Serologic Response to SARS-CoV-2 in COVID-19 Patients with Different Severity

The immense patient number caused by coronavirus disease 2019(COVID-19)global pandemic brings the urge for more knowledge about its immunological features,including the profile of basic immune parameters.In this study,eighty-eight reported COVID-19 patients in Wuhan were recruited from January to February,2020,including 32 severe/critical cases and56 mild/moderate cases.Their mean age was 56.43 years(range 17–83)and gender ratio(male/female)was 43:45.We tested SARS-CoV-2 RNA with commercial kits,investigated the level of serologic IgM and IgG antibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)using magnetic particle chemiluminescence immunoassays,and compared the results of serologic tests and nucleic acid test(NAT).Among 88 patients,95.45%were confirmed as positive by the combination of NAT and antibody test,which was significantly higher(P<0.001)than by single nucleic acid test(73.86%)or serologic test(65.91%).Then the correlation between temporal profile and the level of antibody response was analyzed.It showed that seroconversion started on day 5 after disease onset and IgG level was rose earlier than IgM.Comparison between patients with different disease severity suggested early seroconversion and high antibody titer were linked with less severe clinical symptoms.These results supported the combination of serologic testing and NAT in routine COVID-19 diagnosis and provided evidence on the temporal profile of antibody response in patients with different disease severity.

Detection of SARS-CoV-2 RNA in Medical Wastewater in Wuhan During the COVID-19 Outbreak

Dear Editor,The outbreak of 2019 novel coronavirus disease(COVID-19),caused by the infection of SARS-Co V-2,was first reported in Wuhan,China(Kong et al.2020a,2020b)and has become the most serious public health emergency in the century(Matsuzaki et al.2010;World Health Organization 2020).The fecal shedding of SARS-Co V-2 has been proven by the viral strains isolated from COVID-19 patient’s stool specimens(Wang et al.2020).It proposed the possibility that contaminated waste water and fomites might be involved in disease transmission(Tang et al.2020),especially at the healthcare facilities with large number of patients.