Skip to content

Communicable Diseases

Category: Medical Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf; UCLA EMT Ultimate Study Guide (2026) Last updated: 2026-05-06

Overview

Communicable (infectious) diseases are caused by pathogens — bacteria, viruses, fungi, or parasites — that can be transmitted from one person to another. EMT-B providers face occupational exposure risk on every call. Understanding transmission routes, appropriate PPE, and post-exposure protocols is essential for provider safety and patient protection. Certain diseases are legally reportable to public health authorities.

Key Points

  • Standard Precautions: treat all blood and body fluids as potentially infectious — every patient, every call
  • Transmission routes determine PPE selection: contact, droplet, and airborne require different protection
  • BSI (Body Substance Isolation) is the EMT-B framework: gloves minimum; add mask/eye protection when splash/spray risk exists
  • Post-exposure protocol: report all exposures immediately — timing matters for prophylaxis
  • Reportable diseases: EMT-B has an obligation to report certain exposures/diagnoses to the receiving facility and agency infection control officer; the facility reports to public health authorities
  • Tuberculosis is the highest-occupational-risk airborne pathogen in EMS — N95 respirator required, not a standard surgical mask

Transmission Routes — Core Concepts

Route Mechanism Distance Examples
Contact (Direct) Touching infected person or their fluids Touch HIV (blood), MRSA, skin infections
Contact (Indirect) Touching contaminated surfaces/objects Touch MRSA, C. diff, norovirus
Droplet Large respiratory droplets (>5 µm) <3–6 feet Influenza, meningitis, COVID-19 (primary), pertussis
Airborne Small particles (<5 µm) that remain suspended >6 feet / room TB, measles, varicella (chickenpox)
Vector-borne Mosquito, tick, flea Indirect Malaria, Lyme disease
Fecal-oral Ingestion of contaminated material Indirect Hepatitis A, norovirus

KEY DIFFERENTIATOR — Droplet vs. Airborne: Droplet particles are large and fall quickly — a surgical mask blocks them. Airborne particles are tiny and stay suspended in air — only an N95 (or higher) respirator provides protection. Influenza = droplet. TB = airborne. This distinction is the #1 NREMT-tested PPE question.

High-Yield Pathogen Grid

Disease Cause Transmission EMT PPE Key EMT Facts
Influenza Influenza virus Droplet Surgical mask, gloves, eye protection Seasonal; vaccine recommended annually for providers; Tamiflu within 48 hrs
Tuberculosis (TB) Mycobacterium tuberculosis Airborne N95 respirator, gloves, gown Latent vs. active; cough + night sweats + weight loss; place surgical mask on patient
HIV/AIDS Human Immunodeficiency Virus Blood/body fluids (contact) Gloves; face shield if splash risk Not transmitted by casual contact; needlestick risk ~0.3%; post-exposure prophylaxis (PEP) within 72 hrs
Hepatitis B HBV Blood/body fluids (contact) Gloves; face shield Most preventable by vaccine — all EMS providers should be vaccinated; 100× more infectious than HIV via needlestick
Hepatitis C HCV Blood (contact) Gloves; face shield No vaccine; needlestick risk ~1.8%; treatment available (>90% cure rate)
Meningitis (bacterial) N. meningitidis, H. influenzae Droplet Surgical mask, gloves Rash + fever + stiff neck = meningitis triad; place surgical mask on patient
MRSA Methicillin-resistant S. aureus Contact (skin, wounds) Gloves, gown if wound contact Decontaminate equipment thoroughly; common in patients from hospitals/nursing homes
COVID-19 SARS-CoV-2 Droplet (primarily); airborne in aerosol-generating procedures Surgical mask (standard); N95 for intubation/BVM/nebulizers Aerosol-generating procedures (AGPs) require N95 + eye protection
Ebola Ebola virus Direct contact (blood/fluids of symptomatic patient) Full PPE: N95, gown, gloves, face shield Extremely rare in US; travel history is the key clue; contact your agency/Medical Control immediately
Pertussis (Whooping Cough) Bordetella pertussis Droplet Surgical mask, gloves Characteristic "whoop" on inspiration; highly contagious; Tdap vaccine recommended for EMS
Hepatitis A HAV Fecal-oral Gloves, hand hygiene Vaccine-preventable; common in unsanitary conditions; no chronic form

