Ann, a healthy 37-year-old biology teacher had just returned from Japan, where she was attending a two-week seminar. On the plane trip back to the U.S., Ann began to experience chills, fever, and a severe headache. The day after she arrived home, she visited her doctor. After noticing some abnormal reflex responses, he admitted her to the hospital and obtained a sample of cerebrospinal fluid by spinal tap. He ordered penicillin therapy intravenously and Tylenol for discomfort.
Initial laboratory isolations were unsuccessful in obtaining a bacterial culture from the CSF sample when plated on enrichment media and blood agar. Serological tests were depended on for diagnosis, comparing initial and subsequent antibody titers.
Following the laboratory results, Ann’s treatment was primarily supportive. However, Ann’s condition continued to deteriorate and she was transferred to the ICU. Having lapsed into a coma, she died a week later, without regaining consciousness.
Which of the following diseases is most likely described in this case study?
How might Ann have contracted this disease?