Abstract: Objective　To investigate the prevalence of the serum anti?Toxoplasma gondii antibody among patients with malignant tumors of the digestive tract in Hainan Province. Methods　A total of 1 932 patients with malignant tumors of the digestive tract were enrolled in Hainan Province from 2016 to 2019, including 376 esophageal cancer patients, 475 gastric cancer patients, 401 colorectal cancer patients, 427 hepatic cancer patients and 253 pancreatic cancer patients, and 400 healthy people served as controls. The serum IgG and IgM antibodies specific to T. gondii were detected using enzyme?linked immunosorbent assay, and the seroprevalence was compared. Results　The overall seroprevalence of anti?T. gondii IgG antibody was significantly greater in patients with malignant tumors of the digestive tract than in healthy controls (19.82% vs. 3.75%; χ2 = 60.49, P < 0.01), and no significant difference was seen in the overall seroprevalence of anti?T. gondii IgM antibody between patients with malignant tumors of the digestive tract and healthy controls (1.09% vs. 0.50%; χ2 = 1.17, P > 0.05). The seroprevalence of anti?T. gondii IgG antibody was 15.16%, 19.58%, 21.70%, 23.65% and 17.79% in patients with esophageal cancer, gastric cancer, colorectal cancer, hepatic cancer and pancreatic cancer, which was all significantly greater than in healthy controls ( χ2 = 29.97, 50.29, 58.03, 67.85 and 36.59; all P < 0.01); however, the seroprevalence of anti?T. gondii IgG antibody in patients with esophageal cancer (1.06%), gastric cancer (1.47%), colorectal cancer (0.75%), hepatic cancer (1.17%) and pancreatic cancer (0.79%) did not differ from that in healthy controls ( χ2 = 0.80, 2.02, 0.20, 1.11 and 0.21; all P > 0.05). There was a significant difference in the seroprevalence of anti?T. gondii IgG antibody among various types of malignant tumors of the digestive tract ( χ2 = 10.65, P < 0.05); however, no significant difference was detected in the seroprevalence of anti?T. gondii IgM antibody ( χ2 = 1.33, P > 0.05). Conclusions　There is a high seroprevalence of anti?T. gondii IgG antibody among patients with malignant tumors of the digestive tract in Hainan Province, and there is a significant difference in the seroprevalence in terms of the cancer type. It is suggested that the screening for T. gondii infections should be intensified in patients with malignant tumors of the digestive tract to effective prevent and control the damages to patients with malignant tumors of the digestive tract caused by T. gondii infections.

Key words: Toxoplasma gondii, Malignant tumor of the digestive tract, Hainan Province, Seroprevalence

摘要： 目的　了解海南地区消化道恶性肿瘤患者血清抗弓形虫抗体水平，为消化道恶性肿瘤患者弓形虫病防控提供参考依据。方法　2016–2019年收集海南省1 932例消化道恶性肿瘤患者作为调查对象，其中食管癌患者376例、胃癌患者475例、结直肠癌患者401例、肝癌患者427例、胰腺癌患者253例，以400例健康体检者作为对照。采用酶联免疫吸附试验检测消化道恶性肿瘤患者和健康体检者血清抗弓形虫IgG和IgM抗体，比较组间抗体阳性率差异。结果　消化道恶性肿瘤患者总体血清抗弓形虫IgG抗体阳性率为19.82%，显著高于健康对照的3.75%（χ2 = 60.49，P < 0.01），两者总体抗弓形虫IgM抗体阳性率差异无统计学意义（1.09%和0.50%；χ2 = 1.17，P > 0.05）。食管癌、胃癌、结直肠癌、肝癌和胰腺癌患者抗弓形虫IgG抗体阳性率分别为15.16%、19.58%、21.70%、23.65%和17.79%，均显著高于健康对照（χ2 = 29.97、50.29、58.03、67.85、36.59，P均< 0.01）；抗弓形虫IgM抗体阳性率分别为1.06%、1.47%、0.75%、1.17%和0.79%，与健康对照差异均无统计学意义（χ2 = 0.80、2.02、0.20、1.11、0.21，P均> 0.05）。不同类型消化道恶性肿瘤患者抗弓形虫IgG抗体阳性率差异有统计学意义（χ2 = 10.65，P < 0.05），但抗弓形虫IgM抗体阳性率差异无统计学意义（χ2= 1.33，P > 0.05）。结论 　海南地区消化道恶性肿瘤患者血清抗弓形虫IgG抗体阳性率较高，不同类型消化道恶性肿瘤患者抗弓形虫IgG抗体阳性率间存在显著差异。建议今后应加强消化道恶性肿瘤患者弓形虫感染筛查，从而有效防控弓形虫感染对消化道恶性肿瘤患者造成的危害。

关键词: 刚地弓形虫, 消化道恶性肿瘤, 海南省, 血清阳性率