Clarification of Answer by
26 Aug 2003 20:27 PDT
I'm going to start by addressing each of the subquestions in your
* "Why is it necessary to wash dishes with soap?"
My answer above deals directly with this point. Basically, soap "makes
water wetter" and makes it easier to remove grease and oil from the
dishes. If you still need clarification on this point, please do not
hesitate to ask for further clarification.
* "Isn't rinsing the food off dirty dishes with just water enough?"
Again, my answer above explains this clearly as "No." If you want me
to clarify this as well, I'd be happy to.
* "Do germs or bacteria grow on dishes that have been eaten on and
Yes they do, as I said above. Again, just ask if you need
clarification on this point.
* "If so, do these germs or bacteria cause sickness when we eat on the
same dishes again??...I need to know how NOT washing dishes with soap
can affect your health."
Reading over this question, I've realized that my original answer may
have been unclear in regards to this sub-question. Here, I'll try to
explain this part in more detail. Before doing so, however, I'd like
to remind you that Google Answers is a service which is intended to
provide you with general information. It is not a substitute for
medical advice from a trained medical professional. Also, I am not a
trained doctor. Therefore, I would *highly* advise you to consult with
a real medical professional if you need real medical advice about any
of these subjects.
Healthlink, at the Medical College of Wisconsin has a web page at [
http://healthlink.mcw.edu/article/1008283853.html ] entitled "How to
Stop Food-Borne Illness Before it Starts." It briefly describes
different illnesses that can result from contaminated food, and also
explains how cleanliness is vital to prevention of some of these
"Prime causes of food-borne illness include bacteria, parasites and
viruses such as E. coli, Salmonella, Listeria, Shigella, Giardia,
Cyclospora, Cryptosporidium and hepatitis A virus. These organisms can
be found in a wide range of foods and drinks, including meat, milk and
other dairy products, spices, chocolate, seafood and even water.
Bacteria such as Listeria monocytogenes, Vibrio vulnificus, Vibrio
parahaemolyticus and Salmonella have been found in raw seafood; and
oysters, clams, mussels, scallops and cockles may be contaminated with
hepatitis A virus.
Cross-contamination can occur when cutting boards and kitchen tools
that have been used to prepare one contaminated food (such as raw
chicken) are not cleaned before being used for another food (such as
vegetables). Hot or cold foods left standing too long at room
temperature provide an ideal climate in which bacteria can grow. The
first rule of safe food preparation in the home is to keep everything
Always use clean utensils and wash them between cutting different
Machinery such as food processors, meat grinders and juicers should be
taken apart and cleaned as soon as possible after they are used."
The Federal Citizen Information Center has a page of similar
information at [ http://www.pueblo.gsa.gov/cic_text/food/unwelcome-dinner/dinguest.html
] and which says the following:
"The prime causes of food-borne illness include bacteria, parasites
and viruses such as: Escherichia coli O157:H7, Campylobacter jejuni,
Salmonella, Staphylococcus aureus, Listeria monocytogenes, Clostridium
perfringens, Vibrio parahaemolyticus, Vibrio vulnificus, Shigella,
Giardia lamblia, Cyclospora cayetanensis, Cryptosporidium parvum,
hepatitis A virus, and Norwalk and Norwalk-like virus.
Careless food handling sets the stage for the growth of
disease-causing "bugs." For example, hot or cold foods left standing
too long at room temperature provide an ideal climate for bacteria to
grow. Improper cooking also plays a role in food-borne illness.
Foods may be cross-contaminated when cutting boards and kitchen tools
that have been used to prepare a contaminated food, such as raw
chicken, are not cleaned before being used for another food such as
In both of the above examples, the lessons are clear. Improperly
cooked or prepared foods may harbor various diseases, parasites, and
bacteria. Other "germs" may grow on food which has sat at room
temperature for more than a limited amount of time. If the dishes are
not properly cleaned, then these "bugs" may stay on the dishes,
possibly contaminate nearby dishes and foods, and infect the next
person who uses them. To reiterate one of the statements above, "The
first rule of safe food preparation in the home is to keep everything
A student handout at [
] for a Food Safety and Protection course provides the following
estimate regarding how quickly bacteria can grow at room temperature:
"The following chart shows how rapidly bacteria can grow. Bacteria
reproduce by a process called binary fission. Bacteria reproduce at
different rates and vary in sizes. We start with one bacterium and in
15-20 minutes it divides in two. Bacteria do not start growing right
away, it takes several hours for them to totally adjust to the new
TIME NUMBER OF BACTERIA
15 MINUTES 2
30 MINUTES 4
45 MINUTES 8
1 HOUR 16
2 HOURS 256
3 HOURS 4096
4 HOURS 65,536
5 HOURS 1,048,576
6 HOURS 16,777,216"
The same handout also provides the following information about various
health issues that may be caused by unsafe food:
"(1) Salmonella. Associated with poultry and poultry salads; meat and
meat products; shell eggs and egg products, such as custards and
sauces; sliced melons and raw sprouts. Does not form spores and is
(2) Listeria. Associated with unpasteurized milk and cheese, ice
cream, and chilled ready-to-eat foods. Does not form spores and is
(3) Campylobacter. Associated with unpasteurized milk and dairy
products, raw poultry, non-chlorinated and fecal contaminated water.
Does not form spores.
1. Staphylococcal. Associated with reheated foods and other meats,
poultry, egg products, and other protein foods. The causative agent is
usually present in boils, infected cuts, other sores, and postnasal
drip or sprays expelled from coughing and sneezing. Does not form
spores and is facultative.
2. Clostridium Perfringens. This is commonly known as the leftover
disease. Associated with cooked meats and meat products that have been
improperly cooled and reheated. It is a normal inhabitant of the
intestinal tract of man. It is spore forming and anaerobic.
