Group A Streptococcal Infections in Pediatric Age: Updates about a Re-Emerging Pathogen.

Group A Streptococcus (GAS) presents a significant global health burden due to its diverse clinical manifestations ranging from mild infections to life-threatening invasive diseases. While historically stable, the incidence of GAS infections declined during the COVID-19 pandemic but resurged following the relaxation of preventive measures. Despite general responsiveness to ß-lactam antibiotics, there remains an urgent need for a GAS vaccine due to its substantial global disease burden, particularly in low-resource settings. Vaccine development faces numerous challenges, including the extensive strain diversity, the lack of suitable animal models for testing, potential autoimmune complications, and the need for global distribution, while addressing socioeconomic disparities in vaccine access. Several vaccine candidates are in various stages of development, offering hope for effective prevention strategies in the future.

Clinical and laboratory parameters associated with febrile seizure recurrence within the first 24†h: a ten-year cohort study.

Introduction: We assessed clinical and laboratory parameters associated with early recurrence of febrile seizure in patients presenting at the Emergency Department with a first episode. Methods: Case series of patients admitted to the emergency department with the first episode of febrile seizure for ten consecutive years. Exclusion criteria were focal features and prolonged duration (>15 min). Results: We included 693 patients, 284 (41%) female. Median age of 20 (IQR 15-27) months. Fifty-two (8%) patients had a recurrence within 24 h. At univariate analysis, patients with recurrent seizures had higher use of antipyretics (88% vs. 74%, P = 0.03, OR 2.6, 95% CI: 1.1-7.7), higher median maximal body temperature (39.3 °C, IQR 38.9-39.9, vs. 38.9, IQR 38.4-39.3, P < 0.001, OR 2.3, 95% CI: 1.5-2.6) and presented with a lower proportion of respiratory tract infections (54% vs. 70%, P = 0.02) compared to patients without recurrence. A maximal body temperature equal to or higher than 39 °C was associated with a higher recurrence (11% vs. 4%, P < 0.001, OR 2.9, 95% CI: 1.6-5.6). Hyponatremia was not associated with a risk of recurrence. The multivariate analysis confirmed a direct association with body temperature (OR 2.3, 95% CI: 1.5-3.7, P < 0.001), and an inverse association with respiratory tract infections (OR 0.4, 95% CI: 0.2-0.9, P = 0.01), while antipyretic use was not correlated (OR 1.9, 95% CI: 0.8-5.2, P = 0.2). Conclusions: High body temperature and respiratory tract infections were (directly and inversely) associated with recurrences. Consideration of these conditions might help for anticipating the probability of recurrence.

Preventing HIV mother-to-child transmission in a vertically infected pregnant woman with multiclass drug resistance, role of bis-in-die dolutegravir and neonatal AZT prophylaxis: A case report.

A suppressive antiretroviral therapy (ART) is necessary to prevent mother-to-child transmission (MTCT) of HIV during pregnancy. During this period, it is recommended to continue an ongoing safe and suppressive regimen, but history of multiclass drug-resistance (MDR) might need tailored, uncommon approaches posing tolerability and toxicity issues. This is the case of a 33 years of age, vertically infected woman with MDR HIV infection suppressed on a darunavir/cobicistat + atazanavir regimen switched during pregnancy to lamivudine + darunavir/ritonavir + dolutegravir 50 mg bis-in-die, maintaining complete viral suppression and delivering via caesarian section and without zidovudine (AZT) intrapartum prophylaxis a healthy HIV-negative newborn who received AZT post-exposure prophylaxis and showed regular growth patterns up to 2 years. Our case shows how archived MDR might complicate the preservation of HIV RNA suppression and highlights the importance of a tailored, multidisciplinary approach for pregnant women with MDR HIV and their newborns.

