feet. These patients require a separate room but do not require negative pressure or air filtering. A regular surgical mask should be worn by visitors or health care workers when they enter the patient�s room and by the patient when transported outside of the room.
• Contact precautions are required for patients known or suspected of being infected or colonized by organisms that are spread by direct contact, or by contact with contaminated surfaces. Patients requiring contact isolation also require standard precautions. These patients require a private room with strict disinfection of all equipment after use. Barrier precautions, such as gloves and gowns, are used to prevent contamination of exposed skin and clothing.