Monitoring of alien mosquitoes in Western Austria (Tyrol, Austria, 2018)

Hans-Peter Fuehrer1Ellen Schoener1Stefanie Weiler2Bita Shahi Barogh1Carina Zittra13Gernot Walder24

2020 Jun 23;14(6):e0008433. doi: 10.1371/journal.pntd.0008433. eCollection 2020 Jun.

Abstract

Mosquitoes are of major importance to human and animal health due to their ability to transmit various pathogens. In Europe the role of mosquitoes in public health has increased with the introduction of alien Aedes mosquitoes such as the Asian tiger mosquito, Aedes albopictus; the Asian bush mosquito, Ae. japonicus; and Ae. koreicus. In Austria, Ae. japonicus has established populations in various regions of the country. Aedes albopictus is not known to overwinter in Austria, although isolated findings of eggs and adult female mosquitoes have been previously reported, especially in Tyrol. Aedes koreicus had not so far been found in Austria. Within the framework of an alien mosquito surveillance program in the Austrian province of Tyrol, ovitraps were set up weekly from May to October, 2018, at 67 sites- 17 in East Tyrol and 50 in North Tyrol. Sampling was performed at highways and at urban and rural areas. DNA obtained from mosquito eggs was barcoded using molecular techniques and sequences were analysed to species level. Eggs of alien Aedes species were found at 18 out of 67 sites (27%). Both Ae. albopictus and Ae. japonicus were documented at highways and urban areas in both East and North Tyrol. Aedes koreicus was found in East Tyrol. During this mosquito surveillance program, eggs of Ae. albopictus, Ae. japonicus, and Ae. koreicus were documented in the Austrian province of Tyrol. These findings not only show highways to be points of entry, but also point to possible establishment processes of Ae. japonicus in Tyrol. Moreover, Ae. koreicus was documented in Austria for the first time.Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7337398/

Monitoring of alien mosquitoes of the genus Aedes (Diptera: Culicidae) in Austria

Ellen Schoener1Carina Zittra1Stefan Weiss2Gernot Walder34Bita Shahi Barogh1Stefanie Weiler4Hans-Peter Fuehrer5

Parasitol Res . 2019 May;118(5):1633-1638. doi: 10.1007/s00436-019-06287-w. Epub 2019 Mar 16.


Abstract

Systematic, continuous mosquito surveillance is considered the most reliable tool to predict the spread and establishment of alien mosquito species such as the Asian tiger mosquito (Aedes albopictus), Japanese bush mosquito (Aedes japonicus), and the transmission risk of mosquito-borne arboviruses to humans. Only single individuals of Ae. albopictus have been found in Austria so far. However, it is likely that the species will be able to establish populations in the future due to global trade and traffic as well as increasing temperatures in the course of global climate change. In summer 2017, a project surveilling the oviposition of newly introduced Aedes mosquitoes, using ovitraps, was set up by means of citizen scientists and researchers and was performed in six federal provinces of Austria-Tyrol, Carinthia, Vienna, Lower Austria, Styria, and Burgenland. Eggs of Ae. albopictus were identified in Tyrol during the months August and September, while Ae. japonicus was found in Lower Austria, Styria, and Burgenland. In Vienna and Carinthia, all ovitraps were negative for Aedes eggs; however, Ae. japonicus was found for the first time in Vienna in July 2017 during routine sampling of adult mosquitoes. With this project, we demonstrated the benefits of citizen scientists for ovitrap-based mosquito surveillance. The finding of Ae. albopictus eggs in Northern Tyrol is not yet a proof of the establishment of a self-sustaining population, although it indicates the ongoing introduction of this species along main traffic routes from Italy, where this mosquito is well established. The risk of establishment of the tiger mosquito in the Lower Inn Valley is therefore a given and informing the public about preventive measures to hinder and delay this development is highly recommended.

Keywords: Aedes albopictus; Aedes japonicus; Alien mosquitoes; Monitoring; Ovitraps.

Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6478629/

Guidelines for the Detection of Babesia and Theileria Parasites

Laetitia Lempereur1Relja Beck2Isabel Fonseca3Cátia Marques3Ana Duarte3Marcos Santos3Sara Zúquete3Jacinto Gomes4Gernot Walder5Ana Domingos6Sandra Antunes6Gad Baneth7Cornelia Silaghi8Patricia Holman9Annetta Zintl10

Vector Borne Zoonotic Dis 2017 Jan;17(1):51-65. doi: 10.1089/vbz.2016.1955.


Abstract

The genera Babesia and Theileria (phylum Apicomplexa, order Piroplasmida) are mainly transmitted by Ixodid ticks in which the sexual part of their life cycle followed by sporogony takes place. They include protozoan parasites that infect erythrocytes of a variety of vertebrate hosts, including domestic and wild animals, with some Babesia spp. also infecting humans. Babesia sporozoites transmitted in the tick’s saliva during the bloodmeal directly infect erythrocytes, where they asexually multiply to produce pear-shaped merozoites in the process of merogony; whereas a pre-erythrocytic schizogonic life stage in leukocytes is found in Theileria and precedes merogony in the erythrocytes. The wide spectrum of Babesia and Theileria species and their dissimilar characteristics with relation to disease severity, transmission, epidemiology, and drug susceptibility stress the importance of accurate detection of babesiosis and theileriosis and their causative agents. These guidelines review the main methods currently used for the detection of Babesia and Theileria spp. for diagnostic purposes as well as epidemiological studies involving their vertebrate hosts and arthropod vectors. Serological methods were not included once they did not indicate current infection but rather exposure.

Keywords: Babesia; PCR; Theileria; diagnosis; in vitro culture.

Fulltext: https://orbi.uliege.be/handle/2268/206151

Guidelines for the Direct Detection of Anaplasma spp. in Diagnosis and Epidemiological Studies

Cornelia Silaghi1Ana Sofia Santos2Jacinto Gomes3Iva Christova4Ioana Adriana Matei5Gernot Walder6Ana Domingos7Lesley Bell-Sakyi8Hein Sprong9Friederike D von Loewenich10José A Oteo11José de la Fuente1213J Stephen Dumler1415

Vector Borne Zoonotic Dis . 2017 Jan;17(1):12-22. doi: 10.1089/vbz.2016.1960.


Abstract

The genus Anaplasma (Rickettsiales: Anaplasmataceae) comprises obligate intracellular Gram-negative bacteria that are mainly transmitted by ticks, and currently includes six species: Anaplasma bovis, Anaplasma centrale, Anaplasma marginale, Anaplasma phagocytophilum, Anaplasma platys, and Anaplasma ovis. These have long been known as etiological agents of veterinary diseases that affect domestic and wild animals worldwide. A zoonotic role has been recognized for A. phagocytophilum, but other species can also be pathogenic for humans. Anaplasma infections are usually challenging to diagnose, clinically presenting with nonspecific symptoms that vary greatly depending on the agent involved, the affected host, and other factors such as immune status and coinfections. The substantial economic impact associated with livestock infection and the growing number of human cases along with the risk of transfusion-transmitted infections, determines the need for accurate laboratory tests. Because hosts are usually seronegative in the initial phase of infection and serological cross-reactions with several Anaplasma species are observed after seroconversion, direct tests are the best approach for both case definition and epidemiological studies. Blood samples are routinely used for Anaplasma spp. screening, but in persistently infected animals with intermittent or low-level bacteremia, other tissues might be useful. These guidelines have been developed as a direct outcome of the COST action TD1303 EURNEGVEC („European Network of Neglected Vectors and Vector-Borne Diseases“). They review the direct laboratory tests (microscopy, nucleic acid-based detection and in vitro isolation) currently used for Anaplasma detection in ticks and vertebrates and their application.
Keywords: Anaplasma spp.; PCR; direct diagnosis; in vitro isolation; microscopy; ticks; vertebrate hosts.

