Chapter 25 Sandy Bogucki This chapter reviews measures designed to minimize transmission of infectious diseases to EMS providers. EMS personnel and prehospital transport environments are specifically included as health care providers (HCP) and health care settings, respectively, in guidance published by the Centers for Disease Control and Prevention (CDC), the Health Care Infection Control Practices Advisor Committee (HICPAC), and the Occupational Safety and Health Administration (OSHA) [1]. The EMS medical director should be aware of state and federal regulations as well as current CDC guidelines and other standards for immunization of EMS personnel, circumstances requiring barrier precautions or notification of possible exposure, disinfection of equipment and apparatus, and both immediate management and medical follow-up of providers exposed to infectious pathogens in the course of their duties. An individual EMS provider service may be subject to enforcement of federal or state OSHA regulations, or may have adopted voluntary standards such as National Fire Protection Association (NFPA) occupational health and safety titles. These regulations and standards are generally derived from legislation, CDC guidelines, or other expert consensus processes, and should be considered minimal acceptable practices. Formal guidelines for reducing transmission of infectious diseases in hospital settings have been published since 1970, but the first to include prehospital providers in the definition of HCP were the “universal precautions” and “body fluid isolation” (BSI) documents, published in 1985 and 1987, respectively [2,3]. These were developed to address the risk of occupational exposure to hepatitis B and C, as well as the newly characterized human T-lymphocytotrophic virus-3 (HTLV-3), now known as human immunodeficiency virus (HIV). They defined which body fluids besides blood should be considered infectious (Box 25.1), prescribed the personal protective equipment (PPE) that should be worn by care providers exposed to potentially infectious material, and offered guidance on safer handling of needles and other sharps in clinical settings. Most importantly, these guidelines emphasized the potential prevalence of unrecognized infections with blood-borne pathogens in all patient populations. They mandated the use of appropriate PPE any time procedures involving blood or body fluids are performed, regardless of whether a patient is known to have hepatitis or HIV [2]. These CDC guidelines were updated in 1996, and expanded to include the broader isolation precautions aimed at preventing nosocomial infections in hospitals [4]. At that time, the concepts of universal precautions for procedures involving blood or body fluids [2], and BSI [3] that applies to all moist body substances except for sweat, including mucous membranes and non-intact skin, were synthesized to produce the “standard precautions” that are still used. The introduction of standard precautions for all patient care, alone, is not sufficient to prevent all HCP exposure to infectious agents or nosocomial transmission in health care settings. Full implementation of standard precautions did, however, allow HICPAC to reduce the number of existing sets of isolation precautions to just three types, and these were based on the modes of transmission of the various organisms: air-borne, droplet, and contact. Each of these sets of precautions reinforces the use of standard precautions and then goes on to enumerate additional measures [5]. Many pathogens are infectious through more than one route, so infected patients may require multiple sets of isolation precautions. The 1996 guidelines also emphasized hand hygiene as part of standard precautions. For the first time, hand washing was required after every patient encounter, in between procedures involving the same patient, and every time gloves and other PPE were doffed, regardless of known or suspected exposure to infectious pathogens. Other measures invoked as part of either standard or transmission-specific precautions addressed placement of patients within a facility, precautions that should be used when transporting potentially infectious patients through common areas, and the use of PPE including masks, eye protection, face shields, respiratory protection, gowns, and other protective clothing. These guidelines also defined circumstances that required special handling of patient care equipment or disposable supplies, processing of linens, and cleaning of patient care areas while a patient is there or prior to use for another patient. The current guidelines, published in 2007, largely retained the format of the1996 recommendations, with some important additions [1]. First, the target audience was expanded to include providers in all health care settings, acknowledging the wide variety of venues other than hospitals in which acute patient care now occurs. Standard precautions were updated to include respiratory hygiene (cough etiquette). The list of interventions comprising standard precautions and the corresponding HICPAC recommendations is shown in Table 25.1. Table 25.1 Recommendations for application of standard precautions for the care of all patients in all health care settings *During aerosol-generating procedures on patients with suspected or proven infections transmitted by respiratory aerosols (e.g. SARS), wear a fit-tested N95 or higher respirator in addition to gloves, gown, and face/eye protection. Precautions associated with infectious respiratory syndromes and direct patient contact were updated in the 2007 guidelines to reflect international experience with SARS-CoV and epidemic norovirus, and the increasing prevalence of multiply drug-resistant strains or species of staphylococcus, enterococcus, Clostridium difficile, and Mycobacterium tuberculosis. Transmission-based precautions that should be used when caring for patients with various clinical syndromes, even prior to identification of the infecting organisms, appear in Table 25.2. Table 25.2 Clinical syndromes or conditions warranting empiric transmission-based precautions in addition to standard precautions pending confirmation of diagnosis* *Infection control professionals should modify or adapt this table