Publications by authors named "Vold L"

Objectives: We analysed hepatitis A (HepA) notifications and hospitalisations in Italy, the Netherlands, Norway, Spain, and Sweden for available periods between 1995 and 2014. We aimed to investigate whether decreasing HepA incidence is associated with increasing age at infection and worsening HepA presentation and to identify groups at risk of severe disease.

Methods: We performed a retrospective cohort study including 36 734 notified and 36 849 hospitalised patients.

View Article and Find Full Text PDF

We included 39,524 COVID-19 Omicron and 51,481 Delta cases reported in Norway from December 2021 to January 2022. We estimated a 73% reduced risk of hospitalisation (adjusted hazard ratio: 0.27; 95% confidence interval: 0.

View Article and Find Full Text PDF

In late November 2021, an outbreak of Omicron SARS-CoV-2 following a Christmas party with 117 attendees was detected in Oslo, Norway. We observed an attack rate of 74% and most cases developed symptoms. As at 13 December, none have been hospitalised.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to compare the hospitalization risk of the Delta and Alpha variants of COVID-19 in Norway, focusing on vaccination status.
  • Researchers analyzed 19,055 lab-confirmed cases of SARS-CoV-2 from May to August 2021, finding similar hospitalization risks for both variants.
  • The study concluded that vaccination significantly reduces hospitalization risk, with partially vaccinated individuals having a 72% reduced risk and fully vaccinated individuals having a 76% reduced risk compared to unvaccinated cases.
View Article and Find Full Text PDF

BackgroundThe occupational risk of COVID-19 may be different in the first versus second epidemic wave.AimTo study whether employees in occupations that typically entail close contact with others were at higher risk of SARS-CoV-2 infection and COVID-19-related hospitalisation during the first and second epidemic wave before and after 18 July 2020, in Norway.MethodsWe included individuals in occupations working with patients, children, students, or customers using Standard Classification of Occupations (ISCO-08) codes.

View Article and Find Full Text PDF

Climate change will lead to more extreme weather events in Europe. In Norway, little is known about how this will affect drinking water quality and population's health due to waterborne diseases. The aim of our work was to generate new knowledge on the effect of extreme weather conditions and climate change on drinking water and waterborne disease.

View Article and Find Full Text PDF

Background: Waterborne outbreaks are still a risk in high-income countries, and their early detection is crucial to limit their societal consequences. Although syndromic surveillance is widely used for the purpose of detecting outbreaks days earlier than traditional surveillance systems, evidence of the effectiveness of such systems is lacking. Thus, our objective was to conduct a systematic review of the effectiveness of syndromic surveillance to detect waterborne outbreaks.

View Article and Find Full Text PDF

We describe an outbreak of Agbeni sequence type (ST)2009 infections in Norway. Between 31 December 2018 and 16 March 2019, 56 cases (33 female and 23 male; median age: 50 years, range: 2-91) were reported, of which 21 were hospitalised. Cases were defined as people living in Norway, with laboratory-confirmed infection with .

View Article and Find Full Text PDF

Background: The first case of SARS-CoV-2 infection in Norway was confirmed on 26 February 2020. Following sharpened advice on general infection control measures at the beginning of the outbreak, extensive national control measures were implemented on 12 March, and testing was focused on those with severe illness. We describe the first six weeks of the outbreak in Norway, viewed in light of testing criteria and control measures.

View Article and Find Full Text PDF

Tick-borne diseases are emerging and re-emerging threats causing public health concerns in Europe and North America. Prevention and control requires understanding of human exposure and behaviour. The aim was to measure exposure to tick bites across Scandinavia, its spatial distribution and the associated risk factors.

View Article and Find Full Text PDF

On 6 June 2019, the Norwegian Institute of Public Health was notified of more than 50 cases of gastroenteritis in Askøy. A reservoir in a water supply system was suspected as the source of the outbreak because of the acute onset and geographical distribution of cases. We investigated the outbreak to confirm the source, extent of the outbreak and effect of control measures.

View Article and Find Full Text PDF

Water supply systems, in particular small-scale water supply systems, are vulnerable to adverse events that may jeopardise safe drinking water. The consequences of contamination events or the failure of daily operations may be severe, affecting many people. In Norway, a 24-hour crisis advisory service was established in 2017 to provide advice on national water supplies.

