Page History

...

Relevant genetic characteristics: Plasmids and prophages have been identified in S. Typhi. For example, a resistant plasmid of 218 kb and seven prophages were detected in S. Typhi CT18. Up to 15 Salmonella pathogenicity islands (SPIs) have been detected in S. Typhi, these include SPI-1 to 7, 9, 11 to 13, and 15 to 18. Comparative genomics and phylogenetic analyses have shown that S. Typhi (i) had a monophyletic origin approx. 50,000 years ago (ii) has suffered reductive evolution (approx. 200 genes are functionally inactive), (iii) belongs to clade A, according to den Bakker et al. (2011) classification, and (iv) has 349 gene families unique to this serovar.

Animal reservoir: S. Salmonella Typhi is a human-restricted serovar.

Geographical distribution: Serovar Typhi is globally distributed; however, the prevalence of this serovar varies considerable. In developed countries (U.S., Canada, Europe), S. Typhi isolations correspond to less than 1% of all Salmonella serovars isolated from humans. In developing countries, S. Typhi isolations correspond to up to. 30% of all Salmonella isolated in some countries in Latin America and Asia Crump et al. concluded that typhoid fever incidence is highest in south-central and southeast Asia, with over 100 cases per 100,000 people annually. Medium incidence rates (10–100 cases per 100,000 per year) are found in other parts of Asia, Africa, Latin America, the Caribbean, and Oceania (excluding Australia and New Zealand). In contrast, Europe, North America, and other developed regions report low typhoid fever rates, with fewer than 10 cases per 100,000 people each year.

Human outbreaks: Multiple human outbreaks linked to serovar Typhi has been reported. Below are some examples.

Year	Location	Associated source	Number of cases
2022	Netherlands	Raw sewage	72
2010	US: multistate	Frozen mamey fruit pulp	9
2002	Nepal	Drinking water	5963
2000	US: NY	Food handler	7
1998-1999	US: FL	Imported frozen fruit	At least 16
1998	France	Chicken rice	27
1983	UK	Salad¹	32
1937	UK	Water	341
1915	US: NY	Typhoid Mary	25
1907	US: NY	Typhoid Mary	53

¹ All patients traveled The outbreak was associated with travel to Kos, Greece.

Border rejections: There have been no recent border rejections linked to this serovar.

...

¹ This recall was caused by a multistate outbreak described above. Goya Foods, Inc. and Montalvan’s Sales, Inc. issued voluntary recalls of their fruit pulp products.

Relevant links:

Page tree

Versions Compared

Old Version 22

New Version 23

Key