Phenology of deer ked (Lipoptena cervi) host-seeking flight activity and its relationship with prevailing autumn weather

Diversity of Anaplasma and novel Bartonella species in Lipoptena fortisetosa collected from captive Eld's deer in Thailand

Lipoptena insects are important ectoparasites of cervids and may affect humans that are incidentally bitten. The presence of zoonotic pathogen DNA, such as Anaplasma, and Bartonella, raises the importance of Lipoptena insects in veterinary and human medicine. Eld's deer (Rucervus eldii thamin), an endangered wild ruminant in Thailand, are bred and raised in the open zoo. The semi-wild zoo environment suggests ectoparasite infestation and potential risk for mechanical transmission of pathogens to visitors, zoo workers, or other animals. However, epidemiology knowledge of pathogens related to endangered wild ruminants in Thailand is limited. This study aims to determine the prevalence and diversity of Anaplasma and Bartonella in the L. fortisetosa collected from captive Eld's deer in Chon Buri, Thailand. Of the 91 Lipoptena DNA samples obtained, 42 (46.15%) and 25 (27.47%) were positive for Anaplasma and Bartonella by molecular detection, respectively. Further, 42 sequences of Anaplasma (4 nucleotide sequence types) showed 100% identity to those detected in other ruminants and blood-sucking ectoparasites. Twenty-five sequences of Bartonella (8 nucleotide sequence types) showed 97.35-99.11% identity to the novel Bartonella species from sika deer and keds in Japan. Phylogenetic trees revealed Anaplasma sequences were grouped with the clusters of A. bovis and other ruminant-related Anaplasma, while Bartonella sequences were clustered with the novel Bartonella species lineages C, D, and E, which originated from Japan. Interestingly, a new independent lineage of novel Bartonella species was found in obtained specimens. We report the first molecular detection of Anaplasma and Bartonella on L. fortisetosa, which could represent infectious status of captive Eld's deer in the zoo. Wild animals act as reservoirs for many pathogens, thus preventive measures in surrounding areas should be considered to prevent pathogen infection among animals or potential zoonotic infection among humans.

Molecular pathogen screening of louse flies (Diptera: Hippoboscidae) from domestic and wild ruminants in Austria

BACKGROUND

Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The potential role of hippoboscids as vectors of human and veterinary pathogens is being increasingly investigated, but the presence and distribution of infectious agents in louse flies is still unknown in parts of Europe. Here, we report the use of molecular genetics to detect and characterize vector-borne pathogens in hippoboscid flies infesting domestic and wild animals in Austria.

METHODS

Louse flies were collected from naturally infested cattle (n = 25), sheep (n = 3), and red deer (n = 12) across Austria between 2015 and 2019. Individual insects were morphologically identified to species level and subjected to DNA extraction for molecular pathogen screening and barcoding. Genomic DNA from each louse fly was screened for Borrelia spp., Bartonella spp., Trypanosomatida, Anaplasmataceae, Filarioidea and Piroplasmida. Obtained sequences of Trypanosomatida and Bartonella spp. were further characterized by phylogenetic and haplotype networking analyses.

RESULTS

A total of 282 hippoboscid flies corresponding to three species were identified: Hippobosca equina (n = 62) collected from cattle, Melophagus ovinus (n = 100) from sheep and Lipoptena cervi (n = 120) from red deer (Cervus elaphus). Molecular screening revealed pathogen DNA in 54.3% of hippoboscids, including infections with single (63.39%), two (30.71%) and up to three (5.90%) distinct pathogens in the same individual. Bartonella DNA was detected in 36.9% of the louse flies. Lipoptena cervi were infected with 10 distinct and previously unreported Bartonella sp. haplotypes, some closely associated with strains of zoonotic potential. DNA of trypanosomatids was identified in 34% of hippoboscids, including the first description of Trypanosoma sp. in H. equina. Anaplasmataceae DNA (Wolbachia spp.) was detected only in M. ovinus (16%), while < 1% of the louse flies were positive for Borrelia spp. and Filarioidea. All hippoboscids were negative for Piroplasmida.

CONCLUSIONS

Molecular genetic screening confirmed the presence of several pathogens in hippoboscids infesting domestic and wild ruminants in Austria, including novel pathogen haplotypes of zoonotic potential (e.g. Bartonella spp.) and the first report of Trypanosoma sp. in H. equina, suggesting a potential role of this louse fly as vector of animal trypanosomatids. Experimental transmission studies and expanded monitoring of hippoboscid flies and hippoboscid-associated pathogens are warranted to clarify the competence of these ectoparasites as vectors of infectious agents in a One-Health context.

