Laboratory-based surveillance of invasive listeriosis in Northern Italy over a fourteen-year period: epidemiological and clinical results.

INTRODUCTION: Invasive listeriosis is a rare foodborne disease with a significant impact on public health worldwide, because of the severity of its clinical manifestations and high fatality rate. In this study, we provide a snapshot of epidemiology of listeriosis in Lombardy Region, Northern Italy, reviewing enhanced surveillance data collected over fourteen years, after the implementation of a voluntary laboratory-based surveillance system for the referral of clinical isolates of Listeria monocytogenes to a regional reference laboratory, since 2005. METHODS: Invasive listeriosis cases data from 2005 to 2018 were extracted from the regional laboratory-based surveillance system database and compared with the regional mandatory notification disease system data. RESULTS: Over the fourteen-year period under study, 533 Listeria monocytogenes isolates were detected by the laboratory surveillance system, 55 of which from pregnancy-related cases. The median age of non-pregnancy-associated patients was 71 years, with 64.6% of cases observed in the elderly. Cases with underlying medical risk conditions accounted for 92.1%, and the fatality rate was 26.2%. By integrating data from the mandatory notification system and the laboratory-based surveillance system, a total of 935 cases were recorded. The collection of data through the laboratory surveillance system allowed to increase the surveillance sensitivity by 18%. CONCLUSIONS: Our results documented the growing epidemiological relevance of listeriosis through the analysis of two information sources, the regional mandatory notification system and the regional laboratory-based surveillance system. The data we obtained were consistent with the literature, except for pregnancy-related cases, which are often underdiagnosed. This study highlighted the importance of laboratory-based surveillance system, which led to a significant increase in the sensitivity of the mandatory notification system.

Estimating the real incidence of invasive listeriosis through an integrated surveillance model in use in Lombardy (Italy, 2006-2014).

The annual incidence of listeriosis in Italy is lower (0·19-0·27 per 100 000 inhabitants per year) than in Europe (0·34-0·52 per 100 000 inhabitants per year). Since the observed incidence of listeriosis may be biased downward for underdiagnosis or under-reporting, this work aims to estimate the real incidence of listeriosis during a 9-year period in the Lombardy region, Italy. Data on listeriosis cases were collected from national mandatory notification system (MAINF) and Laboratory-based Surveillance System (LabSS). The two sources were cross-matched and capture-recapture method was applied to estimate the number of undetected cases and the real incidence of invasive listeriosis. Five hundred and eighty invasive listeriosis cases were detected by the two sources between 2006 and 2014: 50·2% were identified only via MAINF, 16·7% were recorded only via LabSS, overlaps occurred in 192 cases (33·1%). The mean annual incidence detected only by MAINF was 0·56 per 100 000 inhabitants, which rose to 0·67 per 100 000 considering also the cases detected by LabSS. The capture-recapture method allowed to estimate an incidence of 0·84 per 100 000. The high incidence of listeriosis may be due to improved sensitivity of the surveillance system, but also reflect a real increase, associated with an increased population at risk.

Observational study to evaluate the impact of internet reminders for GPs on colorectal cancer screening uptake in Northern Italy in 2013.

INTRODUCTION: Colorectal cancer (CRC) is the third most common cancer worldwide and CRC-related mortality can be effectively reduced by population-based screening. Screening uptake is a key indicator of performance, susceptible of several implementation methods. Participation in ASL Milano 1 area (northern Italy) is increasing thanks to reminder invitation sent to non-responders. Here we evaluate the implementation of another strategy among those proved to be effective. METHODS: In the years 2013-2014 we conducted an observational study in patients non-responder to first invitation and subsequent mailed reminder. A list of them was sent to their own GP, who had the task to evaluate possible exclusion criteria and make a reminder, either by personal interview, telephone call or via e-mail. Intervention could be conducted either by the GP himself or by an assistant. Primary outcomes were to assess the overall efficacy of the intervention and the efficacy of its single features (type of intervention and provider), measuring the consequent uptake of CRC screening. RESULTS: Participation in CRC screening was significantly higher (33,5%) in patients who received a reminder from GP, regardless of the type, vs those who did not (19,0%, p < 0.01). No statistically significant difference was detected either by method or by provider of the intervention. DISCUSSION: The results of our study demonstrate that even a modest intervention can have a significant effect in improving compliance to screening for CRC, one of the cancers with highest incidence in developed countries, for which an effective treatment is available in case of early diagnosis.

