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The COVID-19 pandemic has modified the seasonal pattern of respiratory infections. The objective of the present study is to characterize the out-of-season circulation of influenza viruses and an influenza outbreak that occurred in southern Italy in August 2022. Nasopharyngeal swabs collected from patients with influenza-like illnesses (ILI) were tested for the presence of influenza and other respiratory viruses. Epidemiological investigations on 85 patients involved in an influenza outbreak were performed. Sequencing and phylogenetic analysis of hemagglutinin genes was undertaken on samples positive for influenza A. In August 2022, in the Apulia region (Italy), influenza A infection was diagnosed in 19 patients, 18 infected with A/H3N2 and one with A/H1N1pdm09 virus. Seven influenza-positive patients were hospitalized with ILI. A further 17 symptomatic subjects, associated with an influenza outbreak, were also tested; 11 were positive for influenza A/H3N2 virus. Phylogenetic analysis of 12 of the A/H3N2 sequences showed that they all belonged to subclade 3C.2a1b.2a.2. The A/H1N1pdm09 strain belonged to subclade 6B.1A.5a.2. The out-of-season circulation of the influenza virus during the summer months could be linked to changing dynamics in the post-COVID-19 era, as well as to the impact of climate change. Year-round surveillance of respiratory viruses is needed to monitor this phenomenon and to provide effective prevention strategies. [ABSTRACT FROM AUTHOR]

Macrolide-resistant Mycoplasma pneumoniae (MR-MP) infections cause upper and lower respiratory tract infections in both children and adults, and are characterized by a longer duration of symptoms. Here, we undertook a systematic review of studies on MR-MP in Europe. The review meets PRISMA guidelines. The PubMed, Scopus, and Science Direct databases were searched using suitable keywords to identify relevant studies published from 2010 to 2021; 21 studies were included. Overall, a low level of MR-MP spread was reported in Europe. MR-MP spread increased during epidemic waves registered in Europe, particularly in Italy and Scotland, where the highest MR-MP infection rates were registered during the 2010-2011 epidemic. By contrast, no MR-MP infections were reported in Finland and the Netherlands. Continued monitoring of MR-MP in Europe is needed to maintain the low rates of infection. Moreover, a coordinated and structured pan-European surveillance program adequate for public health surveillance is advisable, with the purpose of containing the spread of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

The Omicron variant of concern (VOC), first detected in Italy at the end of November 2021, has since spread rapidly, despite high vaccine coverage in the Italian population, especially in healthcare workers (HCWs). This study describes an outbreak of SARS-CoV-2 Omicron infection in 15 booster-vaccinated HCWs. On 16 December 2021, two HCWs working in the same ward were infected with SARS-CoV-2. The Omicron VOC was suspected due to S gene target failure on molecular testing. Further investigation revealed that 15 (65%) of 23 HCWs attending a social gathering on 13 December were infected with Omicron, as shown by whole-genome sequencing, with a phylogenetic tree suggesting a common source of exposure. Five of these HCWs experienced mild symptoms. A patient with multiple chronic conditions hospitalized in the same ward was also infected by one of the HCWs involved in the outbreak. Despite being booster vaccinated, this patient required ICU treatment. Ten subjects achieved negativity in 10–19 days. The outbreak in booster-vaccinated subjects confirms the high transmissibility and immune evasion of the Omicron VOC. More stringent non-pharmaceutical interventions, administration of booster doses, and genomic surveillance are crucial long-term strategies to mitigate the consequences of the spread of the Omicron VOC. [ABSTRACT FROM AUTHOR]

Differences in the demographic and clinical characteristics of patients infected with the Alpha and Delta SARS-CoV-2 variants of concern in a large region of Southern Italy were assessed. Two cohorts of positive patients were compared. The Alpha group consisted of 11,135 subjects diagnosed between 21 March and 21 April 2021, and the Delta group consisted of 499 positive subjects diagnosed between 21 July and 21 August 2021. A descriptive and statistical analysis of the demographic and clinical characteristics of the two groups was performed. The proportion of patients with mild and moderate infections was significantly higher in the Delta than in the Alpha group (p < 0.001). In fully vaccinated patients, the proportion of symptomatic individuals was significantly higher in the Delta than in the Alpha group. The Delta group showed odds ratios of 3.08 (95% CI, 2.55–3.72) for symptomatic infection and 2.66 (95% CI, 1.76–3.94) for hospitalization. Improving COVID-19 vaccination rates is a priority, since infection with the SARS-CoV-2 Delta variant has a significant impact on patient outcomes. Additional targeted prevention strategies such as social distancing, the use of masks in indoor settings irrespective of vaccination status, and the use of a sanitary passport could be crucial to contain further spread of SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

Abstract: The introduction of Haemophilus influenzae type b (Hib) conjugate vaccines has greatly reduced the incidence of invasive Hib disease. However, concern exists about the possible emergence of “strain replacement”. We report the epidemiology and characterization of isolates from invasive H. influenzae disease in Italy through 2007–2009, 10 years after Hib vaccination was introduced. Invasive H. influenzae disease cases were detected through the National Surveillance of Invasive Bacterial Disease. Seventy-eight H. influenzae strains were serotyped and tested for antimicrobial susceptibility. Genetic basis of resistance to β-lactams was investigated. The annual incidence of invasive H. influenzae infection was 0.06/100,000 in 2007, 0.08/100,000 in 2008 and 0.09/100,000 in 2009 in all age groups. A slight increase in disease incidence has been observed in adults ≥65 years since 2007. Nonencapsulated (ncHi) predominated among H. influenzae isolates from all age groups: 61.5%, 76.0%, and 75.0% for <5, 5–64 and ≥65 years, respectively. Although ncHi mainly caused bacteremia, meningitis due to ncHi increased in comparison with previous data (38.6% in 2007–2009 vs. 26.2% 1997–2002). Prevalence of encapsulated non-Hib strains grew significantly (4.1% in 1997–2002 vs.16.7% in 2007–2009; p <0.001), although they remained rare. Resistance to ampicillin mediated by β-lactamase declined, but that due to altered penicillin-binding protein 3 increased. In conclusion, routine use of Hib vaccines produced both a drastic decrease in the number of invasive H. influenzae cases and epidemiological changes in disease. Overall, pediatric H. influenzae disease has become less common whereas there has been a slight increase of disease in the elderly. A marked change in the predominant serotype from Hib to ncHi has occurred. Changes in the H. influenzae population moderately affected antibiotic resistance trends. [Copyright &y& Elsevier]