Untitled

Abstract

This paper focuses on the history of the two systems that have been adopted in Italy for the surveillance of Salmonellosis and describes their respective characteristics. Both systems have been subsequently modified: (1) The National Laboratory-based Surveillance System (NLSS) which was created in 1967 for Enteropathogenic Bacteria and subsequently, in 1992, became part of the European computerised Laboratory-based Surveillance System of Salmonellae isolates, the SALM-NET (Salmonella network); (2) The National Infectious Disease Reporting System (NIDRS) which was set up in the 1930s, revised in 1990 and has been used, since 1994, along with the Infectious Disease Informative System (IDIS). The results obtained with the different surveillance systems are presented: (1) The number of isolates from the laboratory surveillance from 1973 to 1997 are described. Total Salmonellae isolates have a slope with an increasing trend from 4372 isolates in 1973 to 15,041 isolates in 1988 drastically dropping to 5479 isolates in 1990 and increasing again to 13,596 isolates in 1993. Attention is given particularly to the epidemiology of S. enteritidis in Italy which increased progressively since 1982 (225 isolates) to 5435 isolates in 1994. S. typhimurium showed a slightly increasing trend in the period 1973-1988 (from 1694 to 3383 isolates) then decreased for reaching again previous levels. S. typhi showed a marked reduction from 573 isolates in 1973 to 33 isolates in 1996. On the contrary, other less frequent serotypes increased. (2) The number of cases of Salmonellosis reported during 1971-1997 are also presented. Other Infections by Salmonellae increased from 12,516 cases in 1976 (renamed Non Typhoidal Salmonellosis in 1990) to more than 20,000 cases in 1992. The number of cases of Typhoid Fever and Infections by S. paratyphi are also described. Particular attention has to be paid to the parallel trends of Salmonellosis using both surveillance systems: number of isolates and number of cases, particularly comparing Other Infections by Salmonellae and total Salmonellae isolates: after the 1992-1993 peak, an initial decrease was observed.

Distribution of Salmonella enterica isolates from human cases in Italy, 1980 to 2011

“…detection bias) [27]. However, consistent with other studies [10,11,27], we observed that cases with S. Typhimurium, S. 4, [5],12:i:-, or S. Napoli infection were most likely to be children aged ≤14 years, whereas cases with S. Enteritidis, S. Derby, or S. Infantis infections were more likely to be adults aged ≥15 years. This may be due to the different serovar-specific risk factors to which individuals are exposed at varying age groups [28].…”

“…We found that S. Enteritidis has decreased dramatically in Italy and that S. Typhimurium has become once more the most reported serovar as of 2000. It is noteworthy that between 2000 and 2011, while S. Enteritidis and S. Infantis decreased, S. Typhimurium remained stable and S. 4, [5],12:i:-, S. Derby, and S. Napoli increased. This suggests that the applied control measures are not equally efficient against these serovars and that other sources of infection have probably become increasingly important (e.g.…”

“…During the whole study period, the top six reported serovars were S. Enteritidis (57,499 isolates; 25.1% of the total number of Salmonella isolates; mean isolation rate: 2.99 isolates per 100,000 population/year), S. Typhimurium (56,671; 24.7%; 2.95 per 100,000 population/year), S. Infantis (10,114; 4.4%; 0.53 per 100,000 population/year), S. Derby (8,250; 3.6%; 0.43 per 100,000 population/year), S. 4, [5],12,:i:-(2,381; 1.0%; 0.12 per 100,000 population/year) and S. Napoli (868; 0.4%; 0.04 per 100,000 population/year). The other serovars accounted cumulatively for 93,496 isolates (40.8%; 4.87 per 100,000 population/year) ( Figure 1).…”

“…The monophasic variant of S. Typhimurium, S. 4, [5],12:i:-, characterised by the antimicrobial resistance to Ampicillin, Streptomycin, Sulphonamide, and Tetracycline (pattern ASSuT) is emerging and extensively circulating in Denmark, Italy, the United Kingdom and also recently in Greece [11,23,24]. In Italy, S. 4, [5],12:i:-, showed a dramatic increase since 2003, both in humans and in animals farmed for food production, particularly pigs and bovines [25]. Also S. Napoli is an emerging serovar although it is not emerging homogenously over the whole EU, with most of the cases (87%) reported between 2000 and 2006 having occurred in Italy, France, and Switzerland.…”

“…In Italy, the laboratory-based surveillance system for human Salmonella infections has changed substantially over time to follow the evolution of the surveillance activities for infectious diseases undertaken at the national and international level [5]. The former system was created in 1967 and was based on the Reference Centres for Enterobacteriaceae (RCE) [5,6], which became part of the European Salmonella Network (SALM-NET) project in 1992 [5]. In 1997, SALM-NET was further changed into the Enteric Pathogen Network (ENTER-NET) [7].…”