State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; HKU-Pasteur Research Pole, The University of Hong Kong, Hong Kong Special Administrative Region, China; School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China.
State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Nanshan Medicine Innovation Institute of Guangdong Province Guangzhou, Guangdong, China.
Lancet Infect Dis. 2021 Mar;21(3):385-395. doi: 10.1016/S1473-3099(20)30599-5. Epub 2020 Oct 6.
Middle East respiratory syndrome (MERS) remains of global public health concern. Dromedary camels are the source of zoonotic infection. Over 70% of MERS coronavirus (MERS-CoV)-infected dromedaries are found in Africa but no zoonotic disease has been reported in Africa. We aimed to understand whether individuals with exposure to dromedaries in Africa had been infected by MERS-CoV.
Workers slaughtering dromedaries in an abattoir in Kano, Nigeria, were compared with abattoir workers without direct dromedary contact, non-abattoir workers from Kano, and controls from Guangzhou, China. Exposure to dromedaries was ascertained using a questionnaire. Serum and peripheral blood mononuclear cells (PBMCs) were tested for MERS-CoV specific neutralising antibody and T-cell responses.
None of the participants from Nigeria or Guangdong were MERS-CoV seropositive. 18 (30%) of 61 abattoir workers with exposure to dromedaries, but none of 20 abattoir workers without exposure (p=0·0042), ten non-abattoir workers or 24 controls from Guangzhou (p=0·0002) had evidence of MERS-CoV-specific CD4 or CD8 T cells in PBMC. T-cell responses to other endemic human coronaviruses (229E, OC43, HKU-1, and NL-63) were observed in all groups with no association with dromedary exposure. Drinking both unpasteurised camel milk and camel urine was significantly and negatively associated with T-cell positivity (odds ratio 0·07, 95% CI 0·01-0·54).
Zoonotic infection of dromedary-exposed individuals is taking place in Nigeria and suggests that the extent of MERS-CoV infections in Africa is underestimated. MERS-CoV could therefore adapt to human transmission in Africa rather than the Arabian Peninsula, where attention is currently focused.
The National Science and Technology Major Project, National Institutes of Health.
中东呼吸综合征（MERS）仍然是全球公共卫生关注的问题。单峰骆驼是人畜共患病感染的源头。超过 70%的感染 MERS 冠状病毒（MERS-CoV）的单峰骆驼在非洲被发现，但非洲没有报告人畜共患病。我们旨在了解在非洲接触过单峰骆驼的人是否感染了 MERS-CoV。
我们将在尼日利亚卡诺的一个屠宰场屠宰单峰骆驼的工人与没有直接接触单峰骆驼的屠宰场工人、来自卡诺的非屠宰场工人和来自中国广州的对照者进行比较。使用问卷确定接触单峰骆驼的情况。检测血清和外周血单核细胞（PBMC）中的 MERS-CoV 特异性中和抗体和 T 细胞反应。
尼日利亚和广东的参与者均未检测到 MERS-CoV 血清阳性。18 名（30%）接触过单峰骆驼的 61 名屠宰场工人，而 20 名没有接触过单峰骆驼的屠宰场工人中无一例阳性（p=0·0042），10 名非屠宰场工人或 24 名来自广州的对照者中也没有阳性（p=0·0002）。PBMC 中存在 MERS-CoV 特异性 CD4 或 CD8 T 细胞。所有组均观察到针对其他地方性人类冠状病毒（229E、OC43、HKU-1 和 NL-63）的 T 细胞反应，与单峰骆驼暴露无关。饮用未经巴氏消毒的骆驼奶和骆驼尿与 T 细胞阳性呈显著负相关（比值比 0·07，95%CI 0·01-0·54）。
在尼日利亚，与单峰骆驼接触的人发生了人畜共患病感染，这表明非洲 MERS-CoV 感染的程度被低估了。因此，MERS-CoV 可能会在非洲而不是目前关注的阿拉伯半岛适应人际传播。
国家科技重大专项、美国国立卫生研究院。
