Association between guilds of birds in the African-Western Palaearctic region and the tick species Hyalomma rufipes, one of the main vectors of Crimean-Congo hemorrhagic fever virus

Bidirectional tick transport by migratory birds of the African-Western Palearctic flyway over Turkish Thrace: observation of the current situation and future projection

This study was carried out at a vital stopover site of migrating birds in the Turkish Thrace, European part of Turkey, on the Mediterranean/Black Sea Flyway. Ticks were collected from the birds captured in the four migration periods, i.e., autumn 2020, spring 2021, autumn 2021, and spring 2022, and identified morphologically. Throughout the study, 10,651 birds from 77 species were examined, and 671 belonging to 34 species were found infested. The infestation prevalence in total birds and the mean number of ticks per infested bird were 6.3% and 3.8 (range: 1-142), respectively. A total of 2573 ticks were collected with the following species distribution and numbers: Ixodes spp. 70 larvae, I. frontalis 1829 larvae, 337 nymphs, and 30 adults, I. acuminatus 16 nymphs and 42 adults, I. ricinus 39 larvae, 141 nymphs, and one adult, Hyalomma spp. seven larvae and 60 nymphs, and Haemaphysalis sp. one larva. Prevalence, intensity, and species distribution of the ticks in birds varied depending on the month, season, year, and species-specific migration phenology of the birds. The results show that precise determination of the tick-borne risk associated with migratory birds for a particular region necessarily requires long-term and comprehensive studies and indicates that anthropogenic climate change and habitat degradation can significantly differentiate the risk by influencing the migration phenology in birds and by making new regions suitable for the establishment of different ticks.

Rickettsial Infection in the COVID-19 Era: The Correlation between the Detection of Rickettsia aeschlimannii in Ticks and Storytelling Photography of a Presumable Human Rickettsiosis Case

Rickettsia aeschlimannii infection is an emerging human tick-borne disease with only a few recorded cases. We reported a presumable autochthonous case of rickettsiosis in an Italian cattle breeder associated with a Hyalomma marginatum bite. Rickettsia aeschlimannii DNA was detected in both the tick specimen from the patient and the grazing cattle close to his farm.

The climate niche of the invasive tick species Hyalomma marginatum and Hyalomma rufipes (Ixodidae) with recommendations for modeling exercises

The finding of immature stages of some Hyalomma spp. feeding on migratory birds in Europe is unexceptional. The reports of adults of Hyalomma in Europe (incl. the British Isles) after successful molting from immatures have increased in recent years. It has been claimed that the warming of the target territory could favor the populations of these invasive ticks. Although evaluations of the impact on health or measures of adaptation are on their way, the climate niches of these species remain undefined, preventing preventive policies. This study delineates such niches for both Hyalomma marginatum (2,729 collection points) and Hyalomma rufipes (2,573 collections) in their distribution area, together with 11,669 points in Europe where Hyalomma spp. are believed to be absent in field surveys. Niche is defined from daily data of temperature, evapotranspiration, soil humidity and air saturation deficit (years 1970-2006). A set of eight variables (annual/seasonal accumulated temperature and vapor deficit) has the maximum discriminatory power separating the niches of both Hyalomma and a negative dataset, with an accuracy near 100%. The sites supporting H. marginatum or H. rufipes seem to be controlled by the joint action of the amount of water in the air (accounting for mortality) and the accumulated temperature (regulating development). The use of accumulated annual temperature as the only variable for predictive purposes of colonization of Hyalomma spp. looks unreliable, as far as values of water in air are excluded.

Human Arboviral Infections in Italy: Past, Current, and Future Challenges

Arboviruses represent a public health concern in many European countries, including Italy, mostly because they can infect humans, causing potentially severe emergent or re-emergent diseases, with epidemic outbreaks and the introduction of endemic circulation of new species previously confined to tropical and sub-tropical regions. In this review, we summarize the Italian epidemiology of arboviral infection over the past 10 years, describing both endemic and imported arboviral infections, vector distribution, and the influence of climate change on vector ecology. Strengthening surveillance systems at a national and international level is highly recommended to be prepared to face potential threats due to arbovirus diffusion.

