Background

In 2021, a novel group of Chlamydia strains in wild birds was classified as avian Chlamydia abortus, with unknown zoonotic potential. We report relevant features of avian C abortus infections from a Dutch family cluster and unrelated historical cases using clinical, epidemiological, and microbiological data.

Methods

An outbreak of avian C abortus started in the Netherlands in December, 2022. Source investigation was done using questionnaires to interview patients and environmental sampling. The outbreak strain of avian C abortus was cultured from three patients from whom sufficient material was available for culture and underwent whole-genome analysis. The outbreak strains and retrospective cohort study strains previously submitted to the National Human Psittacosis surveillance programme in the Netherlands between 2010 and 2022 were typed by partial ompA sequencing. Strains with the same aberrant ompA genotype were further analysed with XerC gene plasmid analysis and compared with closely related Chlamydia sequences available in GenBank.

Findings

An avian C abortus strain caused a cluster of respiratory illness in four family members. Three patients were hospitalised with community-acquired pneumonia, one of whom was admitted to the intensive care unit. The faeces of wild birds were considered a probable source for the index infection. For two family members, human-to-human transmission was a plausible route. Ten historical cases could be identified with avian C abortus with the same ompA genotype. All patients had been admitted to hospital, at least five developed pneumonia, and one died.

Interpretation

This cluster supports that avian C abortus strains can cause human infections and underlines that human-to-human transmission should be considered when tracing the source of such infections.

Funding

National Institute for Public Health and the Environment and Dutch Ministry of Agriculture, Fisheries, Food Security and Nature.

Translation

For the Dutch translation of the abstract see Supplementary Materials section.

中文翻译：

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荷兰禽衣原体流产的传播和社区获得性肺炎：一项疫情调查和回顾性队列研究

 背景

2021 年，一组新的野生鸟类衣原体菌株被归类为禽流产衣原体，具有未知的人畜共患潜力。我们使用临床、流行病学和微生物学数据报告了来自荷兰家庭集群的禽流产丙体感染的相关特征和不相关的历史病例。

 方法

2022 年 12 月，荷兰开始爆发禽流产丙型菌。使用问卷调查来访谈患者和环境采样。从三名患者身上培养出流产禽 C 流产的暴发菌株，这些患者有足够的材料可供培养，并进行了全基因组分析。先前在 2010 年至 2022 年期间提交给荷兰国家人类鹦鹉热监测计划的疫情菌株和回顾性队列研究菌株通过部分 ompA 测序进行分型。使用 XerC 基因质粒分析进一步分析具有相同异常 ompA 基因型的菌株，并与 GenBank 中可用的密切相关的衣原体序列进行比较。

 发现

一种禽类流产梭菌菌株导致四个家庭成员出现一组呼吸道疾病。3 名患者因社区获得性肺炎住院，其中 1 人入住重症监护病房。野生鸟类的粪便被认为是指示感染的可能来源。对于两个家庭成员来说，人际传播是一条合理的途径。10 例历史病例可鉴定为具有相同 ompA 基因型的流产禽 C-abortus。所有患者均已入院，至少 5 例发展为肺炎，1 例死亡。

 解释

该集群支持流产禽丙胞胎丙胞菌菌株可引起人类感染，并强调在追踪此类感染源时应考虑人际传播。

 资金

国家公共卫生与环境研究所和荷兰农业、渔业、粮食安全和自然部。

 译本

有关摘要的荷兰语翻译，请参阅补充材料部分。