Comparison of the epidemiological and clinical features of tick-borne encephalitis in children and adults

The aim of this prospective study was to compare epidemiological data and c linical features in children and adults with tick-borne encephalitis (TBE). Patients with aseptic meningitis diagnosed at the University Medical Centr e, Department of Infectious Diseases, Ljubljana, Slovenia, from June to Aug ust 1997, in whom the diagnosis of TBE was ascertained by the presence of s erum IgM antibodies against TBE virus, who were serologically negative for Borrelia burgdorferi sensu late and had a negative PCR CSF result on entero viral infection, were included in the study. Out of 213 patients with asept ic meningitis, 80 (37.56%) fulfilled inclusion criteria. There were to chil dren and 60 adults. In both groups males predominated. Virtually all patien ts had headache and fever, and more than 50% suffered from vomiting. The ma jority of patients in both groups recalled a tick bite, had a biphasic cour se of the illness, and was found to have obviously expressed meningeal sign s. In both groups the median CSF leukocyte count was somewhat lower than 10 0 x 10(6)/l with a predominance of lymphocytes. Children were more often gi ven antibiotics during the initial phase of TBE than adults (p = 0.0095). S everal other statistically significant distinctions (p < 0.05) were found i ncluding the frequency of fatigue, malaise, vertigo, photophobia, myalgias, arthralgias, as well as elevated CSF albumin and protein concentration, el evated albumin quotient and IgG quotient; all these findings were more ofte n present in adults. In addition a longer duration of fever, more frequent need for anti-edematous treatment and longer hospitalization were found in adults. Direct comparison of clinical and epidemiological characteristics o f TBE in children and adults revealed differences in several clinical and l aboratory features and corroborates the previous conclusion that TBE in chi ldhood is a milder illness than TBE in adults.