The Origin and Spread of Human Pathogens in Fruit Production Systems - Microbial Safety of Fresh Produce - page 42

Table 2.1. Fresh fruit commodities or fruit products implicated in outbreaks of foodborne
illness and associated etiological agents
Etiological Agent Implicated Fruit or Fruit Product

Hepatitis A Frozen strawberries

Norovirus Mixed fresh - cut fruit, raspberries, melon

Calicivirus Frozen mixed fruit

Salmonella Melon, apple juice, orange juice, fruit salad

E. coli O157:H7 Cantaloupe, apple cider

E. coli O11:H43 Pineapple

Campylobacter jejuni Melon, strawberries, fruit salad, orange juice

Staphylococcus aureus Strawberries

Clostridium botulinum Carrot juice

Cryptosporidium parvum Apple juice

Giardia lamblia Fruit salad

Cyclospora cayetanensis Raspberries, fruit salad

frequency. However, it should be stressed that detection of enteric viruses in clinical
samples and foods remains technically challenging, and illnesses caused by these
pathogens are likely underreported. Although Campylobacter spp. are recognized as
a major cause of foodborne infections in the Western world, relatively few examples
of transmission through fresh produce have been recorded to date. Consumption of
raw fruit is nevertheless identifi ed as a risk factor for sporadic campylobacteriosis
(Neimann and others 2003). Microbiological surveys indicate that pathogenic species
of this genus are rarely found in crops grown in Western countries but that they fre-
quently contaminate salad vegetables or fruit in developing countries (Garcia-
Villanova Ruiz and others 1987; Chai and others 2007; Hussain and others 2007). The
latter is a concern given expanding international trade and reports of outbreaks associ-
ated with imported products. A notable example occurred in the 1990s when several
infections caused by the single-celled parasite Cyclospora cayetanensis were reported
in Canada and the U.S., countries well outside the geographical range for the species.
Raspberries imported from Central America were implicated in these events (Herwaldt
and Ackers 1997 ).
Although unsanitary handling or processing was responsible for some documented
incidents, the majority could be ascribed to contamination during production. Analysis
of available data also suggests that some commodities are more frequently implicated
in such events, including cantaloupe melons. Fundamental differences imparted by
the nature of the fruit, the characteristics of specifi c production systems, and posthar-
vest handling schemes prohibit strict comparisons across commodities. Nevertheless,
observations derived from outbreak investigations and ensuing research have pro-
vided important data about the ecology of foodborne pathogens in fruit production
systems and the means by which they contaminate crops. The following discussion
therefore draws heavily on information derived from this body of work to summarize
the state of knowledge about the origin and spread of human pathogens in fruit
production systems.