Ch. 18 - Nervous System Infections

Norman-McKay- Microbiology: Basic and Clinical Principles 2nd Edition

Norman-McKay2nd EditionMicrobiology: Basic and Clinical PrinciplesISBN: 9780137661619Not the one you use?Change textbook

Norman-McKay 2nd Edition

Ch. 18 - Nervous System Infections

Problem 6

Chapter 18, Problem 6

During a lumbar puncture procedure, the nurse observed that the patient’s CSF pressure was high. However, when the analysis of the CSF sample comes back, the glucose levels are normal. The nurse would most likely suspect:
a. arboviral meningitis.
b. Neisseria meningitidis.
c. Listeria monocytogenes.
d. poliovirus.

Verified step by step guidance

Step 1: Understand the clinical context—high cerebrospinal fluid (CSF) pressure indicates increased intracranial pressure, which can occur in various types of meningitis or other CNS infections.

Step 2: Recall that CSF glucose levels are typically low in bacterial meningitis because bacteria consume glucose, whereas viral meningitis usually presents with normal glucose levels.

Step 3: Analyze the options: bacterial pathogens like Neisseria meningitidis and Listeria monocytogenes often cause low CSF glucose, while viral infections such as arboviral meningitis and poliovirus usually have normal glucose levels.

Step 4: Consider that arboviral meningitis is a viral infection that can cause increased CSF pressure but typically maintains normal glucose levels, aligning with the nurse's observation.

Step 5: Conclude that the most likely suspicion, given high CSF pressure with normal glucose, is a viral meningitis such as arboviral meningitis.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Cerebrospinal Fluid (CSF) Analysis in Meningitis

CSF analysis is critical in diagnosing meningitis, focusing on pressure, glucose, protein, and cell counts. Elevated CSF pressure indicates inflammation or increased intracranial pressure. Normal glucose levels often suggest viral rather than bacterial meningitis, as bacteria typically consume glucose, lowering its concentration.

Differences Between Viral and Bacterial Meningitis

Viral meningitis usually presents with normal CSF glucose and mildly elevated pressure, while bacterial meningitis often shows low glucose due to bacterial metabolism and high protein levels. Identifying these differences helps distinguish causative agents and guides treatment decisions.

Common Pathogens and Their CSF Profiles

Arboviruses and poliovirus are viral pathogens causing meningitis with normal CSF glucose and elevated pressure. In contrast, Neisseria meningitidis and Listeria monocytogenes are bacteria that typically lower CSF glucose. Recognizing pathogen-specific CSF patterns aids in accurate diagnosis.

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Textbook Question

A patient who has just immigrated to the United States after serving in the Iraqi army is displaying a bruiselike rash, headache, and sensitivity to light. The doctor will immediately recommend administration of

a. ceftriaxone.

b. penicillin.

c. gentamycin.

d. rifampicin.

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Textbook Question

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

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.

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Textbook Question

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?

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.

Textbook Question

A vaccine against Listeria monocytogenes is a challenge to develop because

a. very few people get Listeria meningitis.

b. the antibody-mediated immune response is not effective against L. monocytogenes.

c. better prevention approaches exist, such as food preparation precautions.

d. vaccinations are not used for foodborne illness.

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Textbook Question