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Induced malaria continues to be one of the most pressing public health problems in malaria-endemic countries. Ma- laria parasites remain viable in stored blood at a temperature of 2-6°C for 3 weeks. The paper presents current problems associated with transfusion-induced malaria. In the USSR and then in the Russian Federation, sporadic cases of induced malaria (Plasniodium vivax, P.malariae, rarely P.falciparum) were notified (230 cases in 1958 to 1990 and only 5 in 1991 to 2016). Current (immunological and molecular) methods for the laboratory diagnosis of malaria do not provide a 100% detection rMfteor its pathogens; therefore, it is necessary to search for highly efficient, rapid, and low-cost diagnostic methods to ensure the biological safety of donation.

Infectious diseases are one of the serious threats to biosafety in modern society In recent years, there have been con- siderably increased international migrations: tourism and pilgrimage; labor migration flows; migration of refugees and settlers in times of armed conflicts, household migrations because of family ties and traditions. Since the number of Rus- sian tourists and migrants from endemic countries remains high, these contingents should receive special attention in the malaria epidemiological surveillance system. The paper discusses the risks of possible consequences of population migra- tions and prevention measures.

The paper gives the results of experimental studies, as well as sanitary parasitological ones investigating meat and fish, which have been performed using manual microscopy and Mecos-C2 automated digital microscopy and scanning micro- scopy. It shows the effectiveness of automated versus manual microscopy in performing parasitological studies of foods and the possibility of rationalizing production labor. The investigation has been conducted to develop the reform of labora- tory services of the healthcare system in the Russian Federation and proposes to introduce a hardware technology into a group of mass methods for parasitological analyses in sanitary-epidemiological, veterinary and environmental areas.

There is evidence that in 1923-2014 the sharp aggravations of the epizootic situation of plague in the area of its Caspian sandy natural focus after long interepizootic periods are in time with the ups of the Caspian Sea in the extrema of 11-year solar cycles. There were cases of multiple manifestations of plague in the same areas in the epizootic cycles of 1946-1954, 1979-1996, 2001, and 2013-2014. The paper considers the possible role of amebae of the genus Acanthamoeba and nematodes, the representatives of the orders Rhabditida and Tylenchida in the microfocal pattern of plague manifestations.

The paper describes a clinical case of visceral leishmaniasis in a three-year-old child who Was born and is a permanent resident in Penm. Its clinical symptomatology; laboratory and instrumental findings; stages of a diagnostic search for fever of unknown origin concurrent with hepatosplenomegaly and pancytopenia; differential diagnosis with hemoblastosis; and an epidemiological history are detailed. Visceral leishmaniasis was diagnosed at examination of bone marrow specimens. The paper presents the positive results of combination etiopathogenetic treatment, which are confirmed by the time course of clinical changes and laboratory findings.

The paper gives the results of treatment with micronized albendazole (Gelmodol-BM, World Medicine, UK) in 87 patients of the Department of Medical Parasitology and Tropical Diseases, Clinical and Diagnostic Center, Clinical Center, I.M.Sechenov First Moscow State Medical University. Thirty-two patients with echinococcosis 8 with alveococcosis (including 4 inoperable patients), 10 with ascariasis, 10 with toxocariasis, 15 with enterobiasis, and 12 people diagnosed with larva migrans were treated in 2013-2014. The drug's routine doses and dosage regimens were used. Albendazole (Gelmodol, World Medicine, UK) showed a high efficacy with good tolerability, which is highly competitive with that of the drugs manufactured by IPCA Laboratories Ltd., India (such as nemozole). Both medicaments above-mentioned may be successfully used in the treatment of many helminthisms.

