PREVALENCE AND RISK FACTORS OF ANAPLASMA INFECTIONS IN EASTERN MOOSE (ALCES ALCES AMERICANA) AND WINTER TICKS (DERMACENTOR ALBIPICTUS) IN MAINE, USA

Apparent fatal winter tick (Dermacentor albipictus) infestation in captive reindeer (Rangifertarandus)

The winter tick, Dermacentor albipictus (Ixodidae), commonly infests a wide variety of wild and domestic ungulates throughout North America. This one-host-tick infests animals from October to April, with moose (Alces alces) particularly affected. Animals highly infested may present with anemia, tick-induced alopecia, and alterations in thermoregulation, often resulting in death. Mortality from winter tick infestation has been reported in free-ranging woodland caribou (Rangifer tarandus caribou) and captive reindeer in Alberta, Canada. This historic report raises concern about mortality due to D. albipictus in a wider host range, specifically on translocated caribou. The aim of this report was to describe three cases of winter tick infestation in captive reindeer resulting in severe anemia and mortality likely due to the infestation in New Hampshire, northeastern United States (US). Additionally, ticks were screened molecularly for the detection of tick-borne pathogens. At time of necropsy, all three reindeer showed decreased nutritional status, marked submandibular edema, and had heavy D. albipictus infestation. None of the reindeer exhibited alopecia, which is a common clinical manifestation in moose that die from winter tick infestation. No pathogens were detected via qPCR screening. This report highlights the risk that captive cervids face in areas where winter tick is endemic; therefore, the adoption of preventive control measures should be encouraged to reduce the risk of tick infestation and potential death of these animals.

Prevalence and Genotyping of Anaplasma phagocytophilum Strains from Wild Animals, European Bison (Bison bonasus) and Eurasian Moose (Alces alces) in Poland

Simple Summary

The populations of bison and moose, the largest wild ruminants in Poland, are growing every year. These animals return to Polish forests after many years of risk of extinction or, as in the case of European bison, are reintroduced step by step. Unfortunately, they are still rare and require close health surveillance and monitoring. One serious threat to their health and life is the bacterial parasite Anaplasma phagocytophilum. Moose and bison can also be sources of pathogenic bacteria for humans, which can be transferred through tick bites. In line with the World Health Organization (WHO) “OneHealth” program, indicating that animal health affects human health and vice versa, the following study examines the occurrence of Anaplasma phagocytophilum bacteria in European bison and Eurasian moose populations using molecular biology tools. Our results provide useful data regarding Anaplasma phagocytophilum that could be used in future strategies for the diagnosis and treatment of people and animals.

Abstract

Wild large ungulates, like European bison (Bison bonasus) and Eurasian moose (Alces alces), form an important part of the circulation of Anaplasma phagocytophilum, a Gram-negative, intracellular, tick-transmitted bacterium, in the natural environment. Bison and moose tissue samples were subjected to 16S rDNA, groEL and ankA partial gene marker amplification with specific primers using various variants of PCR. Out of 42 examined individuals, Anaplasma sp. were detected in 4/13 Eurasian moose (31%) and 7/29 European bison (24%). In addition, 12 groEL and 5 ankA partial gene positive samples were obtained from the examined animals. The phylogenetic analysis of the groEL partial gene classified samples from European bison to ecotype I, and samples from Eurasian moose to ecotype I and II; the analysis of the ankA partial gene assigned the samples to clusters I and IV. This study extends knowledge about A. phagocytophilum in wild large ungulates in Poland. This is the first report about the occurrence of Anaplasma sp. in one of the largest populations of free living European bison in the world. Our findings confirm that strains of A. phagocytophilum from Bison bonasus and Alces alces may constitute a natural reservoir of pathogenic HGA Anaplasma strains.