3. Botulism. Associated with foods that were under-processed or
temperature-abused in storage; canned low-acid foods (home canning);
untreated garlic and oil products. This disease has a 65% mortality
rate. Ingestion of the toxin in foods leads to nerve paralysis
manifested by symptoms of weakness, headache, dizziness, and loss of
voice, followed by death due to respiratory or cardiac paralysis. It
is spore forming and anaerobic.
(1) Hepatitis A is a virus that can occur when raw or improperly
cooked seafood is eaten. Also spread from infected food handlers to
food. Contaminated shellfish are commonly implicated in Hepatitis
outbreaks. Symptoms include fever, fatigue, headache, nausea, loss of
appetite, vomiting, abdominal pain, and jaundice after several days.
(2) Norwalk Agent and Rotavirus are gastrointestinal infections that
occur from consuming contaminated water, shellfish, raw vegetables and
ready –to-eat foods, such as fresh fruits and salads. Rotavirus
is more common in children than adults. Symptoms of both viral
infections include vomiting, diarrhea, abdominal pain, headache, and
1. Trichinosis is a parasitic (roundworm) foodborne illness that
occurs from eating raw or under cooked pork or wild game animals.
Symptoms include nausea, diarrhea, abdominal pain, occasional
vomiting, fever, muscle soreness, extreme sweating, chills, and
2. Anisakiasis is a parasitic (roundworm) foodborne illness that
occurs from eating raw, undercooked or improperly frozen seafood
(haddock, pacific salmon, flounder, sushi, and sashimi). Symptoms
include tingling or tickling sensation in throat, vomiting or coughing
up worms, and sever abdominal pain."
Finally, this page lists methods of prevention for many of the
problems described above:
"Organisms causing most disease transmitted through food come in from
people preparing and serving food, although some appear to be
perfectly healthy. They also come from the mouth, nose, or body wastes
of persons who are sick or are carriers of disease. Persons who cough
or sneeze on their hands, wipe their lips with their fingers, fail to
wash their hands after visiting the latrine or handling contaminated
utensils and linen, will have disease organisms on their hands. If
they handle food or clean utensils, these organisms will be passed on
to the food or utensils and then to the unfortunate customers.
Consistently practicing good personal hygiene can prevent this from
Practice of Personal Habits. The overall cleanliness and observation
of good personal hygiene by the food service employee includes not
only his/her personal cleanliness, but also the way he/she performs
routine duties. The following is a list of personal habits to avoid
with appropriate recommendations:
(a) Sneezing or Coughing. Bacteria are present in the mucus or saliva
expelled from a person's mouth or nose when he/she sneezes or coughs.
These droplets may fall on or in the area of food. Therefore, good
sanitary manners require the use of a clean handkerchief. Hand washing
is also in order after coughing or sneezing.
(b) Using Toilet Facilities. Do not forget to wash your hands after
using the toilet. Hands contaminated with human waste is a major cause
of foodborne illness."
Any of the above conditions could be present in food that remains on
dishes which have not been cleaned properly. As you should realize by
now, some of these conditions are caused by contaminated raw food,
some are caused by airborne bacteria which begin growing on food which
has come to room temperature, and others are spread by contact with
infected humans. All of these could remain on plates, dishes, and
cutlery which have not been properly cleaned, and therefore spread to
other people who attempt to eat from them. As you've seen above,
bacteria may grow at an exponential rate, so even a small amount could
cause illness. As stated in my original answer, using soap to clean
dishes is one important factor in ensuring that the dishes will become
Now that I've provided the additional information above, I'm going to
try to address your follow-up questions in the posted clarification
First, let me note that some of these questions appeared to go well
beyond the scope of the original question that you posted. Your
clarification stated that "Maybe I didn't state the question clearly
enough. Sorry for that." Since I don't count mind-reading among my
many skills, I was unable to read these additional questions into your
original question. Nevertheless, I did my best to provide suitable
answers to your follow-up questions in the additional details that I
provided above. Please keep in mind, however, that despite my best
efforts to answer these follow-up questions, some of them are by their
very nature impossible to answer conclusively, and I've detailed my
reasons for believing this below.
* "I want to know if we leave the bacteria and germs on the dishes
will we get sick?"
This question does not lend itself to a simple answer. This depends on
the amount of contamination on the dishes, the strength of the
individual's immune system, and many other factors. By failing to
clean dishes, you certainly create more potential for bacteria,
parasites, viruses, and other "bugs" to make contact with another
human being. Above, I have detailed many different types of "bugs" and
contamination that could exist on uncleaned dishes. There's no way to
absolutely determine if a given individual will get sick, but by
cleaning the dishes you most certainly reduce that potential.
* "if so, with what disease?"
Above, I have provided various lists of known food-borne illnesses,
along with descriptions of what types of foods they are most likely to
contaminate and conditions which encourage their existence on food.
* "how common is it to get sick from eating off off un-washed dishes."
This is also very difficult to answer conclusively. Let's say, for
example, that one day you wake up with mild diarrhea. Can you
conclusively prove that you became ill due to food poisoning from the
dirty dishes you ate on the night before? Perhaps your illness was
instead caused by a bad piece of fruit? Or by failing to wash your
hands after playing with a baby? You'll never know, and since most
people don't report mild cases of diarrhea to their doctors, it's
doubtful that real statistics exist about the commonality of diseases
spread specifically by unclean dishes.
Keep in mind that there very well may be statistics on severe food
poisoning. But, again, we can't be sure if this occurred due to
unclean dishes or other contaminated food. Unclean dishes are almost
certainly one factor in food-borne illness, but I believe it would be
difficult to separate this into a separate statistical category.
I hope this has provided the clarification you needed.