Risk Of Future Infection Research Articles

Protective effect of COVID-19 vaccination against a SARS-CoV-2 reinfection in the Babil Province

Reinfection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has been documented all over the world. Currently, limited evidence exists concerning the protec¬tion afforded by the COVID-19 vaccination against reinfection with SARS-CoV-2. This case-control study was per¬formed in order to assess the association between COVID-19 vaccination and SARS-CoV-2 reinfection in the Babil Province; the study used an electronic questionnaire. The infected patients were 115 (aged ≥18 years) and were confirmed by a positive PCR and/or a CT scan, they were either fully vaccinated or not with a second dose of a (Pfizer, AstraZeneca, or Sinopharm) vaccine before the reinfection date, and they were compared with 300 control partici¬pants. The study’s findings revealed that the unvaccinated individuals had 4.5 times the odds of reinfection compared to those who were fully vaccinated, without preference for the manufacturer of the vaccine. The conclusion suggests that getting fully vaccinated against COVID-19 can significantly reduce the likelihood of reinfection, can enhance overall protection, and can minimize the risk of future infections.

Evaluating the Demand for Nucleic Acid Testing in Different Scenarios of COVID-19 Transmission: A Simulation Study.

The 2019 novel coronavirus (COVID-19) has been recognized as the most severe human infectious disease pandemic in the past century. To enhance our ability to control potential infectious diseases in the future, this study simulated the influence of nucleic acid testing on the transmission of COVID-19 across varied scenarios. Additionally, it assessed the demand for nucleic acid testing under different circumstances, aiming to furnish a decision-making foundation for the implementation of nucleic acid screening measures, the provision of emergency materials, and the allocation of human resources. Considering the transmission dynamics of COVID-19 and the preventive measures implemented by countries, we explored three distinct levels of epidemic intensity: community transmission, outbreak, and sporadic cases. Integrating the theory of scenario analysis, we formulated six hypothetical epidemic scenarios, each corresponding to possible occurrences during different phases of the pandemic. We developed an improved SEIR model, validated its accuracy using real-world data, and conducted a comprehensive analysis and prediction of COVID-19 infections under these six scenarios. Simultaneously, we assessed the testing resource requirements associated with each scenario. We compared the predicted number of infections simulated by the modified SEIR model with the actual reported cases in Israel to validate the model. The root mean square error (RMSE) was 350.09, and the R-squared (R2) was 0.99, indicating a well-fitted model. Scenario4 demonstrated the most effective prevention and control outcomes. Strengthening non-pharmaceutical interventions and increasing nucleic acid testing frequency, even under low testing capacity, resulted in a delayed epidemic peak by 78days. The proportion of undetected cases decreased from 77.83% to 31.21%, and the overall testing demand significantly decreased, meeting maximum demand even with low testing capacity. The initiation of testing influenced case detection probability. Under high testing capacity, increasing testing frequency elevated the detection rate from 36.40% to 77.83%. Nucleic acid screening proved effective in reducing the demand for testing resources under diverse epidemic prevention and control strategies. While effective interventions and nucleic acid screening measures substantially diminished the demand for testing-related resources, varying degrees of insufficient testing capacity may still persist. The nucleic acid detection strategy proves effective in promptly identifying and isolating infected individuals, thereby mitigating the infection peak and extending the time to peak. In situations with constrained testing capacity, implementing more stringent measures can notably decrease the number of infections and alleviate resource demands. The improved SEIR model demonstrates proficiency in predicting both reported and unreported cases, offering valuable insights for future infection risk assessments. Rapid evaluations of testing requirements across diverse scenarios can aptly address resource limitations in specific regions, offering substantial evidence for the formulation of future infectious disease testing strategies.

