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A controlled clinical trial included 115 patients with meningeal and focal tick-borne encephalitis, 38 of them received nonspecific treatment alone, 77 were given adjuvant intramuscular immunoglobulin against tick-borne encephalitis. The latter are shown to improve much more rapidly than patients treated only symptomatically. When calculating adequate immunoglobulin doses, it is necessary to take in consideration not only the amount of the compound, but also the concentration of the specific antibodies. The authors propose treatment schemes for patients with meningeal and focal tick-borne encephalitis.

Using a commercial diagnostic preparation for indirect IFA test, 135 urine samples from 50 patients with HFRS were examined at different periods of the disease. Antibodies were demonstrable in all urine specimens from HFRS patients for 13 days. In 14-20 days they could be detected in half of the patients, and no antibodies could be demonstrated since the 21st day on. The results of urine examination from healthy subjects and some patients with other clinical diagnoses were negative same as controls with normal antigen. The dynamics of antibody titres in the patients' urine differed from that in the blood and was considered as "decreasing" similarly as the clinical disease. The antibody excretion in the urine coincided with the period of renal structure damage and stopped when the normal renal function was restored. The data are discussed from the point of view of the pathogenesis and diagnosis. Special attention was paid to the possibility and advantages of early HFRS diagnosis by antibody determinations in the patients' urine.

A case of group infection with tick-borne encephalitis (TBE) in Bikin, Khabarovsk Territory is reviewed. The disease developed as a result of drinking raw cow milk, bought from one owner, and eating sour-milk products made of that milk. 5 persons from 3 families were ill, in three cases the outcome was lethal. Data of clinical, epidemiological, viral and serological examinations confirm the diagnosis of TBE. Various antibodies to TBE virus have been determined in the blood of cows. The presence of complement-fixing antibodies may indicate fresh infection. The characteristics of TBE viral strain, isolated from the brain of dead Z. N. F. is presented on white mice. The data obtained confirm the previous suggestion on possible transmission of TBE virus with cow milk.

Nucleic acids of Ixodes persulcatus were studied by molecular hybridization in the natural focus of tick-borne encephalitis in Kholmsk District of Sakhalin Province. The studies have shown wide dissemination of viral RNA in the focus. The infectivity of ticks in various sites of habitation varied from 3.5 to 18.5%, their number fluctuating from 0.4 to 300 and more imago per flag-hour. The most active part of the natural focus has been determined using zoological-viral indexes. The viral strain of tick-borne encephalitis has been isolated.

The authors suggest a new technique for the detection of viral antigen in the urine of HFRS patients, based on the method for the differential cytologic rapid diagnosis of acute respiratory viral diseases. HFRS virus antigen was detectable in the urine sediment epithelium in 7 of the 8 patients from the seventh to the thirty-second day of the follow-up. Fluorescent bright-emerald dots could be seen in the urine sediment cells, situated on the cell surface, in the cytoplasm round the nucleus and in the periphery. In one case the antigen was not detected. No HFRS virus-injured cells were detected in the urine sediment epitheliocytes of normal subjects or patients with other renal diseases. The efficacy of the method was 87.5 +/- 12.5%. This method permits monitoring the virus persistence and its isolation from the patient during the acute period of the disease and early convalescence period. The technique is reproducible and takes 8-12 hrs; it can be used at research and practical laboratories.

In the Soviet Union the incidence of tick-borne encephalitis is the highest in the geographical and epidemiological region adjacent to the Amur River (zone of coniferous and broad-leaved forests). 60.43% of all cases fall on years of cyclic rise of the disease incidence. Strains of the tick-borne encephalitis virus can be isolated with a more significant frequency from the blood of encephalitis-sick patients and from the brain of the dead in the years of disease outbreaks.

In natural foci of hemorrhagic fever with renal syndrome (HFRS) located in agricultural landscapes, rodents of various species are infected with the virus, however, regular HFRS epizootics are observed in field mice which present the highest abundance of infected animals in the population. Annually, a high direct correlation is observed between the population density of rodents and the percentage of animals with HFRS virus antigen in the blood and lungs. In 1981, there was a high correlation between the occurrence of rodents with Gamasid mites and the presence of the antigen in the blood. All the foregoing suggests that HFRS agent exists in natural foci due to a combination of different transmission mechanisms (obligate-transmissive mechanism) and penetrates into murine rodents by various modes: air--dust-borne and/or alimentary and transmissive. Non-transmissive modes are likely to be the leading ones.

The method of molecular hybridization of nucleic acids (MHNA) is compared to the traditional bioprobe technique in the study of virus carriership of I. persulcatus ticks collected in the South and in the North of the area of coniferous and broad-leaved forests in the Khabarovsk Territory. Higher sensitivity of the MHNA method than that of the bioprobe was demonstrated by studying the tick pools: 4.9% versus 1.6% (1985), 18.2% versus 3.6% (1986). Virus carriership studied by MHNA in isolated ticks comprised 8.6% (1985) and 10.8% (1986) in the south of the region and 20.0% (1985)--in the north; average content of RNA of the tick-borne encephalitis virus comprised 10 pg. MHNA allows massive studies of individual ticks and better indication of the virus to be carried out; the response can be obtained in 24-48 hours.

A new genetic marker, sensitivity of hemagglutinins of tick-borne encephalitis virus (TBE) strains to the effect of hyamine 10-X (Hs), was used for characterization of the hemagglutinating component of freshly isolated TBE virus variants with differing neurovirulence and for strain grouping. This marked may also be used for directed search of strains highly active in HI.

Eighty strains of tick-borne encephalitis virus isolated from I. persulcatus ticks collected in 1976-1981 in the same biotopes in the south and north of the zone of coniferous-broad-leaved forests, and two biotopes of the southern taiga subzone of the Khabarovsk region and Sakhalin island, as well as from the brains of fatal cases were studied. Significant differences were found between maximal and minimal values of the invasive activity in spatially separated populations of the same zone (t = 2.32, P less than 0.02). Significant interpopulation differences were also found in the value of peripheral activity (t = = 2.77, P less than 0.02) and invasivity index (t = 3.83, P less than 0.01). Natural heterogeneity of the strains was found both by previously known markers (high neurovirulence for mice, invasivity index, plaque size in SPEV cell culture, viremia in mice, stability to thiamine 10X- and a new marker proposed by us: the degree of adsorption of hemagglutinins on an ion-exchanger DEAE-Sephadex A-50. Strains of tick-borne encephalitis virus were grouped in two landscape zones, this grouping indicated the existence of significant interpopulation differences.

Strains of tick-borne encephalitis virus isolated from I. persulcatus ticks collected in various landscape zones of Priamurie differ in their invasiveness and hemagglutinating activity. A relationship between these properties of tick-borne encephalitis virus strains and the percentage of immune subjects in the population has been established. The coefficient of the epidemic danger of a landscape zone is described which includes the index of probability of infection and characteristics of the index of strain invasiveness and permits prognosis of the nature of the epidemic process in the area.