Food Protection Trends - May/June 2017 - 219

manipulation, which can facilitate the spread of hepatitis A,
but also undergoes little if any heating that would otherwise
aid in inactivating the virus. This employee was infected
during a large outbreak in Oahu, the source of which was
contaminated raw scallops. The sushi restaurant was not
alone, in that employees of at least five other restaurants also
were infected during this same outbreak and worked in food
service during their contagious period (8). The employees
of these restaurants were not ultimately the source of the
hepatitis A outbreak, but there were consequences regardless.
Restaurants with infected employees are required to notify
customers that they may have been exposed to the virus,
which can result in considerable impacts such as demands for
vaccination and for post-exposure prophylaxis as well as loss
of business reputation. All this for a disease that is ultimately
vaccine preventable. In view of the decade that has passed
since the adoption of universal hepatitis A vaccination and
the likelihood that hepatitis A will be targeted for eradication,
the food industry should consider and prepare for likely
changes in vaccination policy.
HEPATITIS A VIRUS
Hepatitis A virus (HAV) is the most common cause
of acute viral hepatitis in the world (5, 23). In developed
countries, HAV is transmitted primarily person-to-person
via the fecal-oral route but can also be transmitted via
contaminated food or water (10, 17, 18). On average, 28
days elapse between exposure to the virus and appearance of
signs and symptoms of infection (18). Symptoms associated
with HAV infection include fever, malaise, anorexia, nausea,
abdominal pain, dark urine, and jaundice. In severe cases,
fulminant hepatitis may result from HAV infection (24) and
carries a case fatality rate up to 80%. Acute liver failure due
to HAV may also result in the need for liver transplantation
and/or significant morbidity and associated healthcare costs
(26). The risk for acute liver failure increases with age (13)
and consequently, the case fatality rate due to HAV infection
also increases with age, being estimated at 0.1% in children
< 15 years old and 2.1% in adults over the age of 40 (12).
The epidemiology of viruses spread by the fecaloral route is understandably influenced by sanitation
and hygiene standards, which are in turn influenced by
socioeconomic status (11). Consequently, the majority of
the world's HAV cases occur in lower-income countries
where the virus is particularly common (11). The result
of high endemicity is that most people in low-income
countries are exposed to HAV as children (13). Therefore,
in low-income countries, few adults are susceptible, as
infection in childhood results in lifelong immunity (10,
17, 18). In contrast, high-income countries such as the
United States have low endemicity of HAV and therefore
a high proportion of susceptible adults (13). HAV
infections in the United States have decreased 87% in the
past decade (14), largely because of vaccination.

HEPATITIS A CONTAMINATED FOOD AND
INFECTED FOOD HANDLERS
Contaminated food has been implicated often in the
spread of the hepatitis A virus. Food products can become
contaminated at any step in the continuum from farm
to fork. Products compromised in the field can result
in widespread outbreaks, such as that caused by HAV
contaminated frozen pomegranate arils, which sickened
165 patients in 10 states in 2013 (6). The pomegranate arils
were likely infected by harvesters working in the fields in
Turkey (6). The same scenario occurred a decade earlier
when green onions imported from Mexico sickened 601
people, three of whom died (28); this outbreak resulted
in a temporary ban on products from this particular farm.
Both outbreaks illustrate the risk associated with accidental
importation of HAV (6, 28). As a result of outbreaks such
as this, many have suggested that hepatitis A vaccination
should be used worldwide as a means of protecting the
global food supply (21, 27).
Although foods may become contaminated with the
HAV virus during any one of a number of processing
steps, most reported foodborne outbreaks have been
traced to HAV-infected food handlers at the point of
sale. HAV is the most common vaccine-preventable
disease in the United States, and the food industry
is the single largest private employer in the U.S. (9).
Therefore, at any given point a number of food handlers
are likely to be infected with HAV, especially given that
many food handlers belong to groups at higher risk for
infections, such as younger persons and those from lower
socioeconomic backgrounds (9). Characteristics that
increase the likelihood of HAV transmission include
asymptomatic infections, long incubation periods, and
long-term survival of the virus on surfaces (9). A single
infected food handler can potentially infect foods, coworkers, and dozens if not hundreds of customers (9).
For example, in 1992, an infected food handler working
for a Denver catering facility spread disease to 43 people,
including nine other food service employees at the same
company (7). In total, these nine employees exposed up
to 5,000 people to HAV; however, over 16,000 people
requested post-exposure prophylaxis (PEP) as a result of
this outbreak (7). This PEP immune globulin treatment
accounted for the majority of the costs associated with
this outbreak, which were estimated at over $809,000 (7).
The impact of foodborne outbreaks of HAV can include
many costs, such as providing vaccines, PEP, serology to
test food workers for active infection, medical costs, and
lost productivity (7, 9, 28). The losses to the business
can also include loss of reputation, discarded foods,
lost productivity, and potential lawsuits from victims
(7, 9, 28). Businesses that employee HAV-infected food
handlers are required to provide extensive notification to
exposed patrons, which can lead to further loss of business

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Table of Contents for the Digital Edition of Food Protection Trends - May/June 2017