Differences in the incidence and clinical outcomes of SARS-CoV-2 infection between Italian and non-Italian nationals using routine data.

OBJECTIVES: This study was to compare the incidence and clinical outcomes of SARS-CoV-2 infection between Italian and non-Italian nationals. STUDY DESIGN: We retrospectively analysed data from the COVID-19 Italian integrated surveillance system (14 September 2020 to 17 October 2021). METHODS: We used multivariable Cox proportional hazards models to estimate the hazard ratio (HR) of infection and, among cases, the HRs of death, hospitalisation and subsequent admission to intensive care unit in non-Italian nationals relative to Italian nationals. Estimates were adjusted for differences in sociodemographic characteristics and in the week and region of diagnosis. RESULTS: Of 4,111,067 notified cases, 336,265 (8.2%) were non-Italian nationals. Compared with Italian nationals, non-Italians showed a lower incidence of SARS-CoV-2 infection (HR = 0.81, 95% confidence interval [CI]: 0.80-0.81). However, once diagnosed, they were more likely to be hospitalised (HR = 1.90, 95% CI: 1.87-1.92) and then admitted to intensive care unit (HR = 1.08, 95% CI: 1.04-1.13), with differences larger in those coming from countries with a lower human development index. Compared with Italian cases, an increased rate of death was observed in non-Italian cases from low-human development index countries (HR = 1.41, 95% CI: 1.23-1.62). The HRs of SARS-CoV-2 infection and severe outcomes slightly increased after the start of the vaccination campaign. CONCLUSIONS: Underdiagnosis and delayed diagnosis in non-Italian nationals could explain their lower incidence compared with Italians and, among cases, their higher probability to present clinical conditions leading to worse outcomes. Facilitating early access to vaccination, diagnosis and treatment would improve the control of SARS-CoV-2 transmission and health outcomes in this vulnerable group.

Travel-associated Legionnaires' disease: would changing cluster definition lead to the prevention of a larger number of cases?

According to European Guidelines for Legionnaires' Disease prevention and control, travel-associated Legionnaires' disease (TALD) cases are managed differently if classified as sporadic or as part of a cluster and more stringent control measures are deployed after clusters are identified. In this study, we propose to modify the current cluster definition: 'two or more cases of Legionnaires' disease (LD) who stayed at, or visited, the same commercial accommodation site 2-10 days before onset of illness and whose onset is within the same 2-year period' with a new cluster definition, i.e. accommodation sites associated with multiple cases regardless of the time elapsed between them. TALD cases occurred in Italy and in the Balearic Islands between 2005 and 2015 were analysed applying the current European Legionnaires' Disease Surveillance Network (ELDSNet) cluster definition. In a sample of selected accommodation sites with multiple cases, a microbiological study was also conducted. Using the new definition, 63 additional sites (16.4% increase) and 225 additional linked cases (19.5% increase) were identified. Legionella pneumophila sg1 was isolated from 90.7% of the selected accommodation sites. The use of the here proposed TALD cluster definition would warrant a full investigation for each new identified case. This approach should therefore increase the number of sites that will require a risk assessment and, in the presence of an increased risk, the adoption of LD control measures to hopefully prevent additional cases.

Short-term effects of atmospheric pressure, temperature, and rainfall on notification rate of community-acquired Legionnaires' disease in four European countries.

Legionnaires' disease (LD) is caused by the inhalation of aerosols containing Legionella, a Gram-negative bacteria. Previous national- or regional-level studies have suggested an impact of climate on LD incidence. The objective of this study was to investigate the effect of temperature, rainfall, and atmospheric pressure on short-term variations in LD notification rate. EU/EEA Member States report their LD surveillance data to the European Centre for Disease Prevention and Control. Community-acquired LD cases reported by Denmark, Germany, Italy, and The Netherlands with onset date in 2007-2012 were aggregated by onset week and region of residence. Weather variables were extracted from the European Climate Assessment & Dataset project. We fitted Poisson regression models to estimate the association between meteorological variables and the weekly number of community-acquired LD cases. Temperature, rainfall and atmospheric pressure were all associated with LD risk with higher risk associated with simultaneous increase in temperature and rainfall. Temperatures >20 °C were not associated with a higher risk for LD. LD cases occurring during wintertime may be associated with sources less influenced by meteorological conditions.