Hippobosca equina L. (Hippoboscidae: Hippobosca)-An Old Enemy as an Emerging Threat in the Palearctic Zone

Arthropods of the Hippoboscoidea superfamily are parasites of animals from various systematic groups. Mass appearances of these insects and their attacks on people are increasingly being recorded. Their parasitism has a negative effect on host well-being, as it causes feelings of agitation and irritation as well as skin itching and damage. It may result in weight loss and development of diseases in the long-term perspective. Parasites can be a potential epidemiological threat for their hosts as well. One of such parasites is a cosmopolitan species of the Hippoboscinae subfamily-Hippobosca equina. Studies have confirmed the presence of Corynebacterium pseudotuberculosis equi, Bartonella spp., and Anaplasma spp. in the organism of these insects. The frequency of anaphylactic reactions caused by H. equina attacks has been increasing. The aim of the present paper was to summarize the up-to-date knowledge of Hippobosca equina Linnaeus, 1758 due to its significance in medical and veterinary sciences as a potential vector of pathogens. Given the increasing expansion of ectoparasites, mainly related to climate change, ensuring animal welfare and human health is a priority.

Finding a suitable coat: The ecology of the invasive deer ked (Lipoptena cervi (Linnaeus, 1758); Diptera: Hippoboscidae), an ectoparasite of large mammals in the Czech Republic

Some parasitic diseases of wild animals are transmissible to humans and cause health problems. A widespread ectoparasite of vertebrates is the deer ked, Lipoptena cervi ((L.); Diptera: Hippoboscidae). We studied the interaction of this parasite with habitat-related, host-related, and temporal factors in the Czech Republic. We analysed observations of its abundance in hunted wild animals in the context of their environment. Our results confirmed that cervids are a preferred host species. Most of the other relationships between ked abundance and the studied factors were probably due to the olfactory preferences of keds. Males and older individuals of the game host species were more attractive to the parasites for this reason. The higher abundance of keds at the beginning of the hunting season can be explained by their phenology. The deer ked can significantly affect the management of game species. We conclude that its preference for older male cervids is important for the future conditions of game animals. The population densities of deer keds in areas with high parasitization rates could thus be influenced by active game management.

Distribution of Deer Keds (Diptera: Hippoboscidae) in Free-Living Cervids of the Tuscan-Emilian Apennines, Central Italy, and Establishment of the Allochthonous Ectoparasite Lipoptena fortisetosa

Simple Summary

In recent years, the increased presence of wildlife in habitats close to urban settlements has raised concerns about the risk of pathogen transmission from wild animals to humans due to the spread of different parasites. For this reason, a survey aimed at describing the dispersal and parasitism level of two cervid ectoparasites was carried out in the northern Apennines, in central Italy. The presence of two hippoboscids, the autochthonous Lipoptena cervi and allochthonous L. fortisetosa, native to Eastern Asia and recently recorded in Italy, were assessed on their main host species (red deer, fallow deer, and roe deer), considering host sex and age. The alien species L. fortisetosa was found to be widespread in the study area, most likely competing with L. cervi. Moreover, red deer seemed to be the favored host of both flies, with differences in sex and age class preferences. This study demonstrated the importance of regularly monitoring the populations of these parasites, especially the invasive species, due to the risks to human health, as these insects are potential vectors of pathogens.

Abstract

Lipoptena fortisetosa and L. cervi are hematophagous ectoparasites belonging to the Hippoboscidae family and preferentially living on cervids. In recent years, they have received specific attention due to the great increase in the abundance of their host species, and to their medical and veterinary importance as possible vectors of pathogens harmful to humans and animals. The aim of this study was to investigate the parasitism level of both of these flies on their main hosts in Italy, which are red deer, fallow deer, and roe deer, and to highlight a possible preference for a species, sex, or age class among the hosts. Deer keds were collected by examining 326 cervids hunted in the Tuscan-Emilian Apennines. Outcomes showed that L. fortisetosa has greatly spread throughout the study area, where it competes with the autochthonous L. cervi. Moreover, red deer was the favored host species of both ectoparasites, while different preferences for host sex and age classes were observed in the two hippoboscids. The regular monitoring of deer ked populations, especially the allochthonous L. fortisetosa, which is continuously spreading in Europe, is recommended to expand the knowledge on these parasitic species that are potentially dangerous to public health.