The paper describes a case of disseminated strongyloidosis in a 52-year-old woman living in Volgograd. Filariform and. rhabditiform larvae of the nematode Strongyloides stercoralis were found when analyzing her urine, sputum, and feces. She had been followed up and treated for duodenal ulcer for more than 15 years. During that time, the patient periodically underwent radiographic and ultrasonic studies and clinical and biochemical blood tests. Fecal tests were not been carried out. This case could convince that there was a risk for human strongyloidosis in the arid region having a temperate climate in European Russia and when timely detection of invasion and specific treatment were not performed, there might be disseminated strongyloidosis. The reason for late diagnosis was epidemiological history (possible contact with soil) underestimation and improper-patient examination.

The paper analyzes data on the prevalence and possible epidemiological importance of Rickettsia raoultii. The possible risk of infection in the population was assessed from the results of a serological study of patients after tick suction and from those of molecular biological determination of contamination of removed carriers. The place of Rickettsia raoultii among other rickettsia causing rickettsioses of a tick-borne spotted fever group is assessed in Russia.

The paper considers the functional aspects of a biological component in programs for training specialists in the area of Parasitology for accreditation within the current enactments, including those on modernization of public health and additional professional education. The working program of the module "Fundamental Disciplines" has been used as an example to outline approaches to molding a medical parasitologist's capacity and readiness to solve professional tasks on the basis of knowledge of fundamental disciplines: biology, immunology, and medical geography. Education fundamentalization is shown to suggest more unsupervised work of a learner in the teaching process. The fundamental constituent of a biological component of the 'programs for training learners in the specialty of Parasitology for accreditation is shown in the interaction of all sections of this area with special and allied subjects.

The paper describes a case of acute opisthorchiasis in a 31-year-old female patient after ingestion of dried fish of the family Cyprinidae caught in the Oka River basin on the border of the Moscow and Ryazan Regions. This case could convince of that there was a risk of human Opisthorchis infection despite the zoonotic pattern of circulation of the pathogen in European Russia. The dietary intake of unsterilized fish of the family Cyprinidae caught in the Moscow and neighboring regions may give rise to Opisthorchis invasion and, it a large infectious dose, to acute opisthorchiasis.

The paper analyzes the change that occurred in the habitat of the causative agent of plague in its Gorno-Altaisk natural focus in 1961 to 2012. Since 1961 when the plague microbe was found to come from the southern slopes of the Saylyugem mountain range, which are located in Mongolia, to the northern slopes situated in Russia, a gradual expansion of the habitat of Yersenia pestis subsp. altaica had commenced in South-Eastern Altai. During the considered period, the area where epizootic manifestations were registered showed an 11-fold increase. In most cases, the spread of the plague pathogen within the focus was natural and occurred in the successive and closely related settlements of Mongolian pikas (Ochotona pallasi). By now, the plague microbe has been widely distributed in three populations of this small animal, which inhabit the territory of South-Eastern Altai.

The Faculty of Geography, M.V. Lomonosov Moscow State University, is creating a "Natural Focal Diseases" medical and geographical atlas of Russia. The paper considers the possibilities of the atlas to monitor and assess the epidemiological situation of a number of diseases. The atlas allows one to define a spectrum of the most epidemically significant natural focal diseases in Russia, to quantitatively characterize their incidence in the population, and to visualize it in a series of maps, to make a medical geographical analysis of the prevalence of the nosological entities of natural focal diseases in both individual subjects of the Russian Federation and in Russia as a whole. By using tick-borne encephalitis as an example, the authors consider approaches to analyzing the incidence of natural focal infections, by using different types of the maps given in the atlas.

The paper presents data on the prevalence of helminthiasis in Russia on the basis of the State Reports on the sanitary and epidemiological situation in the Russian Federation. It comparatively characterizes morbidity rates in 2010-2012. Morbidity analysis has revealed the main reasons for the prevalence of parasitic diseases and the possible ways of their elimination.

The paper presents the results of clinical, epidemiological, and epizootological analyses of local cases of human dirofilariasis in the Nizhny Novgorod Region, which suggest that natural and climatic changes, namely the abnormally hot summer in 2010-2011 and increasing migratory processes among human beings and animals, open up possibilities for forming foci ofdirofilariasis outside habitats of Dirofilaria repens.