PPE Selection by Risk Level

Scenario Minimum PPE
All patient contact Gloves
Splash/spray risk (blood, vomiting, suctioning) Gloves + eye protection (goggles or face shield)
Respiratory illness (cough, known droplet disease) Gloves + surgical mask + eye protection
Known or suspected TB / measles / varicella Gloves + N95 respirator + eye protection
Aerosol-generating procedures (BVM, intubation, nebulizer) Gloves + N95 + eye protection + gown
Suspected Ebola or hemorrhagic fever Full barrier PPE: N95, gown, gloves (double), face shield — contact Medical Control

KEY DIFFERENTIATOR — N95 vs. Surgical Mask: A surgical mask protects against droplets — it blocks large particles. An N95 respirator filters 95% of airborne particles — it creates a tight facial seal. Only N95 protects against TB. Putting a surgical mask on the patient (to reduce their droplet output) is also appropriate for droplet-spread diseases.

NREMT RULE — Mask on the Patient: For suspected meningitis, influenza, or other droplet-spread diseases, place a surgical mask on the patient as well as wearing one yourself. This is a common NREMT question about infection control.

Tuberculosis — Special Emphasis

TB is the highest-priority communicable disease for EMS because: - It is airborne — the hardest route to protect against - Latent TB (infected but not yet contagious) is widespread; active TB (symptomatic, contagious) is what EMS encounters - Exposure without proper PPE = mandatory post-exposure evaluation

Recognition: Chronic productive cough (>3 weeks), blood-tinged sputum, fever, night sweats, unexplained weight loss; history of immigration from high-prevalence country, incarceration, or homelessness

EMT-B actions: 1. N95 respirator on before entering the patient's space 2. Surgical mask on the patient 3. Maximize ventilation — open windows if possible; do NOT recirculate ambulance air 4. Notify receiving facility in advance (infection control alert) 5. Report exposure to agency infection control officer

HIV/Bloodborne Pathogens — Post-Exposure Protocol

Needlestick or splash exposure: 1. Immediately wash with soap and water (skin) or flush with water (eyes/mucous membranes) — minimum 15 minutes 2. Report to supervisor and infection control officer immediately 3. Seek medical evaluation — Post-Exposure Prophylaxis (PEP) must be started within 72 hours (sooner = better) 4. Complete incident report / exposure documentation 5. Follow-up testing per agency protocol

KEY DIFFERENTIATOR — HBV vs. HIV needlestick risk: Hepatitis B is 100× more infectious than HIV via needlestick (~6–30% vs ~0.3% per exposure). HBV vaccine is highly effective — all EMS providers should be vaccinated. HIV has PEP; HBV has PEP + HBIG if unvaccinated.

Reportable Diseases

Certain diseases must be reported to public health authorities. In practice, EMS reports to the receiving facility's infection control team; the hospital reports to county/state public health.

Examples of reportable diseases relevant to EMS: - Tuberculosis (active) - Meningitis (bacterial — especially N. meningitidis) - Pertussis - Hepatitis A, B, C (new diagnoses) - Ebola and other hemorrhagic fevers - Rabies exposure - COVID-19 (pandemic-designation dependent)

EMT-B obligation: document suspected communicable disease exposure in the PCR and notify the receiving facility. The facility and public health authorities handle formal reporting.

NREMT Relevance

  • Influenza = droplet = surgical mask. TB = airborne = N95. This is tested.
  • Standard precautions = treat ALL patients as potentially infectious — not just those who look sick
  • Hepatitis B = most infectious bloodborne pathogen via needlestick; vaccine-preventable
  • Post-exposure: wash immediately, report immediately, PEP within 72 hours for HIV
  • Place surgical mask on patient with suspected respiratory infection
  • Ebola: full PPE + contact Medical Control immediately; do not transport without guidance

Sources

  • raw/protocols/nm-sop-guidelines-treatment-2022.pdf — Infection Control / Communicable Disease protocols
  • UCLA EMT Ultimate Study Guide (2026) — Ch 21: Communicable Diseases