School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia.
NSW Health Pathology, Prince of Wales Hospital, Randwick, New South Wales, Australia.
PLoS Negl Trop Dis. 2024 Aug 5;18(8):e0012385. doi: 10.1371/journal.pntd.0012385. eCollection 2024 Aug.
Query (Q) fever is a zoonosis caused by the bacterium Coxiella burnetii typically presenting as an influenza-like illness (ILI) with or without hepatitis. The infection may be missed by clinicians in settings of low endemicity, as the presentation is clinically not specific, and there are many more common differential diagnoses for ILI including SARS-CoV-2 infection.
Residual serum samples were retrospectively tested for Phase 1 and 2 Q fever-specific IgM, IgG, IgA antibodies by indirect immunofluorescence and C. burnetii DNA by polymerase chain reaction. They had not been previously tested for Q fever, originating from undiagnosed patients with probable ILI, aged 10-70 years and living in regional New South Wales, Australia. The results were compared with contemperaneous data on acute Q fever diagnostic tests which had been performed based on clinicians requests from a geographically similar population.
Only one (0.2%) instance of missed acute Q fever was identified after testing samples from 542 eligible patients who had probable ILI between 2016-2023. Laboratory data showed that during the same period, 731 samples were tested for acute Q fever for clinician-initiated requests and of those 70 (9.6%) were positive. Probability of being diagnosed with Q fever after a clinician initiated request was similar regardless of the patients sex, age and the calendar year of sampling.
In this sample, Q fever was most likely to be diagnosed via clinician requested testing rather than by testing of undiagnosed patients with an influenza like illness.
Q 热是一种由贝氏柯克斯体引起的人畜共患病，通常表现为流感样疾病（ILI），伴有或不伴有肝炎。在低流行地区，由于临床表现不具有特异性，且ILI 的更多常见鉴别诊断包括 SARS-CoV-2 感染，临床医生可能会错过这种感染。
回顾性检测了来自新南威尔士州偏远地区 10-70 岁未确诊的疑似 ILI 患者的残留血清样本，以检测 1 型和 2 型 Q 热特异性 IgM、IgG、IgA 抗体（间接免疫荧光法）和 C. burnetii DNA（聚合酶链反应）。这些样本以前没有进行过 Q 热检测。同时，将结果与同期根据临床医生的请求，针对具有相似地理特征人群进行的急性 Q 热诊断检测的相关数据进行了比较。
在对 542 名疑似 ILI 患者的样本进行检测后，仅发现 1 例（0.2%）急性 Q 热漏诊。实验室数据显示，在同一时期，有 731 个样本因临床医生的请求进行了急性 Q 热检测，其中 70 个（9.6%）呈阳性。无论患者的性别、年龄和采样年份如何，临床医生发起请求后诊断 Q 热的可能性相似。
在本研究样本中，通过临床医生请求进行检测而不是对疑似流感样疾病的未确诊患者进行检测，更有可能诊断出 Q 热。
