Tick-borne encephalitis in the Maritime Territory

On the basis of epidemiological analysis carried out at the period of 1940-1987, a decrease in tick-borne encephalitis (TBE) morbidity was registered; at the same time time the disease invariably took, as before, a clinically severe course. The most dangerous foci of TBE were found to be located in the southern Okhotsk region grown with dark coniferous forests. The subsiding and activation of the natural foci of TBE in different regions of the territory were established and some heretofore unknown foci in southern regions of the Maritime Territory were found. Ixodes mites inhabiting the Maritime Territory were shown to have a low level of virus carriership, thus causing the low level of population immunity to TBE virus. Combined foci of TBE and Powassan encephalitis were found.     

Cholera prevalence worldwide and in Ukraine

In the course of the 7th pandemic cholera morbidity has been registered in 163 countries of the world. 5 periods in the development of the pandemic hav been established. The pandemic process has a pronounced tendency to growth. The spread and dynamics of cholera morbidity have their specific features on each continent. In Asia the epidemic process is manifested as permanent morbidity. Africa determines the total morbidity level in the 7th pandemic. In America both the import of cholera infection and large local outbreaks due to the formation of the secondary foci are registered. In Europe the infection is mainly brought from different territories, and in a number of cases an epidemic spread of this infection occurs. The paths of the penetration of cholera to Europe and Ukraine are, probably, identical. In Ukraine 3 pandemic periods have been established, corresponding to the periods of pandemic spread.     

Structure of populations and ecological nishes of ectoparasites in the parasite communities of small forest mammals

The paper reports the results of eight-year investigations on the ectoparasites of rodents and insectivores carried out in southern taiga of the Ilmen-Volkhov lowland (Novgorod Region) and Kurgolovsky reserve (Leningrad Region). Twelve species of small mammals were captured including three dominate species--bank vole Clethrionomys glareolus (2722 specimens), common shrew Sorex araneus (1658 specimens), and wood mouse Apodemus uralensis (367 specimens). Parasite community of the bank vole comprises 34 species of mites, ticks, and insects, the community of common shrew comprises 25 species, and the community of A. uralensis includes 28 species. Taxonomic diversity of the ectoparasite communities was shown to be based on the diversity of types of parasitism and ecological nishes of the host body. Permanent ectoparasites are found to be represented by 2 species of lie and 14 species of acariform mites. The group of temporary parasites includes 13 species of fleas, 10 species of gamasid mites. 3 ixodid species and 1 Trombiculidae. There is a common pool of temporary parasites of small mammals in the ecological system of taiga. Significance of different shrew and rodent species as hosts were found to be dependent on the population density in possible hosts and many other factors. Species diversity in the parasite communities of different small mammal species is dependent on the number of possible ecological nishes in the host body. Actual infill of these nishes by ectoparasites is usually lesser than potential one. Species composition of temporary parasites, their occurrence and abundance changes according to season. Interspecific competition in the temporary parasite species can decrease because of the seasonal disjunction of their population peaks. Diversification of the ecological niches of ectoparasites allow simultaneous feeding of more parasite individuals on one host, than in the case of parasitising of single species or several species with similar ecological nishes. The distribution of parasites on their hosts was also studied. The aggregative distribution has been found in ixodid larvae only, and the distribution of fleas was close to the Poisson distribution. Deviations from the aggregative distribution can be an effect of several independent factors, including limited ability of small mammals for providing numerous parasites with food. On the most part of hosts simultaneous parasitizing of no more than 1-3 individuals of each tick, mite, and flea species was registered. Excessive infestation by ectoparasites may probably be limited by effective reactions of self-purification in the mammal hosts.     

Multiyear and seasonal hepatitis A morbidity in different population age groups in certain areas

At the areas with high activity of hepatitis A (HA) epidemic process the duration of epidemic cycles was shown to differ, the intervals between the peaks of morbidity increasing in older age groups. The beginning of seasonal rises exceeding the average annual HA morbidity level in different age groups was found to depend on the activity of the epidemic process. At the areas with the highest activity of the epidemic process children aged 1-2 years were the first to be affected by the seasonal rise of HA. Stable direct correlation between HA morbidity levels at the beginning of seasonal rises and some markers indicative of unfavorable sanitary conditions (the size of the fly population, the purity of water samples deviating from the requirement of the Government Standard) during the preceding year was demonstrated.     

