Tag Archives: acute and communicable disease prevention

salmonella-typhimurium

Rajneesh Bioterrorism

Outbreak: #1984-001
Product: Restaurant salad bars
Investigation Start Date: 1985
Location: Waso County, Oregon
Etiology: Salmonella Typhimurium
Earliest known case onset date: 9/9/1985
Latest case onset date: 10/10/1985
Presumptive / Confirmed Case Count: 0 / 751
Positive Samples (Food / Environmental): 0 / 0
Rajneesh Salmonellosis Grand Rounds (1/2)
1984 Terror Attack investigation presentation
     by Tom Török, April 24, 2014
This is a two-part presentation on the Oregon Health Authority investigation of this outbreak.
Rajneesh Salmonellosis Grand Rounds (2/2)
1984 Terror Attack investigation presentation
     by Michael Skeels, April 24, 2014
This is a two-part presentation on the Oregon Health Authority investigation of this outbreak.
1984 salmonellosis Rajneesh bioterror attack in The Dalles, Oregon
1984 salmonellosis Rajneesh bioterror attack in The Dalles, Oregon
1984 salmonellosis Rajneesh bioterror attack in The Dalles, Oregon
Outbreak Summary:
The 1984 Rajneesh salmonella outbreak was the single largest bioterrorist attack in United States history. Featured: the two-part presentation on the Oregon Health Authority investigation.
Details:
A leading group of followers of Bhagwan Shree Rajneesh (later known as Osho) had hoped to incapacitate the voting population of the city so that their own candidates would win the 1984 Wasco County elections.

The incident was the first and single largest bio-terrorist attack in United States history. The attack is one of only two confirmed terrorist uses of biological weapons to harm humans since 1945.

751 people contracted salmonellosis as a result of the attack; 45 of them were hospitalized. There were no fatalities.

Although an initial investigation by the Oregon Public Health Division and the Centers for Disease Control did not rule out deliberate contamination, the agents and fact of contamination were only discovered a year later.

On February 28, 1985, Congressman James H. Weaver gave a speech in the United States House of Representatives in which he "accused the Rajneeshees of sprinkling salmonella culture on salad bar ingredients in eight restaurants". At a press conference in September 1985, Rajneesh accused several of his followers of participation in this and other crimes, including an aborted plan in 1985 to assassinate a United States Attorney, and he asked State and Federal authorities to investigate.

Oregon Attorney General David B. Frohnmayer set up an Interagency Task Force, composed of Oregon State Police and the Federal Bureau of Investigation, and executed search warrants in Rajneeshpuram. A sample of bacteria matching the contaminant that had sickened the town residents was found in a Rajneeshpuram medical laboratory. Two leading Rajneeshpuram officials were convicted on charges of attempted murder and served 29 months of 20-year sentences in a minimum-security federal prison.
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Salmonella Enteritidis

Paramount & Raw Almonds

Outbreak: Paramount & Raw Almonds
Product: Almonds
Investigation Start Date: 02/23/2004
Location: Multi-state outbreak
Etiology: Salmonella Enteritidis
Earliest known case onset date: 02/01/2004
Latest case onset date: 04/17/04
Confirmed / Presumptive Case Counts: 7 / 0
Positive Samples (Food / Environmental): 1 / Lots
Hospitalizations: 7
Deaths: 0
  • "Kirkland Signature” almonds from Paramount nuts, as exhibited in the museum.
    "Kirkland Signature” almonds from Paramount nuts, as exhibited in the museum.
Outbreak Summary:
This investigation was rapidly solved by the use of Oregon's "Shotgun" hypothesis-generating questionnaire, a detailed food history interview tool that asks about over 400 different foods and places to eat. A single interviewer at the Oregon state health department used this standardized questionnaire to interview all 5 of the first cases detected as part of the same outbreak. Though the questionnaire only asked about "almonds in the shell," when the first two cases recalled eating raw almonds the interviewer took an iterative approach and modified the questions she asked the next 3 cases to include raw almonds.

Details:
Outbreak of Salmonella Serotype Enteritidis Infections Associated with Raw Almonds — United States and Canada, 2003–2004

On June 4, this report was posted as an
MMWR Dispatch on the MMWR website:
(http://www.cdc.gov/mmwr).