[Investigation of potential risk factors for Salmonella enterica subsp enterica serotype Napoli: a nested case-control study in Lombardia region]. / Identificazione di potenziali fattori di rischio per i casi di infezione da Salmonella enterica subsp enterica sierotipo Napoli attraverso uno studio caso-controllo nidificato con- dotto in Regione Lombardia.

Enter-net surveillance system has detected the re-emergence of Salmonella enterica subsp enterica serotype Napoli (S. Napoli) since 2002. Preliminary data show that food vehicle could not be the only one implicated in the transmission of this serotype. A nested case-control study has been conducted using data form a prospective cohort: for each salmonellosis notification in Lombardia from May 2004 to December 2005 an ad hoc epidemiological investigation has been performed. Cases have been defined as subjects affected by salmonellosis with a positive faecal sample for Salmonella serotype Napoli and controls as subjects affected by salmonellosis with a positive faecal sample for Salmonella serotype not Napoli. Among 2185 salmonellosis notifications collected by 12 of 15 Local Health Authorities, we identified 67 cases and 867 controls. Infection due to S. Napoli were significantly more common among subjects with exposure to surface water (adjusted Odds Ratio (OR) = 3,82; 95% Confidence Interval (C.I.)=1,03-14,19), to domestic animals (adjusted OR = 3,22; 95% C.I. = 1,28-8,10) and among person who practice activities connected to surface water (adjusted OR 3,88; 95% C.I.=1,15-13,05) compared to subjects not exposed to these factors. Hyperendemia of S. Napoli could be attributable to an animal reservoir not yet identified: surface water contamination may be a direct (waterborne infection) or indirect (foodborne infection) vehicle for transmission of S. Napoli. behaviour. Regarding the relations of the neuroendocrine parameters and driving behaviour, positive correlations were observed between dopamine levels and frequency of driving violations while a negative relationship was found between adrenaline levels and frequency of driving errors. In conclusion the identification of psycho-physiological variables related to driving risky behaviour might be a useful instrument to design traffic safety programs tailored to high risk subjects.

[Emergence of Salmonella Typhimurium monophasic serovar: determinants of antimicrobial resistance in porcine and human strains]. / Emergenza di una variante monofasica di Salmonella Typhi- murium: caratteri di antibiotico-resistenza in stipiti isolati dalla filiera suinicola e da casi di infezione nell'uomo.

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a common cause of non-typhoideal salmonellosis in humans and animals; since the end of '90 a monophasic serovar defined by the antigenic formula 4,5:i:- has been emerged. This study shows occurrence of monophasic serovar in Italy (Lombardia Region) and analyses antimicrobial resistance of 147 S. Typhimurium and 45 monophasic strains. Multiple drug resistance (MDR) has been detected in 94,5% and 76,6% of 55 porcine and 137 human isolates, respectively; tetra-resistance pattern AmSSuTe is the most common among in both sources (55 out of 116 strains of MDR S. Typhimurium and 16 out of 41 strains of MDR monophasic variant). Transfer of resistance determinants has been investigated by plasmid conjugation for all the 157MDR strains: only 16 isolates (10,2%) gave positive results, and transfer has almost been partial. Data from our investigation and data reported by other studies show a wide difference in the circulating phenotypes and in polymorphism of S. Typhimurium, confirmed also by the emergence of the monophasic serovar.