The paper shows changes in the size of Ixodes ricinus ticks population and their infection according to the results of their 20-year systematic collections and censuses on the same routes in the Zhukovsky District, Kaluga Region. It has been established that there are always some infected I. ricinus ticks in the season of their activity (April to September). The maximal focal hazard characterized by the highest abundance indices for infected ticks is seen in May-June. This area requires greater attention due to the changes in the regime and borders of the buffer zone of the State Tarusa Complex, a national nature reserve.

The Guard aerosol generator is a universal multioperational device without a field-of-use restriction in the application of permitted chemical and biological substances, by combining the function of a controlled dispersion aerosol generator and a remote small- and large-drop sprayer in one mechanism and can use aerosol pesticides. The drop fractionation range is as follows: 3-50, 50-100, 100-300, and 200-400 microm for aerosol, dead water, small-drop, and large-drop spraying, respectively, with smooth and step control of working liquid drops. Treatment using the Guard generator has been shown to be highly effective against agricultural and forestry pests. This paper describes the advantages of the Guard sprayer over those of the conventional air and ground ones. The long-term use of the Guard generator to control mosquitoes and ticks in the Tyumen region could substantially improve the epidemiological situation of tick-borne infections and protect children's recreation centers from attacks of bloodsuckers.

The paper describes cases of dirofilariasis in the Nizhny Novgorod Region in 2006-2010. During this period 26 patients with dirofilariasis were registered. Their age was 20 to 68 years; the maximum cases (26.9%) were among those aged 50-59 years. Females constituted most cases (70%). In 73% of patients, the helminth was found in different areas of the head, with the predominant involvement of eye lesion (34.6%), in the temple (11.5%), cheek (8%), and nose (8%). Dirofilaria were randomly detected in 2 patients. Helminth migration occurred in 15.3% of cases. No clear seasonality for this helminthiasis was found. Local dirofilariasis was noted in most cases (92.3%). This infection was observed in 13 of 49 districts of the region and in 3 of 8 districts of Nizhny Novgorod. The Nizhny Novgorod Region is situated in a low infection transmission risk area (latitude 54-58 degrees North). However, among 11 areas located in this zone, the Nizhny Novgorod Region registered the maximum cases of dirofilariasis. Dirofilariasis in the Nizhny Novgorod Region shares the manifestations of this helminthiasis in the Russian Federation.

The paper gives data on an opisthorchiasis focus in the Taishetsky district, Irkutsk Region. The species affiliation of Bithynia from the Biryusa River basin was established. These mollusks are morphologically close to Opisthorchophorus hispanica (= Bithynia inflata). No O. felineus trematodes were found in the snails examined. Roach, dace, and bream were the second intermediate hosts. Analysis of long-term data revealed that fish and human infection rates have remained comparatively high for almost 20 years. The peak for Opisthorchis infestation in carps were in 1982 (9.3%), 1983 (2.9%), 1998 (5.5%), 2000 (2.5%), and 2007 (5.9%). In other years, fish infection ranged from 0.4 to 1.6%. The performed investigations showed that dace and bream were most infected. Data on the focus area that was 1500 km2 are first presented. The Irkutsk focus of opisthorchiasis is considered to be little studied since there is no evidence (infection rate, prevalence) for mollusks, wild (muskrat, otter, bank vole, fox, wolf) and domestic (dog, pig) animals. The considerable pathogenicity of the parasite and the natural focal pattern of the disease call for regular investigations at all stages of its life cycle: mollusks, fishes, fish-eating mammals, local residents, as well as for comprehensive analysis and elaboration of preventive and controlling measures.

The paper characterizes the seasonal phenomena of the life cycle of fleas in relation to the intensity of epizootias in the natural foci of plague in the Caucasus. A situation determined by the vital activity of several species of fleas, the parasites of a major vehicle, is, in terms of pathogen transmission, established in each of 9 natural plague foci. They are combined by the nesting-borrow type of parasitism, which provides the wide distribution of plague pathogen among rodents. In each focus, there are the most intensive epizootias in the period of high feeding and reproductive activity of transmitters.

