Sarcocystis rileyi emerging in Hungary: is rice breast disease underreported in the region?

Sándor Szekeres,Alexandra Juhász,László Sugár,Sándor Hornok,Milán Kondor,Nóra Takács

doi:10.1556/004.2019.040

Sándor Szekeres, Alexandra Juhász + Show 4 more

Open Access

https://doi.org/10.1556/004.2019.040

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Abstract

Reports of Sarcocystis rileyi-like protozoa ('rice breast disease') from anseriform birds had been rare in Europe until the last two decades, when S. rileyi was identified in northern Europe and the UK. However, despite the economic losses resulting from S. rileyi infection, no recent accounts are available on its presence (which can be suspected) in most parts of central, western, southern and eastern Europe. Between 2014 and 2019, twelve mallards (Anas platyrhynchos) were observed to have rice breast disease in Hungary, and the last one of these 12 cases allowed molecular identification of S. rileyi, as reported here. In addition, S. rileyi was molecularly identified in the faeces of one red fox (Vulpes vulpes). The hunting season for mallards in Hungary lasts from mid-August to January, which in Europe coincides with the wintering migration of anseriform birds towards the south. Based on this, as well as bird ringing data, it is reasonable to suppose that the first S. rileyi-infected mallards arrived in Hungary from the north. on the other hand, red foxes (Vulpes vulpes), which are final hosts of S. rileyi, are ubiquitous in Hungary, and our molecular finding confirms an already established autochthonous life cycle of S. rileyi in the region. Taken together, this is the first evidence for the occurrence of S. rileyi in Hungary and its region.

Highlights

Reports of Sarcocystis rileyi-like protozoa (‘rice breast disease’) from anseriform birds had been rare in Europe until the last two decades, when S. rileyi was identified in northern Europe and the UK
While the condition resulting from S. rileyi infection is not fatal by itself, it may interfere with the energy and protein metabolism of birds (Moorman et al, 1991)
Despite the potentially high economic losses resulting from S. rileyi, no recently published accounts are available on its presence in most parts of central, western, southern, and eastern Europe

Summary

Materials and methods

Over the past few years, observational records of rice breast disease in Hungary have been provided by official hunters (Table 1). Red foxes (Vulpes vulpes) have been routinely checked by the flotation method for the presence of Sarcocystis sporocysts in their faeces. The sporocyst-containing supernatant of fox faeces (concentrated by standard flotation) was subjected to five freeze-thaw cycles at room temperature and –80 °C, to overnight digestion in tissue lysis buffer and proteinase K (provided with the QIAamp DNA Mini Kit). Altogether six DNA extracts were analysed with a PCR method modified from Ho et al (1996), originally developed to identify cystogenic coccidia on the species level. Since the hosts are migratory birds, only the region is shown for each country (see Fig. 1)

This study

Results and Discussion