Nature Research Centre, Akademijos 2, Vilnius 21, LT-09412, Lithuania.
Parasitology. 2020 Apr;147(5):593-600. doi: 10.1017/S0031182020000116. Epub 2020 Jan 29.
Haemoproteus species (Haemoproteidae) are widespread blood parasites and are transmitted by Culicoides biting midges and Hippoboscidae louse flies. Although these pathogens may cause morbidity or mortality, the vectors and patterns of transmission remain unknown for the great majority of avian haemoproteids. Haemoproteus nucleocondensus has been frequently reported in Europe in great reed warblers Acrocephalus arundinaceus after their arrival from African wintering grounds, but this infection has not been found in juveniles at the breeding sites. The factors that prevent its transmission remain unclear. This study was designed to test whether the sporogony of H. nucleocondensus (lineage hGRW8) can be completed in Culicoides impunctatus, one of the most abundant European biting midge species. Wild-caught females were infected with H. nucleocondensus from great reed warblers. Microscopic examination and PCR-based methods were used to detect sporogonic stages and to confirm species identity. This study showed that H. nucleocondensus completes sporogony in C. impunctatus, suggesting that there are no obstacles to its transmission from the point of view of vector availability and average temperature in Northern Europe. We discuss other ecological factors which should be considered to explain why the transmission of H. nucleocondensus and some other Southern origin haemosporidians are interrupted in North Europe.
血孢子虫属（Haemoproteidae）是广泛分布的血液寄生虫，通过刺蝇和虱蝇传播。尽管这些病原体可能导致发病率或死亡率，但对于绝大多数禽血孢子虫来说，其传播媒介和模式仍不清楚。Haemoproteus nucleocondensus 在欧洲经常在从非洲越冬地返回的大苇莺 Acrocephalus arundinaceus 中被报道，但在繁殖地的幼鸟中未发现这种感染。防止其传播的因素仍不清楚。本研究旨在测试 Haemoproteus nucleocondensus（hGRW8 谱系）是否可以在刺蝇科的一种最丰富的欧洲刺蝇 Culicoides impunctatus 中完成孢子生殖。从大苇莺中感染了 Haemoproteus nucleocondensus 的野生捕获雌性。通过显微镜检查和基于 PCR 的方法检测孢子生殖阶段并确认物种身份。本研究表明，Haemoproteus nucleocondensus 在 C. impunctatus 中完成孢子生殖，这表明从欧洲北部的媒介可用性和平均温度的角度来看，其传播没有障碍。我们讨论了其他生态因素，这些因素应被考虑以解释为什么 Haemoproteus nucleocondensus 和其他一些源自南方的血孢子虫在北欧的传播被中断。