Molecular Characterization of Lipoptena fortisetosa from Environmental Samples Collected in North-Eastern Poland

Simple Summary

Lipoptenafortisetosa is an invasive, hematophagous insect, which lives on cervids and continues to spread across Europe. The species originated from the Far East and eastern Siberia. Besides wild animals, these ectoparasites can attack humans, companion animals, and livestock. These insects may also play a role in transmitting infectious diseases. The objective of this study was to confirm the presence of L.fortisetosa in north-eastern Poland and to characterize the examined population with the use of molecular methods. Deer keds were collected from six natural forests in the region of Warmia and Mazury. DNA of L.fortisetosa was extracted and subjected to molecular studies. Two species of deer keds (Lipoptenacervi and L.fortisetosa) were obtained in each location during field research. There were no differences in the sex distribution of these two ectoparasite species. During the research, more L.cervi than L.fortisetosa specimens were obtained. The studied insects were very closely related to specimens from Lithuania, the Czech Republic, and Japan. Our study indicates various ectoparasite lineages, and such research contributes to the improvement of basic knowledge on the distribution, genetic structure, and variability of the invasive ked fly L. fortisetosa.

Abstract

Recent years have witnessed an increase in the population of Lipoptenafortisetosa in Central Europe. The genetic profile of this ectoparasite has not been studied in Poland to date. The aim of the present study was to confirm the presence of L.fortisetosa in north-eastern Poland and to characterize the examined population with the use of molecular methods. Deer keds were collected between June and July 2019 in six natural, mixed forests. A fragment of the rRNA 16S gene was used as a marker to identify L.fortisetosa by polymerase chain reaction (PCR). DNA samples were sequenced in the last step. Six new locations of L. fortisetosa were confirmed. No significant differences were observed in the sex ratios of L. cervi and L. fortisetosa (L. cervi p-value = 0.74; L. fortisetosa p-value = 0.65). Significant differences were noted between the total size of L. cervi and L. fortisetosa populations (p-value < 0.001). The similarity to GenBank sequences ranged from 95.56% to 100%. The obtained nucleotide sequences were very closely related to L. fortisetosa sequences from Lithuania, the Czech Republic, and Japan. Molecular analyses revealed considerable genetic diversity, which could indicate that various ectoparasite lineages have spread throughout Europe.

Exposure of Humans to Attacks by Deer Keds and Consequences of Their Bites-A Case Report with Environmental Background

Simple Summary

Lipoptena species, also named the deer ked or deer fly, are commonly encountered in temperate areas of Europe, northern China, and North America. Although wild animals seem to be the preferred hosts of these parasitic arthropods, it is increasingly being noted that humans are also directly threatened by their bites. Skin lesions evolving after Lipoptena bites are painful and often lead to the development of inflammation of the skin. Lipoptena species also pose a threat to the health of the host by transferring pathogenic factors, e.g., Bartonella schoenbuchensis, Borrelia burgdorferi, and Anaplasma phagocytophilum. For this reason, knowledge of symptoms caused by Lipoptena bites is worth promoting among not only scientists but also the general public.

Abstract

Insects of the genus Lipoptena, e.g., Lipoptena cervi and Lipoptena fortisetosa, are hematophagic ectoparasites mainly attacking deer, roe deer, moose, horses, and cattle. Humans may also be incidental hosts for these insects. The species are vectors of numerous pathogens, including Bartonella schoenbuchensis, Borrelia burgdorferi, and Anaplasma phagocytophilum. Due to the short time of feeding on humans, usually painless bites, and an initially small trace at the site of the bite, the symptoms reported by the patient may not be associated with deer ked infestation and infection with pathogens transmitted by these arthropods. The aim of the study was to describe the consequences of L. cervi bites in humans with detailed documentation of the development of skin lesions. The knowledge about skin lesions arising after deer ked bites may be useful in clinical practice for monitoring patients for the presence of pathogens transmitted by the parasites.

Temporal-Microclimatic Factors Affect the Phenology of Lipoptena fortisetosa in Central European Forests

Simple Summary

The population of Lipoptena spp. continues to increase in Central Europe. Deer keds are obligatory hematophagous ectoparasites. Environmental conditions play a large role in the prevalence of these insects. However, the relationship between environmental conditions and population size has not been assessed in Lipoptena fortisetosa. The objective of this study was to find a link between L. fortisetosa flights and selected weather conditions in forests. Insects were sampled, and selected climatic factors were measured. The correlations between the number of insects and the examined factors were calculated with the use of statistical methods. The results suggest that the abundance of ectoparasites is correlated with time, temperature, relative humidity and wind speed. The beginning of ked flights could also be associated with variations in climatic conditions. In the future, these relationships can be used to minimize the negative impact of keds on humans, livestock and companion animals.

