Does integration with national registers improve the data completeness of local COVID-19 contact tracing tools? A register-based study in Norway, May 2020 - September 2021

BACKGROUND

During the COVID-19 response in Norway, many municipalities used the Fiks contact tracing tool (FiksCT) to register positive individuals and follow-up contacts. This tool is based on DHIS2, an open source, web-based platform. In this study we examined if data completeness in FiksCT improved after integration with national registers between May 2020 and September 2021.

METHODS

Data from municipalities using FiksCT was extracted from the Norwegian Emergency Preparedness Register for COVID-19 (Beredt C19). We linked FiksCT data to the Norwegian Surveillance System for Communicable Diseases (MSIS), the National Population Register (FREG), and the Norwegian Vaccine Registry (SYSVAK) using unique identification numbers (ID). Completeness for each variable linked with a national register was calculated before and after integration with these registers.

RESULTS

Of the 125 municipalities using FiksCT, 87 (69.6%) agreed to share and upload their data to Beredt C19. Data completeness for positive individuals improved after integration with national registers. After integration with FREG, the proportion of missing values decreased from 12.5 to 1.6% for ID, from 4.5 to 0.9% for sex, and from 1.2 to 0.4% for date of birth. Missing values for vaccine type decreased from 63.0 to 15.2% and 39.3-36.7% for first and second dose, respectively. In addition, direct reporting from FiksCT to MSIS increased the proportion of complete records in MSIS (on the selected variables) from 68.6% before to 77.0% after integration.

CONCLUSION

The completeness of local contact tracing data can be improved by enabling integration with established national registers. In addition, providing the option to submit local data to the national registers could ease workload and reduce the need to collect duplicate data.

Effectiveness of environmental surveillance of SARS-CoV-2 as an early-warning system: Update of a systematic review during the second year of the pandemic

The aim of this updated systematic review was to offer an overview of the effectiveness of environmental surveillance (ES) of SARS-CoV-2 as a potential early-warning system (EWS) for COVID-19 and new variants of concerns (VOCs) during the second year of the pandemic. An updated literature search was conducted to evaluate the added value of ES of SARS-CoV-2 for public health decisions. The search for studies published between June 2021 and July 2022 resulted in 1,588 publications, identifying 331 articles for full-text screening. A total of 151 publications met our inclusion criteria for the assessment of the effectiveness of ES as an EWS and early detection of SARS-CoV-2 variants. We identified a further 30 publications among the grey literature. ES confirms its usefulness as an EWS for detecting new waves of SARS-CoV-2 infection with an average lead time of 1-2 weeks for most of the publication. ES could function as an EWS for new VOCs in areas with no registered cases or limited clinical capacity. Challenges in data harmonization and variant detection require standardized approaches and innovations for improved public health decision-making. ES confirms its potential to support public health decision-making and resource allocation in future outbreaks.

Evaluation of the pilot wastewater surveillance for SARS-CoV-2 in Norway, June 2022 - March 2023

BACKGROUND

During the COVID-19 pandemic, wastewater-based surveillance gained great international interest as an additional tool to monitor SARS-CoV-2. In autumn 2021, the Norwegian Institute of Public Health decided to pilot a national wastewater surveillance (WWS) system for SARS-CoV-2 and its variants between June 2022 and March 2023. We evaluated the system to assess if it met its objectives and its attribute-based performance.

METHODS

We adapted the available guidelines for evaluation of surveillance systems. The evaluation was carried out as a descriptive analysis and consisted of the following three steps: (i) description of the WWS system, (ii) identification of users and stakeholders, and (iii) analysis of the system's attributes and performance including sensitivity, specificity, timeliness, usefulness, representativeness, simplicity, flexibility, stability, and communication. Cross-correlation analysis was performed to assess the system's ability to provide early warning signal of new wave of infections.

RESULTS

The pilot WWS system was a national surveillance system using existing wastewater infrastructures from the largest Norwegian municipalities. We found that the system was sensitive, timely, useful, representative, simple, flexible, acceptable, and stable to follow the general trend of infection. Preliminary results indicate that the system could provide an early signal of changes in variant distribution. However, challenges may arise with: (i) specificity due to temporary fluctuations of RNA levels in wastewater, (ii) representativeness when downscaling, and (iii) flexibility and acceptability when upscaling the system due to limited resources and/or capacity.