Congenital rubella still a public health problem in Italy: analysis of national surveillance data from 2005 to 2013.

In accordance with the goal of the World Health Organization Regional Office for Europe, the Italian national measles and rubella elimination plan aims to reduce the incidence of congenital rubella cases to less than one case per 100,000 live births by the end of 2015. We report national surveillance data for congenital rubella and rubella in pregnancy from 2005 to 2013. A total of 75 congenital rubella infections were reported; the national annual mean incidence was 1.5/100,000 live births, including probable and confirmed cases according to European Union case definition. Two peaks occurred in 2008 and 2012 (5.0 and 3.6/100,000 respectively). Overall, 160 rubella infections in pregnancy were reported; 69/148 women were multiparous and 38/126 had had a rubella antibody test before pregnancy. Among reported cases, there were 62 infected newborns, 31 voluntary abortions, one stillbirth and one spontaneous abortion. A total of 24 newborns were unclassified and 14 women were lost to follow-up, so underestimation is likely. To improve follow-up of cases, systematic procedures for monitoring infected mothers and children were introduced in 2013. To prevent congenital rubella, antibody screening before pregnancy and vaccination of susceptible women, including post-partum and post-abortum vaccination, should be promoted. Population coverage of two doses of measles-mumps-rubella vaccination of ≥ 95% should be maintained and knowledge of health professionals improved.

An unusually long-lasting outbreak of community-acquired Legionnaires' disease, 2005-2008, Italy.

An unusually long-lasting community-acquired outbreak of Legionnaires' disease (LD) occurred in the inhabitants of a town in northern Italy from 2005 to 2008. Overall, 43 cases were diagnosed including five deaths. Hundreds of water samples were collected for Legionella isolation but only two clinical samples were obtained. Clinical strains were ST23 as were environmental isolates detected in most Legionella-positive patients' homes and those from a public fountain. Although no Legionella was found in the municipal water mains, a continuous chlorination was applied in 2008. This action resulted in a halving of cases, although incidence remained tenfold higher than the Italian average incidence until the end of 2013, when it dropped to the expected rate. Retrospective analyses of prevalent wind direction suggested that a hidden cooling tower could have been the main cause of this uncommon outbreak, highlighting the importance of implementation of cooling tower registers in supporting LD investigations.

Legionnaires' disease in Italy: results of the epidemiological surveillance from 2000 to 2011.

According to the Italian Surveillance System for Legionnaires' disease (LD), physicians must fill in a form for every case and send it through the Local Health Units to the National Institute of Health (Istituto Superiore di Sanità, ISS). Forms reported in the period from 2000 to 2011 were analysed and discussed. A total of 9,803 cases of LD were reported to ISS during the study period. The median age of cases was 63 years, with a ratio male/female of 2.6 and a case fatality rate of 11.8%. The number of cases has been steadily increasing from 192 cases in 2000 to 1,235 in 2010 and 1,008 cases in 2011. The reported cases showed a geographical gradient, with the highest number notified in the north and the lowest in the south. The majority of cases (73.0%) were community-acquired, followed by travel-associated (13.5%) and healthcare-associated cases (9.3%), cases acquired in long-term care facilities (2.1%), and other types of exposure (2.1%). Even though the increasing trend of LD in Italy indicates an improvement in the ability to detect and report cases, the geographical gradient highlights the existence of low reporting areas where the epidemiological surveillance of LD should be further strengthened.

Campylobacter seroconversion rates in selected countries in the European Union.

As a major foodborne pathogen, Campylobacter is frequently isolated from food sources of animal origin. In contrast, human Campylobacter illness is relatively rare, but has a considerable health burden due to acute enteric illness as well as severe sequelae. To study silent transmission, serum antibodies can be used as biomarkers to estimate seroconversion rates, as a proxy for infection pressure. This novel approach to serology shows that infections are much more common than disease, possibly because most infections remain asymptomatic. This study used antibody titres measured in serum samples collected from healthy subjects selected randomly in the general population from several countries in the European Union (EU). Estimates of seroconversion rates to Campylobacter were calculated for seven countries: Romania, Poland, Italy, France, Finland, Denmark and The Netherlands. Results indicate high infection pressures in all these countries, slightly increasing in Eastern EU countries. Of these countries, the differences in rates of notified illnesses are much greater, with low numbers in France and Poland, possibly indicating lower probability of detection due to differences in the notification systems, but in the latter case it cannot be excluded that more frequent exposure confers better protection due to acquired immunity.

