According in both children and adults. In the

According
to Institute of Food Science and Technology (2010), food was first recognized
as a vehicle for viruses in an outbreak of raw-milk associated poliomyelitis in
1914 followed with an outbreak in a primary school in Norwalk, Ohio in 1918
where Norwalk virus was identified as the cause of infection in both children
and adults. In the middle of 1950s, shellfish was identified as the
transmission route in Sweden and then in the United States. The introduction of
molecular methods in 1990s led the identification of viruses as the leading
cause of human gastroenteritis in developed countries. There are many different
viruses can cause gastroenteritis including norovirus, adenoviruses,
sapoviruses and astroviruses and the symptoms are similarly to gastroenteritis
caused by bacteria and parasites.

 

Koopman,
M. (2012) described foodborne transmission is one mode of transmission for many
viruses associated with disease ranging from mild diarrhea to severe
neurological symptoms. Foodborne viruses transmission can occur by faecal-oral
route through contamination of food by food handlers during food production, by
contamination of food during the production processes or by consumption of
products of animal origin harboring a zoonotic virus. The viruses will infect
their hosts after ingestion, followed by invasion of cells in the epithelial
lining of the gut and replicate in the same site or in another place  in the body. The most frequently identified
foodborne viruses through those transmission routes are norovirus, Hepatitis A
virus, severe acute respiratory syndrome (SARS)-associated coronavirus, Nipah
virus and Hepatitis E virus.

 

According
to IFST (2010), foods which are associated with foodborne viruses outbreaks
including:

a.     Molluscan
shellfish including oysters, cockles, mussels

b.     Vegetables

c.     Fruits

d.     Drinking water

e.     Fruit juices

f.       
Milk
and milk products

g.     Undercooked wild
boar or deer meat

h.     Pig liver sausage

i.        
Pork
livers

j.        
Salad
dressing and cake icings

 

In
contrast with foodborne bacterial infections which has established microbiological
control criteria as indicators for food contamination, control criteria for
foodborne viruses is unavailable to protect against foodborne virus infection.
According to Diane et al., (2010), the fundamental properties of foodborne
viruses should be understand in order to establish preventive program and to design
appropriate control measures. There are few challenges in dealing with
foodborne viruses as described by Diane et al.,(2010) and IFST (2010):

 

a.     There is no
systematic surveillance for foodborne viral disease

Most countries have some
level of reporting of foodborne illness outbreaks but few of these systems
include viral foodborne illness. Although case based surveillance is established
for hepatitis A and enterovirus, it does not focus on detecting foodborne virus
transmission as a source of infection resulting insufficient statistics on
foodborne viral diseases or under-reporting.

b.     Detection and
isolation of food or waterborne viruses is limited by :

                                         
i.           
the
non-routine nature of testing for the viruses in foods as the viruses need
living host or tissue to replicate

                                       
ii.           
long
incubation of some viruses such as Hepatitis A

                                      
iii.           
difficulty
or inability to culture in laboratory cell cultures

                                    
iv.           
the
low level of virus particles in a contaminated food

                                      
v.           
techniques
previously available are not suitable for routine application with low recovery
rates

c.     Unnoticed
infections of foodborne viruses due to symptoms which are relatively mild. For
example infections of Noroviruses which are recognized as one of the common
causes of gastroenteritis at the community level. As the symptoms are mild,
infections go unnoticed except during major outbreaks especially in health care
institutions such as nursing homes and hospitals.

d.     Application of
appropriate control measures. For example, freezing will not affect infectivity
of viruses, in fact it may help to preserve the viruses. Many fruits and
vegetables are sold unwashed or with little processing.

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