21. Principles of Disease

Conjunctivitis is caused by the following agent types (select ALL that apply):

a. bacteria.

b. viruses.

c. protozoa.

d. fungi.

e. helminths.

Which best describes conjunctivitis (select ALL that apply)?

a. Itchy eyes

b. Scarred cornea

c. Red eyes

d. Inverted eyelashes

e. Scarred conjunctiva

Select the false statement about trachoma:

a. The causative agent is bacterial.

b. It is the leading cause of infectious blindness in the United States.

c. It is transmitted by unhygienic items, such as flies, fingers, and fomites.

d. Uncomplicated cases can be resolved with antibiotics.

e. Severe cases require surgery.

Your diabetic patient has a foot wound that has developed into serious necrosis and the recommended treatment has been sessions in the hyperbaric oxygen chamber. You are explaining to him what has contributed to this condition, including the causative agent, which is:

a. Bacillus anthracis.

b. Clostridium perfringens.

c. Corynebacteria diphtheriae.

d. Streptococcus pyogenes.

e. Pseudomonas aeroginosa.

A child comes into your clinic with impetigo. The lab cultures a sample for further analysis. If the sample is S. aureus, which lab results would you expect? (NCLEX/HESI/TEAS)

a. Gram-positive cocci in clusters, catalase and coagulase positive

b. Gram-negative diplococci, catalase positive, and coagulase negative

c. Gram-positive cocci in clusters, catalase negative, and coagulase positive

d. Gram-positive cocci in chains, catalase positive, and coagulase negative

e. Gram-positive cocci in chains, catalase negative, and coagulase positive

Concept Mapping:

Using the following terms, create a concept map to organize and review microbial diseases of the eyes.

- Acanthamoeba

- Adenoviruses

- Aspergillus

- Candida

- Chlamydia trachomatis

- Flies, fomites, fingers

- Fusarium

- Haemophilus influenzae

- Herpes simplex 1 virus

- Keratitis

- Moraxella

- River blindness

- Scarring of eyelid

- Staphylococcus species

- Streptococcus species

- Turning of lashes and further scarring

A patient is admitted who is complaining of headache, disorientation, and numbness in his left arm. He was bitten by a raccoon two days before. The FIRST step taken to help this patient would be (NCLEX/HESI/TEAS)

a. retrieving and testing the raccoon’s brain tissues for the rabies virus.

b. collecting a CSF sample from the patient.

c. performing a tissue biopsy on the patient to look for Negri bodies.

d. administering an anti-rabies vaccine as well as anti-rabies antibodies.

Viral meningitis is more common than other forms of meningitis because

a. these infectious agents are all intracellular, evading the immune system.

b. there are more types of viruses than bacteria because they evolve more quickly.

c. the small size of viruses makes them able to pass more easily through the blood–brain barrier.

d. viruses are spread person to person more easily than bacteria, fungi, or protozoans.

A patient’s lab data report has come back with a positive ELISA for pneumococcal C polysaccharide from CSF samples. The MOST appropriate next step for a health professional to recommend is to (NCLEX/HESI/TEAS)

a. culture from the CSF sample to test for antibiotic resistance.

b. administer tetracycline.

c. administer cephalosporin.

d. wait for RT-PCR confirmation before antibiotic treatment.

A patient under one year old is vomiting, drowsy, floppy (flaccid), and unresponsive. Both infant botulism and infant meningitis caused by other bacteria are suspected. Which piece of information would best help narrow down the possible diagnosis? (NCLEX/HESI/TEAS)

a. The child has spent almost no time outside the home.

b. The child is being breast-fed.

c. The child was born one month ago.

d. The child has a very high fever.

CSF glucose levels are often assessed to differentiate between bacterial and viral meningitis. This is because

a. bacteria cells use glucose and lower the overall concentration in the CSF.

b. viral meningitis causes inflammation that blocks glucose transport into the CSF.

c. viral infection of the meninges causes cell lysis, releasing glucose into the CSF.

d. None of the above.

Undercooked poultry is commonly a source of infection caused by ____________ bacteria or by ____________ bacteria.

Match the preventative measure to the infectious agent it can help limit:

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Which of the following pathogens are not associated with foodborne infections?

a. Salmonella

b. Shigella

c. Campylobacter jejuni

d. Bacillus cereus

e. Escherichia coli

Describe one way to prevent hookworm infection by N. americanus.