The Food and Drug Administration is expected to issue soon an analysis of the extent and causes of Salmonella contamination in spices with the aim of mitigating risk to human health, according to a recent article in The New York Times.
“Salmonella is a widespread problem with respect to imported spices,” said Michael Taylor, the F.D.A.’s deputy commissioner for food. “We have decided that spices are one of the significant issues we need to be addressing now.”
In its third Reportable Food Registry, which chronicled reports of contaminated foods posing possible health risks entered in the registry from Sept. 8, 2011, through Sept. 7, 2012, the F.D.A. indicated a report on Salmonella in spices would be forthcoming. The agency said, “F.D.A. is finalizing a risk profile to describe the nature and extent of public health risk posed by consumption of spices by identifying the most commonly occurring microbial and filth hazards in spices. The risk profile will also describe and evaluate current mitigation and control options, identify potential additional mitigation and control options and identify research needs and data gaps.”
A study conducted by F.D.A. researchers that analyzed samples from spice shipments seeking entry to the United States in the fiscal years 2007 through 2009 will inform the agency’s efforts to reduce the risk of Salmonella disease outbreaks that may be associated with spice imports. The results of the study were summarized in an article, “Prevalence, serotype, diversity, and antimicrobial resistance of Salmonella in imported shipments of spice offered for entry to the United States,” which was written by F.D.A. researchers and published in October by the journal Food Microbiology.
In the article, the F.D.A. researchers noted that between 2007 and 2010, three large salmonellosis outbreaks in the United States were attributed to the consumption of contaminated spices/seasonings.
They also noted in its first two years of reporting, “spices and seasonings” led nearly all human food categories in the total number of Reportable Food Registry primary entries (ranked second in years one and two of the registry) and the number of primary entries associated specifically with Salmonella (ranked first in year one and second in year two).
Specifically, spices and seasonings accounted for 16 (19%) of 86 primary entries in the R.F.R. for Salmonella in year one, 23 (27%) of primary entries for Salmonella in year two, and 5 (8%) of 63 primary entries for Salmonella in year three.
Turning to their research, the F.D.A. scientists said, “Spice shipments offered for entry to the United States had an overall shipment prevalence for Salmonella of 0.066 (nearly 7%) during the fiscal years 2007-2009. This value is approximately twice the value determined for all other F.D.A.-regulated food shipments offered for import into the United States (including shipments of fresh produce and ready-to-eat foods) sampled during the same time period.”
The researchers said the larger prevalence of Salmonella in imported shipments of spices as compared with other F.D.A.-regulated foods was surprising “because the lower water activity of spices does not support Salmonella growth, whereas the high water activity of many other F.D.A.-regulated foods will support growth when other conditions for growth are met.”
They also pointed out many spices have inhibitory compounds that may provide antibacterial activity against Salmonella. The compounds may limit growth and survival of Salmonella in (wet/inoculated) spices and foods containing spices or their essential oils under some conditions.
“Obviously other factors, including the ability of Salmonella to survive in a variety of low-moisture foods, including some if not all spices, are more important in determining the prevalence of Salmonella in imported spices shipments offered for entry to the United States,” they observed.
The researchers suggested a contributing factor to the higher prevalence of Salmonella contamination in imported spices may be spice plant exposure to pathogen-containing wildlife, insects and soil during growth, harvest or primary processing.
They noted shipments of spices derived from the fruits, seeds or leaves of plants had a larger prevalence for Salmonella than shipments of spices derived from the bark or the flower of spice plants. The researchers found no difference in Salmonella prevalence for shipments of blended spices as compared with non-blended spices.
They also indicated some spice shipments reported to have been subjected to pathogen-reduction process treatments prior to being offered for U.S. entry still were found to be contaminated.
“Salmonella contamination of ‘treated shipments’ could reflect ineffective pathogen reduction treatments, very large initial concentrations of Salmonella, or post-treatment contamination,” they observed.
The researchers found that spice shipments from certain countries had a higher rate of Salmonella contamination than others. For instance, of 136 shipments from Mexico sampled as part of the study, 19, or 14%, were found to be contaminated with Salmonella. This was the highest rate of contamination based on country of origin in the study. The second-highest rate for Salmonella contamination was for samples of spices offered for entry to the United States from India. Of the 1,057 spice import shipments from India sampled during the study, 92, or 9%, were found to be contaminated with Salmonella. In contrast, only one Canadian spice shipment in 110 sampled, or 0.9%, was found to be contaminated with Salmonella.
The researchers noted more than 80% of the spices consumed in the United States are imported (spice imports in 2010 aggregated 1.2 billion lbs, according to the U.S. Department of Agriculture). India is the country of origin for about 40% of all U.S. spice imports, making the study’s findings about prevalence of Salmonella contamination in shipments from India particularly problematic.
The study assertions were contested by some spice exporters. K.C. Babu, director of marketing with the Indian government’s Spices Board, asserted “stringent” quality controls were in place in India regarding export of spices and it was found that 98.5% of the consignments sent to the United States were free of Salmonella.
The F.D.A. scientists said future research “should focus on understanding the differences in Salmonella prevalence among imported spice shipments to aid in the development of appropriate risk management strategies.” They also suggested data should be collected to determine the prevalence of Salmonella in spices at retail.
“These data will provide direct information on the safety of spices consumed and the efficacy of post-import risk management practices currently employed by the spice and food industries and regulatory agencies,” they said.
“Finally, methods development should focus on ways to negate or ameliorate the effects of antimicrobial compounds found in spices, without having to resort to dilution, so that method sensitivity can be improved,” they said.
The authors noted their study was “part of larger effort by the F.D.A. to conduct spice safety research to assess the salmonellosis public health risk posed by spice consumption in the United States and to assist the agency in identifying options to mitigate the risk.”