Cluster of Hemolytic Uremic Syndrome (HUS) Cases in Aquitaine, May–June 2012

The French Institute for Public Health Surveillance (InVS) was notified by the Bordeaux University Hospital of four cases of hemolytic uremic syndrome (HUS) that occurred between June 14 and 20, 2012, in children residing in the departments of Pyrénées-Atlantiques (2 children) and Gironde (2 children).

Hemolytic Uremic Syndrome (HUS) and Shiga Toxin-Producing Escherichia coli (STEC)

HUS is a disease most commonly caused in children by a bacterium belonging to the Escherichia coli (E. coli) family, certain strains of which are more virulent and produce toxins called “shigatoxins” (STEC: shigatoxin-producing E. coli). Contamination can occur through the ingestion of contaminated food (undercooked meat, raw milk products, raw vegetables and fruits), through soiled hands after touching animals carrying the bacteria or their environment, or through contact with an infected person who excretes the bacteria in their stool.

STEC infections initially present with diarrhea (often bloody), abdominal pain, and sometimes vomiting. In 5 to 8% of cases (after about a week), these symptoms can progress to HUS. The child then exhibits signs of severe fatigue, pallor, decreased urine output that becomes darker in color, and sometimes seizures.

Investigations

The close temporal and geographical proximity of several cases of this rare condition (approximately 100 cases of pediatric HUS are reported annually by the national HUS surveillance network) suggested a common source of contamination. An epidemiological investigation, coordinated by the InVS (DMI-EAZ, DCAR-Cire Aquitaine) in collaboration with the Aquitaine Regional Health Agency (ARS), was immediately launched.

The onset dates of symptoms (diarrhea) for the four cases of HUS ranged from June 6 to June 16. All were hospitalized for HUS between June 14 and June 20. An infection with E. coli O157 was confirmed in one of the children. Testing is still ongoing for the other three children.

The children’s parents were interviewed about potential exposures during the 7 days preceding the onset of their child’s diarrhea. The investigation did not identify any common exposure other than, for 3 children, the consumption of fresh Jean Rozé brand ground beef purchased at Intermarché stores. For the fourth case (which developed symptoms one week before the other cases), consumption of hamburger patties of this brand was not reported. It is likely that this case is not linked to this outbreak and was exposed to another source of contamination.

Following receipt of this information on the afternoon of June 22, a traceability investigation was conducted to identify the source of the ground beef consumed by the three children. The three Intermarché stores where the ground beef was purchased were supplied by a common manufacturer located in the Lot-et-Garonne department (47). The ground beef was fresh, with a short best-by date of just a few days.

The batches of ground beef suspected of causing these human cases were identified based on the purchase dates provided by the families of the patients. The ground beef with use-by dates ranging from May 28 to June 15 was thus recalled by the manufacturer. The Intermarché and Netto stores that received this ground beef were located in four regions (Aquitaine, Limousin, Midi-Pyrénées, Poitou-Charentes) in the following departments: 12, 16, 17, 19, 24, 31, 32, 33, 40, 46, 47, 64, 65, 81, 82, 87. The ground beef was sold in the fresh food section under the Jean Rozé, Netto, or Top Budget brands. The use-by dates for the batches of ground beef consumed by the cases expired on June 15 and are therefore no longer on sale. However, it is possible that consumers may have frozen these ground beef products and still have them in their freezers.

Investigations are ongoing to confirm E. coli O157 infection in the children and to test the suspected ground beef for the bacteria.

In light of the initial information available and pending the results of further investigations, authorities have asked the manufacturer to recall the ground beef identified through traceability investigations. A press release was issued on June 23 by the processed meat company in Estillac (47) to inform consumers who may have kept these ground beef patties in their freezers that they should not consume them and should return them to the store where they were purchased.

The batches affected by the recall were as follows:

Modified atmosphere packaging under the JEAN ROZE, NETTO, and TOP BUDGET brands

Product codes: fresh ground beef 15% fat / fresh ground beef 20% fat

Best Before Date: May 28 to June 15, 2012

Bearing the veterinary identification number: FR – 47.091.002 - CE

Sold in the self-service fresh food section from May 22 to June 15 at Intermarché and Netto stores located in the following departments of the Southwest region: 12, 16, 17, 19, 24, 31, 32, 33, 40, 46, 47, 64, 65, 81, 82, 87.

A press release providing an update on the situation was issued on June 25, 2012, by the Aquitaine Regional Health Agency (ARS), and information on the procedures to follow for diagnosing HUS of infectious origin, potentially caused by E. coli, was distributed in Aquitaine to emergency departments, SAMU units, and the CAPTV in Bordeaux.