Organic Affecting Human Health

Influenza: Influenza is an illness affecting upper respiratory tract symptoms of the disease are fever, headache, and pain in the limbs. Watering of eyes and running of nose and it is associated with sore throat.


Fig 20.20 influenza virus

Causative agent

Different strains of viruses are responsible for causing the disease.

The disease is spread by droplet infection (cough, sneezing, and breath).

Treatment and control

There is no particular treatment of the disease. The patient develops immunity and recovers. Rest is the only immediate treatment. Disease can be controlled by keeping patient away from other people.


Measles is a very infectious and worldwide disease of children. The disease starts with fever with cold, cough and a watery discharge from the eyes. On the third day rashes appear first on the face and then spread over the whole body.

Causative organism

The causative organism is a virus, which is air born and is inhaled in droplets. The disease spreads through the discharge from eyes and nose, which becomes air-born and spreads rapidly.

Treatment and control

There is no specific treatment. Child develops immunity and the signs and symptoms of the disease disappear after seven days. The child should be given plenty of drink especially milk.

It is difficult to control the disease because it is highly infectious as the patient becomes infectious about 2 days before the symptom of the disease develop.


Poliomyelitis is most common among the children but young and old people can also become its victims.

It begins slowly. The sufferer has very high fever, headache, nausea, fits and stiffness of limbs. In severe cases, the virus attacks the nerve fibers of the spinal cord causing paralysis of the limbs and muscles of the respiratory tract, sometime proving fatal, apart from permanent disabilities.

Treatment and control

There are two polio vaccines; Sabin vaccine and Salk vaccine. Sabin vaccine is more common and is given orally in the form of drops. Two or three drops are given to infants during their first year which provides life long protection against polio by developing active immunity against it. Salk vaccine is injected in to the body but it is not being practiced in our country.

Causative organism

Poliomyelitis is caused by virus, which as transmitted by infected water. It is also transmitted b droplet infection during coughing and sneezing, of the patient.


Fig 20.21 polio virus

Aids (acquired immune deficiency syndrome)

AIDS is a disease in which body’s immune system. The system which protects our body against infections is destroyed. The body becomes unable to protect itself against many other diseases i.e. immune deficiency develops.

Causative organism

The causative organism is a virus called HIV (human immune deficiency virus).

Signs and symptoms

The word syndrome is used in aids because it is a disease with many symptoms occurring at the same time. The patient may suffer from chronic fever, severe diarrhea lasting for months, pneumonia etc. and even cancer.

Aids is usually transmitted by

  1. Sexual relationship with an infected person.
  2. Blood transfusion from infected person.
  3. By sharing contaminated injection needles. For example when drug addicts share their used syringes.
  4. By using contaminated razors, surgical and dental instruments etc.
  5. Virus may pass from the infected mother to the fetus during pregnancy.

hiv_virus_fig. 20.22

Fig 20.22 HIV

Prevention and control
Aids can be prevented by talking following measures

  1. By keeping to one’s own sex partner.
  2. By avoiding drug abuse as drug addicts share hypodermic needless.
  3. By using disposable syringe.
  4. By sterilizing the medical equipment before examining the patients.
  5. By avoiding the sharing of instruments that cause lesion and be contaminated with blood e.g. toothbrushes and razors.
  6. By using carefully sterilized surgical instruments / equipments.