SARS-CoV-2 infection in children: A 24 months experience with focus on risk factors in a pediatric tertiary care hospital in Milan, Italy.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children is characterized by a wide variety of expressions ranging from asymptomatic to, rarely, critical illness. The basis of this variability is not yet fully understood. The aim of this study was to identify clinical and genetic risk factors predisposing to disease susceptibility and progression in children. Methods: We enrolled 181 consecutive children aged less than 18 years hospitalized with or for SARS-CoV-2 infection during a period of 24 months. Demographic, clinical, laboratory, and microbiological data were collected. The development of coronavirus disease 2019 (COVID-19)-related complications and their specific therapies were assessed. In a subset of 79 children, a genetic analysis was carried out to evaluate the role of common COVID-19 genetic risk factors (chromosome 3 cluster; ABO-blood group system; FUT2, IFNAR2, OAS1/2/3, and DPP9 loci). Results: The mean age of hospitalized children was 5.7 years, 30.9% of them being under 1 year of age. The majority of children (63%) were hospitalized for reasons different than COVID-19 and incidentally tested positive for SARS-CoV-2, while 37% were admitted for SARS-CoV-2 infection. Chronic underlying diseases were reported in 29.8% of children. The majority of children were asymptomatic or mildly symptomatic; only 12.7% developed a moderate to critical disease. A concomitant pathogen, mainly respiratory viruses, was isolated in 53.3%. Complications were reported in 7% of children admitted for other reasons and in 28.3% of those hospitalized for COVID-19. The respiratory system was most frequently involved, and the C-reactive protein was the laboratory test most related to the development of critical clinical complications. The main risk factors for complication development were prematurity [relative risk (RR) 3.8, 95% confidence interval (CI) 2.4-6.1], comorbidities (RR 4.5, 95% CI 3.3-5.6), and the presence of coinfections (RR 2.5, 95% CI 1.1-5.75). The OAS1/2/3 risk variant was the main genetic risk factor for pneumonia development [Odds ratio (OR) 3.28, 95% CI 1-10.7; p value 0.049]. Conclusion: Our study confirmed that COVID-19 is generally less severe in children, although complications can develop, especially in those with comorbidities (chronic diseases or prematurity) and coinfections. Variation at the OAS1/2/3 genes cluster is the main genetic risk factor predisposing to COVID-19 pneumonia in children.

Endocrine Disruptor Chemicals and Children's Health.

We are all exposed to endocrine-disrupting chemicals (EDCs) starting from embryonic life. The fetus and child set up crucial developmental processes allowing adaptation to the environment throughout life: they are extremely sensitive to very low doses of hormones and EDCs because they are developing organisms. Considering the developmental origin of well-being and diseases, every adult organism expresses consequences of the environment in which it developed. The molecular mechanisms through which the main EDCs manifest their effects and their potential association with endocrine disorders, such as diabetes, obesity, thyroid disease and alteration of adrenal hormones, will be reviewed here. Despite 40 years having passed since the first study on EDCs, little is yet known about them; therefore, our purpose is to take stock of the situation to establish a starting point for further studies. Since there is plenty of evidence showing that exposure to EDCs may adversely impact the health of adults and children through altered endocrine function-suggesting their link to endocrinopathies-it is essential in this context to bear in mind what is already known about endocrine disruptors and to deepen our knowledge to establish rules of conduct aimed at limiting exposure to EDCs' negative effects. Considering that during the COVID-19 pandemic an increase in endocrine disruptor effects has been reported, it will also be useful to address this new phenomenon for better understanding its basis and limiting its consequences.

Corrigendum: Disappearance of seasonal respiratory viruses in children under two years old during COVID-19 pandemic: A monocentric retrospective study in Milan, Italy.

[This corrects the article DOI: 10.3389/fped.2021.721005.].

Intrapartum use of zidovudine in a large cohort of pregnant women living with HIV in Italy.

