Basic introduction communicable

1. 13
Communicable Diseases
13.1 Introduction
For happy living, it is necessary to remain healthy and free from any diseases.
However, you must have seen people suffering from diseases. You must have
realised how weak the disease leaves the person! Do you know that a disease, if
prolonged, may also result in death? Diseases may be the result of infection in
the body such as typhoid or chickenpox, or they may be related to the physiology
of the body such as hypertension and diabetes. Then, there are certain deficiency
diseases also like night blindness which occurs because of vitamin A deficiency.
In this lesson, we will study about diseases which occur because of infection in
our body.
13.2 Objectives
After reading this lesson, you will be able to
define the term ‘Disease’ and name some common diseases;
differentiate between communicable and non-communicable diseases;
identify life style diseases and suggest preventive measures;
identify the cause of the communicable diseases;
define and explain ‘incubation period;
explain ‘immunity’ and its types;
state the causes, symptoms, prevention and cure of some communicable
diseases;

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discuss measures to be taken for preventing various communicable dis-
eases;
take adequate care of the patient at home.
13.3 What is Disease?
The state of disease is the opposite to the state of health. Do you remember how
health has been defined? Go back and read lesson 12.
You must have noticed that when a person has a disease there are certain signs
and symptoms. Each disease has associated signs and symptoms which are par-
ticular to that disease only. Did you notice how your sister was feeling when she
had a bad cold? She had a sore throat, a blocked nose, body ache and slight fever.
However, when your friend had chickenpox, a rash developed on her body, face
and neck. She also had a running nose, moderate fever and a headache. You have
seen that in both the cases the patient is uncomfortable. Can you now define
disease?
Disease is a state of discomfort in which the normal function-
ing of the body is disturbed.
Malaria, conjunctivitis (an eye disease), typhoid, chickenpox are some common
diseases. Can you list out some more diseases?
You know that if somebody in the family gets a cold, it does not spare the others.
However, although your grand father suffers from high blood pressure, nobody
else gets it.
Can you tell why this happens?
Yes, you are right, it happens because common cold spreads from person to per-
son while high blood pressure does not.
13.4 Communicable and Non-Communicable Diseases
Communicable diseases are also known as infectious diseases. They spread from
one person to another, that is, a healthy person may catch it from a patient.
A disease is said to be communicable if it spreads from one
person to the other.
A disease is said to be non-communicable if it does not spread
from one person to another.
You are probably thinking that a communicable disease is communicated either
by air or touch. Well, these are two modes of spread but there are others too. For
example, a disease is communicated by food and water too. In other words, com-
municable diseases spread through air, water, food and contact.

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Let us now make a list of all the communicable diseases.
Influenza, polio, typhoid, measles, mumps, chickenpox, tuberculosis, AIDS are
some communicable diseases.
Think of some more communicable diseases and add to the list.
13.5 Life Style Diseases
These days we hear less about infectious diseases like tuberculosis (T.B) or chol-
era. On the other hand, very often we hear about diseases like diabetes, high
blood pressure, obesity, heart diseases, etc. Have you wondered what causes these
diseases? There is no infection in the body, yet these diseases occur.
This happens because of the defective lifestyle that we follow. What is a life
style? A life style is the pattern of living that we follow - how we work, what
and when we eat, how and when we sleep, etc.
You may have observed the following: -
More and more young people are seen smoking and drinking although these
are harmful to health
Our nutritious, balanced meals are giving way to fast food and junk food,
vegetables are being rejected in favour of cheese and butter, soft drinks are
replacing milk
We prefer to use a car or bus instead of walking
More and more machines are being developed each day to help us with our
work.
All of these are factors which are directly responsible for life style diseases.
What can we do?
People need to change their habits in the direction of healthier living. We can do
a lot to prevent the occurrence of life style diseases. Some suggestions are:-
take up regular exercise like walking, yoga, cycling, etc
take a balanced diet at proper meal times
practice yoga or meditation to avoid stress in life
keep away from smoking and drinking as far as possible.
We can have a very healthy life if we remain conscious of our life styles. It is also
possible to keep these diseases under control, if we make sensible alteration in
our life styles.
13.6 What Causes Communicable Diseases?
Communicable diseases are caused by very tiny organisms called germs and para-

