The Transmission ofHaemoproteussp. of English Wood-pigeons byOrnithomyia avicularia

Bird Louse Flies Ornithomya spp. (Diptera: Hippoboscidae) as Potential Vectors of Mammalian Babesia and Other Pathogens

Background: Birds and mammals share various ectoparasites, which are responsible for the transmission of a wide range of pathogens. The louse flies (family Hippoboscidae) are ectoparasitic dipterans feeding strictly on the blood of mammals and birds. Both sexes of the louse flies are obligatory hematophagous and are known to act as the vectors of infectious agents. Materials and Methods: A total of 20 specimens of Ornithomya sp. were collected by hand on birds caught in nets or by hand from humans in two localities in Eastern Slovakia in 2021. The DNA samples were individually screened by species-specific PCRs for the presence of selected vector-borne pathogens. Results: Taxonomic identification folowed by molecular analyses revealed two louse fly species of Ornithomya spp. (O. avicularia and O. biloba). The molecular screening provided negative PCR results for Anaplasma phagocytophilum, Borrelia burgdorferi s.l., Rickettsia spp., Bartonella spp., and Hepatozoon canis. In contrast, positive PCR results were obtained for Babesia spp., Wolbachia spp., and Trypanosoma corvi. Conclusions: Of epidemiological importance is that the louse flies can presumably spread Babesia and other pathogens by host switching which facilitates the transmission and spread of numerous pathogens.

Evolutionary ecology, taxonomy, and systematics of avian malaria and related parasites

Haemosporidian parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus are one of the most prevalent and widely studied groups of parasites infecting birds. Plasmodium is the most well-known haemosporidian as the avian parasite Plasmodium relictum was the original transmission model for human malaria and was also responsible for catastrophic effects on native avifauna when introduced to Hawaii. The past two decades have seen a dramatic increase in research on avian haemosporidian parasites as a model system to understand evolutionary and ecological parasite-host relationships. Despite haemosporidians being one the best studied groups of avian parasites their specialization among avian hosts and variation in prevalence amongst regions and host taxa are not fully understood. In this review we focus on describing the current phylogenetic and morphological diversity of haemosporidian parasites, their specificity among avian and vector hosts, and identifying the determinants of haemosporidian prevalence among avian species. We also discuss how these parasites might spread across regions due to global climate change and the importance of avian migratory behavior in parasite dispersion and subsequent diversification.

Vetufebrus ovatus n. gen., n. sp. (Haemospororida: Plasmodiidae) vectored by a streblid bat fly (Diptera: Streblidae) in Dominican amber

Background

Both sexes of bat flies in the families Nycteribiidae and Streblidae (Diptera: Hippoboscoidea) reside in the hair or on the wing membranes of bats and feed on blood. Members of the Nycteribiidae transmit bat malaria globally however extant streblids have never been implemented as vectors of bat malaria. The present study shows that during the Tertiary, streblids also were vectors of bat malaria.

Results

A new haemospororidan, Vetufebrus ovatus, n. gen., n. sp., (Haemospororida: Plasmodiidae) is described from two oocysts attached to the midgut wall and sporozoites in salivary glands and ducts of a fossil bat fly (Diptera: Streblidae) in Dominican amber. The new genus is characterized by ovoid oocysts, short, stubby sporozoites with rounded ends and its occurrence in a fossil streblid. This is the first haemosporidian reported from a streblid bat fly and shows that representatives of the Hippoboscoidea were vectoring bat malaria in the New World by the mid-Tertiary.

Conclusions

This report is the first evidence of an extant or extinct streblid bat fly transmitting malaria. Discovering a mid-tertiary malarial parasite in a fossil streblid that closely resembles members of a malarial genus found in nycteribiid bat flies today shows how little we know about the vector associations of streblids. While no malaria parasites have been found in extant streblids, they probably occur and it is possible that streblids were the earliest lineage of flies that transmitted bat malaria to Chiroptera.

Studies of growth and development of gametocytes in Haemoproteus columbae Kruse

As determined by their ability to exflagellate and round up, it took the macrogametocyte and the microgametocyte of Haemoproteus columbae in pigeons 68 and 116 h, respectively, after patency to reach maturity. Pigment granules appeared in the undifferentiated gametocytes 8 h after invasion of blood. Vacuoles were observed in young gametocytes and persisted in the older forms. The growth curve of H. columbae is close to the sigmoidal curve for growth in protozoa. Multiple infection was noticed in pigeons with high levels of parasitemia, but no more than 2 gametocytes reached maturity; such multiple infections were rare in relapses. The sex ratio of the gametocytes was 1:1. Strong lateral displacement of the nuclei of infected erythrocytes was the rule; hypertrophy was negligible.