Prevalence of E. coli, thermotolerant coliforms, Salmonella spp. and Vibrio spp. in ready-to-eat foods: Pemba Island, United Republic of Tanzania.

This study is aimed to evaluate the microbiological quality of ready-to-eat foods in Pemba island. A total of 300 food samples have been analysed: 66 household preparations, 115 samples of raw cow milk, and 119 fried sea-foods. The thermotolerant coliforms have been detected in 34% sea-foods, 58% household meals, and 98% milk samples; the coliforms count is 5 x 10(2), 10(3), and 3 x 10(4) cfu/g, respectively. E. coli is the species most frequently isolated: 60 on 100 strains agglutinate one of the tested polyvalent antisera. Salmonella spp. have been found exclusively in cow milk (11%); in 15% sea-foods V. alginolyticus has been isolated. The prevalence of faecal contamination is extremely high in cow milk, a critical vehicle for the transmission of pathogens, probably for a lacking thermal treatment (pasteurization). Salmonella spp., V. cholerae, and V. parahaemolyticus have not been isolated from boiled or fried foodstuffs, but in any case the cooked foods are faecally contaminated: their contamination occurs likely after preparation and before consumption. The identification of risk factors for the faecal contamination could be helpful to plan educational programmes involving food operators and may be an effective preventive measure, especially in settings where financial resources are lacking for the construction of adequate infrastructures.

[Public food service in Milan city and Hinterland: GMP application (Part 1)]. / Ristorazione pubblica: indagine campionaria in due AASSLL dell'area milanese. Nota 1: Applicazione dell'autocontrollo.

Food service establishments are recognized as a critical sector concerning foodborne diseases occurrence, that is associated to contributing factors such as the anticipated preparation of meals that are often highly handled, and long-time distributed. A survey has been planned to evaluate the application of HACCP plan, in order to select a statistically representative sample of food services (restaurant, pizza-shop, bar, ..) in two Milan area' Public Health Units (PHU). During the inspections a proper check-list has been filled up in order to give a conformity evaluation about the global situation and about three specific sections: hygiene of food-handlers, procedures control, temperatures management. The food services have been found satisfactory in 9/106 and 5/54 cases in Milan City and in hinterland, respectively; among the two areas, highly significant differences have been revealed about temperatures management (68% and 28% unsatisfactory, respectively). In Milan City restaurants provided with HACCP plan scores are significantly different from unprovided restaurants scores (global and the three sections' evaluation); in Milan hinterland differences between provided and unprovided HACCP plan restaurants regard temperature management scores only. Useful suggestions to improve the quality of surveillance activity come from complex and heterogeneous findings shown in this study.

[Public food service in Milan city and Hinterland: food-handlers training level (Part 2)]. / Ristorazione pubblica: indagine campionaria in due AASSLL dell'area milanese. Nota 2: Grado di preparazione del personale.

The prevention and control of foodborne diseases play an important role in public health and the responsibility of food-handlers is of great concern: their training on food safety is particularly required in the critical sector of public food service establishments. The food-handlers knowledge has been evaluated by a questionnaire filled up in two Public Health Units (PHU) in Milan City and Milan hinterland. Only 11.5% of food-handlers turned at to be good trained; the wrong answers are concentrated on the section titled "temperatures management" (68 and 59% in Milan City and in Milan hinterland, respectively). Only for 31.4% of food-handlers the attendance to training courses is well documented, although the knowledge level seems to be partially influenced by training activity: exclusively in Milan City food-handlers an highly significant difference has been found among "trained" and "no-trained" workers in correct answers about temperatures management (p= 0.0046). The frequency of exact answers isn't associated to the satisfaction level revealed during inspection of restaurants. Focusing the attention on the insufficient efficacy of training courses and the lacking connection between knowledge and behaviour, a critical revision of training activity quality seems to be necessary. In future some professional training activities in the field should be promoted.