BACKGROUND: Intravenous administration of zidovudine (ZDV) during labour is a key step for vertical HIV transmission (VT) prevention, but there is no evidence of benefit when maternal HIV-RNA at delivery is <50 copies/mL. The aim of this study is evaluating the appropriateness of intrapartum ZDV use in Italy. METHODS: Observational study including mother-infant pairs with perinatal HIV exposure during 2002-2019, enrolled in the Italian Register for HIV Infection in Children. Univariable and multivariable logistic regression were used to evaluate factors associated with VT. RESULTS: A total of 3,861 infants, born from 3,791 pregnancies were included. The frequency of ZDV use was 79.9%, 92.1%, 93.7% and 92.8% when HIV-RNA was not available, ≥400 copies, between 50 and 399 copies, and <50 copies/mL. Thirty-three out of 3861 (0.85%) infants were subsequently diagnosed with HIV, 25/3861 (0.6%) of them born to mothers receiving intrapartum ZDV, and 31 (93.9%) to mothers with HIV-RNA ≥50 copies/mL or not available. In women with HIV-RNA < 50 copies/mL, ART discontinuation during pregnancy was the strongest risk factor for VT (odds ratio, OR, 23.1, 95%CI 2.4-219.3), while a higher gestational age (OR 0.6, 95%CI 0.4-0.8) and PEP administration to the newborn (aOR 0.004, 95%CI <0.0001-0.4) were protective factors. Intrapartum ZDV administration did not influence the final outcome in this group. CONCLUSIONS: In ART era, more transmission events may occur in utero, limiting value of intrapartum ZDV, particularly for women with suppressed HIV-RNA load. More attention to the HIV-RNA testing of mothers before delivery may avoid unnecessary ZDV use.

CLUH controls astrin-1 expression to couple mitochondrial metabolism to cell cycle progression.

Proliferating cells undergo metabolic changes in synchrony with cell cycle progression and cell division. Mitochondria provide fuel, metabolites, and ATP during different phases of the cell cycle, however it is not completely understood how mitochondrial function and the cell cycle are coordinated. CLUH (clustered mitochondria homolog) is a post-transcriptional regulator of mRNAs encoding mitochondrial proteins involved in oxidative phosphorylation and several metabolic pathways. Here, we show a role of CLUH in regulating the expression of astrin, which is involved in metaphase to anaphase progression, centrosome integrity, and mTORC1 inhibition. We find that CLUH binds both the SPAG5 mRNA and its product astrin, and controls the synthesis and the stability of the full-length astrin-1 isoform. We show that CLUH interacts with astrin-1 specifically during interphase. Astrin-depleted cells show mTORC1 hyperactivation and enhanced anabolism. On the other hand, cells lacking CLUH show decreased astrin levels and increased mTORC1 signaling, but cannot sustain anaplerotic and anabolic pathways. In absence of CLUH, cells fail to grow during G1, and progress faster through the cell cycle, indicating dysregulated matching of growth, metabolism, and cell cycling. Our data reveal a role of CLUH in coupling growth signaling pathways and mitochondrial metabolism with cell cycle progression.

Meningococcal Disease in Pediatric Age: A Focus on Epidemiology and Prevention.

Meningococcal disease is caused by Neisseria meningitidis; 13 serogroups have been identified and differentiated from each other through their capsular polysaccharide. Serotypes A, B, C, W, X, and Y are responsible for nearly all infections worldwide. The most common clinical manifestations are meningitis and invasive meningococcal disease, both characterized by high mortality and long-term sequelae. The infection rate is higher in children younger than 1 year and in adolescents, who are frequently asymptomatic carriers. Vaccination is the most effective method of preventing infection and transmission. Currently, both monovalent meningococcal vaccines (against A, B, and C serotypes) and quadrivalent meningococcal vaccines (against serogroups ACYW) are available and recommended according to local epidemiology. The purpose of this article is to describe the meningococcal vaccines and to identify instruments that are useful for reducing transmission and implementing the vaccination coverage. This aim could be reached by switching from the monovalent to the quadrivalent vaccine in the first year of life, increasing vaccine promotion against ACYW serotypes among adolescents, and extending the free offer of the anti-meningococcal B vaccine to teens, co-administering it with others proposed in the same age group. Greater awareness of the severity of the disease and increased health education through web and social networks could represent the best strategies for promoting adhesion and active participation in the vaccination campaign. Finally, the development of a licensed universal meningococcal vaccine should be another important objective.

