What Are the Causes of Communicable Diseases?


Communicable diseases are those that are spread from one person to another person, from animal to animal, or from animal to person, or vice versa. It is likely that everyone will come down with a communicable disease at some point in their lives. It is important to learn about the causes of communicable diseases and ways to prevent their spread. For example, some may say that HIV is caused by sexual contact. This is not true. It is simply the way it is spread. Causes of communicable diseases are dependent on a number of factors, including the agent, environment, transfer method and host.

The Agent

In most cases, communicable diseases are either viruses or bacteria. These are known as agents. Both have the ability to cause remarkably similar symptoms. In most cases, those who are unsure should be checked by a doctor in order to get an accurate diagnosis. In both cases, the doctor can prescribe a treatment plan, if one exists, for the patient.


One of the primary causes of communicable diseases is the environment. Diseases are much more likely to spread in places where hygienic practices are minimal. Furthermore, being around those with communicable diseases is also a high-risk factor. Therefore, care should be taken to keep the environment as clean as possible and avoid direct contact with those who are ill whenever possible.

Transfer Method

Communicable diseases can be transferred in a number of different ways. The most dangerous are those that can be transferred through the air. Bodily fluids also present a prime vehicle for transfer, especially saliva, mucus and blood. Sexual contact is another way to transmit some forms of communicable diseases.


Every virus must have a host in order to carry out a life cycle of replication, which is responsible for eventually making a person becoming ill. Bacteria, which can live for an extended period of time outside of a host, still need to find one eventually. Therefore, these agents are engineered by evolution to seek out a host as quickly as possible.


In order for a communicable disease to flourish, all of these factors must be in place. In some cases, the agent can be prevented through a vaccine. In other cases, fighting communicable disease centers on the environment, transfer method or host. Keeping surroundings clean, avoiding transfer methods and practicing healthy eating and exercise habits can all help. Wearing a mask can also be helpful.


Once a disease does infect a person, there may be a number of different choices. Antiviral medications can help weaken the virus. Antibiotics can kill a bacteria. However, there some viruses that are immune to antiviral products and some bacteria have become resistant to antibiotics. In some cases, treatment relies on controlling, rather than defeating, the infection.