Reduction of rotavirus as a cause of nosocomial diarrhoea in northern Stockholm after introducing the rotavirus vaccine.

Vaccination against rotavirus was offered in Stockholm to children born on 1 March 2014 and onwards with 85% coverage after two years. We investigated changes in nosocomial diarrhoea 2010-2018 in children admitted to Astrid Lindgren Children's Hospital, Stockholm, Sweden. We retrospectively identified cases from diagnostic and virology department registers.

All-cause gastroenteritis hospitalisations of children decreased after the introduction of rotavirus vaccine in Stockholm.

Background: In Stockholm, Sweden, rotavirus vaccination was offered to children born after 1 March 2014. Our aim was to describe rates of hospitalisation due to community-acquired gastroenteritis before and after the introduction of the vaccine, and aetiology, underlying medical conditions and complications in admitted children.

Methods: We retrospectively included patients from our catchment area hospitalised with a diagnosis of gastroenteritis during ten infection seasons 2008/2009-2017/2018, whereof six seasons prevaccination and four seasons postvaccination.

Rates and risk factors of severe respiratory syncytial virus infection in 2008-2016 compared with 1986-1998.

Aim: Since the introduction in 1979 of rapid testing using immunofluorescence, we have collected information about children hospitalised for confirmed respiratory syncytial virus (RSV) infection in the northern Stockholm area. We here report hospitalisation rates, risk factors and complications in 2008-2016 compared with 1986-1998.

Methods: Microbiological laboratory reports and retrospective chart review.

Outbreak of enterovirus D68 of the new B3 lineage in Stockholm, Sweden, August to September 2016.

We report an enterovirus D68 (EV-D68) outbreak in Stockholm Sweden in 2016. Between 22 August and 25 September EV-D68 was detected in 74/495 respiratory samples analysed at the Karolinska University Hospital. During the peak week, 30/91 (33%) samples were EV-D68 positive.

Frequent Respiratory Viral Infections in Children with Febrile Neutropenia - A Prospective Follow-Up Study.

Objective: Febrile neutropenia is common in children undergoing chemotherapy for the treatment of malignancies. In the majority of cases, the cause of the fever is unknown. Although respiratory viruses are commonly associated with this condition, the etiologic significance of this finding remains unclear and is therefore the subject of this study.

Respiratory viruses associated with community-acquired pneumonia in children: matched case-control study.

Background: Community-acquired pneumonia (CAP) is the leading cause of death in children worldwide and a substantial proportion of childhood CAP is caused by viruses. A better understanding of the role of virus infections in this condition is needed to improve clinical management and preventive measures. The aim of the study was therefore to assess the association between specific respiratory viruses and childhood CAP.

Coexistence of two clades of enterovirus D68 in pediatric Swedish patients in the summer and fall of 2014.

In 2014, an outbreak of enterovirus D68 (EV-D68) was observed in North America, with cases of severe respiratory illness and a possible etiological link to cases of acute flaccid paralysis. EV-D68 has also been reported from European countries, but no data from Sweden are available. This study investigated respiratory specimens collected during July-October 2014 from 30 Swedish children aged 0-9 years who were positive for enterovirus and/or rhinovirus in routine clinical PCR.

Self-sampling for analysis of respiratory viruses in a large-scale epidemiological study in Sweden.

Viral diagnosis of respiratory tract infections has so far required sampling by health professionals,hampering large-scale epidemiological studies of virus-specific disease outcomes. As part of a population-based, prospective study of work-related risk factors for transmission of viral infections (SWEDE-I), we developed a scheme for self-sampling with nasal swabs. Random selection from the gainfully employed population of a medium-sized town in central Sweden resulted in a study cohort of 2,237 men and women aged 25 to 63 years.

Clinical utility of PCR for common viruses in acute respiratory illness.

Background: Acute respiratory illness (ARI) accounts for a large proportion of all visits to pediatric health facilities. Quantitative real-time polymerase chain reaction (qPCR) analyses allow sensitive detection of viral nucleic acids, but it is not clear to what extent specific viruses contribute to disease because many viruses have been detected in asymptomatic children. Better understanding of how to interpret viral findings is important to reduce unnecessary use of antibiotics.