View Article and Find Full Text PDF

Background: In Norway, Legionnaires' disease is reportable upon clinical suspicion to public health authorities and mandatorily notifiable through the Norwegian surveillance system for communicable diseases (MSIS) for both clinicians and laboratories. In the summer of 2017, several European countries reported high notification rates for Legionnaires' disease, which was not observed in Norway. We evaluated MSIS to assess if it meets its objectives of detecting cases and trends in incidence of Legionnaires' disease.

View Article and Find Full Text PDF
Article Synopsis
  • An outbreak of skin rash occurred in May 2017 among visitors of a public floating tank in Norway, leading to a study to assess its cause and risk factors.
  • A questionnaire revealed that 22 out of 46 respondents experienced symptoms like rashes and ear canal pain, but no specific risk factors correlated with illness.
  • Water tests showed significant contamination, highlighting the need for improved hygiene practices and better guidance for floating tank operators and local health authorities.
View Article and Find Full Text PDF

In 2016, we reviewed preventive control measures for secondary transmission of Shiga-toxin producing Escherichia coli (STEC) in humans in European Union (EU)/European Free Trade Association (EEA) countries to inform the revision of the respective Norwegian guidelines which at that time did not accommodate for the varying pathogenic potential of STEC. We interviewed public health experts from EU/EEA institutes, using a semi-structured questionnaire. We revised the Norwegian guidelines using a risk-based approach informed by the new scientific evidence on risk factors for HUS and the survey results.

View Article and Find Full Text PDF
Article Synopsis
  • - In September 2017, a cluster of salmonellosis cases due to monophasic Typhimurium was detected in Norway, linked to a café at Oslo Airport, with 21 confirmed cases across 10 counties.
  • - Investigations included molecular techniques like whole genome sequencing (WGS) to trace the outbreak, finding that contamination likely began in mid-August and worsened as the outbreak continued, showing increased incubation periods over time.
  • - Control measures, including the café's temporary closure and kitchen renovations, did not effectively eliminate the source, leading to recommendations for improved hygiene practices amid ongoing environmental contamination during such outbreaks.
View Article and Find Full Text PDF
Article Synopsis
  • Sequence-based typing of hepatitis A virus (HAV) is crucial for detecting and investigating outbreaks, as demonstrated during a significant EU-wide outbreak linked to frozen berries in 2013, though challenges arose due to partial genomic comparability among countries.
  • In 2014, the European Centre for Disease Prevention and Control (ECDC) surveyed EU/EEA countries to assess their HAV surveillance practices and proposed harmonized procedures to enhance cross-border outbreak response, focusing on sequencing methods.
  • Follow-up surveys in 2016 showed an increase in countries participating in centralized collection and sequencing of HAV samples, but disparities in the specific genomic regions sequenced still exist, indicating that further collaboration is needed for effective surveillance.
View Article and Find Full Text PDF

The aim of this study was to investigate implementation of multiplex PCR assays (broad screening PCR) on the distribution and characteristics of notified Shiga toxin-producing Escherichia coli (STEC) cases in Norway, 2007-2017. We described STEC cases notified to the Norwegian Surveillance System for Communicable Diseases (MSIS), 2007-2017 and categorised cases as high-virulent, low-virulent or unclassifiable STEC infections based on guidelines for follow-up of STEC cases. We conducted descriptive analysis and time series analysis allowing for trends and seasonality, and calculated adjusted incidence rate ratios (aIRR) using negative binomial regression for laboratories with and without broad screening PCR.

View Article and Find Full Text PDF

In Norway, incidence of sporadic domestically acquired salmonellosis is low, and most frequently due to Salmonalla Typhimurium. We investigated the risk factors for sporadic Salmonella infections in Norway to improve control and prevention measures. Surveillance data for all Salmonella infections from 2000 to 2015 were analysed for seasonality and proportion associated with domestic reservoirs, hedgehogs and wild birds.

View Article and Find Full Text PDF

BackgroundTravel to countries with high or intermediate hepatitis A virus (HAV) endemicity is a risk factor for infection in residents of countries with low HAV endemicity. The objective of this study was to estimate the risk for hepatitis A among European travellers using surveillance and travel denominator data. We retrieved hepatitis A surveillance data from 13 European Union (EU)/ European Economic Area (EEA) countries with comprehensive surveillance systems and travel denominator data from the Statistical Office of the European Union.

View Article and Find Full Text PDF

Introduction: Many North American cities have a built environment that provides access to energy-dense food and little opportunity for active living. Urban agriculture contributes to a positive environment involving food plant cultivation that includes processing, storing, distributing and composting. It is a means to increase local food production and thereby improve community health.

View Article and Find Full Text PDF