The epidemic spread of the influenza A and B viruses in the USSR in 1985-1986

The data on the spread of influenza A and B in the autumn and winter of 1985-1986 are given. Three epidemics caused by all presently circulating viruses, B, A (H3N2) and A (H1N1), were registered in the USSR. Of these, the greatest one was the epidemic of influenza B; morbidity rate among the adult population during this epidemic was at the level with the morbidity rate characteristic of the epidemics registered at the period of 1962-1972, and morbidity rate among children, especially school children, was even higher.     

Mycopathogens of Mites in Poland - A Review

Studies on diseases of mites caused by entomopathogenic fungi have been undertaken in Poland about a half a century later than in West European countries. Nevertheless, during the last 30 years almost 40 species of arthropod pathogenic fungi have been identified, among them 23 species of Entomophthorales, 12 species of Hyphomycetales and four species of ectoparasitic Laboulbeniales. The most common are representatives of the genus Hirsutella , found both on phytophagous and parasitic or predaceous mites. Percentage infection by H. thompsonii in populations of some tarsonemid and eriophyid mites increases slowly from the end of spring reaching a maximum of 30-60% in August-September. Neozygites floridana is a common entomophthoralean species causing epizootics in spider mite populations; infection also peaks in late summer and autumn. The most numerous fungal taxa have been identified from the resting spores produced internally within the body of the host and show features of the genus Tarichium . From the total number of the taxa recorded within these studies, 22 were described as species new to science. Current research on invertebrate pathology in Poland includes many groups of mites and among their pathogens fungal diseases seem to be the most common.     

Problems of the epidemiology of viral hepatitis in Ryazan Province

The analysis of some features of the course of the epidemic process of viral hepatitis on the territory of the Ryazan region is presented. Periodic rises and falls in viral hepatitis morbidity, varying in their regularity (4-6 years), have been registered in the region. The general level and the seasonal distribution of viral hepatitis morbidity are determined by the morbidity rate among children, the increase in the proportion of children of senior school age being observed in recent years.     

Influenza epidemics in the USSR and Czechoslovakia in 1979-1984

In this work materials characterizing the appearance and development of influenza epidemic at the territories of the USSR and the Czech Socialist Republic are presented, the common features and differences of the epidemic process in both countries are recorded. The work shows that in both countries the appearance of this epidemic is caused by the same virus. In most cases the epidemic started earlier and lasted longer in the USSR, but morbidity rate during the epidemic was, on the whole, higher in the Czech Socialist Republic. Similarity in the course of the primary period of the epidemic processes from their appearance to their maximum rise was observed. In both countries the maximum rise of morbidity rate was registered on weeks 3-4 from the beginning of the epidemic.     

Diphtheria morbidity in Russia today

The data on diphtheria morbidity and the occurrence of carrier state for its causative agent at the period of 2001-2002 were analyzed. The rates of morbidity and detected carrier state for these years were 0.63-0.55 and 0.65-0.64 respectively. Nevertheless, in spite of the relatively low morbidity rates the presence of the toxic forms of diphtheria (400 patients for two years) and lethal cases (with lethality rate reaching 5.4%) indicated that the epidemic situation in diphtheria remained tense. The most unfavorable situation was observed in the North-Western and Central regions of Russia. In urban areas morbidity rates were still 2- to 3-fold higher in than in rural ones, but the latter showed a higher percentage of severe cases (46.6% in 2001 and 39.7% in 2002) and lethal outcomes (13.6% and 19.2%). The latter was indicative of drawbacks in the immunoprophylaxis, diagnostics and treatment of diphtheria in rural areas. In the total structure of diphtheria patients adults prevailed: 75%. The highest morbidity rates were registered among children aged 3-6 years, among adults in the age groups of 18-19 years and 50-59 years. The epidemic process developed mainly among the immunized population, which was indicated by a high proportion of vaccinated persons among those affected by this infection (62.8-66.6%) and a mild course of the disease in the majority of them. The present epidemiological situation in diphtheria was determined by patients not vaccinated against this infection. The proportion of severe cases among nonvaccinated children was 42.4-51.6% and lethal outcomes, 12.9-15.1%. Among nonimmunized adults these figures were equal to 43.1% and 9.3% respectively. The highest percentage of children, not vaccinated during the first years of their life, was registered among those in the asocial families, refugees and homeless persons. Among adults these were persons above 50 years old, as well as jobless persons of working age, pensioners and invalids, who had limited possibilities of undergoing vaccination due to their social position. It was these social and age groups that should be regarded as risk groups with respect to the severity of the course of diphtheria and lethality. To stabilize diphtheria morbidity, the full complex of prophylactic and antiepidemic measures, and primarily the immunization of the population, should be systematically carried out.     

