Salmonella outbreak in German infants linked to aniseed-fennel-caraway tea
What it found
The same Salmonella bacteria found in sick babies in Germany were also found in bags of aniseed, fennel and caraway tea.
The contaminated aniseed came from Turkey.
What they found
Studies in people
Matching bacteria in babies and tea
Out of 165 samples, 36 shared an identical DNA fingerprint. These 36 came from sick babies in Germany, untreated aniseed imported from Turkey, and tea bags containing aniseed, fennel and caraway made by different companies.
One resistant sample
Almost none of the samples carried genes for antibiotic resistance. One exception was a sample from a small outbreak of six patients in Germany, which resisted five antibiotics because it had picked up extra genetic material.
Other findings
Wide variety of strains
Using 14 viruses that infect bacteria, the lab separated the 165 samples into 52 groups. A second DNA method also found 52 patterns. Together, these methods identified 94 distinct types, showing great natural variety within this Salmonella strain.
Dry foods as a source
This outbreak came from a dry plant product rather than meat or eggs. The authors note that other outbreaks of this Salmonella type have been tied to dry foods like toasted oats cereal, dried beef and spices.
What the authors conclude
- They suggest that food monitoring should be expanded to cover dried plant products, not just animal foods.
- They recommend using both DNA fingerprinting methods together to track future outbreaks of this Salmonella type quickly and reliably.
- They expect this strain of Salmonella will remain a public health concern.
How it was done
In 2002 and 2003, more babies than usual in Germany fell ill with a specific type of Salmonella called S. Agona. The researchers wanted to find out where the infections were coming from.
They tested 165 samples of S. Agona bacteria collected between 1969 and 2003 from people, animals, food and the environment across several countries. They used two lab methods to compare the DNA fingerprints of the bacteria from sick babies, imported aniseed and tea bags containing aniseed, fennel and caraway.
What it can’t tell you
- This work traced a past outbreak but cannot show how often these teas carry Salmonella today.
- Because the study looked back at collected samples, it can only link the tea to the illnesses rather than prove exactly how each baby became sick.
Who paid
- Authors work at
- Robert Koch Institute, Germany
The paper
- Title
- Molecular epidemiology of Salmonella enterica serovar Agona: characterization of a diffuse outbreak caused by aniseed-fennel-caraway infusion
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Rabsch W, Prager R, Koch J, et al (2005). Molecular epidemiology of Salmonella enterica serovar Agona: characterization of a diffuse outbreak caused by aniseed-fennel-caraway infusion. Epidemiology and infection. doi:10.1017/S0950268805004152Free full textPubMed 16181503DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error