4. Communicable Diseases :: 201
sites. These germs are present everywhere- in air, water, soil, etc.
When germs enter a healthy body through infected food and water, air, contact or
insects, they multiply and upset the normal functioning of the body, thus, pro-
ducing the symptoms of the diseases.
Incubation Period
You have noted above that the germs take some time to grow and produce the
disease in body.
The gap of time between the entry of germs into the body and
appearance of symptoms of the disease is called the Incuba-
tion Period.
Your friend who is suffering from typhoid, must have consumed food infected with
typhoid germs, say 2-3 weeks earlier.
Incubationperiodisdifferentfordifferentdiseases.Duringthisperiod,thepersonmay
remainperfectlyhealthy.
INTEXT QUESTIONS 13.1
1. What is ‘Disease’?
...................................................................................................................
...................................................................................................................
2. Stateonedifferencebetweencommunicableandnon-communicabledisease.
3. Sort out the diseases into two categories of diseases: arthritis, cholera, cancer,
infleunza,diabetes,polio,hypertension,typhoid.
Communicable; ............................................................................................
Non-communicable: .....................................................................................
13.7 Immunity
You have learnt that when a person is exposed to germs, she gets the disease. But you
will be surprised to learn that germs do not have an easy time. Some people do not
become ill even when exposed to germs. Do you remember, when everybody in the

5. 202 :: Home Science
familyhadviralfeverbutyoudidn’thaveit?
Why do you think this happened?
This happened because your body’s defence system protected you from germs. In
other words you had immunity to viral fever.
Doyouknowhowyourdefencesystemfunctions?
Yourbody’sdefencesystemconsistsofwhitebloodcellswhichactassoldierstofight
germs. The white blood cells produce a substance calledantibodiesto fight germs. In
the fight between the antibodies and germs, if the antibodies are able to resist and
destroy the germs then the disease is prevented and the person is said to be having
immunity.
However, if the germs manage to overpower the antibodies, the symptoms of disease
appear. In other words, the person does not have immunity to the disease.
Immunity is the ability of the body to resist a particular disease.
Types of Immunity
Immunitymaybe
(i) Natural
(ii) Acquired
Natural immunity is present at birth and is only towards particular diseases. Healthy,
hygienicenvironmentandgoodhabitsalsogiveyouanabilitytofightdiseases.
However you can also acquire immunity to a disease in two ways.
(a) NaturallyAcquiredImmunity
When you suffer from a disease, the germs are present in the body. So the antibodies
aredevelopedwhichremaininthebloodafteryourecoverfromdisease andhelpyou
fightagainstfutureattackofthatdisease.Thus,youhaveacquiredimmunitynaturally.
Theimmunityacquiredmaybeforashortperiodlikeinviralfeverorlifelongasincase
of measles or chicken pox.
(Antibodies)
These are special chemi-
cals found in the blood
which act against germs.
infectedchild child after one week

6. Communicable Diseases :: 203
Thisideahasbeenusedtodevelopimmunityartificially.
(b) ArtificiallyAcquiredImmunity
When weakened germs are introduced in your body through vaccination, antibodies
are developed in the blood to prevent an attack of a particular disease. To produce
acquired immunity, we have a national programme called universal Immunisation
Programme.Youmusthaveheardaboutit.Itisessentialforhealthylivingofchildren.
Canyounamesomediseasesagainstwhichthechildrencanbeimmunised?
Tuberculosis, diptheria, whooping cough, tetanus, measles, polio are a few such dis-
eases.Youwillstudyaboutimmunisationandthesediseasesindetailinthenextlesson.
IMMUNITY
NATURAL(Inborn) ACQUIRED
Naturally(afterdisease) Artificially(throughvaccination)
INTEXT QUESTIONS 13.2
1. Suggest two steps you can take at home to prevent the occurence of a life style
diseaseinyourfamily.
2. Statewhetherthefollowingstatementsare‘True’or‘False’:
(i) Acommunicablediseasecannotbecauseduntilthegermsenterthebody.
(ii) Immunityistheabilitytocatchaparticulardisease.
(iii) Naturalimmunityispresentfrombirth.
(iv) Immunisationbringsaboutproductionofgermsinthebody.
13.8 How Does Disease Spread?
You know that germs are present everywhere around us and they can spread through
fourmodes:
(i) Food and water
(ii) Air
(iii) Contact
(iv) Insects
Let us now study these in detail.