Fulltext: https://www.liebertpub.com/doi/10.1089/vbz.2016.1960?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

Practical Guidelines for Studies on Sandfly-Borne Phleboviruses: Part I: Important Points to Consider Ante Field Work

Nazli Ayhan1Amal Baklouti1Jorian Prudhomme2Gernot Walder3Fatima Amaro4Bulent Alten5Sara Moutailler6Koray Ergunay7Remi N Charrel1Hartwig Huemer8

Vector Borne Zoonotic Dis. 2017 Jan;17(1):73-80.  doi: 10.1089/vbz.2016.1957.


Abstract

The purpose of this review is to provide practical information to help researchers intending to perform „from field to laboratory“ studies on phleboviruses transmitted by sandflies. This guideline addresses the different steps to be considered starting from the field collection of sandflies to the laboratory techniques aiming at the detection, isolation, and characterization of sandfly-borne phleboviruses. In this guideline article, we address the impact of various types of data for an optimal organization of the field work intending to collect wildlife sandflies for subsequent virology studies. Analysis of different data sets should result in the geographic positioning of the trapping stations. The overall planning, the equipment and tools needed, the manpower to be deployed, and the logistics to be anticipated and set up should be organized according to the objectives of the field study for optimal efficiency.

Keywords: Bunyaviridae; Toscana virus; arbovirus(es); field studies; sand fly (flies); vector-borne.

Links: PMID: 28055576; DOI: 10.1089/vbz.2016.1957

Borrelia burgdorferi sensu stricto and Borrelia afzelii: Population structure and differential pathogenicity

Sabrina Jungnick1Gabriele Margos2Melissa Rieger1Eldina Dzaferovic1Stephen J Bent3Evelyn Overzier4Cornelia Silaghi4Gernot Walder5Franziska Wex6Johannes Koloczek7Andreas Sing7Volker Fingerle1

Int J Med Microbiol. 2015 Oct;305(7):673-81.  doi: 10.1016/j.ijmm.2015.08.017. Epub 2015 Aug 21.


Abstract

MultiLocus sequence typing (MLST) is considered a powerful method to unveil relationships within bacterial populations and it constitutes an economical and fast alternative to whole genome sequencing. We used this method to understand whether there are differences in human pathogenicity within and between different Borrelia burgdorferi sensu lato species. Therefore, 136 strains from human patients or ticks from Europe were included in MLST analyses. The scheme employed used eight chromosomally located housekeeping genes (i.e. clpA, clpX, nifS, pepX, pyrG, recG, rplB and uvrA). We investigated Borrelia afzelii, one of the predominant species in Europe, and B. burgdorferi sensu stricto (s.s.), because it allowed comparative analysis to strains from the USA. We typed 113 patient isolates as well as 23 tick isolates. For further comparative purposes an additional 746 strains from Europe and the USA were included from the MLST website http://borrelia.mlst.net. We observed an overlap of the B. burgdorferi s.s. populations from Europe and the USA isolated from human patients while there was no overlap of the populations found in tick vectors. Further results indicate that B. afzelii was significantly less associated with disseminated infection than B. burgdorferi s.s. and that B. burgdorferi s.s. from Europe caused neuroborreliosis to a significantly greater extent than B. afzelii or B. burgdorferi s.s. in the USA. Our data suggest that there may be an evolutionary basis of differential interspecies pathogenicity in Borrelia. This was not evident within Borrelia species: we found the same sequence types in patients with disseminated or localized symptoms when the number of strains was sufficiently high. We hypothesize that the finding that B. burgdorferi s.s. in Europe is much more associated with neuroborreliosis than in the USA maybe linked to factor(s) related to the human host, the tick vector or the bacterium itself (e.g. plasmid content and structure).

Keywords: Borrelia afzelii; Borrelia burgdorferi sensu stricto; Human pathogenesis; Lyme borreliosis; Multilocus sequence analysis; Population structure.

Links: PMID: 26341331; DOI: 10.1016/j.ijmm.2015.08.017

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