Publications by authors named "Lauri Ivaska"

Article Synopsis
  • Differentiating between viral and bacterial infections in febrile children is crucial for preventing unnecessary antibiotic use, and MxA is identified as a potential biomarker for this purpose.
  • A study with 228 febrile children compared a point-of-care (POC) MxA blood measurement to a reference method, finding that the POC results were consistent in 87.3% of cases.
  • The POC MxA measurement effectively distinguished between viral and bacterial infections, achieving 92% sensitivity and 91% specificity at a cutoff of 101 µg/L.
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Background: Comparative data are limited on the transmission of respiratory infections positive and negative for SARS-CoV-2 in households with children.

Methods: In June to August 2020, we recruited 700 participants (175 households, 376 children, 324 adults) to be prospectively followed for all respiratory tract infections. Follow-up lasted from recruitment until April 2022.

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Background: Vaccinations against the SARS-CoV-2 are still crucial in combating the ongoing pandemic that has caused more than 700 million infections and claimed almost 7 million lives in the past four years. Omicron (B.1.

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Diagnostic tools to differentiate between community-acquired bacterial and viral meningitis are essential to target the potentially lifesaving antibiotic treatment to those at greatest risk and concurrently spare patients with viral meningitis from the disadvantages of antibiotics. In addition, excluding bacterial meningitis and thus decreasing antibiotic consumption would be important to help reduce antimicrobial resistance and healthcare expenses. The available diagnostic laboratory tests for differentiating bacterial and viral meningitis can be divided microbiological pathogen-focussed methods and biomarkers of the host response.

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Pediatric neck infections and their complications, such as abscesses extending to deep neck compartments, are potentially life-threatening acute conditions. Medical imaging aims to verify abscesses and their extensions and exclude other complications. Magnetic resonance imaging (MRI) has proven to be a useful and highly accurate imaging method in acute neck infections in children.

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The prevalence of seasonal human coronavirus (HCoV) infections in early childhood and adults has not been well analyzed in longitudinal serological studies. Here we analyzed the changes in HCoV (229E, HKU1, NL63, OC43, MERS, and SARS-CoV-2) spike-specific antibody levels in follow-up serum specimens of 140 children at the age of 1, 2, and 3 years, and of 113 healthcare workers vaccinated for Covid-19 with BNT162b2-vaccine. IgG antibody levels against six recombinant HCoV spike subunit 1 (S1) proteins were measured by enzyme immunoassay.

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We observed an intense enterovirus D68 outbreak in children in southwest Finland in August-September 2022. We confirmed enterovirus D68 infection in 56 children hospitalized for respiratory illnesses and in 1 child with encephalitis but were not able to test all suspected patients. Continuing surveillance for enterovirus D68 is needed.

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Immunization during pregnancy (IP) against pertussis is recommended in many countries to protect infants. Although maternal antibodies can influence the infants' antibody responses to primary vaccinations, their effect on the development of functional antibodies and B cells remain poorly studied. We investigated the maternal immune response to IP and the effect of IP and pre-existing antibodies on infants' primary vaccine responses in an open-label, non-randomized trial.

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Introduction: The prime-boost COVID-19 mRNA vaccination strategy has proven to be effective against severe COVID-19 disease and death. However, concerns have been raised due to decreasing neutralizing antibody levels after COVID-19 vaccination and due to the emergence of new immuno-evasive SARS-CoV-2 variants that may require additional booster vaccinations.

Methods: In this study, we analyzed the humoral and cell-mediated immune responses against the Omicron BA.

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Background: Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection primes the immune system; thus individuals who have recovered from infection have enhanced immune responses to subsequent vaccination (hybrid immunity). However, it remains unclear how well hybrid immunity induced by severe or mild infection can cross-neutralize emerging variants. We aimed to compare the strength and breadth of antibody responses in vaccinated recovered and uninfected subjects.

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Pertussis is a highly contagious respiratory infection caused by bacterium. The mainstay of treatment is macrolide antibiotics that reduce transmissibility, shorten the duration of symptoms and decrease mortality in infants. Recently, the macrolide resistance of has been reported globally but is especially widespread in mainland China.

