cough present)
a If an aerosol‐generating medical procedure is anticipated or the patient is known to have a communicable disease that is known to be spread by the airborne route, an N95 respirator is the preferred mask to be worn by personnel treating or in close proximity to the patient.
Table 23.2 Suggested Precautions Based on Suspected Infection
| Level 1a | Level 2b | Level 3c |
|---|---|---|
| Abscesses | Chicken pox | AIDSd |
| Diarrhea | Common cold | Clostridium difficile e |
| Hepatitis A | Croup | Hepatitis Bd |
| Hepatitis E | Diphtheria | Hepatitis Cd |
| Cytomegalovirus | Epiglotitis | Hepatitis Dd |
| Herpes simplex | German measles (rubella) | Coronavirusesf during known outbreaks or when virus known to be producing rapid person‐to‐person spread |
| Herpes zoster | Red measles | Influenza (if contact with respiratory secretions is likely) |
| Lice | Herpes zoster | Viral hemorrhagic feversg (Ebola, Marburg, Crimean‐Congo, Lassa) |
| Viral meningitis | Infectious mononucleosis | |
| Scabies | Meningitis, meningococcal | |
| Syphilis | Meningitis, Haemophilus influenza | |
| Mumps | ||
| Pharyngitis | ||
| Pneumonia | ||
| Streptococcus | ||
| Tuberculosis | ||
| Whooping cough |
a Gloves and handwashing.
b Level 1 plus mask (N95 if airborne or high‐risk pathogen) and full face shield.
c Level 2 plus disposable impermeable gown.
d Level 3 if exposure to blood or body fluid is anticipated; otherwise, Level 1 precautions are appropriate.
e Level 2 is adequate is there is no risk of soiling clothes or uniform. However, if the patient has any risk of soiling, Level 3 precautions are necessary.
f Although transmission of coronaviruses (SARS, MERS, COVID‐19) may be considered to be similar to other highly contagious viral agents listed requiring Level 2 precautions, these viruses require Level 3 precautions, particularly in outbreak situations. In addition, special precautions may be required when transporting patients with coronaviruses.
g Special precautions are required when transporting patients who are symptomatic with known of suspected viral hemorrhagic fevers.
Annual vaccination is the best way to prevent influenza, because vaccination can be given well before influenza virus exposures occur and can provide safe and effective immunity throughout the influenza season. Influenza vaccine is the principal means of preventing morbidity and mortality. The vaccine changes yearly based on the antigenic and genetic composition of circulating strains of influenza A and B found in January to March, when influenza reaches its peak activity. When the vaccine strain is similar to the circulating strain, influenza vaccine is effective in preventing illness among 70‐90% of those younger than 65 years who are vaccinated. Among those aged 65 years and older, the vaccine is 30‐40% effective in preventing illness, 50‐60% effective in preventing hospitalization, and up to 80% effective in preventing death. EMS personnel should be immunized annually, ideally as soon as the vaccine is available locally.
Six licensed prescription influenza antiviral drugs are approved by the U.S. Food and Drug Administration (FDA), four of which (oseltamivir, zanamivir, peramivir, and baloxavir marboxil) were recommended for the 2019‐2020 influenza season. When used for prevention of influenza, they can be 70‐90% effective. However, antiviral agents should be used as an adjunct to vaccination, and not replace it.
The Centers for Disease Control and Prevention (CDC) does not recommend widespread, routine, or pre‐exposure use of antiviral medications for chemoprophylaxis except under specific circumstances [3]. These include short‐term pre‐exposure chemoprophylaxis for unvaccinated health care personnel who are in close contact with persons at high risk of developing influenza complications during periods of influenza activity, when influenza vaccination is contraindicated or unavailable and these high‐risk persons are unable to take antiviral chemoprophylaxis. In addition, there is some weak evidence to suggest that antiviral post‐exposure chemoprophylaxis for unvaccinated EMS personnel can be used during periods of influenza activity when influenza vaccination is contraindicated or unavailable [5, 6]. If post‐exposure chemoprophylaxis is given, it should be administered as soon as possible after exposure, ideally no later than 48 hours. In the setting of an influenza outbreak, EMS systems may opt to restrict duties for EMS clinicians who are not immunized or who have not yet received prophylactic antiviral therapy, in attempts to prevent spread of influenza.
Avian Influenza
Wild birds carry a type of influenza A virus, called avian influenza virus, in their intestines, and usually do not get ill from it. However, avian influenza virus can make domesticated birds, including chickens, turkeys, and ducks, quite ill and can lead to death. Although avian influenza virus is chiefly found in birds, infection in humans from contact with infected poultry has been reported since 1996. A particular subtype of avian influenza A virus, H5N1, is highly contagious and deadly among birds. In 1997 in Hong Kong, an outbreak of avian influenza H5N1 occurred not only in poultry, but also in 18 humans, six of whom died. In subsequent infections of avian influenza H5N1 in humans, more than