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(i) Food and Water
You must have often heard your mother telling you to keep food and water covered.
Can you say why you are told so? Yes, you are right. Uncovered food and water are
likely to get contaminated with germs and spread disease. Do you know how else can
food and water get contaminated? It can get contaminated through:
Unhygienicconditionsofpreparation,servingandstoring
Dirtyhandsandutensils
Houseflieswhichtransfergermsfromrubbishandgarbagetofood.
Drinkingwatershouldbetakenfromasafersource.Waterwhichwegetfromthetaps
is safe to drink. Can you tell why? This is because tap water is cleaned by certain
methods that kill germs before it is sent to our homes. But water from wells, ponds,
streams and even hand pumps is generally unsafe and may contain disease causing
germs.
Diseases such as hepatitis, cholera, typhoid, etc., are spread in this way.
(ii) Air
Can you tell what happens when a person suffering from a disease such as influenza,
diptheria, measles, mumps, etc. coughs or speaks loudly or sneezes? Yes, you are
right.Thepersonsufferingwillletgermsofthatdiseaseintotheairwhichwillenteryour
bodywhenyoubreathein.Soyouwillbelikelytocatchthedisease.Theairofcrowded
places,illventilatedhouses,cinemahousesandsoonismorelikelytocontaindisease
causinggerms.

8. Communicable Diseases :: 205
(iii) Contact
Acommunicablediseasemayalsospreadthroughcontact,whichmaybe:
(a) Directcontact
(b) Indirectcontact
Direct contact means you actually touch a person who has the disease. Whereas you
have indirect contact with a patient when you use anything that they have used like
comb, towel, cup, etc.
For example, suppose your brother is suffering from influenza. He covers his mouth
withhishandwhenhecoughsandthenshakeshandswithhisfriend.Thediseasegerms
arepassedthroughdirectcontactfromyourbrothertohisfriend.However,ifhegives
you a glass of water without washing his hands, then the germs are passed from his
hand to the glass and from the glass to you. This is indirect contact.
Think of more examples to explain direct and indirect contact as a mode of spread of
disease.
(iv) Insects
Manydiseasesarespreadthroughinsects.Fliescarrygermsfromrubbishandgarbage
ontheirbodiesandinfectthefoodonwhichtheysit.Thiscausesdiseaseslikecholera.
Mosquitoescausemalaria.

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13.9 Some Communicable Diseases
Let us now study about a few communicable diseases
Name of Disease
1. Cholera
2. Typhoid
3. Hepatitis
(jaundice)
4. Influenza (Flu)
5. Tuberculosis
(T.B)
6. Malaria
7. Tetanus
Mode of
Spread
Food and
Water
Food and
Water
Food and
Water
Air
Air
Mosquito
bite
Wound
exposed to
dust or
rusted item
Symptoms
(i) Sudden onset of severe, watery di-
arrhoea. The faeces look like rice
water
(ii) Vomitting
(iii) Cramps in the legs
(iv) Patient feels very thirsty
(i) Severe headache
(ii) Fever with low pulse
(iii) Dry white coated tongue
(i) Fever
(ii) Dark yellow urine
(iii) Yellowish tinge in eyes
(iv) General paleness
(i) Fever
(ii) Cold, cough, sneezing
(iii) Headache and body ache
(iv) Nausea
(i) Persistent cough
(ii) Loss of weight and appetite
(iii) Excessive weakness
(iv) Rapid pulse
(v) Chest pain
(vi) Breath has bad smell
(i) Fever
(ii) Alternating chill and perspiration
(iii) Headache and bodyache
(iv) Nausea
(v) Vomiting
(i) Restlessness
(ii) Headache
(iii) Fever0
(iv) Stff neck
(v) Difficulty in chewing and swallow-
ing
(vi) Spasm of muscles of jaw and face
(vii) Bending of back in shape of bow
(viii)Severe pain
Management of the Patient
Dehydration can be dangerous,
so give plenty of fluids. Give
Oral rehydration solution (ORS).
Blood culture and other tests
should be done. Give the pre-
scribed medication to the patient.
Give a carbohydrates rich diet.
Keep the patient in bed as long
as there is fever and till appetite
returns to normal.
Control the fever with medicines
and cough with steam inhalation.
Treatment is prolonged so con-
stant monitoring by the doctor
is essential.
Get the blood test done to con-
firm malaria. Then give pre-
scribed medicines.
Put a ball of cotton between teeth
to prevent biting of tongue.
Incubation
period
1-5 days
14-21 days
20-35 days
1-3 days
4-6 days
10-14 days
4 days to 2
weeks