Protective mucosal SARS-CoV-2 antibodies in the majority of the general population in the Netherlands

Antibodies to SARS-CoV-2 on the mucosal surfaces of the respiratory tract are understood to contribute to protection against SARS-CoV-2 infection. We aimed to describe the prevalence, levels, and functionality of mucosal antibodies in the general Dutch population. Nasal samples were collected from 778 randomly selected participants, 1-90 years of age, nested within the nationwide prospective SARS-CoV-2 PIENTER corona serosurvey in the Netherlands. Spike-specific immunoglobulin (Ig)G was detected in the nasal samples of 94.6% (in case of the wild-type S1 variant) and 94.9% (Omicron BA.1) of the individuals, whereas 44.2% and 62.7% of the individuals were positive for wild-type and Omicron BA.1 S1 IgA, respectively. The lowest prevalence of mucosal antibodies was observed in children under 12 years of age. The prevalence and levels of IgA and IgG were higher in individuals with a history of SARS-CoV-2 infection. Mucosal antibodies inhibited the binding of Wuhan, Delta, and Omicron BA.1 receptor binding domain to human angiotensin-converting enzyme 2 in 94.4%, 95.4%, and 92.6% of the participants, respectively. Higher levels of mucosal antibodies were associated with a lower risk of future infection.

Adjuvants in COVID-19 vaccines: innocent bystanders or culpable abettors for stirring up COVID-heart syndrome.

COVID-19 infection is a multi-system clinical disorder that was associated with increased morbidity and mortality. Even though antiviral therapies such as Remdesvir offered modest efficacy in reducing the mortality and morbidity, they were not efficacious in reducing the risk of future infections. So, FDA approved COVID-19 vaccines which are widely administered in the general population worldwide. These COVID-19 vaccines offered a safety net against future infections and re-infections. Most of these vaccines contain inactivated virus or spike protein mRNA that are primarily responsible for inducing innate and adaptive immunity. These vaccines were also formulated to contain supplementary adjuvants that are beneficial in boosting the immune response. During the pandemic, clinicians all over the world witnessed an uprise in the incidence and prevalence of cardiovascular diseases (COVID-Heart Syndrome) in patients with and without cardiovascular risk factors. Clinical researchers were not certain about the underlying reason for the upsurge of cardiovascular disorders with some blaming them on COVID-19 infections while others blaming them on COVID-19 vaccines. Based on the literature review, we hypothesize that adjuvants included in the COVID-19 vaccines are the real culprits for causation of cardiovascular disorders. Operation of various pathological signaling events under the influence of these adjuvants including autoimmunity, bystander effect, direct toxicity, anti-phospholipid syndrome (APS), anaphylaxis, hypersensitivity, genetic susceptibility, epitope spreading, and anti-idiotypic antibodies were partially responsible for stirring up the onset of cardiovascular disorders. With these mechanisms in place, a minor contribution from COVID-19 virus itself cannot be ruled out. With that being said, we strongly advocate for careful selection of vaccine adjuvants included in COVID-19 vaccines so that future adverse cardiac disorders can be averted.

Incidence of Legionnaires' Disease among Travelers Visiting Hotels in Germany, 2015-2019.

We determined whether the incidence rates of travel-associated Legionnaires' disease (TALD) in hotels in Germany increased after a previous occurrence and whether control measures required by the European Legionnaires' Disease Surveillance Network after a cluster (>2 cases within 2 years) restored the rate to baseline. We analyzed TALD surveillance data from Germany during 2015-2019; a total of 307 TALD cases (163 domestic, 144 nondomestic) in hotels were reported. The incidence rate ratio was 5.5 (95% CI 3.6-7.9) for a second case and 25 (95% CI 11-50) for a third case after a cluster had occurred, suggesting that control measures initiated after the occurrence of TALD clusters might be inadequate to restore the incidence rate to baseline. Our findings indicate that substantial LD preventive measures should be explored by hotels or other accommodations after the first TALD case occurs to reduce the risk for future infections.

