Ecology of Ixodes pacificus Ticks and Associated Pathogens in the Western United States

Lyme disease is the most important vector-borne disease in the United States and is increasing in incidence and geographic range. In the Pacific west, the western black-legged tick, Ixodes pacificus Cooley and Kohls, 1943 is an important vector of the causative agent of Lyme disease, the spirochete, Borrelia burgdorferi. Ixodes pacificus life cycle is expected to be more than a year long, and all three stages (larva, nymph, and adult) overlap in spring. The optimal habitat consists of forest cover, cooler temperatures, and annual precipitation in the range of 200–500 mm. Therefore, the coastal areas of California, Oregon, and Washington are well suited for these ticks. Immature stages commonly parasitize Western fence lizards (Sceloporus occidentalis) and gray squirrels (Sciurus griseus), while adults often feed on deer mice (Peromyscus maniculatus) and black-tailed deer (Odocoileus h. columbianus). Ixodes pacificus carry several pathogens of human significance, such as Borrelia burgdorferi, Bartonella, and Rickettsiales. These pathogens are maintained in the environment by many hosts, including small mammals, birds, livestock, and domestic animals. Although a great deal of work has been carried out on Ixodes ticks and the pathogens they transmit, understanding I. pacificus ecology outside California still lags. Additionally, the dynamic vector–host–pathogen system means that new factors will continue to arise and shift the epidemiological patterns within specific areas. Here, we review the ecology of I. pacificus and the pathogens this tick is known to carry to identify gaps in our knowledge.

THE EFFECT OF ACARICIDAL DRUGS BASED ON HERBAL RAW MATERIAL ON THE FERTILITY OF IXODES RICINUS

Therefore, a problem of successful control of ixodes ticks occupies the important place in veterinary medicine and requires searching of new highly effective ascaricidic drugs. Modern synthetic acaricides has led to the environmental pollution problems and further development of resistance within the target tick populations. It really appeared to be the environmental problem. Taking into consideration this fact, the ixodes tick's population decreasing is one of the most important tasks of veterinary science and it requires searching for new environmentally friendly and highly effective acaricides. The aim of our study was to compare the effect of an acaricidal drug developed by us (based on thymol and citral with the addition of sage essential oil) with a synthetic chemical (based on cypermethrin 0.125%) on the fertility of females Ixodes ricinus. Our research showed that the components of the drug can affect the reproductive function of females of ixodes ticks by prolonging the time of egg formation by 3-4 days and reducing their productivity by 80.8% and lead to the death of females before they have completed the process of egg production. The development of environmentally friendly acaricides to limit the number of ectoparasitic arthropods is of practical importance and can give a new understanding of the possible use of essential oils as a part of acaricidal and repellent drugs with low impact on the environment, as well as on human and animal health.

The effectiveness of acaricidic drugs based on herbal raw material

Limitation the number of ixodes ticks is one of the most important tasks of modern science and requires the search for new, highly effective and environmentally hazardous acaricides, so our experiment was aimed at identifying acaricidal properties of essential oils and their individual active components in the population of ixodes ticks in Zaporizhzhia region. The study of acaricidal properties of essential oils was performed in the laboratory conditions. Tampons with wool were soaked in various concentrations of 0.5%, 1%, 3%, 5% and 10% aqueous emulsion of essential oils such as Caryophyllus floris aetheroleum and Limonis aetheroleum, and essential oils of Thymus serpyllum L., Рinus sylvestris L., Salvia officinalis L., Mentha x piperita L. and Eucalyptus viminalis Labill. The essential oils had a significant effect on the lifespan of adult ticks. The results showed the acaricidal effect of Thymus serpyllum essential oils. When searching the acaricidal and repellent properties of individual essential oils components thymole, menthol and citral showed the high activity as acaricides. In the same time, eugenol and borneol proved the effectiveness as repellent. Our research schowed that essential oils are promising as alternative methods of controlling the number of Ixodes ticks in areas where there are conditions for infection with tick infections.

Molecular Identification of Borrelia spp. from Ticks in Pastures nearby Livestock Farms in Korea

Ticks are vectors that spread pathogenic bacteria, viruses, and protozoa. As the number of ticks increases due to climate change, the importance of the study of tick-borne pathogens has also increased. This study was conducted to investigate the distribution of the major tick species causing Lyme borreliosis and regional differences in the prevalence of Borrelia spp. by tick species. Borrelia infection was confirmed not only in Ixodes ticks, which are the major vectors of Borrelia spp., but also in Haemaphysalis and Amblyomma ticks. PCR targeting the 5S-23S rRNA intergenic spacer region (rrf-rrl) was performed to confirm Borrelia positivity. A total of 6102 ticks (736 pools) were tested, and the proportion was Haemaphysalis longicornis nymphs and adults at 69.2%, Haemaphysalis flava nymphs and adults at 13.9%, Haemaphysalis spp. larva at 14.3%, Ixodes nipponensis at 0.8%, and Amblyomma testudinarium at 1.9%. Ixodes nipponensis showed the highest minimum infection rate (MIR: 34.00; 17 pools/50 ticks) for Borrelia spp., followed by A. testudinarium (MIR: 0.88), and H. longicornis (MIR: 0.05). In particular, to our knowledge Borrelia infection was first confirmed in A. testudinarium in Korea. As a result of phylogenetic analysis, all sequences were grouped with Borreliaafzelii isolates and showed a close relationship with high identity. Considering that B. afzelii causes infectious zoonotic diseases, continuous monitoring and attention are needed, although it has a low prevalence in this study.