10. Communicable Diseases :: 207
INTEXT QUESTIONS 13.3
Fillintheblanks:
1. (i) Germsspreadthrough
(a) .................................................................................................
(b) .................................................................................................
(c) .................................................................................................
(d) .................................................................................................
(ii) Contaminated food contains.........
(iii) If you touch any article used by the patient, you have ...................... con-
tact.
(iv) Two of the diseases that mainly spread through food and water are
.................
(v) ................... is an example of disease caused through an insect bite.
2. Match the following two columns.
Column I Column II
(a) Malaria (i) Food and water
(b) Tetanus (ii) Contact
(c) Cholera (iii) Mosquito bite
(d) Tuberculosis (iv) Air
(v) wound exposed to dust.
3. Fill in the blanks:
(i) Stiff jaw is the symptom of ...................
(ii) T.B. patient requires constant .................
(iii) Rice water stools are characteristic in .....................
(iv) Hepatitis is also known as ...................
(v) The incubation period for typhoid is ....................
4. State whether the following statements are true or false:
(i) A carbohydrate rich diet is recommended for hepatitis patient.
(ii) Alternating chill and perspiration is a symptom of typhoid.
(iii) Houseflies cannot contaminate food and water.
(iv) The air of crowded places may contain disease causing germs.

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(v) Disease can spread through indirect contact when you use things that
the patient has been using.
13.10 AIDS
Most of you must have heard of AIDS which stands for Acquired Immuno Defi-
ciency Syndrome. But do you know what AIDS actually is?
This is a most serious disease which has appeared only during the last couple of
decades. It is caused by a virus that attacks the body’s natural defence system.
Do you remember what the body’s defence system does?
Yes, it defends the body against many infections. Can you guess what will hap-
pen if there is no defence system in the body?
The germs will attack the body and the person will catch the diseases.
How is AIDS virus spread?
The AIDS virus is spread by-
i) sexual contact with an infected person.
ii) exchange of infected body fluids, e.g., blood transfusions.
iii) use of infected needles for injections, or at birth from infected mother to
child during pregnancy or at birth.
You must REMEMBER that AIDS CANNOT spread by:.
i) shaking hands
ii) kissing on the cheeks
iii) using the same toilet seat
iv) standing close to the infected person
v) through the air, that is, sneezing, coughing, etc.
vi) Through cups, glasses, plates
vii) Water or food
There is no cure for AIDS as yet, nor is there any vaccine to protect the people.
However, some preventive measures that can be taken are:
i) restrict the number of sex partners to one
ii) Use protection during sexual contact
iii) Alwaysuseonlyproperlysterilizedneedlesforinjections

