Professor and Head, Depatment of Community Medicine, Dr DY Patil Medical College, Hospital and Research Centre, Dr DY Patil Vidyapeeth, Pune, Maharashtra, India.
Assistant Professor, Depatment of Community Medicine, Dr DY Patil Medical College, Hospital and Research Centre, Dr DY Patil Vidyapeeth, Pune, Maharashtra, India.
Indian J Public Health. 2021 Jul-Sep;65(3):256-260. doi: 10.4103/ijph.IJPH_122_21.
COVID-19 is a public health concern currently demanding continuous efforts to understand its epidemiology. Pimpri-Chinchwad township with a population of over 25 lakhs is located in Maharashtra, one of the worst affected states in India. After the incidence peaked in the township in mid-September 2020, cases started declining even as lockdown restrictions were eased.
A seroprevalence study was conducted to understand the transmission dynamics of the pandemic in this region.
We carried out a population-based seroprevalence study for IgG antibodies for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) among 5000 residents 12 years and above selected by the cluster random sampling. We selected 50 clusters in slums, 80 clusters in tenements, and 70 clusters from housing societies. The field work for collection of samples was carried out from October 07 to October 17, 2020. We used kit from Abbott (SARS-CoV-2 IgG), which employs chemiluminescent microparticle immunoassay technology. The prevalence of IgG antibodies was expressed as point estimates with 95% confidence intervals (CIs). These were weighted for areas and cluster effect and further adjusted for test performance.
The overall seropositivity for IgG was 34.04% (95% CIl 31.3%-36.8%). Slum dwellers had 40.9% positivity rate (95% CI 37.0%-44.7%), those in tenements 41.2% (95% CI 37.7%-44.8%) and people living in housing societies had 29.8% positivity (95% CI 25.8%-33.8%).
A considerable proportion of population had encountered the novel coronavirus approaching partial, if not complete, herd immunity, which may partly explain the declining trend in spite of easing of lockdown restrictions.
COVID-19 是当前公共卫生关注的焦点，需要不断努力了解其流行病学。皮姆普里-钦奇瓦德镇拥有超过 250 万人口，位于印度受灾最严重的邦之一的马哈拉施特拉邦。2020 年 9 月中旬该镇病例达到高峰后，尽管放宽了封锁限制，但病例开始减少。
进行血清流行率研究，以了解该地区大流行的传播动态。
我们通过整群随机抽样选择了 5000 名 12 岁及以上的居民，对他们进行了针对严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的 IgG 抗体的人群血清流行率研究。我们选择了贫民窟中的 50 个群、公寓楼中的 80 个群和住房协会中的 70 个群。样本采集的现场工作于 2020 年 10 月 7 日至 10 月 17 日进行。我们使用雅培试剂盒（SARS-CoV-2 IgG），该试剂盒采用化学发光微粒子免疫分析技术。IgG 抗体的流行率用点估计值表示，置信区间为 95%（95%CI 31.3%-36.8%）。这些数据经过地区和群集效果加权，并进一步根据检测性能进行调整。
总体 IgG 阳性率为 34.04%（95%CI 31.3%-36.8%）。贫民窟居民的阳性率为 40.9%（95%CI 37.0%-44.7%），公寓楼居民为 41.2%（95%CI 37.7%-44.8%），居住在住房协会的居民为 29.8%（95%CI 25.8%-33.8%）。
相当一部分人口已经接触到新型冠状病毒，接近部分（如果不是完全）群体免疫，这可能部分解释了尽管放宽了封锁限制，但病例仍呈下降趋势的原因。
