Issue: In the mid-1990s, several foodborne illness outbreaks associated with both domestic and imported fresh

produce raised U.S. consumer awareness of food safety

problems. For example, in 1996 the potentially dangerous

bacterium Escherichia coli O157:H7 was linked to farmlevel contamination of California lettuce. In the same year,

a large foodborne illness outbreak was linked to

Guatemalan raspberries contaminated with the parasite

Cyclospora, again at the farm level. Many people are concerned about the food safety of imports and want to know

what is being done to resolve any problems.

Background: Despite heightened concern about food

safety, most produce growers for the U.S. market, both

domestic and foreign, have never been involved in food

safety outbreaks. Though statistics show the number of

outbreaks associated with produce increasing over time,

better reporting due to improved outbreak investigations

and diagnostics have undoubtedly contributed to some of

the increase. Some scientists, however, do not believe that

better reporting alone explains the increased level of outbreaks. It is difficult to sort out the competing factors. Nor

is it possible to say whether imported produce is any more

prone to food safety problems than domestic produce.

However, imports represent an increasingly important

share of U.S. consumption and, thus, a potential source of

foodborne illness outbreaks. 

ERS investigated the impact of foodborne illness outbreaks associated with imported produce and what growers, grower organizations, and governments have done to

resolve problems. In particular, three case studies were

examined: imports of Guatemalan raspberries associated

with Cyclospora, imports of Mexican strawberries associated with hepatitis A (contaminated either in Mexico or

the United States), and imports of cantaloupe from Mexico

associated with Salmonella.

Findings: Outbreaks of foodborne illness in the United

States associated with imports of fresh produce affect not

only consumers and the growers of the contaminated

product, but also frequently other suppliers to the U.S.

market, including U.S. producers. Because produce is

perishable, the United States depends on seasonal imports

for a year-round supply of some items. Often by the time

someone falls ill from an imported product and an investigation identifies both the product and its origin, that country may no longer be exporting the product to the United

States. Any producers supplying the market when adverse

publicity breaks may bear the backlash, as in the

Guatemalan raspberry case. In spring and early summer of

1996, the Centers for Disease Control and Prevention

(CDC) received reports of foodborne illness due to

Cyclospora contamination. On June 8, 1996, the Texas

Department of Health issued a health warning that erroneously identified the source of the problem as California

strawberries and recommended that consumers avoid

them. This was a disaster for the California strawberry

industry, then in peak production. On July 18, 1996, the

CDC issued a statement that Guatemalan raspberries were

the mostly likely source of the outbreaks. By that time,

however, the Guatemalan spring export season was over

and growers there suffered little adverse effects. 

Food safety standards and costs tend to increase for

everyone growing the implicated crop, not just those

associated with the contamination. In all three case studies, the foreign producers developed safer standards

through voluntary or mandatory programs. But so did U.S.

growers. The U.S. grower organizations implemented voluntary or mandatory food safety standards for their industry to avoid any future problems and as a means to dissociate themselves from the producers with problems. The

California strawberry industry developed an enhanced

food safety system after the 1996 raspberry problem. The

new program was invoked in 1997 when a problem associated with Mexican strawberries shook consumer demand

for California strawberries for the second year in a row. 

United States

Department of

Agriculture

Economic 

Research

Service

Issues in Diet, Safety, and Health / Agriculture Information Bulletin Number 789-5 February 2004

Response to U.S. Foodborne

Illness Outbreaks Associated

With Imported Produce

Linda Calvin, lcalvin@ers.usda.gov, (202) 694-5244
2 Economic Research Service / USDA

Response to U.S. Foodborne Illness Outbreaks Associated with Imported Produce/ AIB-789-5

The impact of a foodborne illness outbreak on trade

depends on whether foreign producers can quickly correct the contamination problem and convince buyers that

their product no longer poses a risk. Guatemalan raspberries were associated with outbreaks in 2 consecutive years

and Mexican cantaloupe was associated with outbreaks in

3 consecutive years before the U.S. Food and Drug

Administration (FDA) imposed import alerts that denied

all imports of the suspect product from all producers in the

country. When this first happened in Guatemala, it was an

extremely unusual policy response. Typically, FDA issues

an import alert against a particular product and grower

when there are repeated food safety problems. FDA eventually allowed several individual producers in Guatemala

and Mexico to resume shipments to the United States.

While Guatemala eventually developed a strong, but very

expensive, food safety system for raspberries, the industry

never recovered and has been in decline since 1996. The

Mexican raspberry industry, which has never been associated with Cyclospora, took over much of the Guatemalan

industry’s market. It is too early to tell what will happen to

the Mexican cantaloupe industry. In the Mexican strawberry case, after just one outbreak and an initial collapse of

trade, strawberry trade rebounded in the following years. 

Efforts to resolve food safety problems involve growers,

grower organizations, retailers, and governments. Many

individual growers have responded to increased concern

about foodborne illnesses (and attendant financial losses)

by improving their food safety systems voluntarily. FDA’s

guidelines for good agricultural practices (GAPs) for

reducing microbial contamination have provided structure

for U.S. and foreign growers. Grower organizations have

also developed better food safety and traceback systems to

protect the reputation of their particular crops. While individual farmers might not want a contamination problem

traced to their operation, the industry as a whole is more

concerned with accountability. Retailers, who also face

unwanted publicity in a foodborne illness outbreak, have

also taken the initiative by demanding more stringent food

safety programs from their suppliers. Some require that

their produce suppliers have third-party verification that

they are complying with GAP guidelines. FDA has

worked to keep unsafe produce out of the market and to

resolve food safety problems. FDA will work with foreign

governments, at their request, often visiting an area associated with an outbreak to identify practices that are inconsistent with GAP guidelines. FDA also provides training

in foreign countries on GAPs. 

Information Sources:

For full text, see Calvin, Linda. “Produce, Food Safety,

and International Trade: Response to U.S. Foodborne

Illness Outbreaks Associated with Imported Produce,”

chapter 5 in International Trade and Food Safety:

Economic Theory and Case Studies. J. Buzby (ed.).

USDA, Econ. Res. Serv., AER-828, Nov. 2003.

www.ers.usda.gov/publications/aer828/

Calvin, Linda, William Foster, Luis Solorzano, J. Daniel

Mooney, Luis Flores, and Veronica Barrios. “Response to

a Food Safety Problem in Produce: A Case Study of a

Cyclosporiasis Outbreak.” In Global Food Trade and

Consumer Demand for Quality, ed. Barry Krissoff, Mary

Bohman, and Julie Caswell. New York: Kluwer

Academic/Plenum Publishers, 2002.

U.S. imports of raspberries, 1990-2001

Metric tons

Source: U.S. Department of Commerce.

Mexico

Guatemala

1990 92 94 96 98 2000

0

200

400

600

800

1,000

1,200

1,400

1,600

Chile

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