Related Experiment Video

Updated: Aug 27, 2026

Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay
07:23

Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay

Published on: June 9, 2011

Western equine and St. Louis encephalitis in man, California, 1945-1950

E H LENNETTE, W A LONGSHORE

    California Medicine
    |September 1, 1951
    PubMed

    Insights

    Infectious encephalitis is caused by various agents. Identifying specific causes like western equine encephalitis and St. Louis encephalitis requires laboratory evidence, especially for unknown infectious encephalitis agents.

    Area of Science:

    • Neurology
    • Infectious Diseases
    • Virology

    Background:

    • Infectious encephalitis encompasses a broad spectrum of clinical syndromes caused by numerous known and unknown etiologic agents.
    • Distinguishing specific disease entities within this group necessitates diagnostic skill and laboratory confirmation.

    Purpose of the Study:

    • To highlight the diagnostic challenges and importance of laboratory evidence in identifying specific causes of infectious encephalitis.
    • To discuss the epidemiology of two specific encephalitis types in California and the potential for discovering novel causative agents.

    Main Methods:

    • Clinical observation and differential diagnosis.
    • Laboratory analysis of patient specimens.
    • Epidemiological surveillance in defined geographic areas.

    Main Results:

    • Western equine encephalitis and St. Louis encephalitis are common in specific California regions (Central Valley, Imperial Valley) with a seasonal occurrence (June-October).
    • Clinical diagnosis of encephalitis can be difficult, underscoring the need for laboratory support.
    • Proper specimen collection and submission are critical for accurate diagnosis and etiological research.

    Conclusions:

    • Laboratory studies are crucial for diagnosing individual encephalitis cases and advancing etiological understanding.
    • The existence of encephalitis caused by unidentified agents in California is probable.
    • Physician submission of appropriate specimens from obscure central nervous system diseases is vital for isolating new encephalitogenic viral agents.
    Keywords:
    ENCEPHALOMYELITIS, EQUINE

    More Related Videos

    In Vivo Imaging Systems (IVIS) Detection of a Neuro-Invasive Encephalitic Virus10:21

    In Vivo Imaging Systems (IVIS) Detection of a Neuro-Invasive Encephalitic Virus

    Published on: December 2, 2012

    A Model for Epilepsy of Infectious Etiology using Theiler's Murine Encephalomyelitis Virus05:33

    A Model for Epilepsy of Infectious Etiology using Theiler's Murine Encephalomyelitis Virus

    Published on: June 23, 2022

    Related Concept Videos

    Arboviral Encephalitis01:25

    Arboviral Encephalitis

    Arboviral encephalitis refers to brain inflammation caused by arthropod-borne viruses, particularly those transmitted through mosquito vectors. Among these, West Nile virus (WNV), a member of the Flaviviridae family, is a significant public health concern. WNV is an enveloped, positive-sense, single-stranded RNA virus. Human infection typically begins when an infected mosquito introduces the virus into the dermis during feeding. The primary transmission cycle involves birds as amplifying hosts...
    Encephalitis l: Introduction01:19

    Encephalitis l: Introduction

    Encephalitis is inflammation of the brain parenchyma, most often due to infections or autoimmune processes. It presents with neuropsychiatric features such as fever, altered mental status, behavioral changes, cognitive dysfunction, seizures, focal deficits, and sometimes autonomic instability. In some cases, the meninges are also involved, resulting in meningoencephalitis.Infectious CausesInfectious encephalitis is most commonly viral but can also result from bacterial, fungal, or parasitic...
    Encephalitis ll: Pathophysiology01:26

    Encephalitis ll: Pathophysiology

    Encephalitis is inflammation of the brain parenchyma caused by direct viral invasion or immune-mediated mechanisms triggered by infections or tumors. Both processes lead to neuronal injury, disrupted neurotransmission, and diverse neurological symptoms, often with overlapping clinical and pathological features.Autoimmune EncephalitisIn autoimmune encephalitis, antibodies target neuronal antigens on cell surfaces, synapses, or within neurons. A key example is anti-NMDAR encephalitis, which can...
    Rocky Mountain Spotted Fever01:26

    Rocky Mountain Spotted Fever

    Rocky Mountain Spotted Fever (RMSF) is a severe tick-borne illness caused by Rickettsia rickettsii, a Gram-negative, coccobacillary bacterium. This pathogen is an obligate intracellular parasite, requiring a host cell for replication. Transmission occurs through the bite of an infected tick. In the United States, the most important vectors are Dermacentor variabilis (American dog tick) and Dermacentor andersoni (Rocky Mountain wood tick), though other tick species may also serve as vectors.
    Viral Meningitis01:18

    Viral Meningitis

    Viral meningitis is the most common form of meningitis and is often referred to as aseptic meningitis to indicate the absence of bacterial involvement. It is generally milder than bacterial meningitis, with symptoms including fever, headache, stiff neck, drowsiness, nausea, photophobia, and vomiting. Rarely, more severe manifestations or death may occur. Common causative agents include enteroviruses, particularly coxsackie A and B viruses and echoviruses, all members of the Enterovirus genus...
    Poliomyelitis01:17

    Poliomyelitis

    Poliomyelitis is caused by poliovirus, a small, non-enveloped, positive-sense RNA virus of the Picornaviridae family and Enterovirus genus. Transmission occurs primarily via the fecal-oral route, often through ingestion of contaminated water or food. The virus initially replicates in the oropharynx and intestinal mucosa, particularly in lymphoid tissues such as the tonsils, Peyer’s patches, and regional lymph nodes. Primary viremia follows, allowing dissemination throughout the body.In most...