Epidemiologic Investigation

A case was defined as a laboratory-confirmed infection with the outbreak strain of S. Schwarzengrund in a person residing in the United States who either had symptoms beginning on or after January 1, 2006, or (if the symptom onset date was unknown) had S. Schwarzengrund isolated from a specimen on or after January 1, 2006. During January 1, 2006--December 31, 2007, a total of 70 human cases of the outbreak strain of S. Schwarzengrund were reported to CDC via PulseNet from 19 states (Figures 1 and 2). The last reported illness onset date was October 1, 2007. No illness was reported in pets.

The largest number of reported cases was in Pennsylvania (29 cases), followed by New York (nine) and Ohio (seven) (Figure 1). Among 61 ill persons whose age was available, the median age was 3 years (range: 1 month--85 years), and 24 (39%) were aged <1 year; of 45 persons whose sex was known, 22 (49%) were female. Of 38 ill persons for whom clinical information was available, 15 (39%) had bloody diarrhea; of 45 persons whose hospitalization status was known, 11 (24%) had been hospitalized. No deaths were reported.

Case-Control Study

To determine the source of infections caused by the outbreak strain of S. Schwarzengrund, the OutbreakNet team coordinated a multistate case-control study during July 17--September 28, 2007. Case-patient households were defined as those with at least one member infected with the outbreak strain of S. Schwarzengrund with an illness onset date or isolation date occurring during January 1, 2006--August 30, 2007. For each case-patient household, one to three geographically matched control households were recruited using a reverse--digit-dialing system. Persons in each case-patient and control household were asked whether they had been exposed to dry dog or dry cat food, which brands they usually purchased, and which brands they purchased in the 2 weeks before illness onset (for cases) or the 2 weeks before interview (for controls). Data were analyzed as a matched case-control study, and a multivariable logistic analysis was conducted to control for confounding from coexposures.

One person was interviewed in each of 43 case-patient households and 144 control households in eight states: Delaware, Maine, Michigan, Minnesota, New York, North Dakota, Ohio, and Pennsylvania. Case-patient and control households were excluded from analysis where questions were not answered. Contact with a dog was reported by 34 (79%) persons in case-patient households compared with 86 (60%) persons in control households (matched odds ratio [mOR] = 2.7) (Table). Dry dog or cat food produced by manufacturer A usually was chosen for purchase by members of 19 (44%) case-patient households compared with 14 (10%) of control households (mOR = 7.8; 95% confidence interval [CI] = 2.6--27.8).

Among the 19 persons in case-patient households who usually purchased manufacturer A pet food, 11 purchased brand A, three brand B, five brand C, and three brand D. All four brands were produced at plant A. Among the four brands, brand A typically was purchased by 11 (26%) persons in case-patient households compared with six (4%) persons in control households. In multivariable analysis, purchase of brand A was associated with illness (mOR = 23.7) (Table). In Pennsylvania alone, purchase of brand A also was associated with human illness in multivariable analysis (mOR = 15.4; CI = 2.1--infinity).

Environmental Investigation

During 2007, plant A produced approximately 25 brands of dry pet food; specific distribution information for brands produced in plant A was not available. Plant A labeled these dry pet foods with a 1-year shelf life (i.e., sell-by date). On July 12, 2007, PADOH staff members visited plant A and collected 144 swabs of specimens from environmental surfaces; the outbreak strain of S. Schwarzengrund was isolated from one sample. FDA tested previously unopened bags of seven brands (brands E, F, G, H, I, J, and K) of dry dog food produced at plant A. Two brands of dry dog food (E and F) yielded the outbreak strain of S. Schwarzengrund. On August 21, 2007, manufacturer A announced a voluntary recall of 50-pound bags of brand E dry dog food and 5-pound bags of brand F dry dog food. On July 26, 2007, manufacturer A suspended operations at plant A for cleaning and disinfection. In mid-November 2007, plant A resumed normal operations.

Reported by: A Ferraro, PhD, M Deasy, V Dato, MD, M Moll, MD, C Sandt, PhD, J Tait, B Perry, MS, L Lind, MPH, N Rea, PhD, R Rickert, MPH, C Marriott, MPH, C Teacher, MSN, P Fox, MS, K Bluhm, V Urdaneta, MD, S Ostroff, MD, Pennsylvania Dept of Health. E Villamil, MPH, P Smith, MD, Regional Epidemiology Program, New York State Dept of Health. Ohio Dept of Health. JL Austin, PulseNet; T Ayers, MS, S Alexander, DVM, RM Hoekstra, PhD, I Williams, PhD, Div of Foodborne, Bacterial, and Mycotic Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases; C Barton Behravesh, DVM, EIS Officer, CDC.

Editorial Note:

I hope no one was offended by the length of this article. I felt it was important to post this in its entirerty

Thanks for the info. Was this on the CDC website? I wonder if the brands and manufacturer will be disclosed and products recalled? I am on the FDA list and haven't seen anything at this point.

And - everyone worries about the risk of raw feeding...........which I've done for 23 years and never had a problem. i figure my immune system can handle anything by now! ;)

yes, this appeared in the CDC news letter. I too have been feeling raw for 17 years without any of these concerns

I do not know where these People are coming from, anything to jusifiy there jobs it seems

I have been feeding and handling kibble for dogs for near on 40 years and no problem These things get out of hand like this Chicken Flu thing scare mongers is what these people are who write this stuff

Like everything in life, 'WASH' your hands after handling the food thats more common sense than what the poster has wrote putting this on the forum

Steve

Salmonella can be contracted from a wide variety of sources including handling infected animals (inc humans), tortoises, lizards etc etc.

As said before hygiene is the issue.