Infectious Disease Basics Practice Questions

42 multiple-choice questions on Infectious disease basics for paramedic and EMT students, from Chapter 2 (Workforce Safety and Wellness). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

42 practice questions

1. A pathogen is:

   1. A. An organism that causes disease
   2. B. Any microorganism at all
   3. C. A type of white blood cell
   4. D. A weakened component of a vaccine
   Show answer

   Answer: A. An organism that causes disease

   Bacteria, viruses, fungi, and parasites can all be pathogens.

2. Direct contact transmission occurs when:

   1. A. Particles remain suspended in the air
   2. B. An object such as a doorknob carries it
   3. C. Droplets travel a few feet to the host
   4. D. It passes by touch or body fluids
   Show answer

   Answer: D. It passes by touch or body fluids

   Indirect contact involves a contaminated object, or fomite. Spread is person to person.

3. Droplet transmission involves particles that:

   1. A. Travel a few feet, then land
   2. B. Remain suspended in air for hours
   3. C. Penetrate intact skin on contact
   4. D. Require an insect or animal vector
   Show answer

   Answer: A. Travel a few feet, then land

   A surgical mask and eye protection address droplet risk. They land on surfaces or mucous membranes.

4. Airborne transmission is different because the organisms:

   1. A. Stay suspended and are inhaled
   2. B. Are carried by insects or ticks
   3. C. Travel only a few feet, then fall
   4. D. Require direct physical contact
   Show answer

   Answer: A. Stay suspended and are inhaled

   Tuberculosis, measles, and varicella spread this way and call for an N95 respirator. They can be inhaled at a distance.

5. Vector-borne transmission involves:

   1. A. Contaminated medical equipment
   2. B. An animal or insect carrier
   3. C. Inhaled airborne particles
   4. D. Contaminated drinking water
   Show answer

   Answer: B. An animal or insect carrier

   Ticks and mosquitoes are common vectors.

6. Bloodborne pathogens of greatest concern in EMS include:

   1. A. Norovirus and rotavirus
   2. B. Hepatitis B, hepatitis C, HIV
   3. C. Influenza and measles viruses
   4. D. Tuberculosis and pertussis
   Show answer

   Answer: B. Hepatitis B, hepatitis C, HIV

   Hepatitis B is the most transmissible of the three after a needlestick.

7. The incubation period is the time between:

   1. A. Symptom onset and recovery
   2. B. Diagnosis and start of treatment
   3. C. Exposure and symptom onset
   4. D. Exposure and developing immunity
   Show answer

   Answer: C. Exposure and symptom onset

   A patient can sometimes transmit disease during this period.

8. The communicable period is when:

   1. A. Immunity begins to develop
   2. B. The patient can transmit it
   3. C. The patient is hospitalized
   4. D. Symptoms are at their worst
   Show answer

   Answer: B. The patient can transmit it

   It doesn't always match how sick the patient looks.

9. Which condition requires an N95 or higher respirator rather than a surgical mask?

   1. A. Hepatitis B
   2. B. Meningococcal meningitis
   3. C. Influenza
   4. D. Active tuberculosis
   Show answer

   Answer: D. Active tuberculosis

   Airborne organisms pass through a standard surgical mask.

10. A patient with suspected meningococcal meningitis requires:

    1. A. Contact precautions only
    2. B. Droplet precautions
    3. C. No special precautions
    4. D. Airborne precautions only
    Show answer

    Answer: B. Droplet precautions

    Report exposures promptly, since prophylaxis is time-sensitive. Exposed providers may need prophylactic antibiotics.

11. Hepatitis B is a particular hazard because it:

    1. A. Transmits more readily than HIV
    2. B. Causes no long-term disease
    3. C. Spreads by the airborne route
    4. D. Cannot be prevented by vaccine
    Show answer

    Answer: A. Transmits more readily than HIV

    Vaccination is the single best protection. It survives on surfaces but is vaccine-preventable.

