Genomic surveillance of carbapenem-resistant Klebsiella pneumoniae reveals a prolonged outbreak of extensively drug-resistant ST147 NDM-1 during the COVID-19 pandemic in the Apulia region (Southern Italy).

OBJECTIVES: The recent worldwide spread of New Delhi metallo-beta-lactamase-producing Klebsiella pneumoniae (NDM-KP) in health-care settings remains a concern. The aim of the study was to describe an outbreak of extensively drug-resistant ST147 NDM-1-KP in the Apulia region of Southern Italy that occurred between 2020 and 2022 through genomic surveillance of carbapenem-resistant Enterobacterales. METHODS: A total of 459 carbapenem-resistant KP isolates collected from patients hospitalised with bloodstream infections were tested using a commercial multiplex real-time polymerase chain reaction to identify carbapenemase genes. A subset of 27 isolates was subjected to whole-genome sequencing. Core-genome multilocus sequence typing was performed by analysing a panel of 4884 genes. RESULTS: Molecular testing revealed that 104 (22.6%) isolates carried the carbapenemase NDM gene. Phylogenetic analysis of the 27 isolates subjected to whole-genome sequencing revealed high genetic relatedness among strains. All isolates were resistant to all first-line antibiotics. Virulome analysis identified the ybt locus, the two well-recognised virulence factors iucABCDiutA and rmpA, and the genes encoding the type 3 pilus virulence factor. Plasmids IncFIB(pkPHS1), IncFIB(pNDM-Mar), IncFIB(pQil), IncHI1B(pNDM-MAR), IncR, and Col(pHAD28) were identified in all isolates. Moreover, further analysis identified the IncFIB-type plasmid carrying the NDM-1 genes. CONCLUSION: The increasing circulation of extensively drug-resistant NDM-1 ST147 KP strains in Southern Italy in recent years is worrisome, because these clones pose a real risk, particularly in hospital settings. Genomic surveillance is a crucial tool for early identification of emerging threats such as the spread of high-risk pathogens. Rapid infection control measures and antimicrobial stewardship are key to preventing further spread of hypervirulent KP strains.

Echovirus 11 lineage I and other enteroviruses in hospitalized children with acute respiratory infection in Southern Italy, 2022- 2023.

OBJECTIVES: A new variant of echovirus 11 (E11) infection is a major health concern in neonates. Here, we describe the clinical and virological characteristics of enterovirus (EV) infections in children hospitalized with acute respiratory infection in Southern Italy. METHODS: Between July 2022 and August 2023, 173 EV infections were identified. Demographic and clinical characteristics, comorbidities, and coinfections were analyzed. Genotypes were identified by sequencing of VP1. Whole-genome sequencing of five E11 strains was performed. RESULTS: Case numbers peaked in July 2022, November-December 2022, and June-July 2023. Coxsackievirus A2 was identified in 36.7%, coxsackievirus B5 in 13.8%, echovirus E11 in 9.2%, and EV-D68 in 6.4% of cases. No child had critical symptoms or a severe infection. The only neonate infected by E11 recovered fully after 5 days in hospital. Phylogenetic analysis revealed that four E11 strains were closely related to divergent lineage I E11 strains identified in France and Italy. CONCLUSIONS: The new variant of E11 was identified in children in Southern Italy. Although the cases were mild, the data suggest that transmission routes and host factors are likely to be main drivers for the development of potentially severe diseases. Systematic epidemiological/molecular surveillance will help us better understand the clinical impact of EV infections and develop preventive strategies.

Abrupt Increase in Detection of Locally Acquired West-Nile-Virus-Lineage-2-Mediated Neuroinvasive Disease in a Previously Non-Endemic Area of Southern Italy (2023).

