THRESHOLD PARAMETERS OF THE EPIZOOTIC SITUATIONIN THE NATURAL FOCI OF HANTAVIRUSES IN PRIMORSKY KRAI

Natural foci of clonorchiasis are localized on the territory of Primorsky Territory. The incidence of clonorchiasis ranged from 0.57 per 100 thousand population in 2014 (10 cases) to 1.5 per 100 thousand in 2012 (28 cases), and in 2010 (35 cases) to 1.9 per 100 thousand population is the maximum level. Analyzed 100 case histories of patients with clonorchiasis. Women predominated (63%). The age of the patients ranged from 3 to 77 years, the average age was 37 years. 82% of cases fell on the age of 18-70 years, 15% - on children from 3 to 18 years old, 3% - people over 70 years old. In 26% of patients, clonorchiasis proceeded in an acute form, in 74% - in a subclinical form. 89% had C. sinensis cleansing after taking praziquantel. Key words: clonorchiasis, acute, chronic, C. sinensis, Primorsky Krai.

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Transmissible tick-borne infections in the south of the Far East

Sanitarnyj vrač (Sanitary Inspector) ◽

10.33920/med-08-2109-03 ◽

2021 ◽

pp. 33-41

Author(s):

Valeriya Alexandrovna Lubova ◽

Anna Leonidovna Shutikova ◽

Galina Nikolaevna Leonova

Keyword(s):

Far East ◽

Incidence Rates ◽

Ixodid Ticks ◽

Borrelia Burgdorferi Sensu Lato ◽

Enzyme Linked Immunosorbent Assay ◽

Borrelia Miyamotoi ◽

The South ◽

Primorsky Krai ◽

Epidemiological Monitoring ◽

Natural Foci

Natural foci of tick-borne infections associated with tick-borne encephalitis virus (TBEV), borrelia (Borrelia burgdorferi sensu lato), including Borrelia miyamotoi, anaplasma, ehrlichia and rickettsia are widespread in the Primorsky Krai. The carriers of these pathogens are ixodid ticks. The population of Primorsky Krai meets with ticks in natural biotopes, as well as in anthropurgic foci. The aim of the study is to give a comparative assessment of the epizootic activity in the natural foci of transmissible tick-borne infections in the south of Primorsky Krai in the epidemic seasons of 2017–2020. In this periodixodid ticks (3778 samples), taken from humans in natural foci in the Primorsky Territory, were studied. The TBEV antigen was determined by enzyme-linked immunosorbent assay (ELISA), genetic markers of pathogens were detected by real-time polymerase chain reaction (RT-PCR). The incidence of tick-borne infections has been analyzed. Based on the results of monitoring the infection of ixodid ticks, we found that 26.9 % of the studied samples were infected with various pathogens of tick-borne infections. Low infection rate of TBEV in ixodid ticks and high infection with pathogens of a bacterial nature were established. TBEV antigen was detected in 30 cases (1.4 %), TBEV RNA was detected in 20 cases (0.7 %), Borrelia burgdorferis. l. DNA — in 820 cases (30.7 %), ehrlichia — in 64 (2.4 %), anaplasma — in 55 (2.1 %).Genetic marker of Rickettsia spp. was detected in 3 cases (0.9 %) out of 322 examined ixodid ticks, B. miyamotoi — in 26 cases (6.9 %) out of 373 examined samples. A positive correlation was noted between the incidence rates and the cases of detection of TBEV and Lyme borreliosis in ticks. The results obtained indicate the need for annual epidemiological monitoring of infections transmitted by ixodid ticks, to determine the real epidemic situation and the activity of the functioning natural foci transmissible tick-borne infections on the territory of Primorsky Krai.

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At the Origins of the Natural Focality Concept

ЗДОРОВЬЕ НАСЕЛЕНИЯ И СРЕДА ОБИТАНИЯ - ЗНиСО / PUBLIC HEALTH AND LIFE ENVIRONMENT ◽

10.35627/2219-5238/2021-338-5-16-25 ◽

2021 ◽

pp. 16-25

Author(s):

MYu Shchelkanov ◽

GN Leonova ◽

IV Galkina ◽

BG Andryukov

Keyword(s):

Web Of Science ◽

Far East ◽

Primorsky Krai ◽

Basic Principles ◽

Rights Protection ◽

Human Wellbeing ◽

Consumer Rights ◽

The Far East ◽

Natural Foci ◽

Vector Borne

Introduction: The article analyzes the course of scientific research that led to the discovery of tick-borne (Amarillovirales: Flaviviridae, Flavivirus) and Japanese (Amarillovirales: Flaviviridae, Flavivirus) encephalitis viruses and further formulation of the basic principles of functioning of natural foci of vector-borne infections. Materials and methods: We did a literature search in the State Archive of the Primorsky Krai, the Vladivostok City Archive, the Web of Science, PubMed, Scopus, Elsevier, Springer, and Google Scholar databases. Results: In the late 1930s, the Ussuri taiga became a “cradle” of the concept of natural focality first formulated by Academician Yevgeny N. Pavlovsky in 1939. Originally encompassing vector-borne infectious diseases this concept was later expanded to include non-vector-borne infections and sapronoses. A great contribution to the meaningful evolution of the theory of sapronoses was made by Academician Georgy P. Somov (Vladivostok). Conclusion: Establishment in May 1941 of a predecessor of the modern Research Institute of Epidemiology and Microbiology named after G.P. Somovbelonging to the Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing became one of the elements of consistent strengthening of the biological security of the country in the Far East.

