A Single Drop of Fingerstick Blood for Quantitative Antibody Response Evaluation After SARS-CoV-2 Vaccination

Among several COVID vaccines that have been approved, the Moderna and Pfizer-BioNTech vaccines are mRNA vaccines that are safe and highly effective at preventing COVID-19 illness. Studies have demonstrated that neutralizing antibody responses elicited by these vaccines correlate strongly with antibodies measured by immunoassays such as ELISA. To monitor the antibody level duration of vaccine-induced immune responses in vaccinated population, cost-effective and easily implementable antibody testing methodologies are urgently needed. In this study, we evaluated the feasibility of using a single drop of fingerstick blood collected with flocked swabs for a high-throughput and quantitative anti-SARS-CoV-2 spike (S1) IgG antibody immunoassay. A total of 50 voluntary subjects participated and donated fingerstick blood samples before and after receiving the Moderna mRNA vaccine. Among all individuals tested, no anti-SARS-CoV-2 S1 IgG antibody was detected before vaccination and on day 7 after receiving the first vaccine dose. On day 14 after the first dose, a significant amount of anti-SARS-CoV-2 S1 IgG antibody was detected in all participants samples. By the end the third week from the first dose, the median anti-SARS-CoV-2 S1 IgG concentration increased to 44.9 ug/mL. No anti-SARS-CoV-2 nucleocapsid (N) protein IgG antibody was detected in any of the participants during the study period, indicating that the anti-SARS-CoV-2 S1 IgG assay is specific for the mRNA vaccine induced antibodies.Comaprison of venous blood plasma and fingerstick blood for anti-SARS-CoV-2 S1 IgG shown a higher correlation. Furthermore, the fingerstick blood dried swab samples are stable for at least 4 days. In summary, we demonstrated that a single drop of fingerstick blood collected with flocked swab can be used for quantitative detection and monitoring of anti-SARS-CoV-2 spike IgG responses after receiving COVID-19 vaccination. This testing platform does not require venous blood draw and can be easily implemented for large scale antibody testing in vaccinated populations.

A High-throughput Microsphere-based Immunoassay of Anti-SARS-CoV-2 IgM Testing for COVID-19 Diagnostics

The pandemic of novel coronavirus disease COVID-19 is rapidly expanding across the world. A positive result of antibody tests suggests that the individual has potentially been exposed to SARS-CoV-2, thus allowing to identify asymptomatic infections and determine the seroprevalence in a given population. The aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgM antibody detection on the Luminex MAGPIX platform. Clinical agreement studies were performed in 42 COVID-19 patient serum samples and 162 negative donor serum/plasma samples. Positive percent agreement (PPA) was 42.86% (95% CI: 9.90% to 81.59%), 71.43% (95% CI: 29.04% to 96.33%), and 28.57% (95% CI: 13.22% to 48.67%) for samples collected on 0-7 days, 8-14 days, and 2-8 weeks from symptom onset, respectively. Negative Percent Agreement (NPA) was 97.53% (95% CI: 93.80% to 99.32%). There was no cross-reactivity with the SARS-CoV-2 IgG antibody Hemoglobin (200 mg/dL), bilirubin (2 mg/dL), triglyceride (250 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. In conclusion, an anti-SARS-CoV-2 IgM antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up the anti-SARS-CoV-2 IgM testing.

Clinical characteristics of a severe bubionic plague patient / 中华地方病学杂志

Objective:To understand the clinical manifestations and prognosis of severe bubonic plague, and to explore the treatment experience of severe bubonic plague.Methods:A retrospective analysis was conducted on the clinical data and treatment of a case of severe bubonic plague admitted to Huade County on November 11, 2019.Results:The case of bubonic plague was a 55-year-old male, and outbreak after hunting the hare at the foci. The clinical manifestations included fever, fatigue, left armpit skin hard, swelling, heat and pain, distinctness of lymph node enlargement in later stage, hiccups and pleural effusion. Laboratory tests showed diffuse intravascular coagulation (DIC), sepsis and multiple organ dysfunctions. Bubonic plague was confirmed by positive culture of Yersinia pestis and positive phage lysis test on the 3rd day after admission. After platelet, plasma, fluid resuscitation and streptomycin combined with moxixacin, DIC and multiple organ functions were restored to normal and the hard swelling subsided. The course of treatment lasted for 19 days, the body temperature returned to normal and the patient recovered. Conclusions:This patient is a severe case of bubonic plague characterized with lymphangitis, skin sclerosis and abnormal coagulation. Timely identification, evaluation, early and combined treatment is the key to successful treatment.

