While public health investigators shake their collective heads, the cause of the E coli O157:H7 outbreak due to raw cookie dough that has now affected over 70 persons goes unrecognized. FDA has reportedly ruled out sabotage, extensive tests of ingredients did not reveal the agent, and several days of investigation reportedly turned up only minor sanitation issues. FDA was successful in isolating one strain of E coli O157:H7 from an intact package of cookie dough with a manufacture date of 4-20-09. While this isolate was not the so-called outbreak strain, at least three shiga-toxin strains (2 – O157:H7 and 1- O124) have turned up in this rather bizarre outbreak.
Water is an essential ingredient in dough, but FDA has not commented about the water quality at the facility leading to our speculation that FDA is either not testing the water or does not see its use as significant and is not reporting the findings. However, the finding of more than one E coli O157:H7 strain is clearly indicative of a highly contaminated environment reservoir, and this reservoir is likely in the plant or was during the outbreak.
If incoming materials like flour and other common ingredients were highly contaminated, it is unlikely that such broad contamination in the food supply would affect only Nestlé’s cookie dough. When salmonella for example contaminated peanut derived products the repercussions were everywhere, yet, we have not identified outbreaks of this strain of O157 in other products. This fact makes it unlikely that some common additive or ingredient is involved here.
The PFGE pattern for this strain is not an unusual or novel type. PulseNet has reported on this strain for some time. This means the strain of E coli we are seeing at Nestlé’s (or the one called the outbreak strain) is a common circulating strain. This means the environmental reservoirs have had quite a long time to establish themselves in people, cattle, birds and probably a wide assortment of other vectors. Because of these features, water, especially surface water that has had multiple exposures to sewage and farming operations would fit the bill as the vehicle in this case.
Conducting an investigation requires one or more hypotheses. One early hypothesis was that Nestlé’s uses as its water source for cookie dough treated well water or uses a treated surface water source, such as a creek or stream; therefore, we concluded a sanitary survey was an appropriate investigative tool. Since Nestlé’s undoubtedly has to treat this type of water if used, one hypothesis could be failure to disinfect process water or gross overloading by fecal organisms as the cause of the contaminated cookie dough.
Because we did not travel to the plant (and would not likely have been welcomed in!), we used Google Earth to begin our sanitary survey. We identified the Nestlé’s plant, simply plugging in the address 201 Airside Drive, Danville, Virginia into the Google Maps feature; we selected the Satellite View option first. We found the facility is located about five miles out of Danville, Virginia in a semi rural agro-industrial area. Because city utilities often do not run water mains extensive distances, we felt use of well water was a possibility. The satellite image at 100ft/inch resolution shows a number of interesting features at the Nestlé’s plant that we analyzed. One feature that stands out is a structure that appears to be some type of treatment plant located at the south edge of the building complex. In addition, there appears to be a seepage pond at the far southwest corner of the building.
Because these features could easily be appurtenances other than water or wastewater related, we conducted further investigation using the Google Search and Google Maps engines. We decided since wastewater treatment facilities and potable water wells are permitted facilities there might be some public record we could find to help test the hypothesis that this facility utilized a well. Since utilities only run sewer lines with city water, the finding of a well would mean that onsite sewage disposal is also occurring.
Interestingly, after several unsuccessful attempts, searching under the Key Words “Water discharges, 201 Airside Drive, Danville, Virginia” we turned up a recent application for a permit to install a storm water drainage-system! The date of the stamped plans filed by Nestlé’s shows that the Virginia Department of Environmental Quality received the plans on June 1 2009, in other words, during the outbreak period.
The permit application also turned up a schematic of the plant operation and the layout of the grounds. These very valuable documents would have taken much work to procure through the normal routes of discovery and Freedom of Information Act filings.
An analysis of these diagrams is still on going. Although unlikely due to the availability of city water, there appears to be some indication that a well may be in use at this facility, possibly as a back up supply. Studying the schematic also helped to negate the earlier hypothesis that a building to the rear of the facility was a water treatment plant, the drawings of the plant and grounds identify this is as a Grease and Oil Separation Building. We could not find a designation for a seepage pit, drain field or spray field and conclude that the city sewer likely receives all liquid waste.
We queried Google Maps again using the Airside Drive address; we looked this time at the “Street Side View”. Here we can see fire hydrants on Airside Drive and manhole covers in the street. These findings confirm the availability of city sewer and water. The adjacent airport makes it even more likely, that the city would make sewer and water available to this area. Apparently, this is an industrial zone built by the City of Danville and set up to accommodate food manufacturing.
Since the issue of the failure onsite water treatment and/or and wastewater treatment systems now seems unlikely as a direct cause of this outbreak, the issue of flooding and poor drainage has now come to the fore as a meaningful hypothesis for E coli O157:H7 contamination of the facility.
Naturally, many unanswered questions remain regarding this new hypothesis that we generated. We might have to clear some up by an inspection, and we require a further analysis of the documents obtained through our quick search procedures to firm up our hypotheses.
Some of the unanswered questions that we generated as the result of the “poor drainage/flood hypothesis”:
1. Is the plant, due to site topography and elevation subject to flooding from Cane Creek or its tributaries and ditches?
2. What is the significance of the drainage patterns shown on the new permit application?
3. What is the significance of the storm-water permit application filed during the outbreak timeframe?
4. Is Cane Creek polluted?
5. Why is an oil and grease separator building located in the remote rear of the facility, since the sewer is in the front?
6. Is there a sewer lift station?
7. Could the lift station be overcome by storm water leading to a sewage back up in the facility?
8. What are the meanings of the barely visible “Pump Rooms” indicated on the schematic?
To answer the Cane Creek pollution question, we queried Google Search again for the Key Words: “Pollution Dan River, Virginia”. The Dan River is the main body of water in this region. Cane Creek, as can be seen on the permit application, runs near the plant and enters the Dan River about 5 miles downstream. We reviewed several articles indicating the pollution of the Dan River and its tributaries with E coli.
In summary, the Internet and especially the Google Maps, and Google Search capabilities are a very quick method for conducting a sanitary survey and generating hypotheses.
Further work is progressing to make more sense of the findings developed in hopes of coming to a better understanding of what might have gone wrong at Nestlé’s.
Reports in the media that “we may never know” the cause of the Nestlé’s outbreak may turn out to be correct, but we should exhaust all means of finding and uncovering the underlying hazards at this plant before declaring defeat.
We have shown that with the right expertise and fundamental environmental health knowledge the Internet can be both a rich source of data and problem solving tool in foodborne illness investigations especially when environmental factors are suspected.
By Roy E. Costa, R.S., M.S./M.B.A.
Public Health Sanitarian Consultant
Environ Health Associates, Inc.