Epidemiological Situation on Tick-Borne Borreliosis in the Russian Federation in 2019 Compared to the Period of 2002–2018

Objective: to analyze the epidemiological situation on Ixodidae tick-borne borreliosis in the Russian Federation in 2019 in comparison with the period of 2002–2018.Materials and methods. The paper uses the data contained in Form No. 2 of the state statistical reporting for 2002–2019 and information obtained by the Reference Center for Monitoring Borreliosis of the Omsk Research Institute of Natural Focal Infections from 74 constituent entities of Russia in 2019. The main research method is epidemiological one with the use of modern information technologies.Results and discussion. In Russia, 8048 cases of tick-borne borreliosis (Lyme disease – LD) were recorded (5.48 0/0000) in 2019. The actual indicators of the LD incidence for the whole country and federal districts (FD) in 2019 were within the confidence limits predicted with linear regression based on the study of the dynamics of the epidemic process in 2002–2018 in the vast majority of cases. A steady upward trend in the LD incidence was observed during 2002–2019 in the Central Federal District due to 10 out of 18 entities (Moscow, Belgorod, Lipetsk, Moscow, Bryansk, Voronezh, Kursk, Ryazan, Tambov, Tula regions); in the Southern Federal District because of the Krasnodar Territory and the Volgograd Region; in the North Caucasus Federal District – because of the Stavropol Territory. Despite the fact that a downward trend in the incidence of LD has been established over the past 18 years in the North-West, Volga and Ural Federal Districts, in some subjects of these regions a trend towards an aggravation of the epidemiological situation is observed (the Komi Republic and Chuvashia, Penza Region). In the absence of a pronounced tendency to change in the incidence rate of LD in the Siberian and Far Eastern Federal Districts, Kemerovo Region-Kuzbass, the Republic of Tuva and the Trans-Baikal Territory where a growing trend has been identified require special attention. In the Ural and Siberian Federal Districts, the share of non-erythema forms among laboratory-confirmed cases of LD was higher than in other regions, which merits further study of the genome-specific features of borrelia populations and their carriers. Effective control of the LD epidemiological situation in Russia is possible provided that the control is improved and maintained, and the capacity of preventive measures and zoological-entomological monitoring of the activity and structure of the natural foci of LD is enhanced in the entities with the long-term tendency towards increase in the incidence of the disease

Epidemiological Situation on Tick-Borne Borreliosis in the Russian Federation in 2021 and Forecast for 2022

3875 cases of tick-borne borreliosis (TBB) (2.65 per 100000 of population) were recorded in Russia in 2021. Compared to 2020, 61 out of 78 constituent entities experienced a decrease in the incidence rate in 2021. Over the past year, the largest number of cases was registered in the Central Federal District (CFD) – 1797 cases, which is 46.4 % of cases in Russia. Second in the rank by the number of cases of TBB comes the Siberian FD (SFD) – 616 cases (15.9 %), followed by Ural FD – 445 cases (11.5 %), the North-Western FD – 418 (10.8 %), and the Volga FD – 388 (10 %). 134 (3.5 %) and 60 (1.5 % of the total number of cases of TBB) cases were registered in the Far Eastern and Southern Federal Districts, respectively. The last place is occupied by the North Caucasus Federal District (NCFD), where 17 cases were registered, the share of which in the total structure of cases in Russia is 0.4 %. When assessing the long-term dynamics of TBB incidence, a significant trend towards a decrease in the intensity of the epidemic process has been revealed for the North-Western FD, UFD and VFD, as opposed to the CFD and Southern FD, where a significant upward trend was noted. For the Russian Federation on the whole, the Siberian FD, FEFD and NCFD the variation in the incidence rates within the confidence intervals of the long-term annual average values is most likely to be observed in the near future

Results of Epizootiological Monitoring of Natural Foci for Bacterial Vector-Borne Infections in Caucasian Mineral Waters Region of the Stavropol Territory in 2018–2020

The aim of the study was to assess the epizootiological situation on bacterial vector-borne infections in Caucasian Mineral Waters area of the Stavropol Territory over the period of 2018–2020.Materials and methods. 3494 specimens of ticks (473 pools), 257 specimens of small mammals, 9 regurgitates of birds of prey and mammals, 7 excreta samples of small mammals, and 2 water samples were tested. Laboratory research of the field material was carried out using molecular-genetic, serological, biological methods. Statistical analysis of laboratory results was conducted using Microsoft Excel 2010. The data were mapped using QGIS 2.18 software.Results and discussion. The study revealed that the 44.8 % of collected ticks were positive for tick-borne borreliosis, 21.5 % – for tick-borne rickettsiosis, 10.3% – for human granulocytic anaplasmosis, 2.7 % – for Q fever, 0.84 % – for tularemia. There has been an increase in the percentage of positives for tick-borne borreliosis agent samples (more than three times) and a decrease in this indicator for human granulocytic anaplasmosis (1.5 times) as compared with 2010–2012. Investigation of tick infection with the agents of Q fever and tick-borne rickettsioses has not been previously conducted in the region. During the period under review, 19 pools of ticks had mixed infection, which indicates that there are combined foci of bacterial natural-focal infections with vector-borne transmission in the recreation zone of the Stavropol Territory. This necessitates preventive measures and systematical epizootiological surveys in the Caucasian Mineral Waters region