Children with multiple viral respiratory infections are older than those with single viruses.

Aim: To study the clinical impact of multiple viral respiratory infections compared to single infections.

Methods: Demographic data from 37 multiple infection periods in children <5 years of age were compared to data from 193 episodes with single infections. Clinical data derived from patient records of the multiple infection episodes were further compared to data from 93 matched control episodes with single infections.

Respiratory viruses in hospitalized children with influenza-like illness during the h1n1 2009 pandemic in Sweden [corrected].

Background: The swine-origin influenza A(H1N1)pdm09 pandemic of 2009 had a slower spread in Europe than expected. The human rhinovirus (HRV) has been suggested to have delayed the pandemic through viral interference. The importance of co-infections over time during the pandemic and in terms of severity of the disease needs to be assessed.

Flocked nasal swab versus nasopharyngeal aspirate for detection of respiratory tract viruses in immunocompromised adults: a matched comparative study.

Background: Several studies have compared nasal swabs to the more invasive nasopharyngeal aspirate (NPA) for detection of respiratory viruses. Mostly, the comparisons have been performed on immunocompetent children with upper respiratory tract symptoms. The results range from a relatively poor sensitivity for the swabs to an even higher sensitivity than for the NPA.

Respiratory viruses, a common microbiological finding in neutropenic children with fever.

Background: Febrile neutropenia is a common complication in children undergoing chemotherapy for malignancies. A microbial agent is only identified in 15-30% of the fever episodes and corresponds mostly to bacterial findings.

Objective: To investigate viral infections as possible etiologic agents in episodes of febrile neutropenia.

Occurrence of pharyngeal Chlamydia trachomatis is uncommon in patients with a suspected or confirmed genital infection.

Objective: To evaluate how common pharyngeal Chlamydia trachomatis (CT) is among mainly heterosexual women and men with a confirmed or a highly suspicious genital infection having had recent unprotected active oral sex.

Design: Prospective observational study.

Setting: Out-patient clinics for sexually transmitted infections in Stockholm.

Does viral interference affect spread of influenza?

This short communication hypothesises that rhinovirus epidemics occurring after start of school may interfere with the spread of influenza during the period when warm and humid climate decreases the influenza spread by aerosol. Limited laboratory data supporting this hypothesis are included in the article, but the report is written mainly to stimulate interest and research concerning the possibility that viral interaction may affect influenza epidemiology.

Repeat infection with Chlamydia trachomatis: a prospective cohort study from an STI-clinic in Stockholm.

Background: Infection with genital Chlamydia trachomatis (Ct) is the most common notifiable sexually transmitted infection (STI) in Sweden. A mutated Chlamydia, nvCT, has contributed to the increase. The occurrence of repeat infections is not investigated in Sweden.

Development and implementation of a molecular diagnostic platform for daily rapid detection of 15 respiratory viruses.

Acute respiratory tract infections are caused by a large number of viruses. Diagnostic methods have until recently been available only for a limited number of these viruses. With the objective to achieve sensitive assays for all respiratory viruses, a rational workflow in the laboratory, and a short turn-around time, a real-time PCR diagnostic platform for daily rapid detection of 15 respiratory viruses was developed.

High occurrence of a new variant of Chlamydia trachomatis escaping diagnostic tests among STI clinic patients in Stockholm, Sweden.

Background: In 2006, a genetic variant of Chlamydia trachomatis not detectable with the most commonly used diagnostic tests was identified. Initial reports suggested that as many as 10% to 13% of all chlamydia cases would have remained undiagnosed. The aim of the study was to find the occurrence and clinical findings of this genetic variant among a high-risk population in Stockholm, Sweden.

Population-based rates of severe respiratory syncytial virus infection in children with and without risk factors, and outcome in a tertiary care setting.

Unlabelled: The aim of this study was to make a population-based estimate of the risk of hospitalization and complications during virologically confirmed respiratory syncytial virus (RSV) infection in relation to established risk factors, and an estimation of additional risk factors and outcome as seen in a tertiary care referral centre. During a period of 12 y, all children with virologically confirmed RSV infection were included. Recorded complications were: admission to the intensive care unit, mechanical ventilation, death and later hospitalization for wheezing.