12. Which statement about HIV transmission in EMS is accurate?

    1. A. Gloves offer no real protection
    2. B. Risk per needlestick exposure is low
    3. C. It spreads through casual contact
    4. D. It spreads by the airborne route
    Show answer

    Answer: B. Risk per needlestick exposure is low

    Standard precautions address it effectively. Risk comes from blood and certain body fluids, most often through needlesticks.

13. Which patient presentation should raise suspicion of tuberculosis?

    1. A. Sudden, sharp pleuritic chest pain
    2. B. Chronic cough and night sweats
    3. C. Acute vomiting and diarrhea
    4. D. A sudden diffuse rash
    Show answer

    Answer: B. Chronic cough and night sweats

    Place a surgical mask on the patient and wear an N95 yourself. Weight loss and fever are also typical.

14. Multidrug-resistant organisms such as MRSA are spread mostly by:

    1. A. Respiratory droplets from coughing
    2. B. Contact with hands and surfaces
    3. C. Eating contaminated food or water
    4. D. Inhaled droplet nuclei in the air
    Show answer

    Answer: B. Contact with hands and surfaces

    Hand hygiene and equipment cleaning break that chain. MRSA spreads chiefly through contaminated hands, equipment, and surfaces.

15. Giving the hepatitis B vaccine to an EMS provider prevents infection by breaking which link in the chain of infection?

    1. A. The reservoir
    2. B. The susceptible host
    3. C. The portal of exit
    4. D. The mode of transmission
    Show answer

    Answer: B. The susceptible host

    Vaccination makes the provider immune, so the host is no longer susceptible. The reservoir is the infected patient, which the vaccine does not change. The portal of exit is how the virus leaves the source, such as blood. The mode of transmission is the route, such as a needlestick. Gloves and safety devices act on that link, but the vaccine does not.

16. A reservoir is:

    1. A. The route the pathogen uses to spread
    2. B. Where a pathogen lives and multiplies
    3. C. The host who shows signs of illness
    4. D. The point where a pathogen enters a host
    Show answer

    Answer: B. Where a pathogen lives and multiplies

    Humans, animals, and the environment can all serve. A reservoir is the place where a pathogen normally lives and multiplies.

17. A portal of entry refers to:

    1. A. How a pathogen enters a new host
    2. B. Where the organism leaves its reservoir
    3. C. The place where a pathogen multiplies
    4. D. The object that carries the pathogen
    Show answer

    Answer: A. How a pathogen enters a new host

    Broken skin, mucous membranes, and inhalation are examples.

18. A fomite is:

    1. A. An insect that carries a pathogen
    2. B. A body fluid containing pathogens
    3. C. A particle suspended in room air
    4. D. An object that carries pathogens
    Show answer

    Answer: D. An object that carries pathogens

    Stethoscopes and cot rails qualify. A fomite is an inanimate object carrying infectious material.

19. Host susceptibility is increased by:

    1. A. Consistent hand hygiene before meals
    2. B. Balanced nutrition and regular exercise
    3. C. Recent vaccination against the pathogen
    4. D. Age extremes and immunosuppression
    Show answer

    Answer: D. Age extremes and immunosuppression

    The same exposure affects people differently. Chronic disease and broken skin also increase susceptibility.

20. Virulence refers to:

    1. A. Time from exposure to first symptoms
    2. B. The route by which it is transmitted
    3. C. How many people are exposed at once
    4. D. Ability to cause severe disease
    Show answer

    Answer: D. Ability to cause severe disease

    Highly virulent organisms need fewer organisms to cause illness.

21. Bacteria differ from viruses in that bacteria:

    1. A. Require a host cell to reproduce
    2. B. Often respond to antibiotic therapy
    3. C. Are smaller than most viruses
    4. D. Cannot cause disease in healthy people
    Show answer

    Answer: B. Often respond to antibiotic therapy

    Antibiotics do not treat viral illness. Unlike viruses, bacteria can usually reproduce independently.

