Ticks and Tick-borne Diseases最新文献

Accumulation of DNA sequence data and its use in systematics of the family Argasidae reveals new incongruencies between genera and subgenera, since several groups defined by classical taxonomy appear to be paraphyletic, which is the case of the subgenus Pavlovskyella. In order to identify morphological characters unique to one of the monophyletic groupings within Pavlovskyella and improve its system, we describe all active stages of Ornithodoros (Pavlovskyella) tartakovskyi, a species with an incomplete original description. Larvae, nymphs, males and females from Iran were examined with scanning electron microscopy (SEM). The larva of O. (P.) tartakovskyi lacks dorsal plate, posteromedian seta, postcoxal setae and a spinose area in palpal article I; the dorsal surface has 13 pairs of setae and the hypostome has two short rows of denticles in the apex only. The first nymphal instar (N1) has a micromammillated body with faint dorsal and ventral disks. The second nymphal instar (N2) shows mammillated body with an incipient hood, and dorsal disks outlined as in subsequent instars. Both N1 and N2 have a small patch of glabrous surface in the anterior margin of preanal groove, absent in posterior stages. Third nymphal instar (N3) has a small hood and lack cheeks, which are incipient in the fourth nymphal instar (N4). The four nymphal instars (N1–N4) have blunt hypostomes, striated capitula, non-mammillated legs, and 3 humps on tarsi I. Females and males of O. (P.) tartakovskyi have mammillated bodies, small cheeks not covering the capitulum, the anteromedian disk is placed anteriorly to anterior central disks, and a posterior median file of disks is merged with the median disk. We describe all postembryonic stages of O. (P.) tartakovskyi providing morphological characters that define Pavlovskyella sensu stricto and Theriodoros, a sister subgenus that includes similarly shaped species.

The European Centre for Disease Prevention and Control (ECDC) defines a case of tick-borne encephalitis (TBE) as an infection by the TBE virus (TBEV) with clinical manifestations of central nervous system inflammation (e.g., meningitis, encephalitis). To better understand the TBE surveillance landscape, online searches were conducted to determine if cases of TBE, TBEV infection, acute meningitis or encephalitis, or viral meningitis or encephalitis were subject to statutory reporting in European countries in 2023. In countries with statutory reporting, notification responsibility and available information on surveillance-reported cases were determined. The number of TBE cases reported to ECDC were compared with the number of cases recorded in national surveillance reports. Of 44 countries of the Europe Region of the United Nations, 37 (84 %) mandated statutory reporting of cases of TBE, TBEV infection, or acute/viral meningitis/encephalitis. Twenty-six (87 %) of 30 countries with identified surveillance reports recorded TBE cases in 2020–2023. Of these countries, 17 (65 %) required TBE reporting by clinicians and laboratories, 5 (19 %) by clinicians only, and 4 (15 %) by laboratories only. Twenty-four countries reported on TBE cases to ECDC in 2020; however, surveillance for TBE in Europe is heterogeneous. Standardization of TBE surveillance would enhance the understanding of TBE disease burden in Europe.

Revealing interactions between ticks and wild animals is vital for gaining insights into the dynamics of tick-borne pathogens in the natural environment. We aimed to elucidate the factors that determine tick infestation in wild animals by investigating ticks on invasive raccoons (Procyon lotor) in Hokkaido, Japan. We first examined the composition, intensity, and seasonal variation of ticks infesting raccoons in six study areas in Hokkaido from March 2022 to August 2023. In one study area, ticks infesting tanukis (raccoon dog, Nyctereutes procyonoides albus) were collected in May to July in both 2022 and 2023, and questing ticks were collected from the vegetation by flagging every other week in the same period. Next, we screened 17 environmental and host variables to determine factors that affect the number of ticks infesting raccoons using generalized linear (mixed) models. From 245 raccoons, we identified a total of 3,917 ticks belonging to eight species of two genera: the most prominent species were Ixodes ovatus (52.9 %), followed by Haemaphysalis megaspinosa (14.4 %), Ixodes tanuki (10.6 %), and Ixodes persulcatus (9.5 %). Ixodes ovatus was also predominant among questing ticks and ticks infesting tanukis. Although I. tanuki was frequently collected from raccoons and tanukis, it was rarely collected in the field. The variables that significantly affected the infestation on raccoons differed by genus, species and developmental stage of the tick. For instance, the infestation of adult I. ovatus was significantly affected by four variables: night-time temperature during nine days before capturing the raccoon, the size of forest area around the capture site, sex of the raccoon, and sampling season. The first two variables were also responsible for the infestation on raccoons of almost all species and stages of ticks. Our study revealed that the number and composition of ticks infesting raccoons can be affected not only by landscape of their habitats but also by weather conditions in several days before capturing.