Incidental occurrence of neutropenia in children hospitalised for COVID-19.

BACKGROUND: Investigations on haematological alterations in paediatric COVID-19 have been focused mostly on lymphocytes and clotting profiles. Neutropenia has been occasionally reported and its course and impact on the disease have not been elucidated. The aim of this study was to describe the epidemiology, course, and impact of neutropenia in children with COVID-19 hospitalised in a tertiary care referral paediatric ward. METHODS: A single-centre retrospective study was conducted. Hospitalised children between 1 month and 18 years with confirmed COVID-19 and neutropenia were included and compared to non neutropenic patients. Complete blood picture with differential blood count, serum biochemistry, clotting profiles were performed; clinical data, length of hospitalisation, and prescription of drugs were collected. RESULTS: Twelve out of 95 patients (12.63%) with documented SARS-CoV-2 infection were neutropenic and met the inclusion criteria. The mean age was 161 days (range 38-490 days). The mean duration of symptoms in neutropenic children was 3.82 days, while the mean length of hospitalisation was 7.67 days. These findings were not significantly different in the two study groups. All patients had mild clinical manifestations and were discharged without sequelae. CONCLUSIONS: We provided the first comprehensive study on neutropenia in mild paediatric COVID-19 infection. Our findings show that the main features of this haematological disorder in COVID-19 are analogous to the well-known transient benign neutropenia associated with other common viral infections. In our setting, neutropenia does not emerge as a potential negative prognostic factor in paediatric COVID-19.

Disappearance of Seasonal Respiratory Viruses in Children Under Two Years Old During COVID-19 Pandemic: A Monocentric Retrospective Study in Milan, Italy.

Background: The containment measures adopted during COVID-19 pandemic have influenced the epidemiology of other respiratory viruses. Aim: We analyzed the modification of the incidence and etiology of lower respiratory tract infections (LRTIs) in young children during COVID-19 pandemic. Methods: Case series of all children under 2 years old hospitalized at a tertiary care Hospital in the Center of Milan, Italy diagnosed with LRTIs in three consecutive winter seasons (from the 1st of November to the last day of February in 2018/2019, 2019/2020 and 2020/2021). We compared the number of hospitalizations and viral detections in the 2020/2021 with the average of 2018/2019 and 2019/2020 (pre-COVID-19) using the Poisson distribution. Results: we enrolled 178 patients (66 from 2018/2019, 96 from 2019/2020, 16 from 2020/2021) 94 males (53%) and 84 females (47%), with a median (IQR) age of 5 (2-13) months. The number of hospitalizations during the 2020/2021 season was 80% lower than the average of the pre-COVID-19 seasons (16 vs. 81, p<0.001). Overall, 171 (96%) patient's nasopharyngeal aspirate (NPA) detected at least one virus (110, 64%, single-detection, 61, 36%, co-detections). In 2020/2021 we observed the disappearance of Respiratory Syncytial virus (0 vs. 54, p < 0.001), Influenza virus (0 vs. 6.5, p = 0.002), Metapneumovirus (0 vs. 8, p < 0.001), Parainfluenza viruses (0 vs. 3.5, p = 0.03) and a significant reduction of Adenovirus (2 vs. 7, p = 0.03), Bocavirus (2 vs. 7.5, p = 0.02) and Enterovirus (1 vs. 5, p = 0.04). No significant difference was found for Rhinoviruses (14 cases vs. 17, p = 0.2), other Coronaviruses (0 vs. 2, p = 0.1), and Cytomegalovirus (1 vs. 1, p = 0.7). Conclusions: We observed a striking reduction in hospitalizations due to LRTIs and a modification of the etiology, with enveloped viruses mainly affected.

Panton-valentine leukocidin Staphylococcus aureus severe infection in an infant: a case report and a review of the literature.