[Evaluation of dairy production in the alpine regions of Valcamonica and Sondrio, and the adherence to hygienic practice guidelines]. / Valutazione igienico-sanitaria degli alpeggi della Valcamonica e della provincia di Sondrio. Applicabilità di un sistema di autocontrollo.

The Regional Veterinary Service of Lombardy (northern Italian region) developed guideline on good hygienic practices to improve the safety of milk production and transformation in the mountain pastures and to grant the European acknowledgment (EU seal). Therefore we carried out 26 inspections in Valcamonica (Province of Brescia) and 30 in the Sondrio's province (26% and 16% respectively) in mountain pastures that had required the acknowledgment. The data analysis has shown that in Valcamonica 26.9% of the mountains pastures was conform to the regulations, in Sondrio's province instead 6.6% was conform; the frequency of acceptable conformity level increases respectively to 46% and to 33%, if we also consider the mountains pastures in restructuring phase and with very low level of non conformity. Our study emphasizes the need of structural adjustments of these traditional setting and of education of workers in order to improve the food safety and operator's life quality, and also to promote the maintenance of mountain pastures in the Alpine region.

Clonal circulation of Salmonella enterica serotype Heidelberg in Italy?

Phenotypic and genetic characteristics of 21 strains of Salmonella serotype Heidelberg isolated in the years 1999-2003 from different sources in Italy were studied. Susceptibility patterns, plasmid analysis, and PFGE were used as epidemiological markers. Although non-homogeneous drug resistance patterns and plasmid profiles had been detected, PFGE patterns suggest the hypothesis of a nationwide clonal spread of this serotype associated with poultry.

Verocytotoxin-producing Escherichia coli in foodstuffs of animal origin.

While much research effort has been targeted at the verocytotoxin-producing Escherichia coli (VTEC) serotype O157:H7, it is becoming more evident that other VTEC serotypes can also be associated with human foodborne disease. An increasing number of these non-O157 serotypes have been isolated from food sources and from humans suffering from haemolytic-uraemic syndrome and diarrhoea. The aim of our work was to investigate the prevalence of VTEC O157 and non-O157 in foodstuffs of animal origin using two rapid enzymatic procedures. Various types of food samples, 352 in total, were tested: 233 with the Premier EHEC, a screening test which directly detects the presence of verocytotoxin, regardless of serotype, while 119 of these with the Vidas ECO, which is a specific screening test for E. coli O157:H7, together with the Premier EHEC. Two samples were positive for VTEC, one of serogroup O126 and the other was non-serotypable. Another sample was positive in the test specific for E. coli O157:H7, but was not confirmed by culture. This study suggests that VTEC strains are not prevalent in Italy, and that the isolation of serogroup O157 is relatively infrequent. This leads us to conclude that there is little chance of exposure to pathogen for the average consumer in Italy.

A community-based outbreak of Salmonella enterica serotype Typhimurium associated with salami consumption in Northern Italy.

An outbreak of Salmonella enterica serotype Typhimurium belonging to phage type (PT) 193 occurred in autumn 1995 and involved 83 individuals in a large area of Northern Italy (Lombardy Region). Epidemiological and microbiological investigations of strains isolated from clinical and food specimens revealed that the vehicle was a batch of salami, produced on 4 September 1995 by a local firm. The outbreak was contained when the batch was withdrawn from sale. Insufficient ripening of the salami had allowed the salmonella to survive, emphasizing the need to define criteria for the ripening process of foods such as salami.

Epidemiological analysis of strains of Salmonella enterica serotype Enteritidis from foodborne outbreaks occurring in Italy, 1980-1994.