according to local conditions. To ensure that appropriate empiric precautions are implemented always, hospitals must have systems in place to evaluate patients routinely according to these criteria as part of their preadmission and admission care. †Patients with the syndromes or conditions listed below may present with atypical signs or symptoms (e.g. neonates and adults with pertussis may not have paroxysmal or severe cough). The clinician’s index of suspicion should be guided by the prevalence of specific conditions in the community, as well as clinical judgment. ‡The organisms listed under the column “Potential pathogens” are not intended to represent the complete, or even most likely, diagnoses, but rather possible etiologic agents that require additional precautions beyond standard precautions until they can be ruled out. §These pathogens include enterohemorrhagic Escherichia coli O157:H7, Shigella spp, hepatitis A virus, noroviruses, rotavirus, C. difficile. The other major addition to the 2007 guidelines from an EMS perspective was a brief presentation of the precautions that should be used for management of patients infected with CDC Category A bioterrorism threats. These select agents include anthrax, botulism, Ebola and other viral hemorrhagic fevers, plague, smallpox, and tularemia. Summaries of routes of transmission and infectivity together with the consensus recommendations for precautions are outlined in Table 25.3. Table 25.3 Infection control considerations for high-priority (CDC Category A) disease that may result from bioterrorist attacks or are considered to be bioterrorist agents (www.bt.cdc.gov)
Protection of EMS personnel from occupationally acquired infections
Introduction
Standards, laws, and regulations
CDC guidelines
Component
Recommendations
Hand hygiene
After touching blood, body fluids, secretions, excretions, contaminated items; immediately after removing gloves; between patient contacts
Personal protective equipment (PPE)
Gloves
For touching blood, body fluids, secretions, excretions, contaminated items; for touching mucous membranes and non-intact skin
Gown
During procedures and patient care activities when contact of clothing/exposed skin with blood/body fluids, secretions, and excretions is anticipated
Mask, eye protection (goggles), face shield*
During procedures and patient care activities likely to generate splashes or sprays of blood, body fluids, secretions, especially suctioning, endotracheal intubation
Soiled patient care equipment
Handle in a manner that prevents transfer of microorganisms to others and to the environment; wear gloves if visibly contaminated; perform hand hygiene
Environmental control
Develop procedures for routine care, cleaning, and disinfection of environmental surfaces, especially frequently touched surfaces in patient care areas
Textiles and laundry
Handle in a manner that prevents transfer of microorganisms to others and to the environment
Needles and other sharps
Do not recap, bend, break, or hand-manipulate used needles; if recapping is required, use a one-handed scoop technique only; use safety features when available; place used sharps in puncture-resistant container
Patient resuscitation
Use mouthpiece, resuscitation bag, other ventilation devices to prevent contact with mouth and oral secretions
Patient placement
Prioritize for single-patient room if patient is at increased risk of transmission, is likely to contaminate the environment, does not maintain appropriate hygiene, or is at increased risk of acquiring infection or developing adverse outcome following infection
Respiratory hygiene/cough etiquette (source containment of infectious respiratory secretions in symptomatic patients, beginning at initial point of encounter, e.g., triage and reception areas in emergency departments and physician offices)
Instruct symptomatic persons to cover mouth/nose when sneezing/coughing; use tissues and dispose in no-touch receptacle; observe hand hygiene after soiling of hands with respiratory secretions; wear surgical mask if tolerated or maintain spatial separation, >3 feet if possible
Clinical syndrome or condition†
Potential pathogens‡
Empiric precautions (always includes standard precautions)
Diarrhea
Acute diarrhea with a likely infectious cause in an incontinent or diapered patient
Enteric pathogens§
Contact precautions (pediatrics and adult)
Meningitis
Neisseria meningitidis
Enteroviruses
M. tuberculosis
Droplet precautions for first 24 h of antimicrobial therapy; mask and face protection for intubation
Contact precautions for infants and children
Air-borne precautions if pulmonary infiltrate
Air-borne precautions plus contact precautions if potentially infectious draining body fluid present
Rash or exanthems, generalized, etiology unknown
Petechial/ecchymotic with fever (general)
– If positive history of travel to an area with an ongoing outbreak of VHF in the 10 days before onset of fever
Neisseria meningitidis
Ebola, Lassa, Marburg viruses
Droplet precautions for first 24 h of antimicrobial therapy
Droplet precautions plus contact precautions, with face/eye protection, emphasizing safety sharps and barrier precautions when blood exposure likely. Use N95 or higher respiratory protection when aerosol-generating procedure performed
Vesicular
Varicella zoster, herpes simplex, variola (smallpox), vaccinia viruses
Vaccinia virus
Air-borne plus contact precautions
Contact precautions only if herpes simplex, localized zoster in an immunocompetent host or vaccinia viruses most likely
Maculopapular with cough, coryza and fever
Rubeola (measles) virus
Air-borne precautions
Respiratory infections
Cough/fever/upper lobe pulmonary infiltrate in an HIV-negative patient or a patient at low risk for HIV infection
M. tuberculosis, respiratory viruses, Strep. pneumoniae, Staph. aureus (MSSA or MRSA)
Air-borne precautions plus contact precautions
Cough/fever/pulmonary infiltrate in any lung location in an HIV-infected patient or a patient at high risk for HIV infection
M. tuberculosis, respiratory viruses, Strep. pneumoniae, Staph. aureus (MSSA or MRSA)
Air-borne precautions plus contact precautions
Use eye/face protection if aerosol-generating procedure performed or contact with respiratory secretions anticipated.
