Some experts speculated that greater awareness of the West Nile virus, which can cause viral meningitis, has made some health care providers more cognizant of the illness and thus there has been increased reporting. However, a San Bernardino County health officer said the reason may be linked to the virus itself.

Viral meningitis is rarely fatal. The illness causes an inflammation of the tissues surrounding the brain and spinal cord. Common symptoms are fever, severe headache, sensitivity to light, drowsiness, nausea and a stiff neck. Unlike bacterial meningitis, it's almost unheard of for viral meningitis to cause severe brain damage or death, [Tom Prendergast] said.

Because viral meningitis can be a sign of West Nile virus, some health officials fear that the outbreak is an indication that West Nile has arrived.