Seroepidemiology of <em>Toxoplasma gondii</em> Infection among Healthy Blood Donors in Taiwan

Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3–6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5–19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2–3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1–2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6–3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan.刚地弓形虫（Toxoplasma gondii）是一种呈全球分布的机会致病性人畜共患病原体。全球不同地区的弓形虫感染血清流行率存在显著差异。尽管中国台湾地区于2007年将弓形虫病列为法定报告传染病，但目前对普通人群中该病的流行病学特征仍知之甚少。本横断面研究旨在调查中国台湾地区健康献血者中弓形虫感染的血清流行率及其危险因素。本研究与台湾血液基金会合作，共纳入来自全台6个采血服务中心的1783名健康献血者参与。研究人员分别采用酶免疫测定（enzyme immunoassays）和实时荧光定量PCR（real-time PCR）检测血液样本中的弓形虫抗体与DNA，并通过结构化问卷收集弓形虫感染相关危险因素的信息。在1783名参与者中，166名（9.3%）抗弓形虫IgG抗体检测呈阳性，5名（0.28%）抗弓形虫IgM抗体检测呈阳性。这5名IgM抗体阳性献血者的抗体亲和力较高，提示为既往感染。实时荧光定量PCR未检测到活动性虫血症。多因素logistic回归（multivariate logistic regression）分析显示，食用未煮熟猪肉（校正比值比（adjusted odds ratio, OR）=2.9；95%置信区间（confidence interval, CI）：1.3~6.5）、食用生贻贝（校正OR=5.3；95%CI：1.5~19.1）、家中饲养家猫（校正OR=2.0；95%CI：1.2~3.2）、学历水平较低（校正OR=1.6；95%CI：1.1~2.3）以及献血地点位于中国台湾东部（校正OR=2.5；95%CI：1.6~3.9）为弓形虫血清阳性的独立危险因素。本研究结果为中国台湾地区健康献血者中弓形虫感染的血清流行率及流行病学特征提供了相关信息。