Monday Update: Viral meningitis outbreak in California
Susanville in northern California has nine confirmed cases; others are suspected



SUSANVILLE, Calif. (Oct. 2, 2017) -- As of Oct.1, 2017, 38 possible cases of viral meningitis have been reported to Lassen County Public Health (LCPH) since Sept.  23, 2017. We have 20 suspected, 9 confirmed and 9 ruled-out for viral meningitis.

When it became clear that a greater number of cases than average were being reported, LCPH began an epidemiological investigation. The connection has been found between some cases and further investigation will continue with the assistance of California Department of Public Health and Center for Disease Control and Prevention.

To date, spinal fluid for the initial 11 cases of suspected viral meningitis have been submitted to the California Department of Public Health’s Viral and Rickettsial Disease Laboratory (CDPH VRDL) for viral testing. Of those, nine have tested positive for enteroviruses which can be broken into 65 different strains (including, echoviruses, Coxsackie viruses and others). Serotyping will be conducted on the positive enteroviruses samples to determine the exact strain.

One has tested negative for enteroviruses and one is being retested. More samples have been sent and are pending laboratory analysis. Most patients were hospitalized briefly (1-6 days, most 2-3 days), with no deaths.


Enteroviruse occurs most commonly in the summer and fall months and some enteroviruses will have irregularly occurring upsurges. Enteroviruse is a virus comparable to the flu virus (influenza).

Enteroviruses, as a group, are the most common cause of viral meningitis in the U.S. and usually results in a self-limited disease with full recovery and without specific treatment. Enteroviruses will circulate in a community with many not having any notable symptoms or are asymptomatic. Other persons may experience respiratory or gastrointestinal symptoms and a few who develop viral meningitis with associated symptoms (headache, stiff neck, nausea, light sensitivity, etc.) though they are contagious.

Reminder for Providers - Diagnosis & Management

Bacterial meningitis must be ruled out in any case presenting with symptoms suggestive of meningitis. In addition to spinal fluid cell counts, protein and glucose, gram stain and culture, a bactogen panel can be helpful in differentiating viral and bacterial meningitis.

An outbreak associated with viral (aseptic) meningitis case is defined as an illness of those with an onset of symptoms during September 23, 2017, to current with 1) cerebrospinal fluid pleocytosis and negative bacterial culture or 2) an emergency department visit with headache, stiff neck, nausea, light sensitivity, and vomiting.
The state laboratory is also performing viral testing on available Spinal Fluid specimens associated with this upsurge of viral meningitis cases in Lassen County. Providers please notify the Lassen County Public Health if you have a suspect viral meningitis case.

Patients with viral meningitis do not require isolation beyond usual standard precautions, but hand washing and respiratory hygiene should be emphasized.

Prevention and Patient Information

Prevention is following the usual standard precautions with an emphasis on hand washing and respiratory secretion hygiene. There is no vaccine or specific prophylaxis or treatment for most viral meningitis, except those caused by vaccine preventable diseases such as measles, mumps and varicella, or by herpes simplex which is treatable with antivirals. Treatment is generally supportive care and pain management.

Patients and family are frequently very anxious about meningitis and education about viral meningitis that differentiates viral from bacterial meningitis is helpful. Education regarding the importance of hand washing and respiratory hygiene--for everyone community wide--is important to reduce spread. An information sheet on viral meningitis is available on the CDPH website

If you have questions please call (530) 252-2096 for more information.