Infection Control knowledge check

Which of the following is the most effective way to prevent the spread of droplet-transmitted infections such as influenza?

• Wearing a surgical mask and maintaining distance

• Taking antibiotics after exposure

• Using gloves only during patient transfers

• Avoiding vaccination programs

Answer explanation

Rationale: masks block large respiratory droplets at the source and at the receiver; combining masking with physical distance reduces exposure to infectious droplets. (Correct answer) The flu and cold (influenza and rhinovirus) are transmitted typically through airborne or droplet transmission.

• Taking antibiotics after exposure

  • Rationale: antibiotics treat bacterial infections, not viral infections like most influenzas; inappropriate use increases resistance and is not an effective preventive measure. Using antibiotics when they aren't needed can cause our body to become resistant to their benefits. MRSA is a good example. REVIEW MRSA from the textbook.

• Using gloves only during patient transfers

  • Rationale: gloves can protect hands from contamination but do not stop respiratory droplets; gloves-only strategies miss source control and hand-to-face transmission routes. Gloves will help reduce direct/indirect, as long as you keep those gloves away from your face!

• Avoiding vaccination programs

  • Rationale: avoiding vaccines reduces population immunity and increases risk of infection; vaccination is a key preventive measure for influenza, so this option is harmful, not protective.

What type of transmission occurs when a patient touches a contaminated door handle and then touches their face?

• Indirect contact

• Direct contact

• Droplet transmission

• Vector-borne transmission

Answer explanation

• Indirect contact

  • Rationale: pathogens are transferred via an intermediate object (fomite) like a door handle, then to the person — that is the definition of indirect contact transmission. (Correct answer). Direct and indirect are actually termed contract transmission and are technically the same. Indirect is just picking it up from a different surface (counter, door handle) and not the infected person's hand.

• THIS is why cleaning tables, weights, and used equipment (plus hand-washing) is best to reduce that indirect contact! Direct contact

  • Rationale: direct contact requires person-to-person physical contact (e.g., handshake, kissing); a contaminated surface makes the route indirect rather than direct. Handwashing is the best method to break the cycle or chain of transmission.

• Droplet transmission

  • Rationale: droplet transmission involves infectious respiratory droplets landing on mucous membranes at short range; touching a contaminated surface is not a droplet mechanism.

• Vector-borne transmission

  • Rationale: vector-borne transmission requires an animal vector (e.g., mosquito, tick) to carry the pathogen — an inanimate surface does not qualify.

Which infection control practice is required when treating a patient with an airborne infection such as tuberculosis?

• Using a negative pressure room and N95 respirator

• Wearing gloves only

• Using a standard patient room

• Applying contact precautions only

Answer explanation

• Using a negative pressure room and N95 respirator

  • Rationale: negative pressure rooms prevent contaminated air from leaving the room, and N95 respirators filter small airborne particles — both are standard for airborne precautions. (Correct answer)

• Wearing gloves only

  • Rationale: gloves protect against contact with secretions but do not prevent inhalation of airborne particles; they are insufficient alone for airborne pathogens.

• Using a standard patient room

  • Rationale: standard rooms do not control airflow or contain airborne particles, so they are inadequate for airborne infections.

• Applying contact precautions only

  • Rationale: contact precautions focus on preventing transfer via touch or fomites and do not address airborne spread; airborne precautions require additional measures.

Which of the following is an example of a vector-borne disease?

• Malaria

• Influenza

• Tuberculosis

• Hepatitis B

Answer explanation

• Malaria

  • Rationale: malaria is transmitted by Anopheles mosquitoes, a classic vector-borne route. I used the elephantiasis example in class. (Correct answer)

• Influenza

  • Rationale: influenza spreads mainly via droplets/aerosols, not by insect vectors. Droplet precautions

• Tuberculosis

  • Rationale: tuberculosis is airborne and transmitted via inhalation of infectious particles, not by vectors. These particles are much smaller than your typical droplets and can be carried further than droplets, which is what distinguishes them from droplet.

• Hepatitis B

  • Rationale: hepatitis B is primarily bloodborne and sexually transmitted, not vector-borne.

How can PTAs reduce the spread of Clostridioides difficile (C-diff) in clinical settings?

• Washing hands with soap and water after patient contact

• Using alcohol-based sanitizer only

• Wearing a surgical mask

• Avoiding patient contact until symptoms resolve

Answer explanation

• Rationale: C-diff spores are resistant to alcohol-based sanitizers; soap-and-water handwashing physically removes spores and is the recommended practice. (Correct answer). Hand washing is the best method to break the cycle of infection. C-diff results in diarrhea and inflammation of the colon (colitis). It was mentioned in class that a fecal transplant can treat this. This disease takes an extremely long time to runs it's course.