Instead of using the Infection and Treatment Method (ITM)-based vaccine, is it possible to control East Coast Fever (ECF) through blocking Theileria parva transmission in ticks and cattle? This review pursues this question. It's over 100 years since Arnold Theiler (1912) first illustrated the natural ITM as a vaccination approach against ECF-cattle disease. The approach entails infecting cattle with live Theileria sporozoites and co-treatment with long-acting tetracycline. Building on the ITM principle, the “Muguga”-cocktail ECF vaccine was developed in the 1970s and it remains the only commercially available-one. Although the vaccine induces cattle-protection, the vaccination approach still raises several drawbacks. Of those, the most outstanding is the vaccine-safety. This is implied because after ITM vaccination, cattle revert to T. parva pathogen reservoirs, therefore, during blood meal-acquisition, the ticks co-ingest T. parva pathogens. Ultimately, the pathogens are further transmitted transstadial; from larvae to nymph and nymph-adults and later re-transmitted to cattle during blood-meal acquisition. Consequently, the vaccine-constituting T. parva strains are introduced and (re) spread in non-endemic/ endemic areas. Precisely, rather than eradicating the disease, the ITM vaccination-approach promotes ECF endemicity. With advent of novel vaccination approaches toward vector and vector-borne disease control, ECF-control based on ITM of vaccination is considered outdated. The review highlights the need for embracing a holistic integrative vaccination approach entailing blocking Theileria pathogen-development and transmission both in the ticks and cattle, and/or the tick-population.

Migratory birds play an important role in transporting ixodid ticks and tick-borne pathogens between continents. During the Boreal spring, migratory birds reach Europe, mainly from sub-Saharan Africa or from northern African countries but not much is known about the diversity and ecology of the ticks they spread. From 2017 to 2022, in the framework of two consecutive projects focused on sampling migratory birds from Africa to Europe, a total of 27 immature Amblyomma ticks were collected from migratory birds, belonging to 8 species, captured on the Island of Ventotene, an important stop-over site in the Mediterranean Sea. In the absence of adult specimens, morphological identification was limited to assigning these ticks to the Amblyomma genus. In this study, sequencing and comparative analysis of three mitochondrial molecular markers (12S rDNA, 16S rDNA, COI) were performed to achieve taxonomic identification. Sequences obtained from Ventotene specimens matched at 100% identity with Amblyomma sparsum. In conclusion, this study documented that immature stages of this species belonging to the Amblyomma marmoreum complex reached the Pontine Islands for six consecutive years. The entry of alien tick species and their potentially transmitted pathogens deserves further study, also in light of the globally ongoing climate change.

We report a case of posterior reversible encephalopathy syndrome in an adult patient fulfilling criteria for proven early Lyme neuroborreliosis.

Alpha-Gal Syndrome (AGS) is a delayed allergic reaction triggered by IgE antibodies targeting galactose-α-1,3-galactose (α-gal), prevalent in red meat. Its global significance has increased, with over 450,000 estimated cases in the United States alone. AGS is linked to tick bites, causing sensitization and elevated α-gal specific IgE levels. However, the precise mechanisms and tick intrinsic factors contributing to AGS development post-tick bites remain unclear. This study aims to characterize the alpha-gal conjugated lipid antigens in Amblyomma americanum (Am. americanum) salivary glands and saliva. Nanospray ionization mass spectrometry (NSI-MS) analysis revealed the identification of α-gal bound lipid antigens in Am. americanum saliva. Additionally, the activation of basophils by extracted alpha-gal bound lipids and proteins provides evidence of their antigenic capabilities.

Ixodes scapularis, the black-legged tick, is a major arthropod vector that transmits the causative agents of Lyme disease and several other pathogens of human significance. The tick midgut is the main tissue involved in blood acquisition and digestion and the first organ to have contact with pathogens ingested through the blood meal. Gene expression in the midgut before, during, and after a blood meal may vary in response to the physiological changes due to blood feeding. A systems biology approach based on RNA and protein sequencing was used to gain insight into the changes in tick midgut transcripts and proteins during blood ingestion (unfed and partially fed) and digestion (1-, 2-, 7-, and 14 days post detachment from the host) by the Ixodes scapularis female ticks. A total of 2,726 differentially expressed transcripts, and 449 proteins were identified across the time points. Genes involved in detoxification of xenobiotics, proteases, protease inhibitors, metabolism, and immunity were differentially expressed in response to blood feeding. Similarly, proteins corresponding to the same groups were also differentially expressed. Nine genes from major gene categories were chosen as potential vaccine candidates, and, using RNA interference, the effect of these gene knockdowns on tick biology was investigated. Knockdown of these genes had variable negative impacts on tick physiology, such as the inability to engorge fully and to produce eggs and increased mortality. These and additional gene targets provide opportunities to explore novel tick control strategies.