Immunisation registers in Italy: a patchwork of computerisation.

In Italy, the 21 regional health authorities are in charge of organising and implementing their own vaccination strategy, based on the national vaccine plan. Immunisation coverage varies greatly among the regions for certain vaccines. Efforts to increase childhood immunisation coverage have included initiatives to develop and implement computerised immunisation registers in as many regions as possible. We undertook a cross-sectional online survey in July 2011 to provide an updated picture of the use, heterogeneity and main functions of different computerised immunisation registers used in the Italian regions and to understand the flow of information from local health units to the regional authorities and to the Ministry of Health. Comparing current data with those obtained in 2007, a substantial improvement is evident. A total of 15 regions are fully computerised (previously nine), with 83% of local health units equipped with a computerised register (previously 70%). Eight of the 15 fully computerised regions use the same software, simplifying data sharing. Only four regions are able to obtain data in real time from local health units. Despite the progress made, the capacity to monitor vaccination coverage and to exchange data appears still limited.

Syndromic surveillance of epidemic-prone diseases in response to an influx of migrants from North Africa to Italy, May to October 2011.

Following civil unrest in North Africa early in 2011, there was a large influx of migrants in Italy. A syndromic surveillance system was set up in April to monitor the health of this migrant population and respond rapidly to any health emergency. In the first six months, the system produced 67 alerts across all syndromes monitored and four alarms. There were no health emergencies, however, indicating that this migration flow was not associated with an increased risk of communicable disease transmission in Italy.

Measles in Italy, July 2009 to September 2010.

Outbreaks of measles continue to occur in Italy, as in other European countries. We present here details of cases reported through the Italian enhanced measles surveillance system from July 2009 to September 2010. In total, 2,151 cases were reported, 42% (n=895) of which were laboratory confirmed. The median age of cases was 18 years and 1,709 of 1,856 cases (92%) were unvaccinated. Many cases with complications were reported (n=305), including three with encephalitis. A total of 652 of 1,822 cases (36%) were hospitalised. Molecular characterisation revealed circulation of a limited number of measles virus genotypes (D4, D8 and B3), which is consistent with the current epidemiology of the disease in Italy. A national measles elimination plan was approved in 2003 with the aim of interrupting endemic measles transmission by 2007. Since elimination was not achieved, the target date was recently moved to 2015. The emphasis of the new elimination plan, approved in March 2011, is on strengthening surveillance, implementing evidence based-interventions to increase measles-mumps-rubella vaccine uptake in children, adolescents and young adults, and implementing communication activities related to the vaccine. The strategies proposed by the plan should be implemented fully and appropriately by all regions in order to meet the elimination goal by 2015.

Response to the 2009 influenza A(H1N1) pandemic in Italy.

In Italy, the arrival of the 2009 pandemic influenza A(H1N1) virus triggered an integrated response that was mainly based on the 2006 National Pandemic Preparedness and Response Plan. In this article we analyse the main activities implemented for epidemiological surveillance, containment and mitigation of the pandemic influenza and the lesson learned from this experience. Overall, from week 31 (27 July ­ 2 August) of 2009 to week 17 (26 April ­ 2 May) of 2010, we estimate that there were approximately 5,600,000 cases of influenza-like illness (ILI) who received medical attention (with almost 2,000 laboratory-confirmed cases of pandemic influenza from May to October 2009). A total of 1,106 confirmed cases were admitted to hospital for serious conditions, of whom 532 were admitted to intensive care units. There were 260 reported deaths due to pandemic influenza. Approximately 870,000 first doses of the pandemic vaccine were administered, representing a vaccine coverage of 4% of the target population. One of the possible reasons for the low uptake of the pandemic vaccine in the target population could be the communication strategy adopted, for both the general population and healthcare workers, which turned out to be a major challenge. Active involvement of all health professionals (at local, regional and national level) in influenza pandemic preparedness and response should be encouraged in the future.