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Article Synopsis
  • The study focused on detecting group A streptococcus (GAS) in children with febrile pharyngitis, both with and without confirmed viral infections, by using various diagnostic methods.
  • Out of 83 children, 30 were diagnosed with a viral infection, primarily caused by enteroviruses, adenoviruses, and rhinoviruses.
  • The results showed that GAS could be detected in a significant number of patients, suggesting that it can coexist with viral pharyngitis without necessarily being the cause of symptoms.
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The emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made it more difficult to prevent the virus from spreading despite available vaccines. Reports of breakthrough infections and decreased capacity of antibodies to neutralize variants raise the question whether current vaccines can still protect against COVID-19 disease. We studied the dynamics and persistence of T cell responses using activation induced marker (AIM) assay and Th1 type cytokine production in peripheral blood mononuclear cells obtained from BNT162b2 COVID-19 mRNA vaccinated health care workers and COVID-19 patients.

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Two COVID-19 mRNA (of BNT162b2, mRNA-1273) and two adenovirus vector vaccines (ChAdOx1 and Janssen) are licensed in Europe, but optimization of regime and dosing is still ongoing. Here we show in health care workers (n = 328) that two doses of BNT162b2, mRNA-1273, or a combination of ChAdOx1 adenovirus vector and mRNA vaccines administrated with a long 12-week dose interval induce equally high levels of anti-SARS-CoV-2 spike antibodies and neutralizing antibodies against D614 and Delta variant. By contrast, two doses of BNT162b2 with a short 3-week interval induce 2-3-fold lower titers of neutralizing antibodies than those from the 12-week interval, yet a third BNT162b2 or mRNA-1273 booster dose increases the antibody levels 4-fold compared to the levels after the second dose, as well as induces neutralizing antibody against Omicron BA.

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The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concern about increased transmissibility, infectivity, and immune evasion from a vaccine and infection-induced immune responses. Although COVID-19 mRNA vaccines have proven to be highly effective against severe COVID-19 disease, the decrease in vaccine efficacy against emerged Beta and Delta variants emphasizes the need for constant monitoring of new virus lineages and studies on the persistence of vaccine-induced neutralizing antibodies. To analyze the dynamics of COVID-19 mRNA vaccine-induced antibody responses, we followed 52 health care workers in Finland for 6 months after receiving two doses of BNT162b2 vaccine with a 3-week interval.

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Background: Differences in the functioning of the immune system and the anatomical proportions of the neck between children and adults lead to different manifestations of deep neck infections. Magnetic resonance imaging (MRI) may serve as an alternative to computed tomography (CT) as the primary imaging modality.

Objective: To study characteristic MRI findings and the diagnostic accuracy of MRI in pediatric deep neck infections.

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A biomarker for viral infection could improve the differentiation between viral and bacterial infections and reduce antibiotic overuse. We examined blood myxovirus resistance protein A (MxA) as a biomarker for viral infections in children with an acute infection. We recruited 251 children presenting with a clinical suspicion of serious bacterial infection, determined by need for a blood bacterial culture collection, and 14 children with suspected viral infection at two pediatric emergency departments.

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Article Synopsis
  • Health care workers in Turku, Finland, were studied to assess the prevalence of antibodies against SARS-CoV-2 from May to December 2020, focusing on those with direct exposure to COVID-19 patients.
  • Out of 222 participants, only one initially had detectable antibodies, and two others developed them during the follow-up, all of whom had prior confirmed COVID-19 infections.
  • The findings indicate low seroprevalence among the workers, suggesting that effective infection prevention measures and access to testing helped protect them, although the effectiveness against more transmissible virus variants remains uncertain.
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Case: A 10-year-old boy presented with pain in the lateral hip and buttock area and fever. Magnetic resonance imaging revealed osteomyelitis of the pelvis with extensive Brodie's abscess (2.6 × 4.

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As SARS-CoV-2 has been circulating for over a year, dozens of vaccine candidates are under development or in clinical use. The BNT162b2 mRNA COVID-19 vaccine induces spike protein-specific neutralizing antibodies associated with protective immunity. The emergence of the B.

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Blood myxovirus resistance protein A (MxA) has broad antiviral activity, and it is a potential biomarker for symptomatic virus infections. Limited data is available of MxA in coinciding viral and bacterial infections. We investigated blood MxA levels in children hospitalized with a febrile urinary tract infection (UTI) with or without simultaneous respiratory virus infection.

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Dermacoccus spp. have rarely been reported as human pathogens. We describe a case of a 4-year-old boy with congenital heart disease who was diagnosed with a brain abscess.

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Objectives: Besides group A streptococcus (GAS), microbial causes of pharyngitis in children are not well known. We aimed to document the viral and bacterial aetiology of pharyngitis and to assess the pathogenic role of viruses by determining the myxovirus resistance protein A (MxA) in the blood as a marker of interferon response.

Methods: In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis.

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