BACKGROUND: Panton-Valentine leukocidin (PVL) is one of the major virulence factor of Staphylococcus aureus (SA) that might be associated with invasive life-threating infections. A prompt diagnosis and adequate treatment are essential in achieving the best outcome and avoiding serious sequelae. We describe a case of severe invasive PVL-SA infection in an infant. A literature review starting from 2010 was also performed in order to discuss clinical presentations, radiological findings, treatment and outcome. CASE PRESENTATION: This is a case of a 6-month-old boy who rapidly developed high fever and poor general condition. He was diagnosed as having multiple muscular abscesses, multiple foci of osteomyelitis and bloodstream infections caused by Panton-Valentine leukocidin Methicillin-resistant Staphylococcus aureus. He received intravenous antibiotics and surgical drainage of the abscess with progressive recovery. CONCLUSION: Our report highlights the importance of improving awareness of this severe infection, as a prompt diagnosis and adequate manage is essential in order to save life and to prevent serious complications.

Pediatric Septic Arthritis of the Knee Due to a Multi-Sensitive Streptococcus pyogenes Strain Responsive to Clindamycin-A Case Report.

Septic arthritis is an inflammatory process usually generated by a bacterial infection. The knee is one of the most frequently involved joints. The etiology varies depending on age, and hematogenous spread remains the primary cause in children. Herein, we report a case of a previously healthy three-year-old female who was referred to our institution for acute swelling of her right knee. After a clinical and radiological diagnosis of septic arthritis, an empirical treatment with a combination of cefotaxime and clindamycin was initiated. The isolation of a multi-sensitive Streptococcus pyogenes strain from the joint's effusion prompted the discontinuation of clindamycin and the usage of cefotaxime alone. One week later, an ultrasound was executed due to worsening in the patient's clinical conditions, and an organized corpuscular intra-articular effusion with diffuse synovial thickening was revealed. Cefotaxime was therefore replaced with clindamycin, which improved the symptoms. Despite the antibiotic sensitivity test having revealed a microorganism with sensitivity to both cephalosporin and clindamycin, clinical resistance to cefotaxime was encountered and a shift in the antimicrobial treatment was necessary to ensure a full recovery. This case study confirms that an antibiotic regimen based solely on a susceptibility test may be ineffective for such cases.

Diagnosis of SARS-CoV-2 in children: accuracy of nasopharyngeal swab compared to nasopharyngeal aspirate.

The tests currently used for the identification of SARS-CoV-2 include specimens taken from the upper and lower respiratory tract. Although recommendations from the World Health Organization prioritise the usage of a nasopharyngeal swab (NS), nasopharyngeal aspirates (NPA) are thought to be superior in identifying SARS-CoV-2 in children. To our knowledge, however, no paediatric study has been published on the subject. The aim of this study is to evaluate the diagnostic performances of NS referred to NPA for SARS-CoV-2 in children. We calculated the sensitivity and specificity of the NS referred to the NPA of the whole sample and considered both age and collection period as covariates in different analyses. We collected 300 paired samples. The NS had a specificity of 97.7% and a sensitivity of 58.1%. We found similar results for the group of subjects ≥ 6 years old, while for subjects < 6 years old, the sensitivity was 66.7% and the specificity 97.8%. Considering period as a covariate, the sensitivity and specificity for patients hospitalised in March (31 patients, 52 records) were 70.0% and 97.6%, while for patients involved in the follow-up (16 patients, 57 records), they were 57.2% and 89.7%. The NS has a low sensitivity in detecting SARS-CoV-2 in children when referred to the NPA, whereas its specificity is high. Our results suggest that in children under 6 years of age, NSs should be preferred whenever possible. Though statistically not significant, the sensitivity of the NS rises when performed before the NPA.

Pediatric otogenic cerebral venous sinus thrombosis: a case report and a literature review.