22. A virus reproduces by:

    1. A. Using a host cell's machinery
    2. B. Dividing independently by binary fission
    3. C. Forming colonies on body surfaces
    4. D. Releasing spores into the environment
    Show answer

    Answer: A. Using a host cell's machinery

    Antivirals target specific steps in that process. A virus must invade a host cell and use its machinery to replicate.

23. Which organism forms spores that resist many disinfectants?

    1. A. Human immunodeficiency virus
    2. B. Hepatitis C virus
    3. C. Clostridioides difficile
    4. D. Influenza A virus
    Show answer

    Answer: C. Clostridioides difficile

    Soap, water, and friction are required for hand hygiene.

24. Tuberculosis is transmitted by:

    1. A. Mosquito and tick vectors
    2. B. Bloodborne exposure
    3. C. The airborne route
    4. D. Direct contact with skin
    Show answer

    Answer: C. The airborne route

    An N95 or higher respirator is required.

25. Which infection is transmitted primarily by droplets?

    1. A. HIV and syphilis
    2. B. Hepatitis B and hepatitis C
    3. C. Tuberculosis and measles
    4. D. Influenza and meningococcus
    Show answer

    Answer: D. Influenza and meningococcus

    A surgical mask and eye protection address it. Tuberculosis and measles are airborne; hepatitis B, C, and HIV are bloodborne.

26. Hepatitis A is transmitted mainly by:

    1. A. Inhaled respiratory particles
    2. B. Mosquito and tick vectors
    3. C. Blood and body fluid exposure
    4. D. The fecal-oral route
    Show answer

    Answer: D. The fecal-oral route

    Hand hygiene is the key defense. Spread is often through contaminated food or water.

27. Hepatitis C is significant because it:

    1. A. Is bloodborne and often chronic
    2. B. Is prevented by a routine vaccine
    3. C. Always causes acute jaundice
    4. D. Spreads mainly by the airborne route
    Show answer

    Answer: A. Is bloodborne and often chronic

    Treatment has improved substantially. No vaccine exists for hepatitis C.

28. HIV is transmitted through:

    1. A. Saliva alone, such as from sharing cups
    2. B. Casual contact such as hugging
    3. C. Blood, sexual contact, and perinatally
    4. D. Respiratory droplets from coughing
    Show answer

    Answer: C. Blood, sexual contact, and perinatally

    Standard precautions are effective protection. Certain other body fluids can also transmit HIV.

29. Which body fluids are considered infectious for bloodborne pathogens?

    1. A. Urine, stool, sweat, and vomit
    2. B. Only blood and visibly bloody fluids
    3. C. Saliva, tears, sweat, and urine
    4. D. Blood, semen, CSF, and amniotic fluid
    Show answer

    Answer: D. Blood, semen, CSF, and amniotic fluid

    Urine, stool, sweat, and vomit are not unless visibly bloody. The full list: blood, semen, vaginal secretions, and cerebrospinal, synovial, pleural, peritoneal, pericardial, and amniotic fluids.

30. Meningitis becomes an EMS concern when the cause is:

    1. A. Fungal, as in immunocompromised hosts
    2. B. Viral, the most common form
    3. C. Aseptic, from a drug reaction
    4. D. Bacterial, especially meningococcal
    Show answer

    Answer: D. Bacterial, especially meningococcal

    Report exposures immediately. Close exposure to meningococcal disease may require prophylaxis.

31. You transport a nursing home patient with a draining MRSA wound. After the call, which step most reduces the risk to the next patient?

    1. A. Open the windows and air out the patient compartment
    2. B. Spray disinfectant into the air of the compartment and wait
    3. C. Change only your gloves before you take the next patient
    4. D. Disinfect the cot, rails, and BP cuff for the full contact time
    Show answer

    Answer: D. Disinfect the cot, rails, and BP cuff for the full contact time

    MRSA spreads by contact through hands, equipment, and high-touch surfaces. Disinfecting those surfaces with the full wet contact time breaks that route. Airing out or fogging the compartment targets airborne spread, which is not how MRSA moves. Changing gloves alone leaves contaminated equipment for the next patient.

