Abstracts of current literature| Volume 12, ISSUE 3, P216, September 2001

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La Crosse encephalitis in children

        New England Journal of Medicine

        La Crosse encephalitis in children

        Most cases of La Crosse (LAC) encephalitis are undiagnosed. Not only have confirmatory tests been insensitive and expensive, but there have been no specific treatments proven to affect outcome. Furthermore, most patients with this mosquito-borne virus suffer little more than cold symptoms. At the same time, however, not everyone with LAC encephalitis has a benign outcome. Also, some treatments are being developed. This recent article, published in the New England Journal of Medicine, provides an updated description of LAC encephalitis and attempts to identify risk factors for developing severe disease. It also discusses some of the potential treatments available.
        The authors of this study performed a retrospective chart review of 127 children who were diagnosed with LAC encephalitis in Charleston, WV, between 1987 and 1996. Multiple statistical calculations were performed, including univariate analyses. They provide both epidemiological data and clinical data on all 127 children.
        The mean age of patients in this study (± SD) was 7.8 ± 3.5 years, and most cases were diagnosed between July and September. The most common symptoms on presentation were headache, fever, vomiting, mental status changes, and seizures. Although patients who suffered clinical deterioration more often had fevers, vomiting, and seizures, the sensitivity and specificity of these symptoms were too low to be of clinical value. Patients with in-hospital deterioration did, however, have statistically significant lower sodium levels and higher fevers than those with benign outcomes. They also tended to have Glasgow Coma Scores less than 13. Laboratory and radiographic findings were nonspecific. Some patients were given ribavirin therapy, but the results of this therapy will be part of another clinical report.
        Not all children recover from LAC encephalitis free of long-term sequelae. In this study, 15 children (12%) had neurological deficits at discharge. Of the children aged 5 years and older, 28 (32%) were classified as having relatively severe disease. Cognitive testing of these children 10 to 18 months after hospitalization revealed consistently lower IQ scores than average. No proven treatment is available for LAC encephalitis, but new drugs are being tested. Also, antibody screens can more accurately diagnose LAC encephalitis than in the past. Currently, most children are misdiagnosed and are given unnecessary, ineffective antibiotics. Correctly diagnosing LAC encephalitis and recognizing potential markers of clinical deterioration should enable physicians to better treat these children and reduce morbidity.
        (N Engl J Med. 2001;344:801–807) J. E. McJunkin, E. C. De Los Reyes, J. E. Irazuzta, et al.
        Prepared by Ronald Roessler, MD, Medical College of Wisconsin