Mădălina Maria Merișescu

Background/Objectives: Hepatitis B virus (HBV) infection remains an important occupational concern for healthcare students exposed to blood and body fluids. This study aimed to characterize hepatitis B surface antibody (anti-HBs) concentrations according to reported vaccination history among Romanian dental students and to assess the early serological response to a booster dose in participants with baseline anti-HBs concentrations < 10 mIU/mL who completed follow-up. Methods: This cross-sectional study with a prospective follow-up component included 155 dental students. HBsAg and quantitative anti-HBs were assessed alongside demographic characteristics and self-reported vaccination history. Anti-HBs concentrations were categorized as 100 mIU/mL. The association between vaccination history and anti-HBs category was evaluated using the Fisher–Freeman–Halton test with Monte Carlo estimation. An exploratory multivariable logistic regression examined the association of recent immunization, age, and sex with anti-HBs concentrations ≥ 10 mIU/mL. Results: At baseline, 130/155 participants (83.9%; 95% CI, 77.3–88.8%) had anti-HBs < 10 mIU/mL, whereas 25/155 (16.1%; 95% CI, 11.2–22.7%) had concentrations ≥ 10 mIU/mL. Vaccination history was significantly associated with anti-HBs category (Monte Carlo p < 0.001; Pearson χ²(12) = 96.865; Cramer’s V = 0.559). In the restricted regression sample (n = 111; 21 outcomes), recent immunization was strongly associated with anti-HBs ≥ 10 mIU/mL after adjustment for age and sex (aOR, 28.45; 95% CI, 7.52–107.61; p = 8.09 × 10⁻⁷), while age and sex were not significantly associated with the outcome. Of the 130 participants with baseline anti-HBs < 10 mIU/mL, 12 received a booster dose and completed repeat testing approximately one month later; all 12 achieved anti-HBs concentrations > 100 mIU/mL. Conclusions: Most participants had anti-HBs concentrations below the conventional protective threshold, particularly in the absence of recent vaccination. The uniform post-booster response among participants who completed follow-up is consistent with preserved vaccine-induced immune memory despite low baseline antibody concentrations. These findings highlight the importance of documented HBV vaccination and appropriate assessment of hepatitis B immunity among healthcare students at occupational risk.

Background and Clinical Significance: Hypoglossal nerve palsy is an uncommon neurological complication of infectious mononucleosis and is only rarely reported. Putative mechanisms include virus-triggered neuritis (Epstein–Barr virus (EBV) or Cytomegalovirus (CMV)) and/or mechanical compression related to cervical lymphadenopathy. Case Presentation: We report two children with infectious mononucleosis and transient unilateral hypoglossal nerve palsy. Case 1 was a 15-year-old boy with 7 days of fever and typical mononucleosis features who developed leftward tongue deviation accompanied by sialorrhea, dysarthria, and dysphagia. Laboratory testing showed marked hepatocellular injury and EBV-specific IgM positivity. Case 2 was a 9-year-old girl with a 24 h history of bilateral lateral cervical lymphadenopathy with overlying inflammatory signs; examination revealed rightward tongue deviation with similar associated symptoms. CMV-specific IgM antibodies were detected on serological testing. Both patients received systemic corticosteroids and empiric intravenous antibiotics, with supportive care. Hypoglossal nerve function fully recovered within 2–4 weeks of treatment initiation. Conclusions: These cases underscore that isolated hypoglossal nerve palsy may complicate EBV- or CMV-associated mononucleosis in children. Although the prognosis is generally favorable, the presentation warrants careful evaluation to exclude alternative causes of lower cranial neuropathies and close follow-up until complete neurological resolution.

Background: Pediatric SARS-CoV-2 infection is usually mild, but in rare cases may lead to severe complications. Early recognition and comprehensive management are critical for favorable outcomes. Case Presentation: We present the case of a 2-year-old girl, previously healthy and unvaccinated against Streptococcus Pneumoniae (S. pneumoniae), who developed SARS-CoV-2 infection and acute otitis media. Initial laboratory evaluation revealed leukocytosis with neutrophilia and increased inflammatory markers. Antiviral and antibiotic treatment was initiated, but she remained febrile, polypneic, and tachycardic. The diagnosis of MIS-C was excluded; there was no involvement of two organs, and infection with S. pneumoniae serotype 19 F was identified. Given the unfavorable evolution, corticosteroid therapy and immunoglobulin were instituted, and subsequently, following the antibiogram result, antibiotic therapy was escalated to Meropenem and Linezolid. Clinical and laboratory parameters improved, but pericarditis with a small fluid slide and ECG changes were associated. The evolution was favorable with complete cardiac recovery at 30 days. Conclusion: This case highlights the importance of vigilant assessment for secondary bacterial infections and cardiac complications in pediatric COVID-19. Prompt recognition and targeted treatment are essential, and pneumococcal vaccination remains a fundamental preventive measure. Moreover, the scarcity of literature documenting SARS-CoV-2 infections complicated by pericarditis further underscores the uniqueness of this case and its relevance for specialists in the field.

