By Dr.Nithin on 14th July 09

2. • An engineering college has 5 hostels, each having
a separate mess.
• On a particular day between 1 am & 5 am, few
students who ate from one mess were admitted in
the casualty with complaints of vomiting & a few
of them also developed diarrhoea.
• On enquiry, it was learnt that some of the
students who ate from the same mess did not
suffer.
• The food items that were served for dinner were
chapathi, chicken curry, fish fry, peas paneer &

3. • What is the probable diagnosis?
Probable diagnosis is food poisoning
Probable organism is staphylococcus aureus
(short incubation period, sudden onset vomiting,
diarrhoea)

4. 2. How do you proceed to find out the incriminated
food?
a)Secure complete list of people involved & their
history –
 questionnaire concerning the food eaten during the
previous 2 days
 place of consumption
 time of onset of symptoms
 symptoms of illness in order of occurrence
 personal data & any other helpful information.

5. b) Information collected from all those involved is
summarized as follows

6. c) Attack rates are calculated from the collected
information
• The food item likely to be responsible for outbreak is
the one, consumption of which is associated with
highest attack rate

7. d). Laboratory investigation:
 to incriminate the causative agent from stool, vomit, or
remnants of food by inoculating into appropriate media
 to determine the total number of bacteria
 to determine the relative number of each kind of
organism involved
 stool samples of kitchen employees & food handlers
should also be investigated


8. Blood for antibodies:
• is useful for retrospective diagnosis
• Environmental study:
• includes inspection of the eating places, kitchens &
questioning of food handlers regarding food preparation
• Data analysis:
• the data should be analysed according to descriptive
methods of time, place & person distribution

9. 3.Why was it that some students were spared to
from disease?
Some of the students may not have been affected because:
 They did not eat the incriminated food, or they may have
eaten so little of it that it was insufficient to cause
illness
 Individual resistance also plays a role

10. 4.What are the preventive measures that could be
undertaken to prevent such a problem in the
community
A . Food sanitation B. Refrigeration
 Meat inspection  Proper temperature control
 Personal hygiene  Foods not eaten
 Food handlers – medical immediately should be kept
inspection in cold storage
 Food handling techniques  Cook & eat the same day is
 Sanitary improvements a golden rule
 Health education
C. Surveillance