BACKGROUND: Cerebral venous sinus thrombosis in children is a rare but potentially fatal complication of acute mastoiditis, one of the most common pediatric infectious diseases. Due to its subtle clinical presentation, suspicion is essential for a prompt diagnosis and appropriate management. Unfortunately, no standard treatment options are available. To discuss the possible clinical presentation, microbiology, and management, we here report the case of a child with otogenic cerebral venous sinus thrombosis and perform a literature review starting from 2011. CASE PRESENTATION: The child, a 10-months-old male, presented clinical signs of right acute otitis media and mastoiditis. Brain computed tomography scan detected right sigmoid and transverse sinus thrombosis, as well as a subperiosteal abscess. Fusobacterium necrophorum and Haemophilus Influentiae were detected on cultural sampling. A multidisciplinary approach along with a combination of medical and surgical therapy allowed the patient's full recovery. CONCLUSION: Cerebral venous sinus thrombosis is a rare but severe complication of acute otitis media and mastoiditis. The management of this pathological condition is always challenging and an interdisciplinary approach is frequently required. Current therapeutic options include a combination of medical and surgical therapy. A patient-centered approach should guide timing and treatment management.

Abscess of the clivus in an adolescent with complicated acute rhinosinusitis: a case report.

BACKGROUND: Complications of acute sinusitis affecting multiple sites are very uncommon, and generally develop for a delayed diagnosis of the primary infection, with possible severe and life-threatening evolution. Patients can have variable presentations according to the site and extent of the infection. Multiple forms generally include the coexistence of orbital manifestations and intracranial infections. We here present a case with unusual multiple sites locations (i.e.: intraorbital intraconic abscess, sigmoid sinus thrombosis, preclival abscess, multiple splanchnocranium osteomyelitic processes). CASE PRESENTATION: A 13-year-old male presented at our hospital with right progressive orbital oedema with eyesight worsening and signs of meningitis. Computed tomography and magnetic resonance (MRI) demonstrated right intraorbital intraconic abscess, left sphenoidal sinusitis, transverse and sigmoid sinus thrombosis. Ophthalmologic evaluation documented a right optic nerve sufferance. Endoscopic and superior right trans-palpebral surgical decompression was performed, and the abscess was drained. Microbiological analysis revealed the presence of multi-sensitive Streptococcus Intermedius. Subsequent prolonged antibiotic and anti-thrombotic treatments were started. In the following two-weeks the sinusal and ophthalmologic clinical conditions improved, whereas the patients complained of mild to moderate cervical pain and suffered from intermittent pyrexia. Control MRI documented clival abscess extending up to preclival soft tissues posterior to the nasopharynx, associated with mandible osteomyelitis, occipital condyles and anterior part of the temporal bone hyper intensity. Endoscopic trans-nasal surgical approach to the clival compartment with neurosurgery navigation-guided achieved preclival abscess drainage. Complete clinical and radiological recovery was achieved after 45 days of medical treatment. CONCLUSIONS: Multiple sites complicated rhinosinusitis is uncommon, and its management is challenging. A proper history and thorough clinical examination along with a radiological evaluation are key factors in the final diagnosis of patients with complicated multiple sites acute rhinosinusitis. A quick multidisciplinary approach is always necessary to avoid unwanted life-threatening complications.

Henoch-Schönlein Purpura in children: not only kidney but also lung.

BACKGROUND: Henoch-Schönlein Purpura (HSP) is the most common vasculitis of childhood and affects the small blood vessels. Pulmonary involvement is a rare complication of HSP and diffuse alveolar hemorrhage (DAH) is the most frequent clinical presentation. Little is known about the real incidence of lung involvement during HSP in the pediatric age and about its diagnosis, management and outcome. METHODS: In order to discuss the main clinical findings and the diagnosis and management of lung involvement in children with HSP, we performed a review of the literature of the last 40 years. RESULTS: We identified 23 pediatric cases of HSP with lung involvement. DAH was the most frequent clinical presentation of the disease. Although it can be identified by chest x-ray (CXR), bronchoalveolar lavage (BAL) is the gold standard for diagnosis. Pulse methylprednisolone is the first-line of therapy in children with DAH. An immunosuppressive regimen consisting of cyclophosphamide or azathioprine plus corticosteroids is required when respiratory failure occurs. Four of the twenty-three patients died, while 18 children had a resolution of the pulmonary involvement. CONCLUSIONS: DAH is a life-threatening complication of HSP. Prompt diagnosis and adequate treatment are essential in order to achieve the best outcome.