Current status of Botryosphaeriaceae species in Italy: Impacts on agricultural crops and forest ecosystems

Many fungi belonging to Botryosphaeriaceae are well-known as causal agents of diseases in economically and ecologically important agricultural crops and forest trees. In Italy, the high diffusion of Botryosphaeriaceae infections observed over the last decade, has shown the importance of this group of fungi, which are becoming limiting factors for plant production in agricultural systems, nurseries and natural and urban landscapes. Global warming and stress factors such as occasional extreme climatic events can affect the susceptibility of host plants, as well as fungus behaviour, increasing the risk of future infections. Available reports of Botryosphaeriaceae in Italy have been examined, focusing on wood and fruit pathogens, resulting in a list of ten genera and 57 species. Diplodia is the most widespread genus in Italy with 76 records on 44 hosts, while at species level, Neofusicoccum parvum, Botryosphaeria dothidea and Diplodia seriata show the widest host ranges and many records. The ability of the pathogens to remain latent on asymptomatic plants, and uncontrolled trade of plant materials among countries, facilitate the dissemination and potential introduction of new Botryosphaeriaceae species. Preventive detection and adequate control strategies are always needed to limit the potential damage caused by Botryosphaeriaceae. This review had particular emphasis on host-pathogen associations, disease symptoms, geographic distribution, metabolite production, and accurate pathogen identification.

Applicability of the ATP assay in monitoring the cleanliness of hospital environments

BackgroundThe adenosine triphosphate (ATP) assay is widely used for simple and rapid evaluation of the cleanliness of environmental surfaces. However, there remain concerns regarding the reliability of the ATP assay in hospital settings. This study aimed to assess whether the ATP assay could detect inadequate cleaning within hospital environments as well as monitor the effectiveness of routine cleaning. MethodsThe cleanliness of seven types of high-touch surfaces in operating rooms that were routinely cleaned was evaluated by testing the ATP assay and aerobic colony counts (ACC). For pressure redistribution mattresses (Soft-nurse®) that were found to be particularly at risk of infection, cleaning methods were improved, and the effectiveness of these improvements was monitored using the same two methods. ResultsThe ATP assay quantitatively detected contamination on seven high-touch surfaces but showed no correlation with ACC. However, a significant positive correlation between luminescence and ACC was found on one specific surface, allowing for determining a theoretical cutoff value. Additionally, the ATP assay effectively identified the risk of future infection, which the ACC test could not assess. ConclusionsThe ATP assay can monitor the effectiveness of routine cleaning by setting a theoretical cutoff value for each subject. The method provides quantitative and meaningful values when used with an understanding of its limitations.

Antibody levels following vaccination against SARS-CoV-2: associations with post-vaccination infection and risk factors in two UK longitudinal studies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels can be used to assess humoral immune responses following SARS-CoV-2 infection or vaccination, and may predict risk of future infection. Higher levels of SARS-CoV-2 anti-Spike antibodies are known to be associated with increased protection against future SARS-CoV-2 infection. However, variation in antibody levels and risk factors for lower antibody levels following each round of SARS-CoV-2 vaccination have not been explored across a wide range of socio-demographic, SARS-CoV-2 infection and vaccination, and health factors within population-based cohorts. Samples were collected from 9361 individuals from TwinsUK and ALSPAC UK population-based longitudinal studies and tested for SARS-CoV-2 antibodies. Cross-sectional sampling was undertaken jointly in April-May 2021 (TwinsUK, N=4256; ALSPAC, N=4622), and in TwinsUK only in November 2021-January 2022 (N=3575). Variation in antibody levels after first, second, and third SARS-CoV-2 vaccination with health, socio-demographic, SARS-CoV-2 infection, and SARS-CoV-2 vaccination variables were analysed. Using multivariable logistic regression models, we tested associations between antibody levels following vaccination and: (1) SARS-CoV-2 infection following vaccination(s); (2) health, socio-demographic, SARS-CoV-2 infection, and SARS-CoV-2 vaccination variables. Within TwinsUK, single-vaccinated individuals with the lowest 20% of anti-Spike antibody levels at initial testing had threefold greater odds of SARS-CoV-2 infection over the next 6-9 months (OR = 2.9, 95% CI: 1.4, 6.0), compared to the top 20%. In TwinsUK and ALSPAC, individuals identified as at increased risk of COVID-19 complication through the UK 'Shielded Patient List' had consistently greater odds (two- to fourfold) of having antibody levels in the lowest 10%. Third vaccination increased absolute antibody levels for almost all individuals, and reduced relative disparities compared with earlier vaccinations. These findings quantify the association between antibody level and risk of subsequent infection, and support a policy of triple vaccination for the generation of protective antibodies. Antibody testing was funded by UK Health Security Agency. The National Core Studies program is funded by COVID-19 Longitudinal Health and Wellbeing - National Core Study (LHW-NCS) HMT/UKRI/MRC ([MC_PC_20030] and [MC_PC_20059]). Related funding was also provided by the NIHR 606 (CONVALESCENCE grant [COV-LT-0009]). TwinsUK is funded by the Wellcome Trust, Medical Research Council, Versus Arthritis, European Union Horizon 2020, Chronic Disease Research Foundation (CDRF), Zoe Ltd and the National Institute for Health Research (NIHR) Clinical Research Network (CRN) and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust in partnership with King's College London. The UK Medical Research Council and Wellcome (Grant ref: [217065/Z/19/Z]) and the University of Bristol provide core support for ALSPAC.