The clinico-epidemiological characteristics of Powassan encephalitis in the southern Soviet Far East]

The present communication deals with the analysis of 14 cases of Powassan encephalitis. As shown in this study, the course of this infection may be accompanied by symptoms indicating the presence of cerebral and meningeal lesions (in 7 cases meningoencephalitic forms with one fatal outcome and in 2 cases meningeal forms were registered) or take febrile and inapparent forms (5 cases). Powassan encephalitis was found to give characteristic symptoms of cerebellovestibular lesions, differentiating this disease from tick-borne encephalitis (TBE). The cases of mixed infections caused by TBE virus, Powassan encephalitis virus and tick-born Borrelia were found to be possible.     

Tick-borne encephalitis in a northern zone of coniferous and broad-leaved forests of a focal region of the Amur River basin

The geographical variability of the population of tick-borne encephalitis (TBE) virus in the northern part of the zone of combined coniferous and broad-leaved forests was established; this variability was manifested by higher virulence and homogeneity of TBE virus strains, as shown in experiments on white mice receiving the virus extraneurally, in comparison with the southern part of the zone and by higher virus carriership of the ticks Ixodes persulcatus. With the epizootic situation remaining tense and the danger of TBE virus infection still present, TBE morbidity and mortality rates decreased in the years of the construction of the Baikal-Amur Railroad, which was due to greater attention given to measures for the prophylaxis of TBE during this period.     

The results of a seroepidemiologic study of Newcastle dysentery

Differences in the monthly distribution in the number of seropositive individuals among children and adults in years with different intensity of the epidemic process have been revealed. Immunity in cases of dysentery caused by S. newcastle reflects the yearly and seasonal activation of the epidemic process in this Shigella infection both in children and adults, the seroconversion characteristics observed in the year of a high morbidity level being a more objective criterion indicating the beginning of the activation of the epidemic process in dysentery caused by S. newcastle in comparison with the commonly registered morbidity level.     

Retrospective epidemiologic diagnosis of viral non-A, non-B hepatitis with a fecal-oral mechanism of transmission of the causative agent

The possibility of the retrospective epidemiological diagnosis of viral hepatitis non A, non B with the fecal-oral mechanism of the transfer of infection in three cities of Central Asia on the basis of the analysis of the dynamics of registered hepatitis A morbidity is shown. With the irregularity of morbidity levels among the total population being characteristic of all three cities, in Andizhan one rise in morbidity within a period of 3 years (1975-1978) and in Tashauz one rise within a period of 5 years (1975-1980) were registered. The analysis of the dynamics of morbidity observed in individual age and social groups showed that these rises, especially those registered in 1976 in Andizhan and in 1977 in Tashauz, were determined by morbidity levels among school children and adults. This is also true for a rise in morbidity rate registered in Tashauz in 1985. In Andizhan the highest morbidity rates among adults were registered in districts insufficiently equipped with modern amenities. Cases of infection registered as hepatitis A (HA) among persons immune to HA at territories with high intensity of the epidemic process of HA at the above-mentioned periods seem to be due to viral hepatitis non A, non B with the fecal-oral mechanism of the transmission of the infective agent.     

Hepatitis A in Estonia (1990-1999)

During recent 10 years (1990-1999) essential changes occurred the epidemiology of viral hepatitis A (VHA) in Estonia: simultaneously with a decreased level of morbidity (morbidity rate per 100,000 of the population was 78.4 in 1990 and 7.7 in 1996, or 1,241 and 112 cases, respectively), a shift in the age structure of patients from children of preschool age to older age groups took place. Everyday contacts were the main established route of VHA transmission in recent years, but in more than 80% of cases the risk factors of the virus transmission remained obscure. During the regional outbreak of VHA in North Estonia in 1998 (937 out of 989 cases registered in the country) a rise in morbidity was observed among young people aged 15-29 years, when a wide spread of parenteral viral hepatitides B and C and drug addiction were registered in this region. During this outbreak VHA was transmitted mainly through everyday contacts. Still the considerable prevalence of injection drug users who practiced the group use of syringes and needles and took drugs from common containers, a sufficiently high level of the mixed forms of the disease (more than 18% of all registered cases of VHA), detected for the first time, make it possible to suggest that the parenteral transmission route could appear among persons belonging to the above mentioned group. Vaccination is regarded as the most effective measure for the prophylaxis of VHA.     

中国云南洱海周边大足鼠的体表寄生螨

用U检验和相关分析的统计方法对2003～2004年云南洱海(中国滇西北著名的淡水湖泊)周边251只大足鼠体表寄生螨进行了调查.调查点是我国11大鼠疫自然疫源地之一,也是我国恙虫病和出血热的流行地区.大足鼠已经被鉴定为鼠疫、汉坦病毒、恙虫病和流行性出血热的储存宿主.我们的研究发现大足鼠携带好几种与人兽共患病有关的螨类.为了丰富大足鼠体表寄生螨的研究,在此,对大足鼠的体表寄生螨群落和体表寄生螨医学和兽医学的重要性进行了描述.有191只大足鼠寄生有体表寄生螨,侵染率为76%.采集到的体表寄生螨有35种,包括15种恙螨和20种革螨.其中6种以前已经被证明是人类疾病的主要媒介.因此大足鼠很显然成为流行性出血热和恙虫病等病原体的贮存宿主.     

Results of the 20-year study of tick-borne encephalitis in Crimea

The history of tick-borne encephalitis (TBE) study in the Crimea was retraced and the possibility of introduction of TBE virus to the Crimea in the process of the acclimatization of vertebrates from areas enzootic for TBE is discussed. The foci of TBE were found throughout the whole of the mountain forest zone of the Crimea and coincided with the habitat area of lxodes ricinus, the main vector of TBE. Such ticks as Dermacentor reticulatus, D. marginatus and Hyalomma marginatum were also found to take part in the circulation of the virus. Among the residents of the mountain forest zone, 13.9% were found to have immunity to TBE, testifying to the wide contact of the population with the pathogen. TBE morbidity had pronounced seasonal character and the morbidity rate was low with the prevalence of mild clinical forms. The characteristic feature of the virus population was polymorphism: strains identical to the Far-Eastern strains Sofyin (about 60-70%) and strains differing in their antigenic structure circulated here.     

Ixodes tick-borne borreliosis and tick-borne encephalitis in the Udmurt republic: retrospective analysis of their spread

The primary clinical-anamnestic and laboratory data on 1,062 cases, registered in Udmurtia in 1965-1968 and caused by the bites of taiga ticks (ixodes persulcatus), were retrospectively analyzed. The study revealed that not less than 27% of these cases could be regarded as cases of Ixodes tick-borne borreliosis (ITBB); formerly they were classified with tick-born encephalitis (TBE) or diseases of unclear etiology. The spread of ITBB on the territory of the Udmurt Republic was shown to be similar to that of TBE.     

中国云南小兽寄生革螨的群落结构和空间分布

寄生在小兽体表的革螨可能是传播肾综合征出血热和立克次体痘等人兽共患病的媒介。本文报道了云南省28个县(市)小兽体表革螨的野外调查结果, 运用物种数、平均丰富度和Shannon多样性指数对小兽寄生革螨的群落特征和沿环境梯度的空间分布进行了研究, 并用系统聚类分析法 (SPSS 16.0软件)对18种主要小兽的革螨群落相似性进行了比较。在云南省28个县(市)共捕获到小兽14 544头, 隶属于5目（啮齿目、食虫目、攀鼩目、兔形目、食肉目）10科35属67种, 在捕获的小兽体表采集到革螨80 791头, 经鉴定属于10科33属112种。结果分析表明: 主要的宿主动物为黄胸鼠 Rattus tanezumi、齐氏姬鼠Apodemus chevrieri和大绒鼠Eothenomys miletus;纳氏厉螨Laelaps nuttalli、毒厉螨L. echidninus和贵州厉螨L. guizhouensis为革螨的优势种。齐氏姬鼠A. chevrieri、社鼠N. confucianus和黄胸鼠R. tanezumi体表寄生的革螨种类最多;臭鼩鼱Suncus murinus、齐氏姬鼠A. chevrieri和灰麝鼩Crocidura attenuata的革螨群落多样性最高。聚类分析结果表明, 大部分革螨群落的相似程度与相应小兽的亲缘关系及所处生态环境的相似性是基本一致的, 分类地位和生境选择相似的小兽, 它们的革螨群落也被聚为一类。革螨物种数沿纬度梯度的水平分布呈现两个峰值, 最大峰值出现在25°~26°N之间;沿海拔梯度的垂直分布呈单峰分布格局, 峰值在海拔2 000~2 500 m之间。革螨和小兽的多样性沿纬度梯度和海拔梯度的空间分布趋势也均表现出随着纬度和海拔的升高而先升高后降低的单峰型分布格局, 峰值分别出现在北纬25°~27°N和海拔2 000~2 500 m之间。结果提示云南革螨群落种类丰富, 多样性高。云南革螨物种数和多样性的分布格局可能直接受到古北和东洋两区系边缘效应的影响。     

Morbidity and mortality in acute viral hepatitides in a hyperendemic region. The role of viral hepatitis E

Official annual statistical data on morbidity in acute viral hepatitides (AVH), including the number of lethal cases, for 1985-1995 were analyzed. Mortality rates per 100,000 of the population at the period of 11 years were calculated for different age groups, sex and the place of residence. 396 and 99 patients were examined for the presence of serological markers of hepatitides A, B and E, respectively, at the periods of epidemic rises in morbidity and satisfactory epidemic situation. In the course of 11 years AVH caused the death of 22,405 persons. In 1985-1987 the average mortality level (ML) reached 12.3-17.8 per 100,000 of the population (with morbidity being 1,200-1,400 and was essentially higher among the rural population in comparison with the urban population. During these years the highest ML, was registered among children aged 0-2 years (190-50 per 100,000) and, among adults, mainly among women aged 20-29 years (21.4-19.6 per 100,000). During the years when the epidemic of AVH was absent, ML among these groups was essentially lower: 40-20 among children aged 0-2 years and 4-5 among women aged 20-29 years. In 1987 in the Fergana Valley hepatitis E was detected in 72.2% of all examined patients, and in the southern areas of the country in 68.7%. A sharp rise on mortality among women of the productive age at the period of the epidemic rise of AVH morbidity in the endemic region indicated that this epidemic was linked with hepatitis E. High ML among young children may be indicative of a highly unfavorable course of hepatitis E in the group of infants, which had never been registered before. This newly established regularity may be used for the retrospective diagnostics of the outbreak of hepatitis E.     

中国云南洱海周边小兽体表革螨多样性（英文）

云南大理洱海周边是我国流行性出血热的流行地区之一。本文目的是运用Shannon-Wiener、系统聚类分析方法（SPSS 13.0软件）和Levins'niche等对该区3 303只小兽体表寄生革螨的物种多样性、群落结构、相似性、分布和生态位进行研究。选择的洱海周边三个不同方位恰好处于东部无量山、南部哀老山和西部苍山,由于洱海的天然隔离使这三个方位形成了同地域异生境的地理景观。在调查点共捕获小兽宿主3 303只属4目（啮齿目、食虫目、攀鼩目和食肉目）7科15属21种,收集到的小兽体表寄生虫革螨23 196只被鉴定为6科16属43种。研究结果表明革螨群落结构复杂,物种多样性高。在不同方位革螨和它们相对应宿主的分布是不均匀的,但是洱海周边不同方位同样优势小兽上寄生的优势革螨种是一致的。结果暗示：生境影响着革螨和它们相对应小兽的物种构成和分布,如果小兽宿主的分类地位和生境相似,那么相对应的小兽宿主上的革螨群落就相似; 不同方位小兽体表寄生虫革螨的丰富度和物种多样性主要由宿主本身和宿主所栖息的生境决定;这可能是小兽和革螨之间协同进化在生态学上的一个佐证。但通过使用革螨的生态位宽度分析,革螨的宿主特异性很低,这又可能暗示着小兽和革螨之间有协同进化,但协同进化程度不高。