West Nile virus (WNV) is a public health concern in Europe. Rising temperatures and the migration of potential vectors promote the spread of viruses to previously unaffected areas. In 2023, the Apulia region of Southern Italy experienced an unexpected increase in West Nile neuroinvasive disease (WNND); no such cases had been reported in the previous 10 years. Overall, eight autochthonous cases of WNV infection were identified between July and October 2023, six of which were WNND. All cases were male (median age, 73 years). Two of the cases were blood donors. All WNND cases were hospitalized and all recovered within a few weeks. Surveillance data showed that, in the Apulia region, WNV Lineage 2 was detected in humans, mosquitoes, and horses. Based on the number of WNND cases reported, we can assume that a high number of infections occurred during the summer period. Changes in the climate in the region over recent years could be considered among the main drivers of the rapid increase in WNV infections. Therefore, integrated surveillance should be strengthened to avoid the potential massive spread of WNV in Southern Italy. Moreover, the implementation of whole-genome sequencing of WNV strains, as well as seroepidemiological studies in the area, will facilitate a better understanding of circulation dynamics.

Characteristics of the First 284 Patients Infected with the SARS-CoV-2 Omicron BA.2 Subvariant at a Single Center in the Apulia Region of Italy, January-March 2022.

Since its initial detection, the SARS-CoV-2 Omicron sublineage BA.2 has been spreading rapidly worldwide. The aims of this study were to describe the first 284 patients infected with the Omicron BA.2 variant of concern (VOC) in the Apulia region of southern Italy and to assess the differences in the demographic and clinical characteristics of patients infected with the SARS-CoV-2 BA.1 and BA.2 variants. The demographic characteristics of patients, as well as information about symptoms, vaccinations and hospitalizations for COVID-19, were collected. A subset of samples from patients infected with the BA.2 variant was subjected to whole-genome sequencing. The characteristics of the first 284 patients infected with Omicron BA.2 and the first 175 patients infected with Omicron BA.1 were compared. The proportion of patients infected with the BA.2 variant rapidly increased, from 0.5% during the third week of 2022 to 29.6% during the tenth week of 2022. Ten isolates (out of 34 BA.2 isolates) contain the substitutional mutation, H78K in ORF3a, and four isolates include two mutations, A2909V in ORF1a and L140F in ORDF3a. Compared with patients infected with BA.1, those infected with BA.2 were more likely to be symptomatic and booster-vaccinated, and showed a shorter time from the last dose of vaccine to infection. The high transmissibility and immune-evasive properties of Omicron BA.2, which will become the leading SARS-CoV-2 VOC, suggest that short-term public health measures should not be discontinued in Italy.

What's Next for Flu? Out-of-Season Circulation of Influenza Viruses in Southern Italy, August 2022.

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.

Monkeypox Virus Infections in Southern Italy: Is There a Risk for Community Spread?

The ongoing outbreak of the Monkeypox virus (MPXV) is characterized by sustained human-to-human transmission, particularly among men who have sex with men (MSM). The aim of the study was to describe the characteristics of the MPXV infection identified in Southern Italy. Clinical samples for each suspected case identified from 1 June to 1 August 2022 were tested for MPXV, and whole-genome sequencing (WGS) was performed on two strains. Ten cases were identified: eight were young adult males, including six MSMs, and two were female. Nine subjects reported recent sexual exposure. One female subject without sexual exposure only reported attendance at a social gathering. Overall, 7 of 10 skin lesion samples had a high viral load of MPXV DNA, and 6/9 whole blood samples and 6/8 nasopharyngeal swab samples also tested positive. The analyzed sequences belonged to Clade 3, lineage B.1, and B.1.5, respectively. Despite this recent multinational outbreak of MPXV cases having revealed a high proportion of cases occurring among MSM, the identification of cases among heterosexual subjects and in a female subject without sexual risk factors should raise awareness among clinicians about the possible spread of MPXV in the general population.

Symptomatic SARS-CoV-2 Reinfection in a Healthy Healthcare Worker in Italy Confirmed by Whole-Genome Sequencing.