PB2192: THE IMPACT OF DENTAL DISEASE ON THE MANAGEMENT OF HAEMATOLOGICAL DISEASE: A REVIEW OF TWO CASES

Background: Significant numbers of haematology patients are seen on a clinic dedicated to the management of patients with medically complex backgrounds within the Dental Institute of King’s College Hospital. Many are referred for dental assessment and treatment prior to haematopoietic stem cell transplant (HSCT), our clinic aims to provide this service in a timely manner in order to avoid dental concerns delaying transplant. The objective of pre-HSCT dental assessment is the identification and elimination of possible source of dental infection which could otherwise cause significant morbidity or mortality during the transplant process. For most of the patients found to require dental treatment this will involve the extraction of teeth which are non-vital, infected or considered to pose a future risk of infection. Our team includes dental consultants, specialty trainees and hospital grade dentists who work closely with haematology colleagues within our hospital and others. We report two cases in which concerns about oral health identified at dental assessment resulted in planned HSCT being significantly delayed or abandoned. The impact on the patients’ haematological management will be discussed with the aim of highlighting the importance of effective pre-transplant dental assessment and the effects of poor dental health on HSCT. Aims: - To identify patients whose medical outcome was directly adversely affected by their dental health. - To discuss the cases in which findings at dental assessment resulted in significant delay to HSCT. Methods: From the dedicated database of patients managed within our medically complex dental clinic over the last five years, those referred for pre-HSCT dental assessment whose oral health contraindicated proceeding with HSCT around the time this was planned were identified and data pertaining to them extracted. Results: Since 2017 our clinic received more than 600 referrals for pre-HSCT dental assessment from haematology colleagues. The vast majority of patients were deemed dentally fit for transplant either at presentation or after the successful completion of dental treatment. Two patients who could not proceed to transplant due to oral contraindications were, however, identified. Patient 1 had been diagnosed with Hodgkin’s lymphoma 2 years earlier, previous treatment included zolendronic acid. Unfortunately, no dental assessment was undertaken before this bisphosphonate therapy was commenced. He presented with a large, spontaneous osteonecrosis of the left maxilla and a neglected dentition; all remaining teeth required extraction. The patient’s haematologist believed that the presence and extent of the necrotic bone contraindicated HSCT so alternative, less effective treatment, was pursued instead. Patient 2 had received chemotherapy to treat his follicular lymphoma. During pre-HSCT dental assessment a squamous cell carcinoma of the right tongue was noted and later confirmed on biopsy; he subsequently underwent hemi-glossectomy and right neck dissection with free flap reconstruction. HSCT had to be postponed but was successfully completed 3 months after his surgery. Summary/Conclusion: The cases presented highlight the value of pre-HSCT dental assessment and how oral health can impact significantly on wider aspects of healthcare. Although a rare occurrence dental assessment may identify patients who should not proceed to transplant as planned and in doing so may help to prevent adverse outcome of this intervention.