• Using alcohol-based sanitizer only

  • Rationale: alcohol sanitizers do not reliably remove or kill C-diff spores, so they are insufficient as the sole hand hygiene method after C-diff exposure.

• Wearing a surgical mask

  • Rationale: masks protect against respiratory droplets but do not prevent fomite transmission of C-diff, which spreads via spores in stool/environmental contamination.

• Avoiding patient contact until symptoms resolve

  • Rationale: while limiting contact can reduce spread, it is impractical and unnecessary if proper infection control (cleaning, glove use, handwashing) is followed; appropriate precautions are preferred

Which of the following statements best describes standard precautions?

• Infection control measures used with all patients, regardless of diagnosis

• Precautions only used with infectious patients

• Additional PPE required only for airborne infections

• Isolation procedures used for immunocompromised patients

Answer explanation

• Infection control measures used with all patients, regardless of diagnosis

  • Rationale: standard precautions treat all blood and body fluids as potentially infectious and apply universally to prevent transmission. (Correct answer)

• Precautions only used with infectious patients

  • Rationale: this describes transmission-based precautions; standard precautions are used with every patient, not only those known to be infectious.

• Additional PPE required only for airborne infections

  • Rationale: airborne infections require specific PPE (e.g., N95) and environmental controls, but standard precautions are broader and include basic PPE for all patients.

• Isolation procedures used for immunocompromised patients

  • Rationale: isolation for immunocompromised patients is a specific strategy (protective/positive-pressure rooms) and is not the general definition of standard precautions.

Which of the following pathogens is most likely transmitted through contaminated food or water?

• Salmonella

• Influenza

• Measles

• HIV

Answer explanation

• Salmonella

  • Rationale: Salmonella commonly causes foodborne illness from contaminated food or water and is a classic example of enteric transmission. (Correct answer)

• Influenza

  • Rationale: influenza is primarily respiratory (droplet/aerosol), not foodborne.

• Measles

  • Rationale: measles is airborne/droplet-transmitted and not spread via food or water. This is a good example of the measles here.

• HIV

  • Rationale: HIV is transmitted through blood, sexual contact, and perinatal routes, not by ingestion of contaminated food or water.

Which type of infection is caused by fungi and often affects the feet?

• Athlete’s foot

• Impetigo

• Cellulitis

• Strep throat

Answer explanation

• Rationale: athlete’s foot (tinea pedis) is a dermatophyte fungal infection commonly acquired by direct contact or contaminated surfaces (e.g., locker room floors). (Correct answer). Athlete's foot is very similar to ringworm, just found in different body parts and it literally is in a ring shape.

• Impetigo

  • Rationale: impetigo is a superficial bacterial skin infection (usually Staphylococcus or Streptococcus), not fungal. The photo is impetigo

• Cellulitis

  • Rationale: cellulitis is a deep bacterial skin/soft tissue infection, not typically fungal.

• Strep throat

  • Rationale: strep throat is a bacterial pharyngitis caused by Streptococcus pyogenes, not a fungal foot infection.

Regular moderate exercise supports immune health by helping the body:

• Become more resistant to infections

• Produce fewer white blood cells

• Increase fatigue and stress hormones

• Decrease oxygen delivery to tissues

Answer explanation

• Regular physical activity and balanced nutrition

  • Rationale: moderate exercise and adequate nutrition support immune surveillance, lower chronic inflammation, and help the body resist infections. (Correct answer)

• Frequent use of antibiotics

  • Rationale: frequent or inappropriate antibiotic use disrupts the microbiome and can weaken immune defenses and promote resistant organisms.

• Limited sleep and high stress

  • Rationale: sleep deprivation and chronic stress suppress immune function and increase susceptibility to illness.

• Avoiding sunlight exposure

  • Rationale: avoiding all sunlight can reduce vitamin D synthesis, which is important for immune regulation; safe sunlight exposure or supplementation supports immunity.

Which of the following fungal infections most commonly affects the groin area, often causing redness, itching, and irritation?

• tinea pedis

• thrush

• tinea cruris

• tinea corporis

Answer explanation

• Tinea cruris

  • Rationale: Tinea cruris, also known as "jock itch," is a fungal infection that thrives in warm, moist areas such as the groin and inner thighs. It causes itching, redness, and a ring-shaped rash. (Correct answer)

• Tinea pedis

  • Rationale: Tinea pedis, or "athlete’s foot," affects the feet and toes, leading to itching, peeling, and cracking of the skin.

• Thrush

  • Rationale: Thrush is a fungal infection caused by Candida species, typically affecting the mouth or throat with white, creamy patches and soreness.

• Ringworm

  • Rationale: Ringworm (tinea corporis) is a fungal infection of the skin on the body, presenting as circular, scaly patches with raised borders.