Salmonella Napoli

Background: Salmonella enterica subsp. enterica serovar Napoli (antigenic formula 1,9,12:l,z₁₃:e,n,x) is a serovar of the O:9 (D₁) serogroup. This is a rare serovar, in the US only 19 cases were reported from 1999-2009. In other regions of the world S. Napoli is also rare, except for France, Italy, and Switzerland were it appears to have increased considerably. Recently, it was reported in rucola and in wild birds from Italy.

Animal reservoir: poultry and wild birds have been reported as animal sources of this serovar.

Geographical distribution: Serovar Napoli appears to be distributed in Europe, specifically in France, Italy, and Switzerland.

Phylogenetic Information: Serovar Napoli has the typhoid-associated genes hlyE and taiA (SPI-18), cdtB, pltA, and pltB (CdtB-Islet), as well as the GICT18/1 islet.

Symtpoms: Although it is a nontyphodial Salmonella strain some if its symptoms, including a prolonged incubation period (7–14 days), high fever, bacteremia, and elevated rates of hospitalizations, are similar to those caused by typhoidal Salmonella.

Human Outbreaks:

Year	Location	Associated source	Number of cases
1982	England	Chocolate bars	245
2014	Milan, Italy	Ham	47

Border Rejections:

Year	Location	Associated Source	Number of Cases
2022	Finland	Fresh thyme from Italy, packaged in the Netherlands	NA

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Salmonella Napoli