Ticks on the move—climate change-induced range shifts of three tick species in Europe: current and future habitat suitability for Ixodes ricinus in comparison with Dermacentor reticulatus and Dermacentor marginatus

Tick-borne diseases are a major health problem worldwide and could become even more important in Europe in the future. Due to changing climatic conditions, ticks are assumed to be able to expand their ranges in Europe towards higher latitudes and altitudes, which could result in an increased occurrence of tick-borne diseases.There is a great interest to identify potential (new) areas of distribution of vector species in order to assess the future infection risk with vector-borne diseases, improve surveillance, to develop more targeted monitoring program, and, if required, control measures.Based on an ecological niche modelling approach we project the climatic suitability for the three tick species Ixodes ricinus, Dermacentor reticulatus and Dermacentor marginatus under current and future climatic conditions in Europe. These common tick species also feed on humans and livestock and are vector competent for a number of pathogens.For niche modelling, we used a comprehensive occurrence data set based on several databases and publications and six bioclimatic variables in a maximum entropy approach. For projections, we used the most recent IPCC data on current and future climatic conditions including four different scenarios of socio-economic developments.Our models clearly support the assumption that the three tick species will benefit from climate change with projected range expansions towards north-eastern Europe and wide areas in central Europe with projected potential co-occurrence.A higher tick biodiversity and locally higher abundances might increase the risk of tick-borne diseases, although other factors such as pathogen prevalence and host abundances are also important.

PO-702-03 THE GHOSTS OF LEADS PAST: LEAD CASTS AND RECURRENT BACTEREMIA

Lead extraction can be complex and has inherent risk. Many acute complications are related to adhesions and fibrosis developing around chronic leads during removal. However, less appreciated chronic complications include those related to consequences of lead cast(s) retained following lead removal, including but not limited to distal embolization. We report a case of a lead cast identified with 3D intra-cardiac echocardiogram (ICE) after pacemaker extraction and its suspected role in persistent bacteremia. NA A 23-year-old male with repaired Tetralogy of Fallot and complete heart block status post dual chamber pacemaker presented with pacing induced cardiomyopathy. He subsequently underwent extraction of atrial and ventricular leads and implant of a left axillary CRT-D system. Unfortunately, he developed MRSA bacteremia necessitating CRT-D extraction, temporary pacing until bacteremia cleared, and subsequent temporizing leadless pacemaker implantation. During the extraction, two large masses were identified by TEE, which were consistent with fibrin casts retained from the previous atrial and coronary sinus pacing leads. Due to the extent of the retained debris and potential risk of future infection, 3D ICE-guided removal with catheter-based aspiration systems was attempted but was unsuccessful with both the Penumbra and Angiovac systems. Of note, the extent of fibrin deposition was better appreciated on intraprocedural 3D ICE compared to cardiac CT or transesophageal echocardiogram (TEE). One cast in particularly stretched from high SVC into the coronary sinus. In follow-up, bacteremia recurred without alternative source and antibiotics were re-initiated with future plan for surgical removal if required. Lead cast formation after extraction is common and generally carries a benign clinical course when casts are small and bacteremia has cleared; however, we present a case demonstrating both the utility of 3D ICE in visualizing fibrin casts and a concerning clinical course associated with large fibrin casts and development of recurrent bacteremia.

The S-Trimer (SCB-2019) COVID-19 vaccine and reinfection with SARS-CoV-2

The S-Trimer (SCB-2019) COVID-19 vaccine and reinfection with SARS-CoV-2

Is Previous Postoperative Infection an Independent Risk Factor for Postoperative Infection after Second Unrelated Abdominal Operation?

