[Antigenemia and circulation of specific immune complexes in the asymptomatic course of tick-borne encephalitis]

The frequency of the detection of tick-borne encephalitis (TBE) virus antigens, carried out by the method of fluorescent antibodies with the use of erythrocytic immunosorbent, in the blood of persons bitten by virus-carrying ticks, but with no signs of the clinical manifestation of the infection changed from 5.7 +/- 2.4% to 13.8% of cases with different time elapsed after infection, constituting, on the average, 8.5 +/- 1.4%. The detection of the antigen in the examination of patients varied from 35.8 +/- 6.6% to 45.4 +/- 10.6%, the average figure being 39.8 +/- 3.9%. Antigenemia was more frequently detected after infection by virulent TBE virus than after infection by a low-virulent strain of the virus. The frequency of the detection of specific immune complexes in cases of the asymptomatic course of this infection (28.8 +/- 6.7%) was somewhat lower than in TBE patients (36.0 +/- 3.0%). But the difference between these figures was not significant (p > 0.1), which was probably indicative of the relatively weak formation of specific immune complexes in cases of clinical manifestations of TBE in spite of considerable antigenemia in TBE patients and their sufficiently active formation in the asymptomatic course of the disease.