This study describes a case of SARS-CoV-2 reinfection confirmed by whole-genome sequencing in a healthy physician who had been working in a COVID-19 hospital in Italy since the beginning of the pandemic. Nasopharyngeal swabs were obtained from the patient at each presentation as part of routine surveillance. Nucleic acid amplification testing was performed on the two samples to confirm SARS-CoV-2 infection, and serological tests were used to detect SARS-CoV-2 IgG antibodies. Comparative genome analysis with whole-genome sequencing was performed on nasopharyngeal swabs collected during the two episodes of COVID-19. The first COVID-19 episode was in March 2020, and the second was in January 2021. Both SARS-CoV-2 infections presented with mild symptoms, and seroconversion for SARS-CoV-2 IgG was documented. Genomic analysis showed that the viral genome from the first infection belonged to the lineage B.1.1.74, while that from the second infection to the lineage B.1.177. Epidemiological, clinical, serological, and genomic analyses confirmed that the second episode of SARS-CoV-2 infection in the healthcare worker met the qualifications for "best evidence" for reinfection. Further studies are urgently needed to assess the frequency of such a worrisome occurrence, particularly in the light of the recent diffusion of SARS-CoV-2 variants of concern.

An Autochthonous Outbreak of the SARS-CoV-2 P.1 Variant of Concern in Southern Italy, April 2021.

The SARS-CoV-2 P.1 variant of concern (VOC) was first identified in Brazil and is now spreading in European countries. It is characterized by the E484K mutation in the receptor-binding domain, which could contribute to the evasion from neutralizing antibodies. In Italy, this variant was first identified in January 2021. Here, we report an autochthonous outbreak of SARS-CoV-2 P.1 variant infections in southern Italy in subjects who had not travelled to endemic areas or outside the Apulia region. The outbreak involved seven subjects, three of whom had received a COVID-19 vaccine (one had received two doses and two had received one dose). Four patients had a mild clinical presentation. Laboratory investigations of nasopharyngeal swabs revealed that all strains were S-gene target failure-negative and molecular tests revealed they were the P.1 variant. Whole-genome sequencing confirmed that five subjects were infected with closely related strains classified as the P.1 lineage. The circulation of VOCs highlights the importance of strictly monitoring the spread of SARS-CoV-2 variants through genomic surveillance and of investigating local outbreaks. Furthermore, public health measures including social distancing, screening, and quarantine for travelers are key tools to slow down the viral transmission and to contain and mitigate the impact of VOC diffusion, and rapid scaling-up of vaccination is crucial to avoid a possible new epidemic wave.

The Challenge of Using an Antigen Test as a Screening Tool for SARS-CoV-2 Infection in an Emergency Department: Experience of a Tertiary Care Hospital in Southern Italy.

BACKGROUND: In emergency hospital settings, rapid diagnosis and isolation of SARS-CoV-2 patients are required. The aim of the study was to evaluate the performance of an antigen chemiluminescence enzymatic immunoassay (CLEIA) and compare it with that of Real-time Reverse transcription-Polymerase Chain Reaction (RT-qPCR), the gold standard assay, to assess its suitability as a rapid diagnostic method for managing patients in the emergency department (ED). METHODS: Consecutive patients with no previous history of SARS-CoV-2 infection attending the ED of the Policlinico Hospital of Bari between 23rd October and 4th November 2020 were enrolled. Clinical and demographic data were collected for all patients. Nasopharyngeal swabs collected on admission were subjected both to molecular (RT-qPCR) and antigen (CLEIA) tests for SARS-CoV-2. The performance of the CLEIA antigen test was analyzed using R Studio software and Microsoft Excel. Receiver operating characteristics were also performed. RESULTS: A total of 911 patients were enrolled, of whom 469 (51.5%) were male. Of the whole cohort, 23.7% tested positive for SARS-CoV-2 by RT-qPCR and 24.5% by CLEIA. The overall concordance rate was 96.8%. The sensitivity, specificity, positive predictive value, and negative predictive value of the antigen test were 94.9% (95% CI, 91.9-97.0), 97.4% (95% CI, 96.5-98.1), 91.9% (95% CI, 89.0-94.0), and 98.4% (95% CI, 97.4-99.1), respectively. The area under the curve (AUC) was 0.99. The kappa coefficient was 0.91. The overall positive and negative likelihood ratios were 37 (95% CI 23-58) and 0.05 (95% CI, 0.03-0.09), respectively. CONCLUSIONS: Data analysis demonstrated that the antigen test showed very good accuracy for discriminating SARS-CoV-2-infected patients from negative participants. The CLEIA is suitable for rapid clinical diagnosis of patients in hospital settings, particularly in EDs with a high prevalence of symptomatic patients and where a rapid turnaround time is critical. Timely and accurate testing for SARS-CoV-2 plays a crucial role in limiting the spread of the virus.