Infections after abdominal surgery remain a significant problem. Although preoperative antibiotic prophylaxis is a primary strategy used to reduce postoperative infections, it is typically prescribed based on standardized protocols, without attention to previous infection or antibiotic history. Patients with a previous infection after surgery may be at higher risk for infectious complications after subsequent operations owing to antibiotic resistance. We hypothesized that a previous postoperative infection is a significant risk factor for the development of infection after a second unrelated surgery. We performed a retrospective study of patients who had undergone 2 unrelated abdominal operations at a tertiary care center from 2012 to 2018. Clinical variables and microbiological culture results were abstracted. Univariate and multivariable regression models were constructed. Of 758 patients, 15.0% (n = 114) developed an infection after the first operation. After the second operation, 22.8% (n = 26) of those with a previous infection developed another infection, whereas the incidence of an infection after the second operation was only 9.5% (n = 61) in patients who did not develop an infection after the first operation. Multivariable analysis demonstrated that previous infection (odds ratio 2.49, 95% CI 1.46 to 4.25) was associated with future infection risk. Microbiological analysis found that infections after the second surgery were significantly more likely to be antibiotic resistant than infections after the first surgery (82.3% vs 64.1%; p = 0.036). Strikingly, 49% of infections after the second surgery were resistant to the antibiotic prophylaxis given at the time of incision. Previous postoperative infection is an independent risk factor for a subsequent postoperative infection and is associated with resistance to standard prophylaxis. Individualization of antibiotic prophylaxis in patients with a previous postoperative infection is warranted.

Harnessing the Potential of Multiomics Studies for Precision Medicine in Infectious Disease.

The field of infectious diseases currently takes a reactive approach and treats infections as they present in patients. Although certain populations are known to be at greater risk of developing infection (eg, immunocompromised), we lack a systems approach to define the true risk of future infection for a patient. Guided by impressive gains in “omics” technologies, future strategies to infectious diseases should take a precision approach to infection through identification of patients at intermediate and high-risk of infection and deploy targeted preventative measures (ie, prophylaxis). The advances of high-throughput immune profiling by multiomics approaches (ie, transcriptomics, epigenomics, metabolomics, proteomics) hold the promise to identify patients at increased risk of infection and enable risk-stratifying approaches to be applied in the clinic. Integration of patient-specific data using machine learning improves the effectiveness of prediction, providing the necessary technologies needed to propel the field of infectious diseases medicine into the era of personalized medicine.

Seroprevalence of SARS-CoV-2 antibodies in university students: Cross-sectional study, December 2020, England

BackgroundIn England, the reopening of universities in September 2020 coincided with a rapid increase in SARS-CoV-2 infection rates in university aged young adults. This study aimed to estimate SARS-CoV-2 antibody prevalence in students attending universities that had experienced a COVID-19 outbreak after reopening for the autumn term in September 2020.MethodsA cross-sectional serosurvey was conducted during 02–11 December 2020 in students aged ≤ 25 years across five universities in England. Blood samples for SARS-CoV-2 antibody testing were obtained using a self-sampling kit and analysed using the Abbott SARS-CoV-2 N antibody and/or an in-house receptor binding domain (RBD) assay.FindingsSARS-CoV-2 seroprevalence in 2,905 university students was 17.8% (95%CI, 16.5–19.3), ranging between 7.6%-29.7% across the five universities. Seropositivity was associated with being younger likely to represent first year undergraduates (aOR 3.2, 95% CI 2.0–4.9), living in halls of residence (aOR 2.1, 95% CI 1.7–2.7) and sharing a kitchen with an increasing number of students (shared with 4–7 individuals, aOR 1.43, 95%CI 1.12–1.82; shared with 8 or more individuals, aOR 1.53, 95% CI 1.04–2.24). Seropositivity was 49% in students living in halls of residence that reported high SARS-CoV-2 infection rates (>8%) during the autumn term.InterpretationDespite large numbers of cases and outbreaks in universities, less than one in five students (17.8%) overall had SARS-CoV-2 antibodies at the end of the autumn term in England. In university halls of residence affected by a COVID-19 outbreak, however, nearly half the resident students became infected and developed SARS-CoV-2 antibodies.

Measuring Awareness of Infection Control Guidelines for Patients with COVID-19 in Radiology Departments in Saudi Arabia.

