Infectious diseases are caused by the foreign agents, called
pathogenic organisms which infect the body causing serious
complications in the body. As infectious diseases are transmitted from one
individual to another, it is also commonly known as communicable diseases.
Infectious diseases are caused by different classes of
pathogenic organisms. This includes viruses, bacteria, protozoa, and fungi.
Among the various pathogenic organisms, viruses and bacteria are
considered as the main agents of infectious diseases in the human body. Most
infectious diseases are caused when the pathogenic organisms affect a system
within the body. Each class of pathogenic organisms will cause a wide range of
diseases, differing in severity. Most common diseases caused by viruses are
HIV/AIDS, influenza, SARS, smallpox, measles, mumps, hepatitis, Ebola, and
West Nile. Anthrax,
tuberculosis, salmonella, respiratory and diarrheal diseases are caused by
bacteria.
Majority of the infectious diseases are transmitted either
through direct contact or through indirect contact. Direct contact is the
easiest way through which infectious diseases are transmitted. Generally,
direct transmission of infectious diseases takes place in different ways. But,
one of the most common sources is when an uninfected person inhales the
infectious agent in droplets emitted by sneezing or coughing from the infected
person. Some infectious diseases are transmitted indirectly. When the
pathogenic organisms emitted from the host survive in the environment for
longer periods of time, they infect another body. Contaminated water and
inanimate objects contaminated by direct contact are some of the common agents
for spreading infectious diseases indirectly. Cholera, rotavirus infection,
cryptosporidiosis, and giardiasis are some of the infectious diseases spread
through indirect contact.
Treatment of the infectious diseases will vary depending on
the type of the disease. Some complicated infectious diseases like AIDS do not
have a proper treatment till now. So, prevention is best way to reduce the
risk of infectious diseases. Today, most of the infectious diseases are a
major public health problem of both developed and developing countries.