Abstract

The objective of this study was to determine the correlations between the abundance of Lipoptena fortisetosa on new potential hosts and selected temporal-microclimatic conditions in a forest at the beginning of the host-seeking period. Louse flies were collected between 6 May and 15 July of 2019 and 2020 in a natural mixed forest in Poland. Keds were collected by three investigators walking along the same forest route during each sampling session. The number of captured keds and the date (time), temperature (°C), relative humidity (%), air pressure (hPa) and wind speed (km/h) were recorded. A total of five measurements were performed during each sampling session. The influence of temporal-microclimatic conditions on the number of collected ectoparasites was evaluated with the use of a Generalized Additive Model (GAM). A total of 1995 individuals were obtained during field surveys. The results of the GAM revealed a correlation between the number of host seeking L. fortisetosa vs. time, temperature, relative humidity, and wind speed. An increase in temperature was most highly correlated with the abundance of louse flies in the environment.

Keds, the enigmatic flies and their role as vectors of pathogens

Hippoboscid flies (Diptera: Hippoboscidae), commonly known as keds or louse flies, have been for long time overlooked by the scientific community, and their vector role of infectious agents to humans and domestic animals has been scantly investigated. This is partly due to the fact that the host range for most species is primarily restricted to wildlife, being rarely reported on domestic animals and humans. This led to a scarce scientific knowledge about their biology, ecology, behaviour, epidemiology as well as vector competence. However, the life history of some hippoboscid species, e.g., Melophagus ovinus, Lipoptena cervi and Hippobosca equina, suggests that these ectoparasites are important candidates to vector infectious disease agents (e.g., Rickettsia spp., Borrelia spp., Bartonella spp., Anaplasma phagocytophilum, Theileria ovis). Indeed, the peculiar biological and behavioural traits (i.e., obligatory blood sucking and reproductive physiology) of many ked species make them a suitable pabulum for pathogen's multiplication and for their transmission to receptive hosts. Therefore, studies focusing on the ked bio-ecological aspects as well as on their vector role are advocated along with the control of keds affecting different animal species. This review discusses current information on keds, highlighting their importance as vectors of pathogens of medical and veterinary concern to all animal species, with a special focus on mammals.

Molecular detection of Bartonella spp. in deer ked (Lipoptena cervi) in Poland

Background

The bacteria of the genus Bartonella are obligate parasites of vertebrates. Their distribution range covers almost the entire world from America, Europe, Asia to Africa and Australia. Some species of Bartonella are pathogenic for humans. Their main vectors are blood-sucking arthropods such as fleas, ticks and blood-feeding flies. One such dipteran able to transfer vector-borne pathogens is the deer ked (Lipoptena cervi) of the family Hippoboscidae. This species acts as a transmitter of Bartonella spp. in cervid hosts in Europe.

Methods

In the present study, 217 specimens of deer ked (Lipoptena cervi) were collected from 26 red deer (Cervus elaphus) hunted in January 2014. A short fragment (333 bp) of the rpoB gene was used as a marker to identify Bartonella spp. in deer ked tissue by PCR test. A longer fragment (850 bp) of the rpoB gene was amplified from 21 of the positive samples, sequenced and used for phylogenetic analysis.

Results

The overall prevalence of Lipoptena cervi infection with Bartonella spp. was 75.12% (163/217); 86.67% (104/120) of females and 60.82% (59/97) of males collected from red deer hunted in the Strzałowo Forest District in Poland (53°45′57.03″N, 21°25′17.79″E) were infected. The nucleotide sequences from 14 isolates (Bartonella sp. 1) showed close similarity to Bartonella schoenbuchensis isolated from moose blood from Sweden (GenBank: KB915628) and human blood from France (GenBank: HG977196); Bartonella sp. 2 (5 isolates) and Bartonella sp. 3 (one isolate) were similar to Bartonella sp. from Japanese sika deer (GenBank: AB703149), and Bartonella sp. 4 (one isolate) was almost identical to Bartonella sp. isolated from Japanese sika deer from Japan (GenBank: AB703146).

Conclusions

To the best of our knowledge, this is the first report to confirm the presence of Bartonella spp. in deer keds (Lipoptena cervi) in Poland by molecular methods. Bartonella sp. 1 isolates were most closely related to B. schoenbuchensis isolated from moose from Sweden and human blood from France. The rest of our isolates (Bartonella spp. 2–4) were similar to Bartonella spp. isolated from Japanese sika deer from Japan.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2413-0) contains supplementary material, which is available to authorized users.