CONCLUSIONS

Our results showed that the pilot WWS system met most of its surveillance objectives. The system was able to provide an early warning signal of 1-2 weeks, and the system was useful to monitor infections at population level and complement routine surveillance when individual testing activity was low. However, temporary fluctuations of WWS values need to be carefully interpreted. To improve quality and efficiency, we recommend to standardise and validate methods for assessing trends of new waves of infection and variants, evaluate the WWS system using a longer operational period particularly for new variants, and conduct prevalence studies in the population to calibrate the system and improve data interpretation.

Lower transmissibility of SARS-CoV-2 among asymptomatic cases: evidence from contact tracing data in Oslo, Norway

BACKGROUND

Asymptomatic COVID-19 cases have complicated the surveillance and tracking of the pandemic. Previous studies have estimated that 15-25% of all infectees remain asymptomatic.

METHODS

Based on contact tracing data from Oslo, Norway, we estimated transmission and susceptibility dynamics among symptomatic and asymptomatic cases and their contacts as identified by manual contact tracing between September 1, 2020, and September 1, 2021.

RESULTS

Among 27,473 indexes and 164,153 registered contacts, the secondary attack rate (SAR-14) was estimated to be 28% lower through asymptomatic exposure (13%) compared to symptomatic exposure (18%). Furthermore, those infected by asymptomatic cases were almost three times more likely to be asymptomatic compared to those infected by symptomatic cases.

CONCLUSIONS

Symptomatic cases spread the virus to a greater extent than asymptomatic, and infectees are more likely to be asymptomatic if their assumed infector was asymptomatic.

The First GAEN-Based COVID-19 Contact Tracing App in Norway Identifies 80% of Close Contacts in "Real Life" Scenarios

The coronavirus disease 2019 (COVID-19) response in most countries has relied on testing, isolation, contact tracing, and quarantine (TITQ), which is labor- and time-consuming. Therefore, several countries worldwide launched Bluetooth-based apps as supplementary tools. The aim of using contact tracing apps is to rapidly notify people about their possible exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and thus make the process of TITQ more efficient, especially upon exposure in public places. We evaluated the Norwegian Google Apple exposure notification (GAEN)-based contact tracing app Smittestopp v2 under relevant "real-life" test scenarios. We used a total of 40 devices, representing six different brands, and compared two different exposure configurations, experimented with different time thresholds and weights of the Bluetooth attenuation levels (buckets), and calculated the true notification rates among close contacts (≤2 m and ≥15 min) and false notification of sporadic contacts. In addition, we assessed the impact of using different operating systems and locations of the phone (hand/pocket). The best configuration tested to trigger exposure notification resulted in the correct notification of 80% of the true close contacts and incorrect notification of 34% of the sporadic contacts. Among those who incorrectly received notifications, most (67%) were within 2 m but the duration of contact was <15 min and thus they were not, per se, considered as "close contacts." Lower sensitivity was observed when using the iOS operating systems or carrying the phone in the pocket instead of in the hand. The results of this study were used to improve and evaluate the performance of the Norwegian contact-tracing app Smittestopp.

Increased transmissibility of the alpha SARS-CoV-2 variant: evidence from contact tracing data in Oslo, January to February 2021

BACKGROUND

Information about the contagiousness of new SARS-CoV-2 variants, including the alpha lineage, and how they spread in various locations is essential. Country-specific estimates are needed because local interventions influence transmissibility.

METHODS

We analysed contact tracing data from Oslo municipality, reported from January through February 2021, when the alpha lineage became predominant in Norway and estimated the relative transmissibility of the alpha lineage with the use of Poisson regression.

RESULTS

Within households, we found an increase in the secondary attack rate by 60% (95% CI 20-114%) among cases infected with the alpha lineage compared to other variants; including all close contacts, the relative increase in the secondary attack rate was 24% (95% CI -6%-43%). There was a significantly higher risk of infecting household members in index cases aged 40-59 years who were infected with the alpha lineage; we found no association between transmission and household size. Overall, including all close contacts, we found that the reproduction number among cases with the alpha lineage was increased by 24% (95% CI 0%-52%), corresponding to an absolute increase of 0.19, compared to the group of index cases infected with other variants.

CONCLUSION

Our study suggests that households are the primary locations for rapid transmission of the new lineage alpha.

Molecular Monitoring of Enteropathogens in Sewage During NATO Exercise Trident Juncture 2018: Potential Tool in Early Outbreak Warning?

INTRODUCTION

Outbreaks of gastrointestinal disease among military service personnel can have severe impact on operational effectivity and force readiness. Thus, early outbreak detection is critical to minimize spread. This pilot study aimed to explore field-based molecular screening of sewage as a supplemental tool in early outbreak warning before disease is diagnosed in personnel seeking medical care.