A High-throughput Anti-SARS-CoV-2 IgG Testing Platform for COVID-19

BackgroundSerology tests for detecting the antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can identify previous infection and help to confirm the presence of current infection. ObjectiveThe aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgG antibody detection. ResultsClinical agreement studies were performed in 77 COVID-19 patient serum samples and 226 negative donor serum/plasma samples. Positive percent agreement (PPA) was 42.86% (95% CI: 9.90% to 81.59%), 55.56% (95% CI: 21.20% to 86.30%), and 96.72% (95% CI: 88.65% to 99.60%) for samples collected on 0-7 days, 8-14 days, and [≥]15 days from symptom onset, respectively. Negative Percent Agreement (NPA) was 98.23% (95% CI: 95.53% to 99.52%). No cross-reactivity was observed to patient samples positive for IgG antibodies against the following pathogens: HIV, HAV, HBV, RSV, CMV, EBV, Rubella, Influenza A, and Influenza B. Hemoglobin (200 mg/dL), bilirubin (2 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. ConclusionAn anti-SARS-CoV-2 IgG antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up the anti-SARS-CoV-2 IgG testing.

Analysis of a monitoring results on animal plague in Meriones unguiculatus plague natural foci in Inner Mongolia from 2010 to 2014 / 中华地方病学杂志

Objective To analyze the monitoring results on plague in Meriones unguiculatus plague natural foci in Inner Mongolia from 2010 to 2014,to master the epidemic dynamics of the plague and to provide a basis for developing countermeasures.Methods The plague monitoring data in Meriones unguiculatus plague natural foci from 2010 to 2014 were collected;main host density,rate of dye fleas,flea body index and bacteriology were counted;serology detection was done and the epidemic situation was analyzed.Isolation and identification of Yersinia pestis were carried out through a 4-step test (microscopic examination,isolation and culture,phage lysis test and animal experiment).Serum samples were tested by indirect hemagglutination test.Results Within 5 years,21689 Meriones unguiculatus were captured overlap monitored areas of 7116 hm2 totally,the average rat density was 3.05/hm2;other small rodents were clipped 144352 times,3947 mice were captured,capture rate was 2.73％.Totally 26500 Meriones unguiculatus were checked,91 Meriones unguiculatus were infected with epidemic diseases,227 of 59 groups positive fleas were checked from cultured 51262 fleas of 13268 groups.Totally 5426 serum samples of Meriones unguiculatus were checked,5 copies were found positive,the positive rate was 0.09％.Conclusions Inner Mongolia Meriones unguiculatus plague is still active and spreading.We must enhance propaganda of the plague.Surveillance and emergency management should be strengthened to prevent a outbreak of the plague in human being.

Analysis of monitoring results on plague of rats in Lasiopodomys brandti plague natural foci in Inner Mongolia from 2001 to 2013 / 中华地方病学杂志

Objective To analysis the plague monitoring results on plague of rats in Lasiopodomys brandti plague natural foci of Xilin Gol Plateau in Inner Mongolia from 2001 to 2013,to master the dynamics of the plague epidemic,and to provide a basis for developing countermeasures.Methods Plague monitoring data from 2001 to 2013 in Lasiopodomys brandti plague natural foci were collected,main host density,rate of dye fleas,flea body index,bacteriology,serology and epidemic situation were studied.Results Within 13 years,10 153 Lasiopodomys brandti were captured overlapping a monitored area of 2 919.25 hm2,the average rat density was 3.48/hm2;other small rodents were captured 43 632 times,and 1 631 mice were captured,capture rate was 3.74％.Totally 22 752 host animals were checked by etiology,104 animals were infected with epidemic diseases,79 fleas of 31 groups positive fleas were checked from cultured 27 702 fleas of 6 437 groups.Totally 2 237 serum samples of Lasiopodomys brandti were checked using indirect hemagglutination (IHA),2 copies were found positive,the positive rate was 0.09％.Conclusion In Lasiopodomys brandti plague natural foci of Inner Mongolia,the plague bacteria infected host animals are still existed,future outbreak is possible;the monitoring and health education should be strengthened,in order to prevent the plague spreading to human being.