Prevalence of Sarcocystis calchasi in free-ranging host species: Accipiter hawks and Common Woodpigeon in Germany

Sylvia L Parmentier,Michael Lierz,Kristina Maier-Sam,Achim D Gruber,Dirk Enderlein,Klaus Failing

doi:10.1038/s41598-018-35862-x

Sylvia L Parmentier, Michael Lierz + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-35862-x

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Abstract

The apicomplexan parasite Sarcocystis calchasi (S. calchasi) triggers pigeon protozoal encephalitis, a neurologic disease in columbids. Accipiter hawks have been identified as the final host, and Columbidae and Psittaciformes as intermediate hosts. In this study, 368 free-ranging Accipiter hawks and 647 free-ranging common woodpigeons were sampled in a country-wide study in order to identify the prevalence of S. calchasi in these populations. A semi-nested PCR specific for S. calchasi tested positive in 7.3% (4.9–10.5) of submitted samples from Accipiter hawks. Juvenile Accipiter hawks (13.7%; 7.7–22.0) had a significantly higher infection rate with S. calchasi than adult Accipiter hawks (5.8%; 2.7–9.3). The prevalence of S. calchasi in common woodpigeons was 3.3% (5.4–9.7). Positive pigeons were identified in 14/16 federal states, and a region-dependency was detected, with higher rates of infection in the eastern parts of Germany. The results of this study suggest that the common woodpigeon is a natural reservoir for S. calchasi. In a study of one region for four consecutive years, an increase in prevalence was not detected. Findings indicate that the parasite is not newly introduced to Germany, but rather long established. The prevalence suggests that there is a substantial risk of S. calchasi infections in other free-ranging as well as captive host species.

Highlights

The apicomplexan parasite Sarcocystis calchasi (S. calchasi) is the causative agent of pigeon protozoal encephalitis (PPE)[1]
In the period of 2012–2016, 368 samples of free-ranging Accipiter hawks were collected across Germany
Limited outbreaks of pigeon protozoal encephalitis have been reported in Germany, the United States and Japan[1,5,7]

Summary

Introduction

The apicomplexan parasite Sarcocystis calchasi (S. calchasi) is the causative agent of pigeon protozoal encephalitis (PPE)[1]. The common woodpigeon (Columba palumbus palumbus) is the most common free-ranging pigeon species in Germany, with approximately 9–17 million birds[11]. The high density of woodpigeons supports the hypothesis that the population may serve as main natural reservoir of S. calchasi[9,18]. Sparrowhawk migration is mostly age- and season-dependent, with reaches into central and southern Europe and North Africa[27,31]. Both sexes of goshawks prey on adult woodpigeons, mostly during the winter months and while breeding[25,32,33,34,35]. The overlapping distributions of goshawks, sparrowhawks and woodpigeons results in a close predator-prey relationship[37,38,39,40]

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