MATERIALS AND METHODS

Sewage from permanent (n = 3) and temporary (n = 3) military camps, hosting national and international military personnel, were sampled during the NATO Exercise TRJE18 taking place in southern Norway during fall 2018. Samples were screened for 22 gastrointestinal pathogens using multiplex PCR.

RESULTS

Markers of multiple enteropathogens were detected in samples from all locations with some variations in diversity. Yersinia enterocolitica, pathogenic Escherichia coli, adenovirus, and Giardia were detected in sewage from all six camps during the exercise. Agent diversity seemed to increase with population size, regardless of nationality. Only a minor outbreak (n = 6) of norovirus was reported in one of the permanent camps. From the same camp, genetic markers of norovirus were detected in sewage 2 days before outbreak notification. No other outbreaks of gastrointestinal disease were reported during the exercise, indicating that markers of several enteropathogens can be normally found in sewage from healthy soldier populations. Thus, discriminating between true outbreaks and nonrelevant "background levels" would be of critical importance for correct decision-making in operational contexts.

CONCLUSIONS

Molecular screening of sewage allows rapid detection of multiple gastrointestinal pathogens in biological waste from military camps. However, background levels of pathogens challenges interpretation of qualitative analyses in outbreak situations. As such, quantitative measures, as well as high-resolution sequence-based methods, which allows strain identification and broader target spectrum, should be further explored in future studies.

Multiplex polymerase chain reaction detection of enteropathogens in sewage in Norway

The primary objective of this small-scale study was to investigate the occurrence of enteropathogens in sewage (municipal wastewater) in Norway using the commercially available FilmArray^® multiplex polymerase chain reaction (PCR) system with the gastrointestinal (GI) panel. Our findings indicate that DNA/RNA of several enteropathogens are present simultaneously in Norwegian wastewater systems. The spectre was broad even in smaller communities. With some exceptions, occurrence corresponded more or less to the reported cases of infectious human gastrointestinal disease in the same geographical regions. The effects of different sewage purification techniques were assessed on a limited number of samples indicating that neither chemical nor biological treatment was sufficiently effective to reduce gene material from the pathogens to undetectable levels. Further studies are required to assess the performance and suitability FilmArray^® multiplex PCR when used on collective sewage samples in outbreak situations. Additionally, screening sewage samples using multiplex-PCR could be valuable in order to detect new and emerging pathogens and for preliminary analysis of samples before proceeding to more work demanding confirmatory techniques.

Identification and quantification of lichenysin - a possible source of food poisoning

Lichenysin produced by 53 different Bacillus licheniformis strains has been structurally examined with a qualitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using quadrupole-time-of-flight mass spectrometry. The same lichenysin isoforms are produced from all strains, indicating that the growth conditions have a stronger influence on the lipopeptide production than the genotype. A rapid method for the quantification of lichenysin from bacterial cell cultures with LC-MS/MS after a simple methanol extraction has been refined. For the first time commercially available lichenysin has been used as calibrant, making quantification more accurate. The trueness for C15-lichenysin has been improved to 94% using matrix-matched calibration with lichenysin compared with 30% using solvent calibration with surfactin. The quantitative method was fully validated based on Commission Decision 2002/657/EC. The LOD of the method was below 1 µg g(-1) and the repeatability ranged from 10% to 16%.

Lichenysin is produced by most Bacillus licheniformis strains

AIMS

The aim of this study was to elucidate the prevalence of lichenysin production in Bacillus licheniformis and to see whether this feature was restricted to certain genotypes. Secondly, we wanted to see whether cytotoxicity reflected the measured levels of lichenysin.

METHODS AND RESULTS

Fifty-three genotyped strains of B. licheniformis, representing a wide variety of sources, were included. lchAA gene fragments were detected in all strains by polymerase chain reaction (PCR). All 53 strains produced lichenysins with four molecular masses as confirmed by LC-MS/MS (liquid chromatography-tandem mass spectrometry) analysis. The amounts of lichenysin varied more than two orders of magnitude between strains and were irrespective of genotype. Finally, there was a strong association between lichenysin concentrations and toxicity towards boar spermatozoa, erythrocytes and Vero cells.

CONCLUSIONS

Lichenysin synthesis was universal among the 53 B. licheniformis strains examined. The quantities varied considerably between strains, but were not specifically associated with genotype. Cytotoxicity was evident at lichenysin concentrations above 10 μg ml(-1) , which is in accordance with previous studies.

SIGNIFICANCE AND IMPACT OF STUDY

This study might be of interest to those working on B. licheniformis for commercial use as well as for authorities who make risk assessments of B. licheniformis when used as a food and feed additive.