CDC: Foodborne disease outbreaks increase but illnesses down

In an annual report​, the agency said there were 864 foodborne disease outbreaks, resulting in 13,246 illnesses, 712 hospitalizations, 21 deaths, and 21 recalls in 2014.

The data includes those reported by February 17 this year in which the first illness was in 2014.

The year before​, 818 outbreaks were reported with 13,360 illnesses, 1,062 hospitalizations, 16 deaths and 14 food recalls.

An outbreak of foodborne disease is defined as two or more cases of a similar illness resulting from ingestion of a common food.

Food commodities involved​

Ground beef was the contaminated food or ingredient in five of the 25 multistate outbreaks. Four were caused by Shiga toxin-producing E. coli and one by Salmonella.

Fish (43 outbreaks), chicken (23), and dairy (19, of which 15 were due to unpasteurized products) were the most common single food categories implicated.

The most outbreak-associated illnesses were from seeded vegetables (e.g. cucumbers or tomatoes, 428 illnesses), chicken (354), and dairy (267).

In 2013, the categories were fish (50 outbreaks), mollusks (23), chicken (21), and dairy (21, with 17 due to unpasteurized products).

Eleven of 26 outbreaks were caused by Salmonella, Vibrio parahaemolyticus, STEC and Listeria caused four each, and hepatitis A virus, Cyclospora cayetanensis and niacin all caused one each.

Cause of outbreaks​

Bacteria caused the most outbreaks (247 outbreaks, 53%), followed by viruses (161, 35%), chemicals (46, 10%), and parasites (seven, 2%). Although numbers varied it was the same pattern as 2013 data.

Norovirus was the most common cause of confirmed, single-etiology outbreaks, accounting for 157 (34%) and 3,835 (43%) illnesses, according to the 2014 report.

Salmonella accounted for 140 (30%) outbreaks and 2,395 (27%) illnesses. Among the 131 confirmed outbreaks with a serotype reported, Enteritidis was the most common (40 outbreaks, 31%), followed by Typhimurium (15, 11%), I 4,[5],12:i:- (6, 5%), Javiana (six, 5%), and Newport (six, 5%).

Shiga toxin-producing E. coli (STEC) caused 23 confirmed, single-etiology outbreaks, of which 12 (52%) were caused by serogroup O157, three each by O111 and O26, two by O121 and one each by O103, O145 and O186.

The pathogen-food category pairs responsible for most outbreaks with a single confirmed etiologic agent were ciguatoxin in fish (19), scombroid toxin (histamine) in fish (16 outbreaks), and Salmonella in chicken (11).

Pairs responsible for the most illnesses in outbreaks with a single confirmed etiologic agent were Salmonella in seeded vegetables (357 illnesses), Salmonella in chicken (227), and Staphylococcus aureus enterotoxin in turkey (184).

Data from the year before, found the pathogen-food category pairs responsible for most outbreaks were scombroid toxin (histamine fish poisoning) in fish (25 outbreaks), ciguatoxin in fish (15), and Vibrio parahaemolyticus in mollusks (13).

Pairs responsible for the most outbreak-associated illnesses were Salmonella in chicken (700 illnesses), Salmonella in pork (436), and Salmonella in seeded vegetables (268).

Bruker partnership​

Meanwhile, the CDC has expanded MicrobeNet which has been in use since 2013.

It provides laboratorians with free access to CDC's virtual microbe library of more than 2,400 rare and emerging infectious bacteria and fungi.

In partnership with Bruker, CDC added a new module to the tool that allows labs to search the protein signatures of the bacteria and compare them to the rare pathogens in CDC's MicrobeNet library by using Bruker's MALDI Biotyper system.

Previously, the network was searchable by DNA sequence or biochemical tests (chemical reactions caused by the bacteria).

CDC said MicrobeNet can cut the time for testing from about a week to a few hours.