This paper is devoted to the scientific activity of Russia's most eminent parasitologist N. I. Latyshev. The paper gives its stages and the main areas of his studies of parasitic tropic diseases (malaria, tick-borne relapsing fever, pappataci fever, leishmaniasis, etc.) in the areas of Central Asia and Caucasus. N. I. Latyshev's scientific works made a great contribution to the teaching of the natural focal pattern of leishmaniasis and could further substantiate the principles of cutaneous leishmaniasis control in the endemic areas.

The paper assesses the investigations on leishmaniases at the E.I. Martsinovsky Institute of Medical Parasitology and Tropical Medicine in 1920 to 2009. The analysis includes papers on biology, ecology, taxonomy, and experimental transmission of the agents of leishmaniases via the bites of sand flies, the principle in the control of zoonotic cutaneous leishmaniasis (ZCL) during the agricultural development of extensive territories in the Karshin steppe, on quantitative approaches in the epidemiology of ZCL, a search for Russian effective medicaments to treat patients with this disease and the development of criteria for selecting L. major strains for individual and mass vaccinations against ZCL, the revision of Leishmania circulating in great gerbil populations, and the description of the new species L. turanica, an important parasite for L. major persistence from one transmission season to the next. The first investigations on leishmaniasis were made by Prof. E.I. Martsinovsky, the founder and the first director of the Institute in the early 20th century.

The paper presents 4 cases of Echinococcus alveolaris infection in rural areas of the middle belt of the European part of Russia--in the Bryansk, Kostroma, Smolensk, and Tambov Regions. In all cases, human infection occurs in the areas of residence. The fact that there may be infection in another area is ruled out. Possible reasons for the emergence of infestation cases in human beings in the areas that do not belong to the natural foci of alveococcosis are discussed.

The paper describes cases of dirofilariasis in the residents of Tula and the Tula Region. One of the cases does not fit into the traditional concepts. On excising a tumor in an adolescent, two live actively moving nonencapsulated helminths: a male and a female Dirofilaria repens worms were removed, which were identified at the parasitology laboratory, Center of Hygiene and Epidemiology in the Tula Region.

Along with regenerated interest in passive immunization during flavivirus infections, there is an increase in the number of reports with negative opinions as to the expediency of postexposure immunoglobulin prophylaxis (IGP) of tick-borne encephalitis (TBE). Analysis of the publications (since 1959) on this problem has indicated that more than half of them, including all papers with negative opinions as to IGP, contain the results of studies whose design are unsuitable for the solution of the problem associated with the efficiency of medical interventions in the context of evidence-based medicine. Analysis of the results of cohort studies has established that the timely single administration of an immunoglobulin (IG) preparation against TBE in a dose of 0.05 ml/kg body weight ensures protection on average in 79% of cases. Increasing the single dose to 0.1 ml/kg, as re-administration of IG, provides no additional protective effect. The preventive efficacy of IG preparations against TBE varies under the influence of factors, such as the infectious virus dose inoculated from tick suckling, the age of a victim, the antiviral activity of preparations with a antihemagglutinin titer of 1:20 with high infectious virus doses and the absence of reliable rapid tools for its determination on tick suckling, it is necessary to use IG with a titer of at least 1:80 and, desirably, more active in children, for postexposure prophylaxis of TBE.

This paper assesses the trends in the identification of different Dirofilaria species in the Rostov Region and comparatively analyzes the general clinical and biochemical blood indices in dogs with and Without helminthism. Seasonal variations in the invasion and species composition of the parasite have been established. At present, there is a gradual replacement of the species Dirofilaria repens by Dirofilaria immitis in this area. The blood general clinical and biochemical studies in ill dogs with dirofilariasis have ascertained that the pathogenic action on the animals is more pronounced with Dirofilaria immitis being parasitizing and with the mixed invasion of two helminth species.

The paper analyzes relationships of the plague bacilli to the representatives of different types of living organisms inhabiting the burrows. The authors give their own data on the qualitative and quantitative composition of indicoles of the burrow of little sousliks (Spermophillus pygmaeus). They assess the role of mutagenic agents in burrow microbiocenoses.

The paper gives the results of a study dealing with the detection of the antigens of arboviruses of West Nile, Sindbis, Batai, Crimean-Congo hemorrhagic fever, a serocomplex of Californian encephalitis in the field material gathered in the Saratov Region in 2000-2006. The bloodsucking arthropods inhabiting the region were shown to be actively involved in the circulation of arboviruses in natural biotopes. The conclusion that it is expedient to organize an annual monitoring of arbovirus-induced infections in the areas where positive findings have been notified is justified.

The paper analyzes the results of monitoring the number and species composition of arthropods, which are of epidemiological and sanitary important, in the city of Voronezh in 1998 to 2007. Many years' periodical observations have revealed the main places of breeding for blood sucking insects and ticks, their ecological features, including these under antropogenic stress. There is evidence for the changes in the species composition and the influence of some species on the recent epidemiological situation, which permits the approaches to and tactics of preventive measures to be corrected at the present budgetary stage oriented to outcome, with emphasis on the most significant sections of work.

The paper gives a new checklist of the mosquitoes (Diptera: Culicidae) of Russia based on the last (2000-2006) data of Culicidae, which covers 104 species.

The paper presents calculations and estimations of the economic damage caused by cases of trichinosis in the North Caucasus before and after economic reforms. Before ruble denomination, the economic damage from a case ofsubclinical, mild, moderate, severe, and very severe (and fatal) trichinosis was 246.9, 374.6, 621.6, 882.1, and 63,000 rbl., respectively. After the country's economic transition to market relations, it was 10,688, 12,935, 24,885, 37,596, and 139,592 rbl., respectively, as shown by the 2003 data. Before and after economic reforms, the mean cost of a case of trichinosis was 1,342 and 21,526 rbl., respectively. According to the author's estimates, the damage caused by cases of trichinosis to the economy of the North Caucasus in the period of 1990 to 2004 was over 50 million rbl. Only did the 2001 large-scale outbreak of invasion in the Krymsky District, Krasnodar Territory, cause damage at 7 million rbl.

A total of 10566 specimens of 10 species of Ixodes ticks, such as Dermacentor marginats, D. reticulatus, D. niveus, Rhipicephalus rossicus, Ixodes ricinus, I. persulcatus, I. crenulatus, Haemaphysalis punctata, Hyalomma scupense, and H. marginatum, were collected and identified in the Saratov Region in 2002-2006. Dermacentor marginats and D. reticulatus were found to be the most dominant species. Rhipicephalus rossicus, Ixodes ricinus, and Hyalomma scupense were also constantly detected in the region. I. persulcatus considered earlier untypical of the Saratov Region was detected. The paper presents data on the confined geographical and environmental features of individual species of Ixodes ticks in the Saratov Region.

The paper presents the results of a study of the infection rates of mollusks of the family Bythiniidae (Bithynia tentaculata, Opisthorchophorus troscheli) and fishes with the larval stages of Opisthorchidae in different districts of the Yaroslavl Region. A total of 3,708 mollusks from the water reservoirs of different types (small rivers, lakes, ponds, and canals) were examined in the Nekouzsky, Yaroslavsky, and Pereslavsky Districts of the Yaroslavl Region in 1989 to 1999. Opisthorchis cercarias were found in 7 of the 10 studied water reservoirs. The total rate of infection of mollusks with all types with Trematoda partenitas and cercarias in different water reservoirs averaged 18.5 +/- 3.5% for Bithynia tentaculata and 19.1 +/- 4.1% for Opisthorchophorus troscheli. Trematoda metacercarias of the family Opisthorchidae were revealed in roaches, ides, verkhovkas, silver breams, and chubs in four different water reservoirs (small rivers and a lake) of the region. Pseudamphistomum truncates, Opisthorchis felineus, and Metorchis xanthosomus were present among the metacercarias found. It is concluded that there may be sporadic cases of Opisthorchis infection in wild and domestic animals and humans in the Yaroslavl Region.

The present paper presents the epidemiological and clinicoimmunological aspects of the outburst of trichinosis in the Krymsky District of the Krasnodar Territory in January 2001. Six hundred and forty-eight persons ate infested wild boar meat, 119 (74.8%) fell ill with moderate and severe trichinosis. The authors provide the results of 3.5-year immunological studies of the patients with trichinosis and convalescents, infection-risk and healthy individuals; those of autopsies of the corpses of those who died from accidental causes unassociated with trichinosis, as well as examinations of domestic, synanthropic, and wild animals. The findings indicate that there is a focus of trichinosis with the low level of endemia in the Krymsky District of the Krasnodar Territory.

The paper presents the results of the studies made in 2002-2004 to examine the species-specific composition of Ixodes ticks. The ticks were gathered for a flag (155km routes being covered and 405 ticks being gathered); 48 dogs were examined, 320 ticks being gathered; 212 ticks were collected from human beings. The town dwellers' visit rates were grouped by ages and months. In the republic, Borreliae, the causative agents of Lyme borreliosis, were first isolated from Ixodes ricinus by darkground microscopy. Thus, there is one more available Lyme borreliosis focus. Enzyme immunoassay was used to study the sera from the dwellers bitten by ticks. Anti-M and anti-G antibodies were isolated. The paper presents the distribution of Ixodes ticks gathered for the flag and taken from dogs in accordance with the biotopes, establishes seasonal variations, and provides calculations of the abundance index on the dogs.

The paper describes a method for mastering and maintaining skills at the parasitological diagnosis of malaria. The number of educational blood smears, which are to be studied to develop reliable skills at the detection of malaria parasites in the smear preparations showing different level of parasitemia, has been determined. It has been ascertained that parasites that develop with the use of antimalaria drugs may be reliably detected by a skilled parasitologist who constantly uses his experience in practical work. The experiment has indicated that parasitologists and laboratory assistants should monthly view collections of educational smear preparations in nonendemic areas in order to maintain their skills at the parasitological diagnosis of malaria.

The paper describes the first case of diagnosis of dirofilariasis from the microfilariae detected in the subcutaneous tumor punctate from a person who has the clinical manifestations of D. repens invasion and resides in the Saratov Region that is endemic in dirofilariasis. The fact of detection of microfilariae in the man undergone invasion is assessed not only as the first case in the lifetime diagnosis of the first case of diagnosis of subcutaneous dirofilariasis, but also as the first case of verification of that a female can achieve sexual maturity in the organism of an accidental host and its impregnation if there are even single specimens of both sexes, which is characteristic in human invasiveness. On this basis, the authors consider it wrong to refer this helminthiasis to as a group of diseases defined as "Larva migrans cutaneous" since this is inconsistent with the biology of a causative agent that accomplishes migration at the adult stage in the host's organism and does not orient a physician to establish a correct clinical and parasitological diagnosis.

The paper presents the results of a sanitary-and-parasitological assessment of non-centralized water supply sources (shaft and pipe wells, spring cappings) for the population. It has been shown that the water of the wells contains helminthic eggs, the proportion of positive tests varies and depends on the improvement of a water source, on the presence of a sanitary zone, etc. The water on non-centralized water supply presents a risk for infection with intestinal parasitic diseases.

The paper shows it necessary to estimate the average number of borreliae in the infected ticks, by using the geometric mean of a sign rather than the arithmetic mean.

The paper presents data on the rates of Lamblia cyst dissemination of surface water sources in foreign countries, the Russian Federation, Moscow, and the Moscow Region. It shows a role of drinking water in the spread of intestinal parasitic diseases. In accordance with parasitological parameters, specific data on improvement of methodological control of water quality are presented. The dosages of ultraviolet radiation are given in relation to water decontamination of parasitic disease germs.

The paper presents a prediction of changes in the potential areas of tertian malaria till 2025. It shows that possible climatic changes whose main features are an increase in average annual temperatures do not imply a uniform expansion of areas for parasitic infections. The regional and seasonal trends of temperature changes in Russia (both established for the 20th century and predicted for the early 21st century) will both expand the area in its one part and reduce in its another part. Overall, the changes caused by climatic factors in the potential area of human malaria in Russia in the first quarter of the 21st century will not lead to a drastically aggravated malaria epidemiological situation.

Malaria does not belong to a group of diseases that are markers of HIV infection; a combined transmission of malaria and HIV infection does not occur (except for cases of vertical and syringe-associated transmission of causative organisms), but HIV infection is more common in the malaria-endemic areas since both diseases are socially related. Expansion of both infections is associated with the same social processes in society. This paper analyzes the relationship of the spread of HIV-infection to the routes of migration of narcotic agents in case of Russia, by comparing the spread of HIV infection with the regional distribution of cases of malaria imported by Tadjikistan inhabitants. Importation of malaria from other CIS countries was compared as a control. The authors estimated the coefficients of correlation between the affliction of Russia's population with HIV infection and the rate of malaria importation from Tadjikistan (0.733) and other CIS countries (0.496), as well as between the importation of malaria to Russia and the total volume of a migratory flow from Tadjikistan in the period of 1992 to 2001 (-0.931). The findings indirectly support the assumption that there is a relationship of malaria importation from Tadjikistan to illegal migration, which suggests that the intensive importation of malaria from Tadjikistan may serve as a marker of importation of injectable narcotic drugs and hence that the spread of HIV infection in Russia may be intensified. The authors again emphasize that prevention of the spread of socially related infections requires that the whole society should combine efforts since public health care should not be a hostage of social problems.

The paper presents data on the infection of fishes from the Gulf of Peter the Great with an A. simplex nematode. A total of 308 fishes of 19 species were examined for parasites. Of them 5 species were found to be free from nematodes. The highest infection rates were noted in fishes of the species Oncorhynchus keta, Hexagrammos octogrammus, and Theragra chalcogramma. Differences in the infection rates of fishes of the gulf were explained by the specific features of their vital activity and by the saturation of the environment with an invasive agent. Based on the infection of secondary intermediate hosts with the nematoda, it may be suggested that there are the populations of fishes whose representatives accomplish their life cycle under the conditions of the internal waters of the gulf. The infection rate of these fishes with the parasite is low. The altered situation--an increase in the invasion rate--was associated with the seasonal migration of fishes of these species from the open marine spaces to the cost of the Gulf of Peter the Great. The opposite values of the infection rates of deep-sea (herrings) and bottom-dwelling (bases, greenlings) fishes make it possible to assume that bottom-dwelling invertebrates function as the first intermediate hosts in the life cycle of the nematode.

The paper shows it necessary to exercise control over the quality of natural, waste, and portable water in terms of parasitological indices. The standard techniques of sampling and sanitary and parasitological studies of water, which allow water quality control to be effectively exercised in accordance with the current sanitary regulations, are considered.

The climatic temperature conditions of the atmospheric surface layer in the given point of geographic space are considered in this paper to be favourable for human malaria if the number of years whose temperature conditions allow the causative agent to complete sporogony in the vector if only once is at least 90%. In another case, the conditions are considered to be unfavourable. This model criterion determines the potential region of the disease. The diagrammatic maps depicting such potential regions, as well as their changes in the period of 1966-1995 as compared to the period of 1936-1965, are given in this paper for tertian (P. vivax) and tropical (P. falciparum) malaria. The threshold empirical relationship of sporogony success to the variations of the mean diurnal temperature in a specific year and the series of diurnal data of meteorological observations made for many years at 223 weather stations situated on the territory of the former USSR. An analysis shows that there has been a slight increase in the regions in Asian Russia for 30 years while there has been a just more noticeable reduction in them in European Russia. By and large the changes in the regions may be regarded as just moderate.