Characterization of tick-borne encephalitis virus in Kazakhstan by serological and molecular-biological techniques

Tick-borne Encephalitis virus (TBEV), leading to one of the most dangerous neuroviral infection in humans named Tick-Borne Encephalitis (TBE) and West Nile fever virus that is a cause of neurotropic infection West Nile fever (WNF) are both belonging to the viral family of flaviviruses.In the Republic of Kazakhstan only limited data about TBEV, TBE and WNFV are available. In the last ten years 348 cases of TBE were registered but they are based on unreliable serological investigations. Furthermore, in 400 cases between 2017-2019 the aetiological agent of serous meningitis could not be determined and hence they were declared as cases of serous meningitis with unknown origin. TBEV is transmitted by ticks and up to date there is hardly any information about the rate of infected ticks in Kazakhstan. The presence of WNFV in the Republic of Kazakhstan was confirmed in mosquitos and by the presence IgG specific antibodies in human sera in West Kazakhstan. However, there is no official registration of WNF cases or monitoring of mosquitos and/or birds as vectors.The similarity of the antigenic structure of the members of the flavivirus leads to the need for reliable diagnostic meth-ods to discriminate between these pathogens. In our study we investigated three regions of Ka-zakhstan with TBE cases that are East Kazakhstan Oblast, Almaty and Akmola Oblast including 166 sera and 130 cerebrospinal fluid (CSF) samples from patients with meningitis symptoms. In addition, participants needed to answer a questionnaire with focus on socio-demographic factors, travel history, contact to animals and vectors, tick bites, vaccination status and clinical symptoms to understand more about the mode of infection. All samples were tested for flaviviruses by screening for IgG and IgM antibodies in an ELISA, an immunofluorescence assay using a flavivirus biochip and a TBEV specific real-time RT-PCR. Our findings show TBEV and WNFV antibodies in 31 samples. In Kazakhstan also only limited data on the phylogenesis of TBEV is available. Hence, TBEV in its tick vector was also investigated in our studies. In more than 10,000 screened ticks from the three regions 0.5% of pools were found to be positive for TBEV using a specific real-time RT-PCR. Phylogenetic analysis of gained sequences showed the Siberian subtype of TBEV to be predominant in Kazakhstan. In this study, we present a broad investigation of the spread of TBEV in Kazakhstan in humans and also in ticks. Our results have an impact on diagnostic algorithms in Kazakhstan and medical doctors should be aware of TBEV and WNFV to play a role in meningeal diseases of unknown origin in the Republic of Kazakhstan

Abundance of <i>Ixodes persulcatus</i> ticks in Komi Republic as a function of an air temperature

The sharp rising incidence of tick-borne encephalitis (TBE) in Komi Republic at the North-east of European Russia was recorded last decades. Tick-bite incidence also was grown. Rapid rise of TBE incidence growth and Ixodidae ticks depends on a number of factors, and the impact of climate change being one of them. Ixodes persulcatus ticks is considered as a main vector of TBE in Komi. Our objective is to estimate the influence of air temperature change on the tickbite incidence and Ixodes persulcatus population in Komi. Komi Republic is located near the Polar circle where the northern frontier of Ixodes persulcatus ticks situated and we expected the growth of tick’s population. The number of Komi inhabitants seeking medical care after tick bites in 1992–2014 was considered. Gridded monthly air temperature data with grid size 0.5 degree were recalculated to temperature referred to Komi administrative units. The time series of annual number of tick victims from 1992 till 2014 and model air temperature from 1948 till 2016 for all Komi administrative units were compiled. We analyzed the data on tick-bite incidence in Komi administrative units in relation to changes in local annual average air temperature within the study area. The linear dependence of the tick-bite incidence on air temperature was established when of the tick-bite incidence is represented in logarithm form. The tick population depends not only on temperature but humidity, landcover and hosts. Described areas of Komi belong to humid climate, where precipitations exceed evaporation. Most of the Komi territory is covered by taiga with underwood, grass and bush. Hosts of the first and the major levels are represented by birds and rodents. The dependence of tick-bite incidence and temperature looks like “Malthus’s law”, but the development of population depends on temperature not on time. The exponential growth in the nearest future will ceased and the population will proceed to stable phase. Ticks population in Komi Republic is moving to the North and the air temperature determines the dynamics of population

Uusien vektorivälitteisten tautien mahdollinen saapuminen Suomeen ilmastonmuutoksen ja ihmisten liikkuvuuden kylkiäisinä