Polymerase chain reaction (PCR-) ribotyping was performed on 243 strains of Salmonella enterica serotype Enteritidis isolated during the years 1980-1994 from 58 foodborne outbreaks occurring in different regions of Italy. The majority (37) of the outbreaks were attributed to phage type (PT) 4, followed by PT1 (seven outbreaks); the latter was identified in 1993 in Italy in epidemic strains of Enteritidis. In eight cases more than one phage type was recognised from a single event. Nine PCR-ribotypes (PCR-RTs) were detected, with a strong prevalence of PCR-RTs f7 and e5 (23 and 21 outbreaks, respectively). In two instances two distinct PCR-RTs were identified within strains from a single outbreak. All but one of the PT1 outbreaks were caused by PCR-RT f7, whereas PT4 outbreaks could be subdivided into six subsets. Clustering of isolates was consistent with data obtained from epidemiological investigations. PCR-ribotyping proved to be an effective and reliable tool for subtyping isolates of Enteritidis belonging to the most frequent phage types. Nevertheless, in terms of laboratory expertise and lack of inter-laboratory standardisation, this typing technique is best suited for reference laboratories.

[Foodborne diseases: a survey on working methods used by 6 Public Health Services in the Lombardy Region. 1. Outbreaks]. / Infezioni-tossinfezioni alimentari: indagine conoscitiva sulla metodologia di intervento in sei USSL della Regione lombardia. Nota 1: Forme epidemiche.

Since foodborne diseases, especially those caused by bacteria, have become an increasingly important public health problem, the Authors conducted a survey in order to evaluate the organization of, and the intervention carried out by, six Public Health Services in the Lombardia region, after reports of foodborne diseases outbreaks. Lack of correct methodology was detected, not to mention the usual omission of epidemic curves and attack rates. Besides, too many microbiological tests were made and it took too much time to take care of and to report the outbreaks to Regional and National Health Authorities. Forty-one outbreaks were examined: 415 cases occurred (AR: 28.7%), most of which home-made food-related. In 25 outbreaks the suspected food vehicles were eggs or fish, but only 5 of them were confirmed by laboratory tests. Salmonella enterica, either serovar Eenteritidis or group D, appeared responsible for 26 of the outbreaks [corrected].

rRNA probing of chromosomal DNA of epidemic and sporadic isolates of Salmonella enterica subsp. enterica serovar Kottbus from northern and southern Italy.

Fifty-two strains of Salmonella enterica subsp. enterica serovar Kottbus, identified at the Centres of Enterobacteriaceae of Northern and Southern Italy, were investigated by molecular genetic methods. Thirteen isolates were recovered during two food-poisoning outbreaks that occurred in May 1987 in Lombardy. The rDNA gene restriction patterns, obtained by probing endonuclease cleaved chromosomal DNA with photobiotin labeled Escherichia coli rRNA, revealed some heterogeneity among strains isolated from Southern Italy, whereas Northern Italy isolates exhibited virtually identical banding patterns.

Molecular analysis of strains of Shigella boydii isolated in northern and southern Italy.

In the years 1981-1988, Shigella boydii played a very limited role in the aetiology of diarrhoeal disease in Italy. However, between September and November, 1985, 19 isolates of serotype 2 were recovered in northern Italy from a dysentery outbreak which occurred in a geriatrics hospital in Abbiategrasso (Milan, Lombardy) and seven were identified in southern Italy during the period January-July, 1986 from apparently unrelated infection cases occurring in Brindisi (Apulia). These isolates were compared by molecular methods to seven strains of S. boydii of serotype 2 isolated since 1981 from the same geographic areas. Plasmid DNA analysis showed a large variety of patterns, whereas hybridization of chromosomal DNA with E. coli rRNA identified only two different profiles, one of which was exclusively found in all isolates from the hospital outbreak. No differences were detected among rDNA patterns of the remaining strains of S. boydii, irrespective of their geographic origin. These findings are consistent with the hypothesis that the infrequent cases of infection from S. boydii of serotype 2 which occurred during the years under study could probably be attributed to two different bacterial clones. Hybridization procedure and detection of hybrids were simplified by replacement of radioactive labelling of rRNA by the use of photobiotin.