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TBE in China

Tick-borne encephalitis - The Book ◽

10.33442/26613980_12b6-3 ◽

2020 ◽

Keyword(s):

Western China ◽

Ixodes Persulcatus ◽

West China ◽

North West ◽

Haemaphysalis Concinna ◽

Viral Subtype ◽

Japanese Military ◽

Natural Foci ◽

Far Eastern ◽

The Brain

The first TBE patients in China were reported in 1943, and the TBEV was isolated from the brain tissues of 2 patients in 1944 by Japanese military scientists,1 and from patients and ticks (Ixodes persulcatus and Haemaphysalis concinna) in 1952 by Chinese researchers.2 The Far Eastern viral subtype (TBEV-FE) is the endemic subtype that has been isolated from all 3 known natural foci (northeastern China, western China, and southwestern China).14 Recently a new “Himalayan subtype” of the TBEV (TBEV-HIM) was isolated from wild rodent Marmoata himalayana in the Qinghai-Tibet Plateau15. The main vector of the TBEV in China is I. persulcatus.3 One recent report suggests that the TBEV-SIB is prevalent in the Uygur region (North West China)13 but epidemiological modelling indicates that the TBEV may occur even widely all over China (Figure 3).4 Likely, the disease is often missed by clinicians due to a lack of the availability of specific diagnostic assays16.

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TBE in Romania

Tick-borne encephalitis - The Book ◽

10.33442/978-981-14-0914-1_12b-26 ◽

2019 ◽

Author(s):

Lidia Chitimia-Dobler ◽

Adriana Hristea ◽

Wilhelm Erber ◽

Tamara Vuković Janković

Keyword(s):

Epidemiological Survey ◽

Carpathian Mountains ◽

Territorial Expansion ◽

Tbe Virus ◽

Natural Foci ◽

Risk Areas

Based on an epidemiological survey performed, human TBE- virus neuroinfections may have an endemic emergent course, and natural foci are in full territorial expansion. Identified risk areas are Tulcea district, Transylvania, at the base of the Carpathian Mountains and the Transylvanian Alps.

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TBE in Romania

Tick-borne encephalitis - The Book ◽

10.33442/26613980_12b26-3 ◽

2020 ◽

Keyword(s):

Surveillance System ◽

Epidemiological Survey ◽

Passive Surveillance ◽

Notifiable Disease ◽

Territorial Expansion ◽

Country Level ◽

Regular Screening ◽

Passive Surveillance System ◽

Natural Foci ◽

Risk Areas

Based on an epidemiological survey,1 human TBEV neuroinfections may have an endemic emergent course, and natural foci are in full territorial expansion. Identified risk areas are Tulcea district, Transylvania, at the base of the Carpathian Mountains and the Transylvanian Alps.2,3 TBE has been a notifiable disease since 1996. Surveillance of TBE is not done at the country level, only regionally in some counties (northern/central/western part, close to Hungary). The passive surveillance system was implemented in 2008. However, there is no regular screening and the relative risk of contracting this disease is unknown. In 1999, an outbreak of TBE in humans was recorded with a total of at least 38 human cases.4

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Chapter 11: General epidemiology of TBE

Tick-borne encephalitis - The Book ◽

10.33442/26613980_11-3 ◽

2020 ◽

Keyword(s):

Eastern Siberia ◽

Genetic Lineages ◽

Phylogenetic Studies ◽

Tick Borne Encephalitis ◽

Natural Foci ◽

Genetic Sequences ◽

Tick Borne Encephalitis Virus ◽

Almost All ◽

Far Eastern ◽

Reservoir Hosts

Tick-borne encephalitis virus (TBEV) exists in natural foci, which are areas where TBEV is circulating among its vectors (ticks of different species and genera) and reservoir hosts (usually rodents and small mammals). Based on phylogenetic studies, four TBEV subtypes (Far-Eastern, Siberian, European, Baikalian) and two putative subtypes (Himalayan and “178-79” group) are known. Within each subtype, some genetic lineages are described. The European subtype (TBEV-EU) (formerly known also as the “Western subtype”) of TBEV is prevalent in Europe, but it was also isolated in Western and Eastern Siberia in Russia and South Korea. The Far-Eastern subtype (TBEV-FE) was preferably found in the territory of the far-eastern part of Eurasia, but some strains were isolated in other regions of Eurasia. The Siberian (TBEV-SIB) subtype is the most common and has been found in almost all TBEV habitat areas. The Baikalian subtype is prevalent around Lake Baikal and was isolated several times from ticks and rodents. In addition to the four TBEV subtypes, one single isolate of TBEV (178-79) and two genetic sequences (Himalayan) supposed to be new TBEV subtypes were described in Eastern Siberia and China. The data on TBEV seroprevalence in humans and animals can serve as an indication for the presence or absence of TBEV in studied area.

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