Department of Microbiology, Shanghai Key Laboratory of Medical Biodefense, Second Military Medical University, Shanghai, China.
Microbiology Laboratory, Center for Disease Control and Prevention of Xuhui District, Shanghai, China.
J Clin Virol. 2014 Jul;60(3):305-8. doi: 10.1016/j.jcv.2014.04.006. Epub 2014 Apr 13.
To investigate serologic status for novel avian influenza A (H7N9) virus in different areas in China, we examined serum samples collected in winter of 2011 from adult population of Shanghai (eastern China), Guangzhou (southern China) and Yunnan (southwest China) for the antibody responses to this virus.
A total of 900 stored serum samples of adult outpatients (300 samples for each area) were subjected to anti-hemagglutinin (HA) antibodies assay using enzyme-linked immunosorbent assay (ELISA) and neutralizing antibodies assay using H7N9 pseudotyped particles (H7N9pp) and authentic H7N9 virus based neutralization test.
Anti-H7 antibodies were detected in 164, 186 and 123 samples from three areas above, respectively. Among anti-H7 positive sera, 20, 42 and 13 samples had neutralizing titers of ≥10 when 8×10(2) focus-forming units (FFU) of H7N9 pseudotyped particles (pp) were adopted in neutralizing assay, respectively. When neutralizing antibodies were assayed using classic microneutralization (MN) test, MN titers of ≥10 were found in 7 samples from Guangzhou, but none from Shanghai and Yunnan.
Low levels of protective immunity pre-existed in some general adult population of the three areas, and pre-existing immunity against H7N9 in Guangzhou appears stronger than that in Shanghai and Yunnan.
为研究中国不同地区人群对新型甲型 H7N9 流感病毒的血清学状况，我们检测了 2011 年冬季采集的来自上海（华东地区）、广州（华南地区）和云南（西南地区）成年门诊患者人群的血清样本，以了解这些人群对该病毒的抗体反应。
共检测了 900 份来自成年门诊患者的储存血清样本（每个地区 300 份），采用酶联免疫吸附试验（ELISA）检测抗血凝素（HA）抗体，采用 H7N9 假型颗粒（H7N9pp）和真实 H7N9 病毒中和试验检测中和抗体。
3 个地区的血清样本中分别有 164、186 和 123 份抗-H7 抗体阳性。在抗-H7 阳性血清中，采用 8×10(2)焦点形成单位（FFU）H7N9 假型颗粒（pp）进行中和试验时，有 20、42 和 13 份血清的中和滴度≥10。采用经典微量中和（MN）试验进行中和抗体检测时，在来自广州的 7 份血清中发现 MN 滴度≥10，而来自上海和云南的血清均未发现。
在这 3 个地区的部分普通成年人群中存在低水平的保护性免疫，广州人群对 H7N9 的预先存在的免疫似乎比上海和云南更强。
