What clinically relevant observations support the diagnosis of meningitis associated with the infectious organism and What laboratory testing supports the diagnosis of meningitis associated with the infectious organism?

What clinically relevant observations support the diagnosis of meningitis associated with the infectious organism and What laboratory testing supports the diagnosis of meningitis associated with the infectious organism?

CASE STUDY 15.4 

A disoriented 58-year-old man with a history of poorly controlled diabetes mellitus and chronic obstructive pulmonary disease presents to the ED. The patient has been smoking cigarettes for many years. He has been taking steroid medications for his pulmonary disease. Physical examination shows that he is slightly febrile, lethargic, and respiratory failure. A diagnosis of meningitis is being considered. A lumbar puncture is done, and cerebrospinal fluid (CSF) is collected for a smear and culture. 

Laboratory Data 

A CSF specimen is collected and sent to the laboratory. A cytocentrifuged preparation of the CSF is stained, using calcofluor white for yeast by staining the yeast cell walls. The smear shows encapsulated, thick-walled budding yeasts. A cryptococcal antigen test is completed and is positive. The culture of CSF identifies Cryptococcus neoformans. 

Multiple Choice Questions 

1. Fungi are widespread in the environment but rarely cause central nervous system (CNS) infection. C. neoformans is the most common cause of fungal meningitis. It is especially common among immunocompromised patients. This type of infection is known as which of the following?
2. Nosocomial infection
3. Opportunistic infection
4. Community-associated infection
5. Health care-associated infection

ANS: b. Opportunistic infection 

1. What additional laboratory test could have been completed for a presumptive identification of C. neoformans?
2. Gram stain
3. Acid-fast stain
4. India ink prep
5. Trichrome stain

ANS: d. Trichrome stain 

Critical Thinking Discussion Questions 

What clinically relevant observations support the diagnosis of meningitis associated with the infectious organism and What laboratory testing supports the diagnosis of meningitis associated with the infectious organism?