SPECIAL REVIEWS

NEUROTROPIC VIRUS DISEASES

¹ The Department of Epidemiology and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh.

Editors: JOSEPH STOKES JR., M.D..

AMONG a large group of neurotropic viral infections of man, poliomyelitis is currently of greatest importance to pediatricians of most countries. In all areas of the temperate and tropical zones where surveys have been made, poliomyelitis infection rates, as measured by the neutralization test, are approximately the same as those for rubeola or other common acute infectious diseases of childhood. In many countries the fatal and paralytic cases assume considerable importance in pediatric practice and, above all, in public interest and demand for control, In many tropical and subtropical areas, however, paralytic rates are reputedly low, and this disease is not recognized as a problem of any importance.

In some areas of the world other neurotropic viruses assume an importance equal to or greater than that of poliomyelitis. Epidemics of these other viruses may occur at intervals as frequent as those of poliomyelitis epidemics or at longer or shorter intervals, but when epidemics do occur they are occasionally of major proportions. Outbreaks of Japanese B encephalitis have occurred principally in children in the past 15 years in Japan, Okinawa and certain other Far Eastern areas. Western equine encephalitis virus has been responsible for important outbreaks in children in the central valley areas of California, and the St. Louis virus has also been responsible for local outbreaks involving principally children in the western United States. These viruses are all members of the arthropod-borne group of viral encephalitides.

Epidemic parotitis, although not usually listed among the neurotropic viruses, has come to occupy a more and more important position as the serologic tests for its diagnosis have received more widespread use in the diagnosis of cases of the nonbacterial meningoencephalitides.