Epidemiology of Shiga Toxin-Producing Escherichia coli Infections in Southern Italy after Implementation of Symptom-Based Surveillance of Bloody Diarrhea in the Pediatric Population.

Shiga toxin-producing Escherichia coli (STEC) infections result in a significant public health impact because of the severity of the disease that, in young children especially, can lead to hemolytic-uremic syndrome (HUS). A rise in the number of HUS cases was observed in the Apulia region of Italy from 2013 to 2017, and so, in 2018, a symptom-based surveillance system for children with bloody diarrhea (BD) was initiated in order to detect and manage STEC infections. The objective of the study was to describe the epidemiology of STEC infections in children from June 2018 to August 2019. Children <15 years old with BD were hospitalized and tested for STEC. Real-time PCR for virulence genes (stx1, stx2, eae) and serogroup identification tests were performed on stool samples/rectal swabs of cases. STEC infection was detected in 87 (10.6%) BD cases. The median age of STEC cases was 2.7 years, and 60 (68.9%) were <4. Of these 87 cases, 12 (13.8%) came from households with diarrhea. The reporting rate was 14.2/100,000, with the highest incidence in cases from the province of Bari (24.2/100,000). Serogroups O26 and O111 were both detected in 22/87 (25.3%) cases. Co-infections occurred in 12.6% of cases (11/87). Twenty-nine STEC were positive for stx1, stx2, and eae. Five cases (5.7%) caused by O26 (n = 2), O111 (n = 2), and O45 (n = 1) developed into HUS. A risk-oriented approach based on the testing of children with BD during the summer may represent a potentially beneficial option to improve the sensitivity of STEC surveillance, not only in Italy but also in the context of Europe as a whole.

High Public-Health Impact in an Influenza-B-Mismatch Season in Southern Italy, 2017-2018.

BACKGROUND: Yearly influenza epidemics have considerable effects on public health worldwide. The 2017-2018 influenza season in Italy was of greater severity than previous seasons. The aim of this study was to describe the 2017-2018 influenza season in Southern Italy and the molecular characteristics of the circulating viral strains. METHODS: The incidence of influenza-like illness (ILI) was analysed. Nasopharyngeal swabs collected from patients with ILI from week 46/2017 to week 17/2018 were tested to identify influenza A viruses (IAV) and influenza B viruses (IBV). Sequencing and phylogenetic analysis of haemagglutinin genes were also performed on 73 positive samples (35 IBV, 36 IAV H1, and 2 IAV H3 strains). RESULTS: During the 2017-2018 season, the peak incidence was 14.32 cases per 1,000 inhabitants. IBV strains were identified in 71.0% of cases. The 35 characterised IBV strains belonged to Yamagata lineage clade 3, the 36 A/H1N1pdm09 strains clustered with the genetic subgroup 6B.1, and the 2 A/H3N2 strains clustered with the genetic subgroup 3C.2a. Intensive-care unit (ICU) admission was required in 50 cases of acute respiratory distress syndrome (ARDS). Among the >64-year age group, 18 out of 26 ICU-ARDS cases (69.2%) were caused by IBV, and 14 of these (77.8%) were B/Yamagata lineage. CONCLUSIONS: The 2017-2018 influenza season was one of the most severe in a decade in Southern Italy. IBV mismatch between the trivalent vaccine and the circulating strains occurred. The high number of ICU-ARDS cases caused by B/Yamagata strains in the >64-year age group suggests that further data on the effectiveness of the available influenza vaccines are needed to determine the best way to protect the elderly against both IBV lineages.