On May 12, 2004, the Oregon State Public Health Laboratory identified a cluster of five patients infected with Salmonella enterica serotype Enteritidis (SE) isolates that were matched by using two-enzyme pulsed-field gel electrophoresis (PFGE). The five patients were from four Oregon counties; their onsets of illness occurred during February–April 2004. A subsequent investigation, still ongoing, has identified a total of 29 patients in 12 states and Canada with matching SE isolates, since at least September 2003. Seven patients have been hospitalized; no one has died. Raw almonds distributed throughout the United States and internationally have been implicated as the source of the SE infections. As of May 21, approximately 13 million pounds of raw almonds had been recalled by the producer.

Routine interviews of the initial five patients with salmonellosis had not indicated a common exposure. However, prompted by the May 12 laboratory data, the patients were reinterviewed by using a standard hypothesis–generating questionnaire that included questions about consumption of approximately 400 specific food items and their shopping and eating venues during the 5 days before illness onset. Using binomial distribution, consumption rates for selected foods were compared with background rates estimated from a 2002– 2003 population-based survey of residents of Oregon (1). The initial five patients from Oregon all reported consuming Kirkland Signature brand raw almonds, purchased at Costco warehouse stores. Survey data (1) indicated that an estimated 9% of Oregon residents (86 of 921 surveyed) consumed raw almonds from any source in the preceding week. Even assuming that 20% of all Oregon residents ate Kirkland Signature brand raw almonds each week, the binomial probability of finding five of five sporadic cases with that history is <0.001. No other foods or food sources were associated with illness.

After determining that the raw almonds were distributed widely, U.S. and Canadian epidemiologists and state and federal regulatory agencies were notified on May 13 via electronic information networks. Through PulseNet, the national molecular subtyping network (2), laboratories were queried for reports of isolates matching the outbreak PFGE patterns (XbaI: JEGX01.0049; BlnI: JEGA26.0008 or JEGA26.0009, reflecting minor variation later observed with the second enzyme). Laboratories that did not routinely screen SE isolates by using PFGE were encouraged to do so for isolates collected since February 1, 2004. Phage typing was performed by standard methods. As additional PFGE-matching isolates were identified, a brief, customized questionnaire was used in interviews with persons about their nut consumption.

Raw almonds from an opened package recovered from one patient’s household were tested for Salmonella by enzyme immunoassay. Unopened packages of nuts from the supplier’s warehouse and environmental samples collected at the almond processor and at huller-shellers supplying the processor were tested for Salmonella by using standard microbiologic methods.

As of June 2, a total of 29 patients with SE infections matching both XbaI and BlnI PFGE patterns had been identified in 12 states and one Canadian province. Symptom onsets ranged from September 2003 to April 2004 (Figure). Patients ranged in age from 11 months to 91 years (median: 40 years); 17 (59%) were female. Seven patients were hospitalized; no one died. Multiple other cases with matching PFGE patterns and onsets earlier in 2003 remain under review. To date, nine isolates from the

current outbreak have been phage typed; all are type 9c, which is uncommon. Among 26 patients interviewed, 24 recalled eating raw almonds during the week before illness onset; 20 patients identified brands packaged or supplied by Paramount Farms (Lost Hills, California). One infant patient was presumed secondarily infected. Through retailer computer records linked to membership cards or customer receipts, dates and places of almond purchase were verified for 10 households of patients. The dates of verified almond purchases ranged from November 3, 2003, to January 28, 2004.

Efforts to identify specific production lots associated with illness, based on almond purchase dates and locations and store inventory data, are ongoing. On May 18, Paramount announced a nationwide recall* of all raw almonds sold under the Kirkland Signature, Trader Joe’s, and Sunkist labels. Costco mailed 1,107,552 letters to members known to have purchased the recalled product in the United States. The recall was expanded subsequently to include nuts sold in bulk to approximately 50 other commercial customers, some of whom repackaged almonds for sale under other brand names. In addition to sales in the United States, almonds were exported to France, Italy, Japan, Korea, Malaysia, Mexico, Taiwan, the United Kingdom. The majority of the recalled almonds likely were consumed months ago; however, raw almonds have a shelf life of >1 year, and consumers might still have the implicated products.