Spirometrosis (sparganosis) in animals and man is a serious ecological problem in Russia, which requires the constant attention of veterinary and medical services. The paper presents data on the biology of the parasite Spirometra erinacei europaei Muller, 1937, an account and diagram of a developmental cycle, and original photos of parasitic eggs, plerocercoids, strobiles, and cestode joint from animals.

The paper presents the data of an epidemiological investigation on the outbreak incidence of leptospirosis in the Ulyanovsk Region. One hundred and forty-one recording forms under No. 171/y filled in for patients with leptospirosis have been examined. All the outbreaks have been found to be of seasonal nature (June to August) and to show an aqueous transmission of infection. The occupational nature of the disease was absent among the patients.

The paper presents the results of a long-term comparative study of the infection of Ixodes tick imagoes with the pathogen of tularemia by using the biological assay and antibody neutralization test. The infection rates determined by both methods were found to be identical or close. If there was a difference in the rates in some years, it was not statistically significant. A statistically significant difference could not be found in the infection rates for ticks and in the dependence on their species composition though the level of infection in representatives of one species greatly differed from that in others. The serological study of Ixodes tick imagoes, aimed at determining their infection with a tularemia pathogen, yielded the results which are comparable with those of the biological assay and may be used in epizootological studies without using the biological test or by significantly limiting its use.

The paper considers the trends of morbidity due to tick-borne encephalities (TBE) and lxodes tick-borne borrelioses (lTBB) in Udmurtia during 35 years (1965-2000) and evaluates the long-term influence of measures aimed at suppressing natural foci by eliminating the basic vector on this process. For this, data on 1062 cases of fevers occurring after the bite of a tick in Udmurtia in 1965-1968, the similar data on 1509 cases in 1983-1987, and the official data on the incidence of these infections in 1996-2000 have been retrospectively analyzed. It has been shown that in Udmurtia the natural foci of lTBB coexisted with those of TBE long before the pathogens of borrelioses were described and notification of the infection of this group was initiated. In the 1990s, there was a drastic rise in the incidence of TBE and lTBB as compared with the 1960s and 1980s, which was due to an increase in the rate of contacts of the population with natural foci and to the better diagnosis of these infections. The prevalence of lTBB coincides with that of TBE. There is a long (more than 30 years) epidemiological effect in eliminating the vector Ixodes persulcatus.

The present paper characterizes a natural focus of tick-borne borreliosis in the Yaroslavl Region, analyzes the incidence of this infection in the Region, and thus concludes that the density of the population living in the areas of the natural foci of tick-borne borreliosis has a significant impact on its epidemic process. The incidence of tick-borne borreliosis in the Yaroslavl Region has remained a challenge in the past 7 years. By the number of cases, this infection heads the list of naturally focal infections recorded in the Region. Examining long-term changes in the incidence and prevalence of tick-borne borreliosis in the Region revealed its high incidence in the population residing in the tidal marshlands and forest areas. At the same time the potential activity of natural foci of borreliosis due to the conditions that maintain the population of Ixodes ticks is high in the forest-field, southern, and meadow-forest-field regions.

The paper provides evidence that Cryptosporidium oocysts should be necessarily included as an index of the epidemic safety of drinking water in our country. This is evidenced by: the wide spread of cryptosporidiosis among animals and human beings; that of the pathogen of this disease in the environment; large-scale outbreaks of cryptosporidiosis in the world's population; no sanitary and parasitological drinking water monitoring in our country; the use of this parasitological index to evaluate drinking water quality in some countries (USA, UK, Ukraine, etc.).