Due to the contagious nature of the COVID-19 virus, healthcare workers are at a great risk of infection. Since medical imaging plays a significant part in the healthcare system and is often used in the diagnosis of potential COVID-19 patients, the radiology personnel are at a very high risk of becoming infected. Purpose: This study aims to assess the enforcement of infection control guidelines for patients with COVID-19 during medical imaging procedures and raise awareness of infection control in different hospitals in Saudi Arabia. Methods: A total of 128 responses were collected from four hospitals across Saudi Arabia using a new structured questionnaire, which was created for health workers by the WHO specifically for this purpose. Data were collected during the COVID-19 pandemic in April 2020. Results: Most participants correctly followed the guidelines of the WHO and Centers for Disease Control and Prevention (CDC) on infection control in the X-ray and general radiology departments. Guideline awareness was higher among magnetic resonance imaging (MRI) and computerised tomography (CT) radiographers, which reduced the risk of future infections. Out of the total respondents, 98.4% stated that they had received formal training in hand hygiene. Only 40.6% of participants, however, knew that respiratory droplets are the primary mode of transmission of the virus from person to person. Conclusion: The knowledge of healthcare professionals in the radiology department regarding infection control needs to be continually assessed. A focus on educational interventions on infection control is required in order to maintain well-informed medical staff.

Association of SARS-CoV-2 Seropositive Antibody Test With Risk of Future Infection

Understanding the effect of serum antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on susceptibility to infection is important for identifying at-risk populations and could have implications for vaccine deployment. The study purpose was to evaluate evidence of SARS-CoV-2 infection based on diagnostic nucleic acid amplification test (NAAT) among patients with positive vs negative test results for antibodies in an observational descriptive cohort study of clinical laboratory and linked claims data. The study created cohorts from a deidentified data set composed of commercial laboratory tests, medical and pharmacy claims, electronic health records, and hospital chargemaster data. Patients were categorized as antibody-positive or antibody-negative according to their first SARS-CoV-2 antibody test in the database. Primary end points were post-index diagnostic NAAT results, with infection defined as a positive diagnostic test post-index, measured in 30-day intervals (0-30, 31-60, 61-90, >90 days). Additional measures included demographic, geographic, and clinical characteristics at the time of the index antibody test, including recorded signs and symptoms or prior evidence of coronavirus 2019 (COVID) diagnoses or positive NAAT results and recorded comorbidities. The cohort included 3 257 478 unique patients with an index antibody test; 56% were female with a median (SD) age of 48 (20) years. Of these, 2 876 773 (88.3%) had a negative index antibody result, and 378 606 (11.6%) had a positive index antibody result. Patients with a negative antibody test result were older than those with a positive result (mean age 48 vs 44 years). Of index-positive patients, 18.4% converted to seronegative over the follow-up period. During the follow-up periods, the ratio (95% CI) of positive NAAT results among individuals who had a positive antibody test at index vs those with a negative antibody test at index was 2.85 (95% CI, 2.73-2.97) at 0 to 30 days, 0.67 (95% CI, 0.6-0.74) at 31 to 60 days, 0.29 (95% CI, 0.24-0.35) at 61 to 90 days, and 0.10 (95% CI, 0.05-0.19) at more than 90 days. In this cohort study, patients with positive antibody test results were initially more likely to have positive NAAT results, consistent with prolonged RNA shedding, but became markedly less likely to have positive NAAT results over time, suggesting that seropositivity is associated with protection from infection. The duration of protection is unknown, and protection may wane over time.

How to Advise Persons Who Are Antibody Positive for SARS-CoV-2 About Future Infection Risk

Raymond A. Harvey, MPH; Jeremy A. Rassen, ScD; Carly A. Kabelac, BS; Wendy Turenne, MS; Sandy Leonard, MPH; Reyna Klesh, MS; William A. Meyer III, PhD, D(ABMM), MLS(ASCP)CM; Harvey W. Kaufman, MD, MBA; Steve Anderson, PhD; Oren Cohen, MD; Valentina I. Petkov, MD, MPH; Kathy A. Cronin, PhD; Alison L. Van Dyke, MD, PhD; Douglas R. Lowy, MD; Norman E. Sharpless, MD; Lynne T. Penberthy, MD, MPH

High burden of infections in Indian patients with Idiopathic Inflammatory Myopathy: validation of observations from the MyoCite dataset.

