Contagious disease and infectious disease are medical terms that are confusing to the laymen. Diseases are infections that are mostly caused by micro organisms such as viruses or bacteria. These microscopic organisms somehow get into our body to interfere with normal body functions causing problems for us. Some of these infections are communicable in the sense that they can spread from one person to another. These are the diseases that are called as contagious diseases. Then there are diseases that you can catch, not from another person but from an insect, rodent or another animal (may be your own pet). Malaria is an example of such a disease as you catch it after being bitten by a mosquito which is an insect.
Thus a contagious disease is a disease that is passed from one person to another either by direct contact or through an object that the infected person has touched. Some examples of this type of diseases are measles and chicken pox which can quickly pass on to one person to another. This is why it is seen that if a person catches chicken pox, some more members of his family also fall prey to this disease if they do not take precaution.
Infectious diseases on the other hand are more dangerous in the sense that they can be contacted by a person even though he may not have come in direct touch with the infected person. This is because these diseases are also air borne or water borne. Air and water become carriers of these infectious diseases.
Flu, colds and some other viral infections are examples of contagious diseases. They can spread through direct contact such as touching, handshaking or kissing infected person. However you can also catch these diseases when the germs reach you through air as when the patient sneezes or coughs. Using infected person’s towel or any other garment is also a cause of spread of these diseases.
Here it is important to remember that not all persons who are exposed to infection or disease that is contagious fall ill. This is because some people have a higher degree of immunity than others. It is the level of our immunity that decides whether we will catch an infection or not. Then there are some viruses that are harder to catch though the diseases may be contagious. The virus of AIDS, though it is a contagious disease does not spread by touching or kissing. Thus AIDS is less contagious though it is more dangerous than many other contagious diseases.
Many people think that contagious and infectious diseases are one and the same thing but there are many significant differences between the two. Though as a general rule, every contagious disease is infectious, but, all infectious diseases are not contagious.
In human beings, there is a comprehensive list of infectious diseases. Here it would be appropriate to mention Dengue that almost caused a terror a few months ago. This life threatening fever is caused by a mosquito called DENV. Humans bitten by DENV get infected with Dengue which is a serious disease but not contagious.
There are many ways of protecting ourselves against infectious and contagious diseases. By keeping good hygiene and eating a well balanced diet, we can have a good immune system to ward of many infectious diseases. By washing our hands every now and then, we can safeguard ourselves from many communicable diseases. Another important method to protect ourselves is to get a shot of vaccine to immunize ourselves from infectious diseases when they are prevalent.