[On the problem of the nature of diphasic meningoencephalitis in the Leningrad area].
D004660:Encephalitis; D004671:Encephalitis, Arbovirus / Q000453:epidemiology*; D004675:Encephalitis, Tick-Borne; D058872:Epidemics; D008590:Meningoencephalitis
ENCEPHALITIS, EPIDEMIC/epidemiology