Tests of raw almonds recovered from a patient’s household and samples collected at Paramount were negative for Salmonella; however, Salmonella was isolated from one environmental sample collected at Paramount and from three samples from two huller-shellers that supplied Paramount during the period of interest. Serotype and PFGE analyses of these isolates have not been completed, and additional sampling continues.

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e-coli-o157

Cal-Farms Parsley

Outbreak: Cal-Farms Parsley
Product: Parsley
Investigation Start Date: 10/20/2005
Location: Deschutes County, OR
Etiology: E. coli (STEC) O157:H7
Earliest known case onset date: 10/08/2005
Latest case onset date: 10/27/2005
Confirmed / Presumptive Case Counts: 3 / 61
Positive Samples (Environmental / Water): 10 / 2
Outbreak Summary:
This 2005 McGrath's Fish House outbreak of E. coli O157:H7 infections was traced back to parsley from Cal-Farms. The journey to finding the source was interesting: 206 people interviewed, 64 ill people, extremely muddy field conditions, cattle near the flooded parsley fields, and even evidence of heavy deer presence.

Details:
Background

On October 20, 2005 we were notified of two E. coli O157:H7 cases from two adjacent counties, Deschutes and Jefferson. Routine follow-up interviews revealed that both ate at a popular restaurant in Bend on the same day, October 12, 2005. Seeing this as a possible common-source exposure, the Deschutes County Health Department in Bend attempted active case finding by obtaining the names of restaurant patrons who used credit cards on October 12th. An initial quick survey identified several other diners who reported gastrointestinal symptoms after their meal. A formal case-control study was launched using an expanded list of credit card names from October 12-15, and a questionnaire based on restaurant menu as well as characterization of illness, if any.

Methods

Names from the credit card list were used to look up telephone numbers on the Internet. Deschutes County staff and MPH students from the Acute and Communicable Disease Program (ACDP) of the Oregon Department of Health Services interviewed people. Several people reported gastrointestinal illness after eating at the restaurant. On October 23, 2005, the Deschutes County Health Department decided to issue a press release. Medical alerts were sent to the local physicians and emergency rooms. The press release stimulated additional reports of illness. E. coli O157:H7 isolates were subtyped by pulse-field gel electrophoresis (PFGE) People who reported GI illness were asked to submit stool specimen for confirmation. Some gave specimens to the local health department, while others gave specimens to their doctors.

Environmental Inspection

The Deschutes County Environmental Health section inspected the restaurant. Employees were asked about recent GI illness. Environmental samples and food samples were collected.

We visited Cal-Farms in Oregon City, reviewed their operations, and obtained parsley sales records for September and October. We were shown 2 fields that were the source of parsley harvested in September and October, and collected ~100 convenience samples of soil and parsley stubble on November 7th from both fields. There were no obvious deficiencies in operating conditions to these inexpert observers. Several potential sources of O157 were noted, including livestock in nearby fields (goats, lamas), river water used for irrigation (in drier months), and a deer presence heavy enough to merit repellent next to parsley fields. Because extremely muddy conditions made it difficult to seal sample bags, these were pooled into 6 composite samples – 3 from each field. These samples were enriched and tested by multiplex PCR and cultured on CT-SMAC for O157 at the Institute for Environmental Health (Lake Forest Park, WA; courtesy Dr. Masour Samadpour).

Results

A total of 206 people were interviewed, including people who called in after the press release was issued. Of 120 completed interviews derived from the credit card names, 33 (27%) reported GI illness, of whom 23 (19%) met a working case definition (three or more loose stools in a 24 hour period, and incubation period > 1 day and < 10 days). In total, we identified 64 people who reported three or more loose stools (Figure 1). The median incubation period was 2.6 days. Forty-three (67%) were females, and the median age was 51 (range 4-87). Meal dates for those who were ill were from October 2 – October 22 (Figure 2). Symptom profile is shown on Table 1. Twenty-one people reported having bloody diarrhea, and only 7 (33%) of these sought medical care. Of those who sought medical care, 6 (86%) were asked to give stool specimen.