Measles remains a major public health issue, particularly among paediatric populations who are unvaccinated or lack of maternal antibody transfer. Although the majority of cases manifest with moderate clinical forms, certain patient categories are at risk for severe disease progression. This study aims to describe the clinical and epidemiological characteristics of paediatric measles cases hospitalized in the Paediatric Departments of the “Prof. Dr. Matei Balș” National Institute of Infectious Diseases, Bucharest, Romania during two distinct epidemic waves: 2017–2019 and 2023–2024. A retrospective analysis evaluated mortality rates, distribution by age and sex, as well as clinical disease patterns. The 2023–2024 measles epidemic was marked by a higher number of paediatric cases (3.114 vs. 1.068), a lower mortality rate (0.32% vs. 3.74%), a shift towards older age groups, and a greater frequency of complications—particularly gastrointestinal, haematological, and ophthalmological—compared to the 2017–2019 wave. The findings underscore the urgent need for strengthened vaccination programs and targeted public health interventions, particularly among vulnerable groups and patients at risk of developing severe forms of the disease. Owing to a sustained decline in measles vaccination coverage among the paediatric population, Romania has experienced two major measles outbreaks within the past decade, interrupted by the COVID-19 pandemic. This study draws attention to the increasing incidence of measles in older children, suggesting a cumulative effect of reduced immunization rates over time.

Mycoplasma pneumoniae is an atypical bacterium with a tropism for the respiratory tract, but it can also cause numerous extrapulmonary involvements. The incidence of high rates varies in epidemiological waves, occurring at a frequency of 3–7 years. Since the end of 2023, an increase in the incidence of M. pneumoniae infection cases has been noted internationally. We conducted a retrospective study of children hospitalized and confirmed with M. pneumoniae infection in our clinic during the last two epidemiological peaks. We retrieved data from the hospital database and divided the patients into two groups, corresponding to the years 2018–2019 and 2023–2024, respectively. Fisher’s exact test was used to compare the proportions. In the years 2023–2024, we observed a higher incidence of patients with respiratory failure (p = 0.032), pleural reaction (p = 0.016), and pulmonary consolidation (p = 0.016) compared to the group in the years 2018–2019. Gastrointestinal involvement was more frequent in the years 2018–2019 (p = 0.004). The incidence of other extrapulmonary complications did not show significant differences. Infection with M. pneumoniae has varied clinical manifestations. In patients with community-acquired pneumonia, even in cases of consolidation, the possibility of infection with M. pneumoniae must also be considered.

Antiviral therapy such as oseltamivir has been recommended for hospitalized children with suspected and confirmed influenza for almost 20 years. The therapy is officially authorized for newborns two weeks of age or older, however, questions about its safety and effectiveness still surround it. Our goals were to assess the epidemiological features of two consecutive seasonal influenza cases in children following the COVID-19 pandemic; to observe the clinical effectiveness and tolerability of oseltamivir in hospitalized children who were not vaccinated against influenza and had different influenza subtypes, including A(H1N1), A(H3N2), and B; and to identify specific comorbidities associated with influenza in children. We performed an observational study on 1300 children, enrolled between 1 October 2022 and 30 May 2023 and between 1 October 2023 and 4 May 2024, to the IX Pediatric Infectious Diseases Clinical Section of the National Institute of Infectious Diseases “Prof. Dr. Matei Balș”. During the 2022–2023 influenza season, 791 pediatric patients tested positive for influenza and received oseltamivir. Of these, 89% (704/791) had influenza A, with 86.4% having subtype A(H1N1) and 13.6% of cases having A(H3N2), and for influenza B, 11% (87/791) of the pediatric patients. Of the total group, 59% were male, and the median age was 2.4 years (1.02–9.28). For the 2023–2024 influenza season, 509 pediatric patients tested positive for influenza, with 56.9% being of the male gender and who were treated with oseltamivir. Of these patients, 81.6% had influenza A and 18.4% had influenza B. Treatment with neuraminidase inhibitors, specifically oseltamivir, 2 mg/kg/dose administered twice daily for 5 days, was well tolerated by the children, and we recorded no deaths. The duration of hospitalization for patients with a fever after the oseltamivir administration was significantly longer for patients with A(H1N1) infection than A(H3N2), during both seasons. We identified more complications in the 2022–2023 season and a decreasing number of influenza B for the 2023–2024 season. Among children with comorbidities, the most common were asthma, gastrointestinal diseases, and metabolic and endocrine diseases. In terms of effectiveness, oseltamivir significantly reduced the intensity of influenza symptoms, thus reducing the number of days of hospitalization (p = 0.001) as well as post-infection complications (p = 0.005) in both groups. In this study, we evaluated the clinical effectiveness of oseltamivir therapy for all influenza types/subtypes in children, and the length of hospitalization. We identified comorbidities associated with the prolonged duration of hospitalization. Influenza vaccination should be the main tool in the prevention of influenza and its complications in children, especially those with comorbidities.

Antiviral therapy such as Oseltamivir has been recommended for hospitalized children with suspected and confirmed influenza for almost 20 years. The therapy is officially authorized for newborns two weeks of age or older, however, questions about its safety and effectiveness still surround it. Our goal was to assess the epidemiological features of two consecutive seasonal in-fluenza cases in children following the COVID-19 pandemic and also to observe the clinical ef-fectiveness and tolerability of oseltamivir in hospitalized children who were not vaccinated against influenza and who had different influenza subtypes, including A (H1N1), A (H3N2), and influenza B, and to identify specific comorbidities associated with influenza in children. We performed an observational study on 1300 children, enrolled between 1st October 2022 and 30th May 2023 and 1st October 2023-4th of May 2024, to the IX Pediatric Infectious Diseases Clinical Section of the National Institute of Infectious Diseases "Prof. Dr. Matei Balș". During the 2022-2023 influenza sea-son, 791 pediatric patients tested positive for influenza and received Oseltamivir. Of these, 89% (704/791) had influenza A, with 86.4% subtypes A(H1N1) and 13.6% of cases had A(H3N2), and influ-enza B 11%(87/791) pediatric patients. Of the total group, 59% were male, and the median age was 2,4 years (1.02-9.28). For the 2023-2024 influenza season, 509 pediatric patients tested positive for influen-za, 56.9% were male gender and were treated with Oseltamivir. 81.6 % had Influenza A, and 18.4% had influenza B. Treatment with neuraminidase inhibitors like Oseltamivir, 2mg/kg/dose twice daily for 5 days, was well tolerated by the children, and we recorded no deaths. The duration of fever hospitaliza-tion after the Oseltamivir administration was significantly longer for patients with A(H1N1) infection than A(H3N2), during both seasons. We identified more complications in the 2022-2023 season and a decreasing number of Influenza B for the 2023-2024 season. Among children with comorbidities, the most common were asthma, gastrointestinal disorders, and metabolic and endocrine diseases. In terms of effectiveness, oseltamivir significantly reduced the intensity of influenza symptoms, thus reducing the number of days of hospitalization (p=0.001) as well as post-infection complications (p=0.005) in both groups. Oseltamivir was less effective in Influenza A (H1N1) than A(H3N2), (p=0.0035). In this study, we evaluated the clinical effectiveness of oseltamivir therapy for all influenza types/subtypes in children, and the length of hospitalization. We identified comorbidities associated with prolonged dura-tion of hospitalisation. Influenza vaccination should be the main tool in the prevention of influenza and its complications in children, especially with comorbidities.

Streptococcus pneumoniae is one of the associated bacteria that can cause the rare but high mortality hematological pathology known as purpura fulminans (PF) in both adults and children. Pediatric patients with PF can progress quickly to sepsis and multiorgan failure, especially immunocompromised individuals and young children. Due to the thrombotic blockage of blood arteries in PF, there is diffuse intravascular thrombosis and hemorrhagic infarction of the skin, which evolves from ecchymosis to skin necrosis, risk of limb sequelae, sepsis and fatality. We present a case of a previously healthy 1-year and 9-months old female who was admitted to the Intensive Care Unit of the National Institute of Infectious Diseases "Prof. Dr. Matei Balş"- Bucharest, Romania. On physical examination, she was febrile, hypotensive, tachycardic, and had erythematous patches on her left upper limb and trunk. Initial blood work was significant for creatinine 4.45 mg/dL, aspartate aminotransferase 112 U/L, alanine aminotransferase 130 U/L and fibrinogen 596 mg/dL. Hematological workup showed a white blood cells count of 34 × 10⁹/L, hemoglobin 9.7 g/dL, platelets 23000/L, D-dimers 89000 μg/L, and elevated PT and aPTT. Broad-spectrum antibiotics vancomycin and ceftriaxone were administrated. A lumbar puncture was performed for cerebrospinal fluid (CSF) analysis and culture grew Streptococcus pneumoniae serotype 1A. She required peritoneal dialysis due to acute kidney injury (AKI) and surgeries for affected skin areas. After multiple organ system failures, our patient evolved rapidly to irreversible tissue necrosis and death. We aim to report a rare case of PF associated with pneumococcal meningoencephalitis in an immunocompetent child, to better appreciate the risk of fatal evolution when managing this disease in children.

The 2022–2023 influenza season in Romania was characterized by high pediatric hospitalization rates, predominated due to influenza A subtypes (H1N1) pdm09 and H3N2. The lowered population immunity to influenza after the SARS-CoV-2 pandemic and the subsequent stoppage of influenza circulation, particularly in children who had limited pre-pandemic exposures, influenced hospitalization among immunosuppressed children and patients with concurrent medical conditions who are at an increased risk for developing severe forms of influenza. This study focused on the characteristics of influenza issues among pediatric patients, as well as the relationship between different influenza virus types/subtypes and viral and bacterial co-infections, as well as illness severity in the 2022–2023 season after the SARS-CoV-2 pandemic. We conducted a retrospective clinical analysis on 301 cases of influenza in pediatric inpatients (age ≤ 18 years) who were hospitalized at the National Institute of Infectious Diseases “Prof. Dr. Matei Balș” IX Pediatric Infectious Diseases Clinical Section between October 2022 and February 2023. The study group’s median age was 4.7 years, and the 1–4 year age group had the highest representation (57.8%). Moderate clinical forms were found in 61.7% of cases, whereas severe versions represented 18.2% of cases. Most of the complications were respiratory (acute interstitial pneumonia, 76.1%), hematological (72.1%, represented by intra-infectious and deficiency anemia, leukopenia, and thrombocytopenia), and 33.6% were digestive, such as diarrheal disease, liver cytolysis syndrome, and the acute dehydration syndrome associated with an electrolyte imbalance (71.4%). Severe complications were associated with a risk of unfavorable evolution: acute respiratory failure and neurological complications (convulsions, encephalitis). No deaths were reported. We noticed that the flu season of 2022–2023 was characterized by the association of co-infections (viral, bacterial, fungal, and parasitic), which evolved more severely, with prolonged hospitalization and more complications (p < 0.05), and the time of use of oxygen therapy was statistically significant (p < 0.05); the number of influenza vaccinations in this group was zero. In conclusion, co-infections with respiratory viruses increase the disease severity of the pediatric population to influenza, especially among young children who are more vulnerable to developing a serious illness. We recommend that all people above the age of six months should receive vaccinations against influenza to prevent the illness and its severe complications.

The 2022-2023 influenza season in Romania was characterized by high pediatric hospitalization rates, predominated by influenza A subtypes H1N1 and H3N2. Lowered population immunity to influenza after the SARS-CoV-2 pandemic and subsequent stoppage of influenza circulation, particularly in children who had limited pre-pandemic exposures, influenced hospitalization among children immunosuppressed, and patients with concurrent medical conditions who are at increased risk for developing severe forms of influenza. This study focused on the characteristics of influenza issues among paediatric patients, as well as the relationship between different influenza virus types and viral and bacterial coinfections and illness severity in the 2022-2023 season after the SARS-CoV-2 pandemic. We conducted a retrospective clinical analysis on 301 cases of influenza in pediatric inpatients (age ≤ 18 years), hospitalized at the National Institute of Infectious Diseases "Prof. Dr. Matei Balș" IX Pediatric Infectious Diseases Clinical Section between October 2022 and February 2023. The most significant age group was 57.8% representing children between one to four years old and female. The average clinical forms were found in 61.7%, whereas severe versions represented 18.2% of cases. Most of the complications were respiratory (acute interstitial pneumonia, 76.1%), hematological (72.1%), represented by intra-infectious and deficiency anemia, leukopenia, thrombocytopenia), 33.6% were digestive, such as diarrheal disease, liver cytolysis syndrome, and the acute dehydration syndrome associated with electrolyte imbalance (71.4%). Severe complications were associated with a risk of unfavorable evolution: acute respiratory failure and neurological complications (convulsions, encephalitis). No deaths were reported. We noticed that the flu season 2022-2023 was characterized by the association of co-infections (viral, bacterial, fungal and parasitic) more frequent than in previous years (26.2% vs. 16%), which evolved more severely, with prolonged hospitalization and more complications (p 0.05); influenza vaccination in this group was zero. In conclusion, coinfections with respiratory viruses increase the severity of the pediatric population's immunity to influenza, especially among young children who are more vulnerable to developing a serious illness. All people above the age of six months should get vaccinated against influenza to prevent the illness and its severe complications.