If tuberculosis is unlikely and there are no air-borne infection isolation rooms and/or respirators available, use droplet precautions instead of air-borne precautions
Tuberculosis more likely in HIV-infected individual than in HIV-negative individual
Cough/fever/pulmonary infiltrate in any lung location in a patient with a history of recent travel (10–21 days) to countries with active outbreaks of SARS, avian influenza
M. tuberculosis, severe acute respiratory syndrome virus (SARS- CoV), avian influenza
Airborne plus contact precautions plus eye protection
If SARS and tuberculosis unlikely, use droplet precautions instead of airborne precautions
Respiratory infections, particularly bronchiolitis and pneumonia, in infants and young children
Respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus, human metapneumovirus
Contact plus droplet precautions; droplet precautions may be discontinued when adenovirus and influenza have been ruled out
Skin or wound infection
Abscess or draining wound that cannot be covered
Staph. aureus (MSSA or MRSA), group A streptococcus
Contact precautions
Add droplet precautions for the first 24 h of appropriate antimicrobial therapy if invasive group A streptococcal disease is suspected
Disease
Anthrax
Site(s) of infection; transmission mode Cutaneous and inhalation disease have occurred in past bioterrorist incidents
Cutaneous: contact with spores
RT (inhalation of spores)
GIT (ingestion of spores – rare)
Comment: Spores can be inhaled into the lower respiratory tract. The infectious dose of B. anthracis in humans by any route is not precisely known. In primates, the LD50 (i.e. the dose required to kill 50% of animals) for an aerosol challenge with B. anthracis is estimated to be 8,000–50,000 spores; the infectious dose may be as low as 1–3 spores
Incubation period
Cutaneous: 1–12 days
RT: usually 1–7 days but up to 43 days reported
GIT: 15–72 hours
Clinical features
Cutaneous: painless, reddish papule, which develops a central vesicle or bulla in 1–2 days; over next 3–7 days lesion becomes pustular and then necrotic, with black eschar; extensive surrounding edema
RT: initial flu-like illness for 1–3 days with headache, fever, malaise, cough; by day 4 severe dyspnea and shock, and is usually fatal (85–90% if untreated; meningitis in 50% of RT cases)
GIT: if intestinal form, necrotic, ulcerated edematous lesions develop in intestines with fever, nausea and vomiting, progression to hematemesis and bloody diarrhea; 25–60% fatal
Diagnosis
Cutaneous: swabs of lesion (under eschar) for IHC, PCR, and culture; punch biopsy for IHC, PCR, and culture; vesicular fluid aspirate for Gram stain and culture; blood culture if systemic symptoms; acute and convalescent sera for ELISA serology
RT: CXR or CT demonstrating wide mediastinal widening and/or pleural effusion, hilar abnormalities; blood for culture and PCR; pleural effusion for culture, PCR, and IHC; CSF if meningeal signs present for IHC, PCR, and culture; acute and convalescent sera for ELISA serology; pleural and/or bronchial biopsies IHC
GIT: blood and ascites fluid, stool samples, rectal swabs, and swabs of oropharyngeal lesions if present for culture, PCR, and IHC
Infectivity
Cutaneous: person-to-person transmission from contact with lesion of untreated patient possible, but extremely rare
RT and GIT: person-to-person transmission does not occur
Aerosolized powder, environmental exposures: highly infectious if aerosolized
Recommended precautions
Cutaneous: standard precautions; contact precautions if uncontained copious drainage
RT and GIT: standard precautions.
Aerosolized powder, environmental exposures: respirator (N95 mask or PAPRs), protective clothing; decontamination of persons with powder on them (www.cdc.gov/mmwr/preview/mmwrhtml/mm5135a3.htm)
Hand hygiene: handwashing for 30–60 seconds with soap and water or 2% chlorhexidene gluconate after spore contact (alcohol handrubs inactive against spores [Weber DJ JAMA 2003;289:1274])
Postexposure prophylaxis following environmental exposure: 60 days of antimicrobials (either doxycycline, ciprofloxacin, or levofloxacin) and postexposure vaccine under IND
Disease
Botulism
Site(s) of infection; transmission mode
GIT: ingestion of toxin-containing food
RT: inhalation of toxin-containing aerosol
Comment: toxin ingested or potentially delivered by aerosol in bioterrorist incidents. LD50 for type A is 0.001 µg/mL/kg
Incubation period
1–5 days
Clinical features
Ptosis, generalized weakness, dizziness, dry mouth and throat, blurred vision, diplopia, dysarthria, dysphonia, and dysphagia followed by symmetrical descending paralysis and respiratory failure
Diagnosis
Clinical diagnosis; identification of toxin in stool, serology unless toxin-containing material available for toxin neutralization bioassays
Infectivity
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Protection of EMS personnel from occupationally acquired infections
Source: Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf
Source: Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf
Source: Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf
