Zoonoses and potential zoonoses of bears

Thelazia callipaeda Eyeworms in American Black Bear, Pennsylvania, USA, 2023

We identified a Thelazia callipaeda eyeworm in an American black bear in Pennsylvania, USA, on the basis of its morphological features and molecular analysis. Our finding highlights emergence of a T. callipaeda worm sylvatic transmission cycle in the United States.

Wildlife and parasitic infections: A One Health perspective in Greece

While research on the parasitic fauna of wildlife in Greece is currently limited, conducted studies have provided valuable insights into the prevalence of parasitic infections in wild carnivores, omnivores, and herbivores. This review consolidates the existing data on the endoparasites detected in wild animals in Greece, specifically focusing on those that pose established or potential zoonotic risks. Over the last 60 years, various parasite species such as Leishmania infantum, Cryptosporidium spp., Toxoplasma gondii, Sarcocystis spp., Toxocara canis, Ancylostoma caninum, Capillaria spp., Baylisascaris spp., Trichinella spp., Thelazia callipaeda, Dirofilaria immitis, Echinococcus granulosus, Mesocestoides sp., Taenia spp., Alaria alata, and Dicrocoelium dendriticum have been identified in wildlife in Greece. These findings have become increasingly relevant due to the growing interaction between humans and wild animals, which now extends to urban environments, as well as the increased contact between wild and domestic animals. This is further complicated by the geographical expansion of vector-borne diseases due to global warming and the increased movements of humans and animals. Surveillance and monitoring of parasitic infections in Greek wildlife is warranted, and it should be based on interdisciplinary investigations considering the interconnectedness of human, wild, and domestic animals, as well as environmental health, in line with the One Health approach.

Hematological and plasma profiles and ticks and tick-borne pathogens in wild Formosan black bears (Ursus thibetanus formosanus)

BACKGROUND

The endangered Formosan black bear (Ursus thibetanus formosanus) is the largest native carnivorous mammal in Taiwan. Diseases, poor management, illegal hunting, and habitat destruction are serious threats to the survival of bear populations. However, studies on the impact of diseases on bear populations are limited. Therefore, this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites, blood parasites, and vector-borne pathogens.

METHODS

Formosan black bears were captured in Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan. Blood samples were collected from each bear for hematological analysis and plasma biochemistry using a hematology analyzer. Parasites and pathogens were detected using a thin blood smear with Wright-Giemsa staining and polymerase chain reaction (PCR) assay. Additionally, macroscopic ectoparasites were collected from bears to detect blood parasites and other pathogens. Moreover, the relationships between the bear variables (sex, age, and occurrence of parasites or pathogens), ectoparasites, and infectious agents were also analyzed.

RESULTS

In all, 21 wild bears (14 in YNP and 7 in DSY) were captured and released during the satellite tracking studies. Hematological analysis and plasma biochemistry indicated significant differences in white blood cells (WBC), segments, creatine kinase (CK), and lactate dehydrogenase (LDH) levels between foot snare and culvert-captured bears. Additionally, there were significant differences in total plasma protein (TPP), creatinine, Ca2+, Mg2+, and K+ levels between male and female bears. Moreover, pathogen-infected bears had significantly higher erythrocyte sedimentation rate (ESR; 30 min and 1 h) and globulin levels than uninfected bears. In total, 240 ticks were collected from 13 bears, among which eight adult tick species were identified, including Haemaphysalis flava, Haemaphysalis hystricis, Amblyomma testudinarium, Ixodes ovatus, Dermacentor taiwanensis, Haemaphysalis longicornis, Ixodes acutitarsus, Amblyomma javanense, and nymphs belonging to Haemaphysalis spp. PCR revealed that 13 (61.90%) and 8 (38.10%) bears harbored Hepatozoon ursi and Babesia DNA, respectively. Among the ticks examined, 157 (65.41%) and 128 (53.33%) samples were positive for H. ursi and Babesia, respectively.

CONCLUSIONS

To the best of our knowledge, this is the first study to establish a database of the hematological and plasma profiles of wild Formosan black bears and investigate ectoparasite infestation and Hepatozoon and Babesia spp.

INFECTION

In conclusion, these findings may serve as a reference for monitoring the health and population of locally endangered bears.

Preliminary findings on the gastrointestinal parasites of the brown bear (Ursus arctos) in the Cantabrian mountains, Spain

No study is currently available on the parasitofauna of the population of brown bears (Ursus arctos) inhabiting the Cantabrian Mountains in Spain. The aim of the present study was to obtain novel information on diversity and prevalence of gastrointestinal parasites in these individuals. During August 2016 and from May to July 2017, 14 fecal samples were collected from the western Cantabrian bear subpopulation, in the Somiedo Natural Park, in the Spanish province of Asturias. The prevalence of parasites detected was 71% and two genera were identified: Dicrocoelium sp. and Trichuris sp. Since the impact that pathogens such as endoparasites can have on the health of bears, together with other stressors, is still poorly understood, research efforts that include disease surveillance are critical to the successful protection of this emblematic species. Our preliminary findings require further investigations, with a wider sampling effort, and bring awareness for the need of carrying further studies on this area as a part of a proactive species management plan.