The Biological and Ecological Features of Northbound Migratory Birds, Ticks, and Tick-Borne Microorganisms in the African-Western Palearctic

Identifying the species that act as hosts, vectors, and vehicles of vector-borne pathogens is vital for revealing the transmission cycles, dispersal mechanisms, and establishment of vector-borne pathogens in nature. Ticks are common vectors for pathogens causing human and animal diseases, and they transmit a greater variety of pathogenic agents than any other arthropod vector group. Ticks depend on the movements by their vertebrate hosts for their dispersal, and tick species with long feeding periods are more likely to be transported over long distances. Wild birds are commonly parasitized by ticks, and their migration patterns enable the long-distance range expansion of ticks. The African-Palearctic migration system is one of the world's largest migrations systems. African-Western Palearctic birds create natural links between the African, European, and Asian continents when they migrate biannually between breeding grounds in the Palearctic and wintering grounds in Africa and thereby connect different biomes. Climate is an important geographical determinant of ticks, and with global warming, the distribution range and abundance of ticks in the Western Palearctic may increase. The introduction of exotic ticks and their microorganisms into the Western Palearctic via avian vehicles might therefore pose a greater risk for the public and animal health in the future.

Bird Communities and the Rehabilitation of Al Karaana Lagoons in Qatar

Qatar, a peninsular country in the Persian Gulf, is significant to avian species due to its location along the African–Eurasian Flyway, a key migratory path. Receiving untreated domestic and industrial liquid waste from Qatar in the past, Al Karaana Lagoons have since been reconstructed as an artificial wetland to address the growing environmental concern posed by contamination build-up. This study documents the changes in biodiversity at Al Karaana Lagoons following their environmental remediation. Data collected (2015 and 2017) by Ashghal (Public Works Authority) prior to project implementation was analyzed alongside data collected independently following project completion (2019–2021). There was a marked increase in bird biodiversity following remediation, including substantial use by migratory species and resident breeders. Further analysis of water quality data of the TSE (treated sewage effluent) ponds shows that they are eutrophic but still support substantial bird life. The project’s success demonstrates how reclaimed lands can provide important habitats to local and migratory birds and encourages similar restoration efforts in the future in both Qatar and elsewhere. We call for the continued monitoring of the site and the implementation of guidelines for the use of the site that balance human activities and habitat quality.

Direct and Indirect Role of Migratory Birds in Spreading CCHFV and WNV: A Multidisciplinary Study on Three Stop-Over Islands in Italy

The annual movements of migratory birds can contribute to the spread of African ticks and tick-borne pathogens of potential public health concern across Europe. The aim of the study was to investigate their role in the possible introduction of African ticks and tick-borne pathogens into European countries during spring migration. A total of 2344 ticks were collected during three spring seasons from 1079 birds captured on three Italian stop-over islands during their northbound migration. Once identified, each tick was tested by RT-PCR for the presence of Crimean-Congo hemorrhagic fever (CCHFV), West Nile (WNV), and Usutu (USUV) viruses. Moreover, carcasses of birds found dead were collected and tested for the possible presence of WNV and USUV. Results confirmed a higher contribution of trans-Saharan migrants compared to intra-Palearctic ones and the prevalence of African tick species in the sample. CCHFV was detected for the second time in Italy in a Hyalomma rufipes, and WNV was found in two ticks of the same genus, all carried by trans-Saharan birds. WNV lineage 1 was also found in the organs of a Garden warbler. These results confirm the role of migratory birds in carrying African ticks, as well as viruses of zoonotic importance, from Africa into Europe.

Co-Occurrence of Francisella, Spotted Fever Group Rickettsia, and Midichloria in Avian-Associated Hyalomma rufipes

The migratory behavior of wild birds contributes to the geographical spread of ticks and their microorganisms. In this study, we aimed to investigate the dispersal and co-occurrence of Francisella and spotted fever group Rickettsia (SFGR) in ticks infesting birds migrating northward in the African-Western Palaearctic region (AWPR). Birds were trapped with mist nests across the Mediterranean basin during the 2014 and 2015 spring migration. In total, 575 ticks were collected from 244 birds. We screened the ticks for the species Francisella tularensis, the genus Francisella, and SFGR by microfluidic real-time PCR. Confirmatory analyses and metagenomic sequencing were performed on tick samples that putatively tested positive for F. tularensis during initial screenings. Hyalomma rufipes was the most common tick species and had a high prevalence of Francisella, including co-occurrence of Francisella and SFGR. Metagenomic analysis of total DNA extracted from two H. rufipes confirmed the presence of Francisella, Rickettsia, and Midichloria. Average nucleotide identity and phylogenetic inference indicated the highest identity of the metagenome-assembled genomes to a Francisella-like endosymbiont (FLE), Rickettsia aeschlimannii, and Midichloria mitochondrii. The results of this study suggest that (i) FLE- and SFGR-containing ticks are dispersed by northbound migratory birds in the AWPR, (ii) H. rufipes likely is not involved in transmission of F. tularensis in the AWPR, and (iii) a dual endosymbiosis of FLEs and Midichloria may support some of the nutritional requirements of H. rufipes.