KA Senger, State Epidemiologist, South Dakota State Dept of Health. BT Haslam, CR Nichols, MPA, State Epidemiologist, Utah Dept of Health. S Jenkins, MD, M Cader, MD, GR Miller, Jr, MD, State Epidemiologist, Virginia State Dept of Health. JM Kobayashi, MD, State Epidemiologist, Washington Dept of Social and Health Svcs. W Schell, JP Davis, MD, State Epidemiologist, Wisconsin State Dept of Health and Social Svcs.
Cases occur principally in children.
Boys, who account for two-thirds of cases, are at highest risk because of their greater outdoor exposure. In the decade between 1977 and 1986, the average number of cases per year reported to CDC was 83. However, LaCrosse virus infections may be significantly underreported. Viewed from this perspective, LaCrosse virus infections are an important public health concern as a cause of CNS morbidity among children in endemic areas. No naturally infected mosquitoes or instances of human infections with California viruses have been attributed to this vector.