SymptomsNumber%
Diarrhea64100%
Cramps5180%
Nausea3352%
Headache2641%
Myalgia1930%
Bloody diarrhea1727%
Vomiting1320%
Fever813%

By our initial univariate analysis, crab and artichoke dip, coconut prawns, and vegetables were all significantly associated with illness, but none of these items accounted for more than 20% of the cases.

As we were considering these results, first-enzyme PFGE results on the initial isolate were posted to PulsNet revealing a match to a recently investigated cluster (2 restaurant groups, and 2 sporadic cases) in Washington. Washington epidemiologists had identified parsley (traced to an Oregon supplier and grower) as the likely vehicle for those cases. Armed with this knowledge, we then considered parsley as a potential vehicle for the McGrath’s outbreak. We determined that parsley from the same supplier (Pacific Coast Fruit) and farm (Cal-Farms, Oregon City) had been the sole source of parsley at McGrath’s from XX through ~ October 10 (last delivery date on October 10th). Parsley was used on a large number of menu items, including several side dishes that unfortunately had been omitted from the questionnaire. We reanalyzed our data, using a composite variable standing in for all the food items served with parsley. Limiting the analysis to meal dates from October 12-15 and adding abdominal cramps to the case definition, we found parsley to be significantly associated with illness (OR=3.32, p-value = 0.02). This variable could explain about 80% of the cases. Other food items that were significant included vegetables (OR=3.18, p-value = 0.02) and red potatoes (OR=4.44, p-value = 0.03), both of which had parsley. Interestingly, we learned that the crab and artichoke dip was always served with parsley-topped bruchetta.

Food samples and environmental samples tested negative at the Oregon State Public Health Laboratory (OSPHL). Water and the filter from the ice machine were tested, and were negative.

ParsleyCaseControlTotal
Yes244165
No63440
(Total)3075105
OR = 3.3295% CI = 1.11-10.39P-value = 0.028
VegetablesCaseControlTotal
Yes121325
No186280
(Total)3075105
OR = 3.1895% CI = 1.11-9.18P-value = 0.027
Red PotatoesCaseControlTotal
Yes6410
No247195
(Total)3075105
OR = 4.4495% CI = 0.98-21.10P-value = 0.03

Discussion

Parsley from Cal-Farms was the apparent cause of the McGrath’s outbreak, by extension, all recent Oregon and Washington cases with matching PFGE. The only food item that explained most of the cases was the parsley. The fact that the three confirmed cases matched the Washington cluster suggest a common source. Seven of the 8 cases in Washington had foods that had parsley, and the parsley came from the same grower. The Washington cases had other things in common, such as romaine lettuce, roma tomatoes, red cabbage, and onions, but these food items came from different distributors.

The parsley farm distribute to various places including grocery stores. Pacific Coast Fruit, the distributor for the restaurant, is only one of a number of their customers. It is not clear why this distributor would get a contaminated batch and why only a few restaurants would get contaminated parsley. This wholesaler got about 28% of the sales from 9/1/05 – 10/28/05.
We would have expected to see a lot more cases since the parsley was distributed to other places too.

During the visit to the farm, a number of possible sources of contamination were noted. There were deer repellents, and deer tracts. Samples of parsley and dirt were tested, but were negative.

Only 3 cases were confirmed out of 64 ill people. Five additional cases were tested, but no E. coli O157 were detected. The specimens were collected 9-15 days after onset of diarrhea. Most adults do not excrete the organism after ~2 weeks, and 3 weeks in kids. Three cases were tested through their private physicians, and
were negative. Interestingly, most cases did not seek medical care, even those with bloody diarrhea. Of those with bloody diarrhea, 33% sought care, and of these, 86% were cultured.

The restaurant voluntarily closed on October 24th and was cleaned thoroughly. All the food workers were tested and were negative. The restaurant was reopened on November 1st. We did not hear of new cases after the restaurant was reopened.

The recommendations were:

1) Throw out all left over foods.
2) Emphasize employee hand washing.
3) Ill employees should not work until symptoms resolve, or if they are culture positive for E. coli O157, they should have 2 negative stools before returning to work.

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