32. Which statement about influenza is accurate?

    1. A. It only causes illness in older adults
    2. B. It can spread before symptoms appear
    3. C. It cannot be prevented by vaccination
    4. D. It spreads mainly by insect vectors
    Show answer

    Answer: B. It can spread before symptoms appear

    This complicates screening.

33. A patient with a rash and fever who has not been vaccinated should raise concern for:

    1. A. Lyme disease from a tick bite
    2. B. Scabies spread by skin contact
    3. C. Measles or varicella
    4. D. Hepatitis A from contaminated food
    Show answer

    Answer: C. Measles or varicella

    Ask about travel and exposures. Both measles and varicella require airborne precautions.

34. Pertussis transmission is by:

    1. A. Respiratory droplets
    2. B. Mosquito vectors
    3. C. Bloodborne exposure
    4. D. Contaminated food or water
    Show answer

    Answer: A. Respiratory droplets

    Tdap protects providers and vulnerable patients.

35. Which patient presentation warrants a surgical mask placed on the patient?

    1. A. An unresponsive diabetic patient
    2. B. A coughing patient with a fever
    3. C. A closed extremity fracture
    4. D. A patient with chest pain
    Show answer

    Answer: B. A coughing patient with a fever

    Source control protects everyone in the compartment. A cough with suspected respiratory infection is the indication.

36. An asymptomatic carrier is:

    1. A. Contagious without symptoms
    2. B. Always identified by routine screening
    3. C. Immune to the organism after recovery
    4. D. Exposed but not yet able to transmit it
    Show answer

    Answer: A. Contagious without symptoms

    This is why standard precautions apply universally. The carrier is infected and can transmit the organism while appearing well.

37. The single most important factor in preventing disease transmission in EMS is:

    1. A. Daily vehicle cleaning
    2. B. Masks for every patient
    3. C. Gowns on every call
    4. D. Consistent hand hygiene
    Show answer

    Answer: D. Consistent hand hygiene

    It is also the most frequently skipped.

38. Which describes an emerging infectious disease?

    1. A. Newly appearing or spreading
    2. B. A disease eradicated worldwide
    3. C. A disease with a licensed vaccine
    4. D. A long-standing chronic disease
    Show answer

    Answer: A. Newly appearing or spreading

    EMS is part of early detection. It may be newly appearing, increasing rapidly, or spreading into new areas.

39. Vector-borne diseases relevant to EMS include:

    1. A. Tuberculosis and pertussis
    2. B. Hepatitis B and hepatitis C
    3. C. Lyme disease and West Nile virus
    4. D. Influenza and RSV
    Show answer

    Answer: C. Lyme disease and West Nile virus

    Protective clothing and repellent are preventive. Rocky Mountain spotted fever is another example.

40. An immunocompromised patient should be protected by:

    1. A. Fewer precautions to speed care
    2. B. Hand hygiene and clean equipment
    3. C. No change from routine practice
    4. D. Isolation without other measures
    Show answer

    Answer: B. Hand hygiene and clean equipment

    Protection goes both directions. A coughing provider should also mask around them.

41. The incubation period matters to EMS because:

    1. A. It tells which PPE the crew needs
    2. B. It determines which drug to give
    3. C. Spread can occur before symptoms
    4. D. It predicts how severe illness will be
    Show answer

    Answer: C. Spread can occur before symptoms

    Exposure follow-up uses it. Exposed providers may also need monitoring through that period. PPE is chosen by route of transmission, not by incubation period.

42. Which is the most accurate statement about airborne precautions?

    1. A. Gloves and a gown are sufficient
    2. B. A fit-tested N95 is required
    3. C. They are rarely needed in EMS
    4. D. A surgical mask alone is adequate
    Show answer

    Answer: B. A fit-tested N95 is required

    Ventilating the patient compartment helps. An N95 or higher respirator is the minimum; mask the patient when possible as well.