Tässä selvityksessä on käsitelty 50 patogeenia vektoreineen. Se perustuu lähes seitsemänsataan tieteelliseen julkaisuun. Ihmisen kasvava liikkuvuus tuovat patogeeneja nopeasti pitkiä matkoja. Lemmikkien pito ja niiden kuljetukset voivat myös olla uhka ihmisten terveydelle. Vaatetäi on palannut Suomeen ja sen mukana myös vaatetäiden välittämien tautien uhka. Ilmaston muuttuminen luo uusia olosuhteita myös vektorivälitteisille taudeille. Aasian tiikerihyttynen on tärkein Euroopan uusista hyttyslajeista. Tiikerihyttynen voi selvitä talvesta sopivassa mikroilmastossa. Uusia puutiaislajeja voi myös saapua, joko ihmisen toimesta tai muuttolintujen mukana. Suomessa tärkeät arbovirukset ovat hyttysten tai puutiaisten levittämiä. Suomessa esiintyy pogostan tautia sekä puutiaisenenkefaliittia. Useat bakteerit ovat myös hyönteisten tai puutiaisten levittämiä. Suomessa esiintyy kotoperäisenä hyttysten välittämä jänisrutto ja puutiaisten välittämä borrelioosi. Kotoperäinen malaria on hävinnyt Suomesta. Välittäjänä toimiva horkkahyttynen on yleinen koko maassa. Hyönteisiä vektoreina käyttävät ja ihmisissä loisivat sukkulamadot ovat harvinaisia Suomessa. Ne voivat yleistyä tulevaisuudessa. Hyönteisten syömisen kautta tarttuvat patogeenit ovat mahdollinen uhka Suomessa

Investigation of zoonotic pathogens in Central Asia

Kazakhstan ranks ninth in the world in terms of country size. With its varied landscapes and hot and dry climate, it is a perfect home for many naturally occurring dangerous infectious diseases. Many of them are not well studied and due to the lack of contemporary diagnostic no or only poor differential diagnostics can be performed. Currently in Kazakhstan, most infectious diseases are diagnosed by physicians on an analysis of the clinical picture. Only in officially endemic areas for certain pathogens, physicians might be aware of the possibility of an infection with a pathogen, and only in these areas cases are publicly recorded. This system implies that there is a lack of reliable clinical laboratory diagnostics, trained laboratory staff and well-equipped laboratories all over Kazakhstan. In many cases, the aetiological agent cannot be determined, and patients with only having a fever, are diagnosed with fever of unknown origin. If patients’ symptoms also include headache, their diagnosis is suspected meningitis. In addition, the prevalence of many zoonoses is not well investigated in humans, hosts (like rodents) and vectors (like ticks). To address this issue, we investigated several viral and bacterial zoonotic pathogens in humans, rodents and ticks in areas of Kazakhstan that are not yet officially endemic for specific pathogens. The studies included viral pathogens belonging to the family of Flaviviridae like Omsk haemorrhagic fever virus (OHFV), Tick-borne encephalitis virus (TBEV) and West Nile virus (WNV). Also, Orthohantavirus and the bacterial genus of Rickettsia were investigated. The investigations were performed in human samples for OHFV, TBEV and WNV, in biopsies from small mammals for OHFV, Orthohantavirus, Rickettsia spp. and ticks for OHFV in several regions of Kazakhstan

Mathematical models of infectious diseases in ungulate populations

In this thesis we develop a suite of mathematical models to understand the epidemiological dynamics of infectious diseases in ungulate hosts. Using ordinary differential equation frameworks, we explored the key routes of transmission that promote the persistence of the highly virulent African swine fever (ASF) infection in wild boar and tested control strategies that could limit ASF outbreaks and its persistence. These modelling techniques were extended to investigate the impact of an ASF outbreak on endemic tuberculosis in wild boar. The generality of the model framework meant the results could add new perspective on the coexistence of multiple pathogens. Motivated by the work on the persistence of ASF, we used a suite of stochastic continuous-time Markov chain models to show that latent and chronic infection could have a significant impact on the mean time to pathogen extinction. We also developed a model framework to assess how hosts, including ungulates, contribute to tick-borne infections. This expands on previously studied models such that the regulation of tick density is dependent on the density of the specific hosts on which different tick stages feed. Our results outlined the effect host density and composition could have on tick-borne prevalence and incidence levels. The work in this thesis has highlighted how mathematical models are important tools for understanding epidemiological dynamics in wildlife systems with our work having had an impact on the management of key, current, endemic and emerging diseases in ungulates.The UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/L016508/01

Babesia and Human Babesiosis

Babesiosis, caused by tick-transmitted intraerythrocytic parasites (Babesia spp.), occurs worldwide. The disease mainly affects livestock, but records of infections in humans are increasing, and the disease is considered to be emerging worldwide. This book provides a comprehensive and holistic view of Babesia species that can infect humans. Numerous experts analyze, in detail, basic aspects of the biology of Babesia, the pathology of the babesiosis highlighting the pathogenesis of babesiosis in sickle cell, the eco-epidemiology of tick vectors and the impact of climate change on them, the current status, and future prospects for laboratory diagnosis and measures to prevent transfusion transmission. The book also focused on unidentified Babesia parasites that continue to emerge, most likely from wildlife, for which neither tick vector species nor vertebrate reservoir host species are currently known. Lastly, current and new therapies for infected patients, in vitro and in vivo culture systems for antibabesial evaluation and measures to prevent infections are also considered