12. Communicable Diseases :: 209
iv) Insist on getting properly tested blood when in need of blood transfusion
v) Avoidpregnancy,ifinfectedwithAIDS.
INTEXT QUESTIONS 13.4
1. The full form of AIDS is ..........................
2. Choose the correct alternative-
(i) AIDS is spread by-
a) shakinghands
b) playingtogether
c) infectedneedles
d) water or food
ii) AIDS cannot be spread by-
a) Sneezing
b) Bloodtransfusion
c) Sexualcontact
d) Infectedneedles
13.11 Preventive Measures
Nowthatyouhavestudiedhowcommunicablediseasesspread,canyouthinkofsome
ways in which they can be prevented? Let us list some precautions that should gener-
ally be observed.
(1) The personal belongings of the patient, that is, clothes, utensils, should bekept
separately.
(2) Safe drinking water - Keep the water at home in clean, covered containers.
Boil the water for 10 minutes to ensure it becomes free of germs. Boil milk
beforeusingit.
(3) Cover food - All food, even left–over scraps, vegetables, fruits, sweets, milk,
etc. should be kept covered.
(4) Wash fruits and vegetables before use– Avoid eating and buying cut fruits,
vegetables, etc. from the market, specially if left uncovered.
(5) Wash all utensils before using them for storing food, milk or water.
(6) Wash your hands before cooking food, before eating food and after using
the toilet.
(7) Keep the house and place of work well-ventilated in order to allow ad-

13. 210 :: Home Science
equateamountofsunlightandairtocomein.
(8) Avoidcrowded places such as cinema houses, specially during an epidemic.
(9) Maintainpersonalhygienebyhavingregularbath,keepingnailscleanandcut
short.Also,washhairregularly.
(10) Keep your house and surroundings clean- Do not let garbage accumulate,
see that drains are clean and covered. See that all doors and windows have a
wiremeshtoprevententryoffliesandmosquitoes.Donotdefecateinopen,use
asanitarylatrine.
(11) Donotspitanywhereandeverywhere.Ifyoumustcough,useahandkerchiefto
cover your nose and mouth.
(12) Immunizechildren-Allchildrenshouldbegiventhepropervaccinationsafter
birth in order to protect them from many diseases.
13.12 Caring for the Sick At Home
Younowknowthemeasuresyoucantakeinordertopreventthespreadofcommuni-
cablediseases.Butifsomeoneinthefamilyfallsill,whatarethethingsyouwillkeepin
mind so that the patient recovers as fast as possible? Some of these things are-
(1) Consultthedoctorimmediatelyinsteadofwaitingfortheintensityofthedisease
to increase.
(2) Follow the doctor’s advice, whatever medicines are prescribed should be given
ontime.
(3) Give the patient a proper and balanced diet as advised by the doctor.
(4) See that the patient takes adequate rest.
(5) Keep the patient’s room clean. The patient’s clothes should be changed every-
day and may be given a sponge bath, if possible.

14. Communicable Diseases :: 211
DISEASES
Prevented
by Immunity
Natural
Types
Acquired
Naturally Artificially
Communicable Non-communicable Life style diseases
Caused by germs
Spread by
Food and water Air Contact Insects
Direct Indirect
Signs, symptoms
and care of:
Cholera
Typhoid
Hepatitis
Tetanus
Influenza
Tuberculosis
Malaria
AIDS
13.13 What You Have Learnt
For your convenience, here are the main points of the lesson:
13.12 Terminal Exercise
1. What is a communicable disease? How is it different from a non-communi-
cable disease?
2. Which of the following may be considered direct contact?

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(i) Using a patient's handkerchief
(ii) Shaking hands with a patient.
(iii) Using a patient’s comb.
(iv) Reading a book read by a patient.
(v) Sleeping on the bed of a patient.
13.13 Answers to Intext Questions
13.1 1. Give the definition of ‘disease’.
2. Communicable- spreads from one person to another whereas non-
communicable does not spread from person to person.
3. Communicable-cholera, influenza, polio, typhoid.
Non-communicable-arthritis, cancer, diabetes, hypertension.
13.2 1.. Increase exercise, encourage balanced meals at regular time, avoid
stress, any other.
13.2 2. (i) T (ii) F (iii) T (iv) T (v) F.
13.3 1. (i) (a) Food and water
(ii) (b) Air (c) Contact (d) Insect
(i) disease germs
(ii) indirect
(iii) cholera, typhoid
(iv) Malaria
2 (a) (iii) (b)(v) (c)(i) (d)(iv)
3 (i) Tetanus (ii) monitoring (iii) cholera
(iv) jaundice (v) 14-21 days
4. (i) T (ii) F (iii) F (iv) T (v) T
13.4 1. Acquired Immuno Deficiency Syndrome.
2. (i) (c) (ii) (a)