Volponi Stefano, De Marco Maria Alessandra, Benigno Roberta, Savorelli Enea, Frasnelli Matteo, Fiorentini Laura, Tosi Giovanni, Bardasi Lia, Toschi Elena, Taddei Roberta, Cocchi Roberto
Wildlife Service, Institute for Environmental Protection and Research (ISPRA), 40064 Ozzano dell'Emilia, BO, Italy.
Office of Sustainability Education and Animal Welfare, Environmental and Land Protection Service, Comune di Ravenna, 48124 Ravenna, Italy.
Animals (Basel). 2024 Aug 6;14(16):2291. doi: 10.3390/ani14162291.
Avian botulism is a paralytic disease due to the ingestion of botulinum neurotoxins (BoNT) produced by anaerobic, sporigenic bacteria (notably, ). Wild waterbirds worldwide are affected with variable recurrence and severity, and organic material decaying in wetland habitats may constitute a suitable substrate for the replication of clostridia strains producing BoNT in conditions of high temperatures and the absence of oxygen. Here, we describe a large outbreak of avian botulism that occurred in the Valle Mandriole protected area of northeastern Italy (VM). After the recovery in late summer of a few duck carcasses that molecularly tested positive for BoNT-producing clostridia, in October 2019, the avian botulism escalation led to a total of 2367 birds being recovered (2158 carcasses and 209 sick birds). Among these, 2365/2367 were waterbirds, with ducks accounting for 91.8% of the total (2173/2367) and green-winged teals representing 93.5% of the ducks. After the quick collection of dead and sick birds (from 4 to 11 October 2019) and the flooding of the VM wetland (from 5 to 12 October 2019), the 2019 botulism emergency apparently ended. Following two water inputs in May and July 2020, only one pooled sample obtained from 16 bird carcasses found that year in VM tested positive for clostridia type C by real-time PCR, whereas, after to the implementation of measures deterring the bird's presence, new avian botulism cases-due to clostridia type C and C/D, according to molecular and animal-model tests of confirmation-led to the collection of 176 waterbirds (82 carcasses and 94 sick ducks) and 16 waterbirds (9 carcasses and 7 sick ducks) in the summers 2021 and 2022, respectively. In conclusion, the prevention, management, and control of the disease rely on habitat management, the quick and careful collection/removal of animal carcasses, and the regular monitoring and surveillance of live and dead birds.
禽肉毒中毒是一种麻痹性疾病，起因是摄入了由厌氧产孢细菌（特别是 ）产生的肉毒杆菌神经毒素（BoNT）。全球范围内的野生水鸟都会受到影响，其复发情况和严重程度各不相同，湿地栖息地中腐烂的有机物质可能为在高温无氧条件下产生 BoNT 的梭菌菌株的繁殖提供适宜的基质。在此，我们描述了意大利东北部曼德里奥山谷保护区（VM）发生的一次大规模禽肉毒中毒疫情。在夏末发现几只鸭尸体经分子检测对产 BoNT 的梭菌呈阳性后，2019 年 10 月，禽肉毒中毒疫情升级，共回收了 2367 只鸟（2158 具尸体和 209 只病鸟）。其中，2365/2367 只为水鸟，鸭占总数的 91.8%（2173/2367），绿翅鸭占鸭总数的 93.5%。在迅速收集死鸟和病鸟（2019 年 10 月 4 日至 11 日）以及 VM 湿地被淹没（2019 年 10 月 5 日至 12 日）之后，2019 年的肉毒中毒紧急情况显然结束。在 2020 年 5 月和 7 月两次注水后，当年在 VM 仅从 16 只鸟尸体采集的一个混合样本经实时 PCR 检测对 C 型梭菌呈阳性，然而，在实施了阻止鸟类进入的措施后，根据分子和动物模型确诊试验，由 C 型和 C/D 型梭菌导致的新的禽肉毒中毒病例分别在 2021 年和 2022 年夏季致使回收了 176 只水鸟（82 具尸体和 94 只病鸭）以及 16 只水鸟（9 具尸体和 7 只病鸭）。总之，该病的预防、管理和控制依赖于栖息地管理、迅速且谨慎地收集/清除动物尸体以及对活鸟和死鸟进行定期监测和监视。
