Antibody seroprevalence in the epicenter Wuhan, Hubei, and six selected provinces after containment of the first epidemic wave of COVID-19 in China.
Lancet Reg Health West Pac
; 8: 100094, 2021 Mar.
Article
in English
| MEDLINE | ID: covidwho-1082570
ABSTRACT
BACKGROUND:
China implemented containment measures to stop SARS-CoV-2 transmission in response to the COVID-19 epidemic. After the first epidemic wave, we conducted population-based serological surveys to determine extent of infection, risk factors for infection, and neutralization antibody levels to assess the real infections in the random sampled population.METHODS:
We used a multistage, stratified cluster random sampling strategy to conduct serological surveys in three areas - Wuhan, Hubei Province outside Wuhan, and six provinces selected on COVID-19 incidence and containment strategy. Participants were consenting individuals >1 year old who resided in the survey area >14 days during the epidemic. Provinces screened sera for SARS-CoV-2-specific IgM, IgG, and total antibody by two lateral flow immunoassays and one magnetic chemiluminescence enzyme immunoassay; positive samples were verified by micro-neutralization assay.FINDINGS:
We enrolled 34,857 participants (overall response rate, 92%); 427 were positive by micro-neutralization assay. Wuhan had the highest weighted seroprevalence (4â¢43%, 95% confidence interval [95%CI]=3â¢48%-5â¢62%), followed by Hubei-ex-Wuhan (0â¢44%, 95%CI=0â¢26%-0â¢76%), and the other provinces (<0â¢1%). Living in Wuhan (adjusted odds ratio aOR=13â¢70, 95%CI= 7â¢91-23â¢75), contact with COVID-19 patients (aOR=7â¢35, 95%CI=5â¢05-10â¢69), and age over 40 (aOR=1â¢36, 95%CI=1â¢07-1â¢72) were significantly associated with SARS-CoV-2 infection. Among seropositives, 101 (24%) reported symptoms and had higher geometric mean neutralizing antibody titers than among the 326 (76%) without symptoms (30±2â¢4 vs 15±2â¢1, p<0â¢001).INTERPRETATION:
The low overall extent of infection and steep gradient of seropositivity from Wuhan to the outer provinces provide evidence supporting the success of containment of the first wave of COVID-19 in China. SARS-CoV-2 infection was largely asymptomatic, emphasizing the importance of active case finding and physical distancing. Virtually the entire population of China remains susceptible to SARS-CoV-2; vaccination will be needed for long-term protection.FUNDING:
This study was supported by the Ministry of Science and Technology (2020YFC0846900) and the National Natural Science Foundation of China (82041026, 82041027, 82041028, 82041029, 82041030, 82041032, 82041033).
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Type of study:
Observational study
/
Prognostic study
/
Randomized controlled trials
Topics:
Long Covid
/
Vaccines
Language:
English
Journal:
Lancet Reg Health West Pac
Year:
2021
Document Type:
Article
Affiliation country:
J.lanwpc.2021.100094
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