To determine the prevalence, profile and predictors of infections in an Indian cohort with idiopathic inflammatory myopathies (IIM). We reviewed the records of a retrospective cohort with IIM enrolled from consecutive patients being followed up in the clinic, and these constituted the observation cohort. A newly diagnosed inception cohort with IIM were followed prospectively as the validation cohort for confirmation of observations and comparison with the observation cohort. Among the 68 patients in the observation cohort (average age 33.4 years, female:male 4.2:1), 37 (54.4%) experienced 54 infections between them; of these 54 infections, 21 (38.8%) were major and recurrent infections and they occurred in 11 patients (16.17%) over 3.08 years. Tuberculosis was the most common infection (12, 22.2%), with a predominance of extrapulmonary forms. Serum protein [odds ratio (OR) 0.44], platelets (0.44) at disease onset and daily steroid dose (1.04) predicted major infections on multivariate analysis. A higher daily dose of steroids at first infection correlated with number of recurrent infections. The infection-free 1-year survival was 73.8%.Of the 70 patients in the validation cohort (average age 35.7 years, female:male 3.7:1), 3 had myositis attributed to an infection. A similar proportion of the cohort experienced infections (22, 33.3%) with similar number of major (10, 45.4%) and recurrent (4, 18%) infections being recorded. The most common infection was community-acquired pneumonia, followed by tuberculosis, with serum albumin (OR 0.25) at disease onset being the only predictor. The one-year infection-free survival rate was 64.7%. Those who had a major infection had increased mortality at 1 year, with a survival rate of 60%, compared with 89.09% in those without.In both cohorts, a daily prednisone dose >6.25 mg predisposed to major infections. Major and recurrent infections are common in Indian IIM patients and confer higher risk for future infections and lower survival. Respiratory and atypical bacterial infections such as tuberculosis occur throughout the disease course.

The Duration, Dynamics, and Determinants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antibody Responses in Individual Healthcare Workers.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibody measurements can be used to estimate the proportion of a population exposed or infected and may be informative about the risk of future infection. Previous estimates of the duration of antibody responses vary.MethodsWe present 6 months of data from a longitudinal seroprevalence study of 3276 UK healthcare workers (HCWs). Serial measurements of SARS-CoV-2 anti-nucleocapsid and anti-spike IgG were obtained. Interval censored survival analysis was used to investigate the duration of detectable responses. Additionally, Bayesian mixed linear models were used to investigate anti-nucleocapsid waning.ResultsAnti-spike IgG levels remained stably detected after a positive result, for example, in 94% (95% credibility interval [CrI] 91–96%) of HCWs at 180 days. Anti-nucleocapsid IgG levels rose to a peak at 24 (95% CrI 19–31) days post first polymerase chain reaction (PCR)-positive test, before beginning to fall. Considering 452 anti-nucleocapsid seropositive HCWs over a median of 121 days from their maximum positive IgG titer, the mean estimated antibody half-life was 85 (95% CrI 81–90) days. Higher maximum observed anti-nucleocapsid titers were associated with longer estimated antibody half-lives. Increasing age, Asian ethnicity, and prior self-reported symptoms were independently associated with higher maximum anti-nucleocapsid levels and increasing age and a positive PCR test undertaken for symptoms with longer anti-nucleocapsid half-lives.ConclusionsSARS-CoV-2 anti-nucleocapsid antibodies wane within months and fall faster in younger adults and those without symptoms. However, anti-spike IgG remains stably detected. Ongoing longitudinal studies are required to track the long-term duration of antibody levels and their association with immunity to SARS-CoV-2 reinfection.