A disease is an illness to the body. A person suffering from a disease becomes sick and weak. Diseases that spread from one person to another, are called communicable diseases. Communicable or infectious diseases spread from a sick person to a healthy person. Such diseases are caused by microscopic organisms called germs.
There are different types of germs as follows:
(1) Bacteria : Bacteria are single-celled plants which may be round, rodshaped or spiral in shape. Micro-organisms are extremely small living creatures that can be seen with the help of a microscope only. Disease-causing bacteria are also called germs or pathogens. Bacteria can cause typhoid, cholera and tuberculosis etc.
(2) Viruses : Viruses are much smaller than bacteria and can be seen with the help of an electron microscope only. They become active only on entering a living body. They are filterable. Viruses cause influenza (flu), rabies, measles and small pox etc.
(3) Protozoa: Protozoa are much bigger than bacteria. They are single celled creatures. Amoebic dysentry and malaria are diseases caused by protozoa, amoeba and plasmodium respectively.
(4)Fungi : Fungi are very small non-green plants. They are larger than bacteria. Fungi cause disease called ringworm.
How do we become sick?
Germs live everywhere. They are present in air, dirty water and in all kinds of uncleaned items around us. They also live inside the body of animals and human beings.
At times germs enter the human body in large numbers and make person sick and infected. These germs do not allow the body to function properly. A particular disease is caused by a specific kind of germ. For example, typhoid is caused by a germ which is different from that which causes cholera.
Every disease has some definite symptoms. For example, the virus that causes common cold affect the throat and lungs of the person. A person suffering from common cold coughs and has a running nose.
Similarly, if a person vomits and passes watery stools several times a day, he might be suffering from cholera. The doctors are able to diagnose the disease by studying its symptoms. At times a person suffering from infectious disease is shifted to a hospital for proper care and medical treatment.
How germs get transferred from one person to another?
Communicable diseases pass from one person to another through different ways. These different ways are called modes of transmission. These are :
(1) Air: Coughing or sneezing by an infected person releases germs into the air When a healthy person breathes this air, germs enter his body and make him sick. For example, when a person suffering from common cold or tuberculosis, coughs or sneezes, the germs present in his throat and lungs are thrown out into the air. When a healthy person breathes in this air, the germs enter his body and make him sick. Germs of certain diseases like chicken pox, common cold and tuberculosis spread through air.
(2) Infected food and water : Sometimes food and water is infected by germs. Flies carry germs. When they sit on our food, they pass on these germs to our food. When we eat this infected food, we fall sick. Impure water also contains germs. Drinking this water can make us sick. Diseases such as cholera, typhoid, jaundice and diarrhoea are spread by infected food and water.
Precautions taken to get infected by a communicable disease
(i) Some germs grow in over-ripe fruits and stale food. Don’t eat such food. (ii) Food cooked in unclean vessel or kept in uncleaned places may have germs. Keep your surroundings clean. Do not eat food kept in uncleaned utensils.
(iii) Germs can get into your food when you handle it with dirty hands. Wash your hands before touching food or water
(iv) Germs from the air often settle on food and drinking water kept uncovered. Do not eat food or take fruits juices or water from roadside stalls.
(v) Flies carry germs: Keep food and water covered.
(vi) Germs can get into your body through faeces. Wash your hands with soap and water after you go to the toilet
(3) Direct contact: The clothing and other articles used by a sick person are infected. When a healthy person comes in direct contact with these, some germs enter his body. These germs may cause diseases like chicken-pox, measles and common cold through direct contact.
(4) Insect bites : Some insects are blood-sucking. When mosquito bites a person suffering from malaria, it sucks his blood that contains the germs of malaria. When this mosquito bites a healthy person, the germs pass on to the healthy person and he also gets an attack of malaria. Diseases like, plague and malaria are spread by insect bites.
Houseflies feed on dirt. They can cause cholera and typhoid.
The Aedes mosquito causes dengue, a very fearful disease. The symptoms of dengue are fever with shivering bodyache, eyeache and rashes on the body. Mosquitoes also spread a dangerous disease called chikungunia.
Malaria, dengue and chikungunia can be controlled by the following measures :
Do not allow water to collect around homes, gardens, schools, offices and playgrounds as mosquitoes lay their eggs in water. Introduce fish in the ponds. They feed on mosquito larvae and do not let mosquitoes multiply. Use mosquito repellent cream to keep mosquitoes away. Use a mosquito net to sleep in. If malaria is common in your area, ask your doctor to prescribe preventive medicines and take them regularly.
Clean habits help prevent the spread of diseases. A clean person is a healthy person. Do the following to maintain your personal hygiene.
(i) Brush your teeth at least twice a day. Clean your tongue with a tongue cleaner.
(ii) Wash your hands with soap and water after you visit the toilet.
(iii) Have a bath daily. Clean your nose and ears after taking bath.
(iv) Keep your finger nails short and clean. Do not bite your finger nails.
(v) Always wear clean clothes and keep your surrounding clean.
(vi) Do regular exercise and take enough rest to keep your mind and body healthy.
Prevention of Communicable diseases
Communicable diseases are contagious. They can, however, be prevented if we follow some basic guidelines:
(i) Keep yourself and your surroundings clean. Wash your hands before and after eating anything. Keep the garbage in the dustbin and always cover it. Use disinfectants to kill the germs.
(ii) Let sufficient air and sunlight enter your house. Sunlight is a natural disinfector.
(iii) Boil or purify water and store it in a clean, covered container. This way you may not get suffered from water-borne diseases.
(iv) Mosquitoes breed in stagnant water. Remove water from water coolers time-to-time. Use mosquito repellents to keep mosquitoes away.
(5) Vaccination: Germs are present everywhere. They often enter your body but many times they do not cause diseases. That is because your body has the capacity to kill the germs before they are able to attack you. This capacity of the body can be increased by taking vaccines.
Vaccines protect a person from certain diseases. They kill micro-organisms causing diseases and reduce the risk of infection.
After vaccination the body is ready to fight away the infection. Thus preventing the occurrence of that disease. Vaccines are available for many diseases such as, polio, diphtheria, whooping cough, typhoid etc. There are certain diseases for which all be immunized in childhood.
New discoveries in the field of modern medicine and personal hygiene can help to protect us from diseases. There are natural programmes to eradicate communicable diseases.