Otogenic temporomandibular septic arthritis in a child: a case report and a review of the literature.

BACKGROUND: Acute otitis media is one of the most common infectious diseases in the paediatric age and although its complications such as acute mastoiditis have become rare thanks to improvements in therapeutic approaches, possible serious complications such as septic arthritis of the temporomandibular joint may develop. A prompt diagnosis and adequate treatment are essential to achieving the best outcome and avoiding serious sequelae. We describe a case occurring in a previously healthy 6-year-old female and review the literature currently available on this topic. CASE PRESENTATION: The patient presented a right temporomandibular septic arthritis with initial mandibular bone involvement secondary to acute otitis media. She presented with torcicollis, trismus, right preauricular swelling over the temporomandibular joint and was successfully treated with antibiotic treatment alone. CONCLUSIONS: Septic arthritis of the temporomandibular joint is a rare complication of acute otitis media or acute mastoiditis in children. It should be suspected in patients presenting with trismus, preauricular swelling or fever. No guidelines on the diagnosis and treatment of this infectious disease are currently available.

Neisseria meningitidis serogroup B carriage by adolescents and young adults living in Milan, Italy: Prevalence of strains potentially covered by the presently available meningococcal B vaccines.

Recently, two vaccines against meningococcal serogroup B (MenB) have been developed. They are prepared according to the reverse vaccinology approach and contain 4 (4CMenB) and 2 (MenB-FHbp) cross-reactive surface proteins. In Italy 4CMenB vaccine has been included in the official vaccination schedule only recently and recommended only for infants and toddlers, whereas MenB-FHbp is not licensed. In order to collect information about the present carriage of Neisseria meningitidis serogroup B (MenB) in Italian adolescents and to evaluate the potential protection offered by the presently available MenB vaccines, 2,560 otherwise healthy, high school students aged 14-21 years (907 males, 35.4%, median age 16.2 years) were enrolled in Milan, Italy. A swab to collect posterior pharynx secretions was collected from each subject and meningococcal identification, serogrouping, multilocus sequence typing analysis, sequence alignments and phylogenetic analysis were performed. A total of 135 (5.3%) adolescents were meningococcal carriers. Strains belonging to serogroup B were the most common (n = 58; 2.3%), followed by MenY (n = 32; 1.2%), MenC (n = 7; 0.3%), MenW (n = 6; 0.3%) and MenX (n = 5; 0.2%). The remaining bacteria were not capsulated. The identified MenB strains belonged to eleven clonal complexes (CCs): ST-162 CC (n = 12; 20.7%), ST-865 CC (n = 12; 20.7%), ST-41/44/Lin.3 CC (n = 11; 19.0%), ST-35 CC (n = 6; 10.3%), ST-32/ET-5 CC (n = 4; 6.9%), ST-269 CC (n = 3; 5.2%), ST-213 CC (n = 2; 3.4%), ST-198 CC (n = 1; 1.7%), ST-461 CC (n = 1; 1.7%), ST-549 CC (n = 1; 1.7%), and ST-750 CC (n = 1; 1.7%). This study showed that MenB was the most commonly carried meningococcal serogroup found in adolescents living in Milan, Italy. The MenB vaccines presently licensed could have theoretically induced the production of antibodies effective against the greatest part of the identified MenB strains (100% in the case of 4CMenB and 95% in case of MenB-FHbp) Monitoring carriage remains essential to evaluate MenB circulation, but further studies are necessary to evaluate the effect on carriage and the final efficacy of both new MenB vaccines.