Characteristics of reoffending accommodation sites in Europe with clusters of Legionnaires disease, 2003-2007.

Between 2003 and 2007, 21% (n=100/477) of accommodation sites linked to clusters of two or more cases of Legionnaires' disease that were investigated by the European Surveillance Scheme for Travel-Associated Legionnaires' Disease (EWGLINET) went on to be associated with at least one further case, despite reporting that satisfactory control measures had been implemented at the time the cluster was first detected. This paper examines these sites (termed reoffenders) in order to determine whether they share any characteristics that may have contributed to the reoffence. All investigations conducted at cluster sites between 2003 and 2007 were included in the analysis, giving a total of 615 investigations conducted at 477 sites. Every country that investigated more than three cluster sites had to deal with at least one reoffence, and one site reoffended five times. The cases involved in the cluster that stayed elsewhere during their incubation periods could be used to help assess the probability of exposure, and therefore the risk, posed by particular cluster sites. A more extensive investigation and control regime may be needed in some instances to better control the risk of Legionnaires' disease at an accommodation site.

The epidemiology of mumps in Italy.

In Italy, although vaccination has been recommended for a number of years, vaccination coverage for mumps is still sub-optimal. The objective of the present study was to evaluate the seroprevalence of mumps antibodies in the Italian population, stratified by age, gender and geographical area. The proportion of individuals positive for mumps antibodies remained stable in the age classes 0-11 months and 1 year (25.4% and 30.8%, respectively) and showed a continuous increase after the second year of life. The percentage of susceptible individuals was higher than 20% in persons 2-14 years of age and exceeded 10% in persons 15-39 years of age. No statistically significant differences were observed by gender or geographical area. Comparison between these results and the data obtained from a 1996 survey showed a statistically significant increase in seroprevalence in the age class 2-4 years. No changes were observed in the other age-groups. The results of this study confirm that the efforts made in recent years to improve vaccination coverage within the second year of life should be strengthened.

Clusters of travel-associated Legionnaires disease in Italy, Spain and France, July 2002 - June 2006.

For several years, over 50% of the cases of travel-associated Legionnaires' disease (TALD) reported to the European Working Group for Legionella Infections (EWGLINET) have been among travellers to France, Italy, and Spain. We describe clusters of TALD cases reported in these countries during a four-year period. We analysed data from EWGLINET and from the individual countries. In all three countries, upon notification of a cluster, local health authorities are alerted by the national collaborator and immediately begin an environmental investigation at the accommodation site, which includes risk assessments and analysis of water samples. From July 1, 2002 to June 30, 2006, 2,101 accommodation sites were associated with TALD cases and reported by EWGLINET to Italian, Spanish and French collaborators. Of these, 252 sites (12%) were associated with clusters: 13.8% (96/697) in Italy, 13.2% (81/615) in Spain and 9.5% (75/789) in France. Overall, 641 cases were reported. Hotels, camping sites and ships and other sites represented respectively 83%, 10% and 7% of the total accommodation sites, with similar proportions in the three countries. In 99% of the sites, samples were collected; 62% of them were found to be positive for Legionella. The findings of this study highlight that disinfection and long-term preventive measures were correctly implemented by the large majority of sites. However, additional efforts must be made to further reduce the percentage of re-offending sites so as to reduce the number of accommodations that are contaminated by Legionella.

The comparative sero-epidemiology of varicella zoster virus in 11 countries in the European region.

The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of varicella zoster virus (VZV) in 11 participant countries. In each country, serum banks were collected between 1996 and 2003 and tested for VZV antibodies. Assay results were standardised so that international comparisons could be made. Age-specific forces of infection were calculated for three age groups (<5, 5-9 and >or=10 years of age) and used to estimate the base reproduction number (R(0)) and the herd immunity threshold (H). Most VZV infection occurred in childhood, but there was a wide variation in transmissibility, with R(0) ranging from 16.9 in the Netherlands to 3.3 in Italy. Herd immunity thresholds varied from 70% in Italy to 94% in the Netherlands. There are substantial differences in VZV sero-epidemiology within the European region, which will need to be taken into account in designing national policies regarding VZV vaccination.

