Background

Over 1 year since the first reported case, the true COVID-19 burden in Ethiopia remains unknown due to insufficient surveillance. We aimed to investigate the seroepidemiology of SARS-CoV-2 among front-line hospital workers and communities in Ethiopia.

Methods

We did a population-based, longitudinal cohort study at two tertiary teaching hospitals involving hospital workers, rural residents, and urban communities in Jimma and Addis Ababa. Hospital workers were recruited at both hospitals, and community participants were recruited by convenience sampling including urban metropolitan settings, urban and semi-urban settings, and rural communities. Participants were eligible if they were aged 18 years or older, had provided written informed consent, and were willing to provide blood samples by venepuncture. Only one participant per household was recruited. Serology was done with Elecsys anti-SARS-CoV-2 anti-nucleocapsid assay in three consecutive rounds, with a mean interval of 6 weeks between tests, to obtain seroprevalence and incidence estimates within the cohorts.

Findings

Between Aug 5, 2020, and April 10, 2021, we did three survey rounds with a total of 1104 hospital workers and 1229 community residents participating. SARS-CoV-2 seroprevalence among hospital workers increased strongly during the study period: in Addis Ababa, it increased from 10·9% (95% credible interval [CrI] 8·3–13·8) in August, 2020, to 53·7% (44·8–62·5) in February, 2021, with an incidence rate of 2223 per 100 000 person-weeks (95% CI 1785–2696); in Jimma Town, it increased from 30·8% (95% CrI 26·9–34·8) in November, 2020, to 56·1% (51·1–61·1) in February, 2021, with an incidence rate of 3810 per 100 000 person-weeks (95% CI 3149–4540). Among urban communities, an almost 40% increase in seroprevalence was observed in early 2021, with incidence rates of 1622 per 100 000 person-weeks (1004–2429) in Jimma Town and 4646 per 100 000 person-weeks (2797–7255) in Addis Ababa. Seroprevalence in rural communities increased from 18·0% (95% CrI 13·5–23·2) in November, 2020, to 31·0% (22·3–40·3) in March, 2021.

Interpretation

SARS-CoV-2 spread in Ethiopia has been highly dynamic among hospital worker and urban communities. We can speculate that the greatest wave of SARS-CoV-2 infections is currently evolving in rural Ethiopia, and thus requires focused attention regarding health-care burden and disease prevention.

Funding

Bavarian State Ministry of Sciences, Research, and the Arts; Germany Ministry of Education and Research; EU Horizon 2020 programme; Deutsche Forschungsgemeinschaft; and Volkswagenstiftung.

中文翻译：

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埃塞俄比亚 SARS-CoV-2 的血清流行病学和基于模型的预测：一线医院工作人员和社区的纵向队列研究

背景

自第一例报告病例以来的一年多以来，由于监测不足，埃塞俄比亚真正的 COVID-19 负担仍然未知。我们旨在调查埃塞俄比亚一线医院工作人员和社区中 SARS-CoV-2 的血清流行病学。

方法

我们在吉马和亚的斯亚贝巴的两家三级教学医院进行了一项基于人群的纵向队列研究，涉及医院工作人员、农村居民和城市社区。两家医院都招募了医院工作人员，并通过便利抽样招募了社区参与者，包括城市大都市环境、城市和半城市环境以及农村社区。如果参与者年满 18 岁，已提供书面知情同意书，并且愿意通过静脉穿刺提供血液样本，则他们符合资格。每个家庭只招募一名参与者。在连续三轮中使用 Elecsys 抗 SARS-CoV-2 抗核衣壳检测进行血清学检测，测试之间的平均间隔为 6 周，以获得队列中的血清阳性率和发病率估计值。

发现

2020 年 8 月 5 日至 2021 年 4 月 10 日期间，我们进行了三轮调查，共有 1104 名医院工作人员和 1229 名社区居民参与。在研究期间，医院工作人员的 SARS-CoV-2 血清阳性率显着增加：在亚的斯亚贝巴，它从 2020 年 8 月的 10·9%（95% 可信区间 [CrI] 8·3-13·8）增加到 53 ·2021 年 2 月为 7% (44·8-62·5)，发病率为 2223/100 000 人周 (95% CI 1785-2696)；在鸡马镇，从2020年11月的30·8%（95% CrI 26·9-34·8）上升到2021年2月的56·1%（51·1-61·1），发病率每 100 000 人周 3810 的比率 (95% CI 3149–4540)。在城市社区中，观察到 2021 年初的血清阳性率增加了近 40%，吉马镇的发病率为每 100 000 人周 (1004-2429) 1622 例，亚的斯亚贝巴的发病率为每 100 000 人周 (2797-7255) 4646 例。农村社区的血清阳性率从 2020 年 11 月的 18·0%（95% CrI 13·5-23·2）增加到 2021 年 3 月的 31·0%（22·3-40·3）。

解释

SARS-CoV-2 在埃塞俄比亚的传播在医院工作人员和城市社区中非常活跃。我们可以推测，最大的 SARS-CoV-2 感染浪潮目前正在埃塞俄比亚农村发展，因此需要重点关注卫生保健负担和疾病预防。

资金

巴伐利亚州科学、研究和艺术部；德国教育和研究部；欧盟地平线 2020 计划；Deutsche Forschungsgemeinschaft；和大众汽车基金会。