Influenza A encephalopathy is rare in adults.1 We report a case of a pregnant woman with influenza A encephalopathy in whom the influenza A/Hong Kong virus (H3) was isolated from cerebrospinal fluid (CSF).
A 32-year-old pregnant woman presented with influenza symptoms (elevated temperature of 39°C and a stiff neck) at 9 weeks' gestation on January 9, 1999. The patient did not take the medicine that was prescribed to her because she was pregnant. There was no history of aspirin use. The patient gradually developed a stiff neck and continued high fever for 5 days. On admission to our hospital on January 13, the patient was fully conscious, but extremely restless. Peripheral blood cell count, chemistry test results, and urinalysis results were normal. Cerebrospinal fluid was clear and colorless with a normal cell count and normal protein and glucose levels. Influenza A/Hong Kong virus (H3) was isolated from the CSF on January 13. No Epstein-Barr virus, cytomegalovirus, herpes simplex virus 1, or mumps virus was isolated from the CSF on January 13. The serum influenza A virus (H3N2) hemagglutination inhibition (HI) titer was remarkably elevated (HI >8 on January 13; HI=128 on January 26). There was no elevation of the titers of antibodies to the Epstein-Barr virus, cytomegalovirus, herpes simplex virus 1, or mumps virus. No abnormal finding was revealed on computed tomographic scan and magnetic resonance imaging of the brain. Electroencephalography showed no abnormal wave. On January 22, the patient's level of consciousness deteriorated to a score of 3 on the Glasgow Coma Scale. On January 25, she underwent an abortion at 12 weeks' gestation. On February 9, she had a secondary generalized focal-motor seizure in the right hand. At that time, her CSF was clear and colorless, with a normal cell count and normal protein and glucose levels, and influenza A/Hong Kong virus (H3) was not isolated from the CSF. On March 12, the patient's level of consciousness improved to a score of 6 on the Glasgow Coma Scale, but did not improve further. It was not possible to wean her from the respirator because her spontaneous respiration was very weak. The patient's general condition was a persistent vegetative state, and she remained unresponsive and speechless.