[Rubella epidemiology in Italy in years 1998-2004]. / Epidemiologia della rosolia in Italia negli anni 1998-2004.

In November 2003 the National Plan for the elimination of measles and congenital rubella was approved, with the aim of reducing and maintaining the incidence of congenital rubella syndrome (CRS) at less than 1 case per 100,000 live births by 2007. In order to describe the epidemiology of rubella in Italy, we conducted a serosurvey and evaluated incidence and vaccination coverage data available for the period 1998-2004. In the years considered, national mean coverage of measles-mumps-rubella vaccination within the second year of life, even though still below the 95% threshold, has progressively increased reaching 87%. In addition, previously existing differences in coverage among regions have diminished. In the same period the incidence of rubella has decreased, with a historic minimum of 461 cases notified in 2004. The cyclic pattern typical of rubella persists, but with a prolongation of the interepidemic period and an increased mean age of acquisition of the infection. Although the proportion of immune individuals has increased, the percentage of women of childbearing age susceptible to rubella remains high (11% in the 15-19 year age group and 8% in the 20-39 year age group) and CRS cases continue to occur. Despite the clear results achieved through the implementation of vaccination strategies in children within the second year of life, a continued strong public health commitment is required to increase the proportion of vaccinated individuals and absolute priority must be given to immunising women of childbearing age.

[Availability of laboratory tools for microbiological diagnosis of lower respiratory tract infections in Italian hospitals]. / Disponibilità di tecniche di laboratorio per la diagnosi eziologica delle infezioni delle basse vie respiratorie negli ospedali italiani.

To assess the availability of laboratory tools for microbiological diagnosis of lower respiratory tract infection, a survey was conducted on a sample of Italian hospital laboratories during the period April-July 2005. Overall, 261 hospitals, one third of the total Italian hospitals, were randomly selected. All these laboratories were sent a standardized questionnaire collecting information on diagnostic tools available for testing a list of bacterial, viral and fungal organisms responsible for lower respiratory tract infections. Forty eight percent of the sample completed and returned the questionnaire. A part from few pathogens such as Enterobacteria, Enterococcus Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Herpes simplex e Candida spp, for which no differences in diagnostic capacity among hospitals was found, for all the other pathogens considered, significant differences among geographical areas were found.

Rubella seroprofile of the Italian population: an 8-year comparison.

The objective of this study is to evaluate how increasing MMR infant vaccination coverage in recent years has modified the epidemiology of rubella in Italy. A cross-sectional population-based seroprevalence study of rubella antibodies was conducted on 3094 sera, in 2004, and results were compared with data obtained by the same method in 1996. The overall proportion of rubella-seropositive individuals was found to be significantly higher in 2004 with respect to 1996 (84.6% vs. 77.4%). However, an increase in seropositivity was observed only in the 1-19 years age groups. Recent increases in childhood MMR vaccination coverage, therefore, have not had an impact on seroprevalence in women of childbearing age, over 5% of whom remain susceptible to rubella. Preconception screening and postpartum vaccination of susceptible women are fundamental if the WHO target of less than one case of congenital rubella syndrome per 100,000 live births is to be attained.

Capture-recapture estimation of underreporting of legionellosis cases to the National Legionellosis Register: Italy 2002.

The objective of this study was to evaluate the degree of underreporting to the Italian National Legionellosis Register (NLR). For the year 2002, all cases of Legionellosis notified to the NLR were compared with cases recorded in the hospital discharge record (HDR) database. The number of unreported cases and the total number of cases in the population were estimated using the capture-recapture method with two independent data sources. Seventeen out of 21 Italian regions participated in the study. Overall, underreporting was estimated to be 21.4% and was found to be significantly greater in the Centre-South (28.2%) than in the North (20.0%). However, even after taking into account the higher degree of underreporting, a significantly lower incidence of the disease is registered in central-southern Italy. The hypothesis, which needs to be verified, is that, in addition to underreporting, under-diagnosis of legionellosis is more widespread in this geographical area.