key: cord-0945414-jmne2t1z
authors: Lippi, Giuseppe
title: Potential drawbacks of SARS-COV-2 seroprevalence surveys
date: 2020-12-21
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2020.12.011
sha: dff546ef6b2760ab01ef0f02280a58e59ab577f3
doc_id: 945414
cord_uid: jmne2t1z

nan

Sir, I read with interest the recent meta-analysis of Galnis and collegues [1] , who provided an estimation of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in health care workers. Although seroprevalence surveys can be regarded as an important tools for exploring disease burden and progression of herd immunity, especially in front-line health care staff, there are important drawbacks and limitations that shall be considered when analyzing their pooled outcomes.

Reliable evidence has been provided that seroconversion varies widely in patients with SARS-CoV-2 infection, with up to one-third of all asymptomatic subjects even failing to mount a detectable humoral response with anti-SARS-CoV-2 IgG and thus remaining completely under-diagnosed [2] . The progressive, time-dependent decline of anti-SARS-CoV-2 antibodies is another important issue, whereby it could be proven that over 50% of anti-SARS-CoV-2 IgG seropositive subjects may become seronegative as early as two months after initial molecular diagnosis [3] . Since the first peak of the SARS-CoV-2 outbreak was reached in most worldwide countries during the first months of 2020 [4] , it is conceivable that many infected individuals may have lost a detectable humoral response later in the course of the year. Last but not least, the diagnostic sensitivity of anti-SARS-CoV-2 antibody testing is extremely variable, with consensus-positive interpretation that is often unsatisfactory, and which may hence be associated with a non-negligible risk of obtaining false negative test results [5] .

Altogether, these three aspects would lead the way to concluding that serologic 

Seroprevalence of SARS-CoV-2 antibodies and associated factors in health care workers: a systematic review and meta-analysis

Post-lockdown SARS-CoV-2 nucleic acid screening in nearly ten million residents of Wuhan, China

Change in Antibodies to SARS-CoV-2 Over 60 Days Among Health Care Personnel in

Global perspective of COVID-19 epidemiology for a full-cycle pandemic

None declared.

None