Estimation of Ixodes ricinus (Acari: Ixodidae) Populations of Kaylaka Park in the Town of Pleven, Bulgaria

(1) Background: Ticks are vectors of a large number of pathogenic microorganisms, which cause serious diseases in both humans and animals. Kaylaka Park is located in northern Bulgaria close to the city of Pleven. Part of the park is urbanized and visited daily by many citizens. The aim of our study was to determine the presence and distribution of hard ticks in the park area by surveying and comparing four urbanized with four wild areas. (2) Methods: Ticks were collected by flagging from 2016 to 2020 during the spring–summer season (March–July). Air temperature, relative humidity, collection time and flagging area were measured during the campaign. (3) Results: A total of 622 ticks were collected: 285 females (46%), 272 (44%) males and 64 (10%) nymphs. All were identified as Ixodes ricinus. Wild areas showed statistically significant higher values of ticks collected per minute (p = 0.009) and nymph densities (p = 0.003) compared to urbanized sampling sites. Other densities indices did not have a significant difference between urban and wild areas. Highest numbers of Ixodes ticks were collected at a temperature of 20 °C and at 60% relative humidity. The active questing began in March, peaked in end of April and declined in June. (4) Conclusions: In the present study, we found that ecological factors in the Kaylaka Park area are favourable for the development and distribution of tick populations. The results give us reason to consider that there is a high risk to visitors from tick bites in the Kaylaka Park area.

О находках Rhipicephalus (Boophilus) annulatus (Say, 1821) (Acari, Ixodidae) на западе Атырауской области

Blood-sucking ticks are vectors of protozoal, bacterial, viral and rickettsial diseases. The study of ixodes ticks: fauna, ecology, biology is of great importance not only for epidemiology but is also of scientific interest. Changes in natural and climatic conditions, hydrological regime, rapid development of human economic activities lead to the changes in the fauna of invertebrates including ixodid ticks. As they invade new territories ticks may expand their habitats for these dangerous for animals and humans infections. That is why the study of tick fauna, changes in species diversity of ticks and monitoring of their abundance is so important for monitoring of natural foci. The emergence of a new species of ixodid tick Rhipicephalus annulatus, in western Kazakhstan, which began to be registered from 2019 in Kurmangazy district of Atyrau region, bordering the Astrakhan region of the Russian Federation and its re-finding in 2020 is a very important fact to assess the epidemiological danger for humans and animals in this territory.

DYNAMIC CHANGES OF IN INCIDENCE OF IXODES TICK BITE CASES IN ADULT POPULATION OF VINNITSA REGION, UKRAINE

Not all ticks carry dangerous pathogens, but their bites can threaten humans with diseases such as Ixodes tick-borne borreliosis (Lyme disease), Miyamoto disease, tick-borne viral encephalitis and about 150 other nosological entities. The season of life activity of Ixodes ticks begins in March and usually lasts until November and has two pronounced seasonal peaks during the year: over April – May and August – September. The relevance of the investigation is determined by the lack of the information on the incidence of tick bite cases among the population in Ukraine, and there no well elaborated sets of measures in order to prevent this problem. The purpose of this study is to provide a detailed analysis of the incidence of Ixodes tick bite cases among the adult population in the Vinnytsia region and in the city of Vinnytsia, to compare the number of detected cases for the period from 2013 to 2018, and to identify the most reliable and available prevention methods. The research was conducted at the laboratory of the municipal non-profit enterprise "Vinnytsia City Hospital G1" (KNP "VMKL"); statistical data were provided by the State Regional Sanitary and Epidemiological Station. We compared the prevalence of the disease in different districts of the Vinnytsia region and its insidence for the period from 2013 to 2018. During this period, the number of detected cases of tick bites resulted in the occurrence of various dangerous diseases went up from 53 to 317 cases among the entire adult population of the Vinnytsia region. For all years except 2018, the highest incidence rate was consistently observed in the Mogilev-Podilsk district district, even exceeding the level in more densely populated and large areas. Over the period from 2013 to 2018, the number of detected cases of tick bites in the adult population that resulted in various dangerous diseases rapidly and significantly increased. This necessitates to elaborate the set of preventive measures and to educate the population of all ages. Much attention should be paid to promoting vaccination as the only reliable way and the development of sanitary and hygienic recommendations for residents of municipal and rural areas (in the spring and summer).