Dr. Murai Éva szerk.: Parasitologia Hungarica 24. (Budapest, 1991)

incidence of monosymptomatic ECM among young children is apparent. The ratio of monosymptomatic and total ECM cases decreased with age (Fig. 21). The relative risk of the development of Lb symptoms in children is shown in Table 5. Lyme arthritis is rare in childhood (Table 6). Among Lb patients, facial palsy was twice as common in children (Table 7). Sex A total of 1563 males and 1741 females were examined. Among Lb patients 589 males and 586 females were found. The relative risk of Lb was higher in men (relative risk: 1.12; p<0.05). Without ECM, the odds ratio of Lb was 1.5 times higher in men (p< 0.001). Males were more often seropositive (p< 0.001) and infrequently suffered from ECM (p<0.05). Neuritis and carditis caused by Bb were found more often among men (p<0.05). Serology The time elapsing from the tick bite till serology is very important in the judgement of a serological test. Each interval of Figure 22 contains ten per cent of the patients. A relatively big portion of patients was found to be seropositive shortly after the tick bite. The mean antibody titers are shown in Table 8. Only the typical Lb symptoms are presented here. Which parameters determine the seropositivity? It can be assumed that systemic infection has a bigger chance to result in seropositivity than a localized one. Time is another factor that significantly affects seropositivity. Figure 23 shows the seropositivity ratio as a function of time elapsing from tick bite to the onset of ECM. "Complicated ECM" contains cases not just with major symptoms (e.g. facial palsy or meningitis) but with all the general symptoms (e.g. headache, fever, fatigue) as well. It is not surprising that more seropositives were found among patients with complicated ECM, but it is astonishing that incubation time has an effect on the serological results: the longer time elapsed from tick bite the more patients became seropositive in the complicated ECM group. In monosymptomatic ECM, the opposite was found. Taking all ECM cases, the time that elapsed from the onset of ECM to serology had no effect on the seropositivity ratio. The surprising result was due to two opposite tendencies: complicated ECM cases became seropositive more often as a function of the elapsed time, while monosymptomatic cases were more often found to be seronegative (Fig. 24). In Fig. 25, the incidence of complication is shown as a function of the time that elapsed from the onset of ECM to the serology (start of therapy). There is a significant increase in each group, but seropositive ECM became more frequently complicated with the elapsed time than did the seronegative one. Because most of the patients had become seropositive by the time of the serological test, seroconversion was registered in 109 patients only. A significant difference was found in seroconversion rate between the different clinical symptoms of Lb (Fig. 26). It can be assumed that the early manifestations of Lb give a possibility