(i) Preventing overcrowding
(ii) Providing safe drinking water
(iii) Cleanliness in the school premises and also in the classroom.
(iv) Use of handkerchief or towel while sick student is sneezing or coughing.
(v) Use of clean toilets.

For eliminating polio, the vaccines are prepared from weakened infectious agent.These vaccines are in liquid form, usually called poliodrops.polio drops or preparations stimulate the body to produce antibodies against the polio virus and make body immune to the polio disease.As polio virus affects children, campaigns are organised to provide polio drops periodically to children under 5 years of age.

This is because when the immune system of our body first comes across an infectious organism like a virus causing small pox, it responds against virus and then remembers it specifically.When next time that particular microbe or its close relatives enter the body, the immune system of the body responds with the pathogen even with greater vigour.This eliminates the infection more quickly than the first time and thus we do not suffer with disease again.

(i) To reduce the effect of the disease
(ii) to kill the cause of the disease.

DPT vaccination also called Triple antigen because this affects three antigens to produce antibodies three diseases.They are
(i) diphtheria
(ii) pertussis
(iii) tetanus

(i) Headache
(ii) Cough
(iii) Loose motion.
Even seeing one symptom, I will go to doctor .
Reason.A single symptom is the sign of a disease.On delaying it may lead to serious illness.For example, headache may mean meningitis 

(i) Infection
(ii) poor health
(iii) Lack of proper and sufficient food
(iv) Lack of public services
(v) Genetic defects.

(i) Remain away from specific and particular cause for discomfort or disease.For which personal and public cleanliness and good physical environment are necessary.
(ii) proper and sufficient food necessary for functioning of cells and tissues of the body.

Group of diseases:
(i) Infection diseases: These diseases are caused by some parasitic organism, such as bacteria, viruses and can be transmitted to other examples of such diseases are malaria, jaundice, etc.
(ii) Non-infection diseases: They may be genetic or due to malfunctioning of internal body organ without infection.They do not spread in the community.For example, high blood pressure.

(i) Exposure to air borne diseases can be prevented by providing living conditions that are not overcrowded.
(ii) Exposure to water borne microbes can be prevented by providing safe drinking water i.e., water treated to kill any microbial contamination.
(iii) The person suffering from an infectious disease should be kept in isolation
(iv) One should take balanced diet to make the immune system strong.This will also help in preventing infectious diseases.

1. The tissue-specificity of the infection leading to very general-seeming effect is seen in case of HIV infection.In this case, HIV infecting virus goes to the immune system and damages its functions.Therefore, body cannot fight off the many minor infections that we face daily.
2. For example, small cold can become pneumonia; a minor gut infection leads to major diarrhoea with blood loss.These and other such diseases may cause death of HIV-AIDS patient.Thus, the other infections kill people that are suffering from HIV-AIDS.
3. The tissue-specify of the infection is lymph nodes.General seeming effects are loss of immunity to even minor other diseases or other minor infections that lead to death of the patient.

(c) You are more likely to fall sick when your friend is suffering from measles. This is because measles is highly contagious and can easily spread through respiration i.e., through air. Thus, if your friend is suffering from measles, stay away from him otherwise you might easily get infected with the disease.

(i) Immediate cause of disease is Infectious organisms like virus, bacteria, fungi, protozoan etc.For example, the cause of loose motions can be an infection with a virus, Here viruses is the immediate cause of disease.
(ii) Contributory cause of disease:
(a) poor health due to lack of good nourishment.
(b) poor economic condition due to which one does not get proper and sufficient food and lives in unhygienic conditions.
(c) genetic defects which cause some people more prone to disease than others.
(d) Lack of public services.

Prevention of Infection
"Infection of various kinds is the most important single cause of disease and death in this age period" This cannot be observed by an untrained midwife at the time delivery of in home.
The basic principles underlying preventive measures are:
1.Prevention of contact with infected individuals.
2.Maintenance of cleanliness.
3.Follow immunization procedures as given below:

(b) (1) Community service
(2) Social responsibility.

(i) Vaccination against small pox.
(ii) BCG vaccination against tuberculosis.
(iii) Polio drops against polio disease
(iv) Vaccination against chicken pox.
(v) Vaccination against Hepatitis
(vi) DPT vaccination against dipheria, pertusis
(viii) Immunisation against measles.
Major health problems are:
(i) Hepatites
(ii) Chicken pox
(iii) Tuberculosis
(iv) Tetanus.