Infectious diseases are the cause of invasion by microorganisms such as parasites, bacteria or viruses which affects an organism which plays host to the microbes within the human body. The ways through which these foreign replicators enter the human body include bites from insects, eating contaminated food, physical contact and exposures to the ill effects of the environment. The microorganisms that affect the body are pathogens which cause illness and disruption to the tissue system. Some pathogens cause diseases by invading hosts which are susceptible while some others known as opportunistic pathogens can only harm a person when the particular person is less immune to diseases.
Causes of infectious diseases are due to invasion of viruses, bacteria, parasites and fungi which enters the body through direct and indirect means. Direct contact includes person to person contact which is most common. Other ways of direct contact are animal to person through bites, handling of waste from animals and transmission of germs from a mother to unborn child. Indirect means include picking up germs from any infected person through any media, bites from poisonous insects and contaminated food.
Some of the common infectious diseases are:
Cholera: This disease is generally associated with drinking unsafe water and unhealthy sanitary conditions. The symptoms are cramps in the legs, vomiting and diarrhea which cause dehydration and can lead to death.
Dengue: Severe headaches, high fever, joint and muscle pains and rash are associated with Dengue which is caused by bites from mosquito belonging to the Aedes Aegypti species.
Hepatitis A, B and C: This is also a contagious disease which affects the liver and symptoms include dark color urine, fatigue, fever and jaundice. Vomiting is also associated with Hepatitis B which is most common.
AIDS: This is one of the most dreaded infectious diseases which is spread through contacts between male and female or through blood transmission from an affected person.
Influenza: This is a common type of disease which is caused by virus attacks on the respiratory organs and results in coughing, nasal congestion, fatigue and fever.
Malaria: This is a disease borne by mosquito which results in high fever, weakness and anemia besides other symptoms.
Measles: Most commonly seen in infants, this disease causes diarrhea, rashes over the body, pneumonia, coughing and high fever.
Meningitis: Meningitis is an infection of the spinal cord caused by bacteria or viruses. Meningitis attacks by bacteria are more severe and can result hearing loss, damage to the brain and other types of disabilities.
Treatment for infectious diseases includes use of antibiotics that are only for bacterial infections and is grouped according to the type of bacteria attacking the body. Antivirals have been developed to combat certain types of diseases like AIDS, Hepatitis B and C, influenza and others. Fungal infections can be fought by using antifungals which enhances the immunization and helps in the process of convalescence. Anti-parasitics are applied in case of infections from parasites.