Seroepidemiological research on viral encephalitis in Karachi Pakistan--preliminary report.

Seroepidemiological investigations were done during the study of viral encephalitis in and around Karachi, Pakistan. Serum and /or cerebrospinaF fluid (CSF) from 352 persons (72 patients with encephalitis, 199 patients without neurological disease and 81 healthy volunteers) were collected during the period from June, 1983 to March, 1984. Of 72 encephalitis patients, serum antibody positivity rates were over 45 percent against Herpes simplex type I virus (HSV), measles and rubella virus, and less than 33 percent against entero-70 virus consistently through the investigation period. In contrast, the antibody positivity rate against Japanese encephalitis (JE) virus increased from pre-rainy to post-rainy seasons in both encephalitis patients and controls. Positive antibody in CSF was detected in nine cases against HSV, in five cases each against measles and JE virus, and in four cases against rubella. (JPMA36:177, 1986).