Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
mSphere. 2023 Feb 21;8(1):e0052222. doi: 10.1128/msphere.00522-22. Epub 2023 Jan 19.
Industrial livestock operations (ILOs), particularly processing facilities, emerged as centers of coronavirus disease 2019 (COVID-19) outbreaks in spring 2020. Confirmed cases of COVID-19 underestimate true prevalence. To investigate the prevalence of antibodies against SARS-CoV-2, we enrolled 279 participants in North Carolina from February 2021 to July 2022: 90 from households with at least one ILO worker (ILO), 97 from high-ILO intensity areas (ILO neighbors [ILON]), and 92 from metropolitan areas (metro). More metro (55.4%) compared to ILO (51.6%) and ILON participants (48.4%) completed the COVID-19 primary vaccination series; the median completion date was more than 4 months later for ILO compared to ILON and metro participants, although neither difference was statistically significant. Participants provided a saliva swab we analyzed for SARS-CoV-2 IgG using a multiplex immunoassay. The prevalence of infection-induced IgG (positive for nucleocapsid and receptor binding domain) was higher among ILO (63%) than ILON (42.9%) and metro (48.7%) participants (prevalence ratio [PR], 1.38; 95% confidence interval [CI], 1.06 to 1.80; reference category ILON and metro combined). The prevalence of infection-induced IgG was also higher among ILO participants than among an Atlanta health care worker cohort (PR, 2.45; 95% CI, 1.80 to 3.33) and a general population cohort in North Carolina (PRs, 6.37 to 10.67). The infection-induced IgG prevalence increased over the study period. Participants reporting not masking in public in the past 2 weeks had higher infection-induced IgG prevalence (78.6%) than participants reporting masking (49.3%) (PR, 1.59; 95% CI, 1.19 to 2.13). Lower education, more people per bedroom, Hispanic/Latino ethnicity, and more contact with people outside the home were also associated with higher infection-induced IgG prevalence. Few studies have measured COVID-19 seroprevalence in North Carolina, especially among rural, Black, and Hispanic/Latino communities that have been heavily affected. Antibody results show high rates of COVID-19 among industrial livestock operation workers and their household members. Antibody results add to evidence of health disparities related to COVID-19 by socioeconomic status and ethnicity. Associations between masking and physical distancing with antibody results also add to evidence of the effectiveness of these prevention strategies. Delays in the timing of receipt of COVID-19 vaccination reinforce the importance of dismantling vaccination barriers, especially for industrial livestock operation workers and their household members.
工业牲畜养殖场（ILO），尤其是加工设施，在 2020 年春季成为 2019 年冠状病毒病（COVID-19）爆发的中心。COVID-19 的确诊病例低估了真实的流行率。为了调查针对 SARS-CoV-2 的抗体流行率，我们从 2021 年 2 月至 2022 年 7 月在北卡罗来纳州招募了 279 名参与者：90 名来自至少有一名 ILO 工人（ILO）的家庭（ILO），97 名来自高 ILO 强度地区（ILO 邻居 [ILON]），92 名来自大都市区（大都市）。与 ILO（51.6%）和 ILON 参与者（48.4%）相比，更多的大都市（55.4%）参与者完成了 COVID-19 初级疫苗接种系列；与 ILON 和大都市参与者相比，ILO 参与者完成疫苗接种的中位数日期晚了 4 个多月，尽管这两个差异均无统计学意义。参与者提供了唾液拭子，我们使用多重免疫测定法分析了针对 SARS-CoV-2 IgG 的拭子。ILO（63%）参与者的感染诱导 IgG（核衣壳和受体结合域阳性）的流行率高于 ILON（42.9%）和大都市（48.7%）参与者（患病率比 [PR]，1.38；95%置信区间 [CI]，1.06 至 1.80；参考类别 ILON 和大都市合并）。与亚特兰大医疗保健工作者队列（PR，2.45；95%CI，1.80 至 3.33）和北卡罗来纳州一般人群队列相比，ILO 参与者的感染诱导 IgG 流行率也更高（PRs，6.37 至 10.67）。感染诱导的 IgG 流行率在研究期间有所增加。在过去 2 周内报告在公共场所不戴口罩的参与者的感染诱导 IgG 流行率（78.6%）高于报告戴口罩的参与者（49.3%）（PR，1.59；95%CI，1.19 至 2.13）。教育程度较低、每个卧室的人数较多、西班牙裔/拉丁裔种族以及与家庭以外的人接触较多，也与感染诱导的 IgG 流行率较高有关。很少有研究在北卡罗来纳州测量 COVID-19 的血清流行率，尤其是在受影响严重的农村、黑人以及西班牙裔/拉丁裔社区。抗体结果表明，工业牲畜养殖场工人及其家庭成员中 COVID-19 的发病率很高。抗体结果增加了与 COVID-19 相关的社会经济地位和种族健康差异的证据。戴口罩和保持身体距离与抗体结果之间的关联也增加了这些预防策略有效性的证据。COVID-19 疫苗接种时间的延迟强调了消除疫苗接种障碍的重要性，特别是对于工业牲畜养殖场工人及其家庭成员。
