Transplacental infection with Japanese encephalitis virus.

During a widespread epidemic of Japanese encephalitis, five pregnant women affected by the illness were observed. The diagnosis of Japanese encephalitis virus (JEV) infection was established on the basis of clinical presentation, rising titers of hemagglutination-inhibiting antibody, and the presence of specific IgM antibodies. Two women aborted, two were delivered of apparently normal children, and the fate of one case is not known. From brain, liver, and placental tissues of one of the aborted fetuses, JEV was isolated. This appears to be the first report of human transplacental infection with JEV.

Variable effect on peripheral blood leucocytes during JE virus infection of man.

The peripheral blood leucocytes of twenty-four cases of Japanese encephalitis (JE) were studied and the findings were compared with those in twenty-five normal health controls of matching age and sex. In the early phases of the disease marked neutrophil leucocytosis was seen which returned to almost normal levels by the fourth week. Lymphopenia was associated with diminished T lymphocytes but the number of B lymphocytes remained within the normal range. Though the number of T lymphocytes was reduced, their function of leucocyte migration inhibition in the presence of JE virus antigen was significantly higher. The phagocytic activity of the neutrophils, as shown by the uptake of neutral red dye, was diminished but the phagocytic activity of monocytes as shown by the uptake of neutral red dye, was diminished but the phagocytic activity of monocytes as shown by the uptake of neutral red dye or ingestion of latex particles remained unaffected. HI antibodies against JE virus were significantly higher in cases of encephalitis as compared with the control group. Thus, JE virus infection in man has a variable effect on different components of the peripheral blood leucocytes.