Infectious diseases are still a danger to the human race. These diseases can spread from people to people as well as animals to people. Some infectious diseases have a short-term, mild effect whereas some have a serious effect leading to permanent damage to the patient. In this article, we shall see some information related to infectious diseases and know more about the different form of illnesses.
What are Infectious Diseases?
Infectious diseases are illnesses that are caused by a biological agent such as bacteria, virus, fungi or parasites. The human body gets infected by these foreign organisms, mostly microorganisms. These microbes are invisible to the naked eye and present all around you. Some are even present on your body and within the body. They make up the natural flora of the human body. They do not cause any harm, but some of them are opportunistic pathogens like Staphylococcus, that cause infection when the body has low immunity.
The microbes that lead to infections are called as pathogenic organisms or pathogens. The bacteria and virus are the most common pathogens. Other pathogens include fungi, protozoa as well as certain parasites like tapeworm.
The human body is a host for a number of microbes. These microbes invade the human body and cause disruption and weakness in the normal functioning of the body. In response to the invading microbe, the body launches a defense attack. This immune system gets into an overdrive and starts cleaning or killing the microbes. The attack causes one to develop inflammation at the site of infection, fever, vomiting, etc.
How Do Infectious Diseases Spread?
Microbes invade the host body and begin multiplying using the host body resources. Thus, this causes problems in the normal functioning of the infected part, organ or tissue. Microbes can enter the body by the following mode of entry:
- Respiratory Tract Illnesses: Illnesses like the flu, common cold, sore throat, measles, etc. can spread through inhalation of airborne droplets containing microbes. These droplets are spread after an infected person sneezes or coughs. These droplets can also spread after one comes in contact with surfaces contaminated by these droplets. These include doorknobs, toys, pens, etc. Serious infections such as polio too can spread through the respiratory tract. Thus, one should always cover their mouth and nose when they sneeze and cough.
- Food Borne Illnesses: Infections can spread through contaminated food and drinks. There are many bacteria, fungi, viruses as well as parasites that gain entry into the body by ingestion of contaminated food and drinks. Maintaining hygiene, washing and cooking foods properly as well as avoiding roadside eatables is a way of preventing the spread of food borne illnesses. Most of these illnesses are due to fecal-oral transmissions, where pathogens from the fecal-oral route contaminates food as well as water.
- Vector Borne Illness: Infections that spread by a vector who serves as an intermediate host to a healthy person is called as vector borne illness. Diseases such as malaria , Lyme disease, etc. spread through the bite of a mosquito or deer tick.
- Person-To-Person Contact: Many illnesses spread by direct contact with the infected person. Body fluids that contain microbes can enter the body through saliva, blood, semen, pus or an open wound. Many diseases like leprosy, chicken pox, impetigo, warts, etc. spread through direct contact with an infected person or body fluids. In many cases, diseases like Hepatitis B, C or HIV spreads through contaminated blood transfusion.
- Sexual Transmission:STDs like gonorrhea, syphilis, HIV/AIDS, etc. spread through unsafe intercourse with an infected person.
- Vertical Transmission: When an infected woman gets pregnant or acquires an infection during pregnancy, it results in vertical transmission. This means, the infection can spread from the mother to her embryo, fetus or child during pregnancy or childbirth.
- Latrogenic transmission: Infection that spreads due to medical error or lapse, that is injection or transplantation of an infected material into a healthy individual.
- Animal to person: When diseases from animals spread to humans they are called as zoonotic diseases. Rabies is an example of such an infectious disease. Other illnesses such as toxoplasmosis or getting infected with tapeworm are examples of diseases or parasites spread through animals.
What Are the Symptoms of Infectious Diseases?
Every infection has its own set of signs and symptoms. The symptoms help one recognize what type of infection it is, that is, bacterial or viral. Fungal infections are mostly related to a particular body part. Parasites can lead to loss of appetite, vomiting, nausea, weight loss or inflammation, swelling and reddening of the affected part. Infections also cause fever, muscle ache, fatigue, loss of appetite, rash, breathing problems, seizures, etc.Some of the common signs to differentiate between viral or bacterial infections include:
Bacterial Infections: cause
- Redness, swelling, and heat on the infected part
- Pain at the site of infection
Viral Infection: causes
- Symptoms are mostly systemic, that includes runny nose, cough, body aches
- Not all viral infections cause pain
- One usually complains of itching or burning sensation at the site of infection
Note : Signs and symptoms of infectious diseases are not just limited to the ones mentioned in the preceding paragraphs. These are some of the general symptoms that usually accompany infections. There are many other specific symptoms that are specific, if not exclusive, for every infection and disease.
How Are Infectious Diseases Diagnosed?
The diagnosis of infectious diseases is made by noting the physical symptoms and taking the medical history of the patient. There are various diagnostic tools that help diagnose a particular infection. Some of the common diagnostic methods to detect infection include:
- Blood tests
- Microbial culture
- Stool samples
- Microscopical tests
- Biochemical tests
- Molecular diagnostic tests
How Are Infectious Diseases Treated?
Infectious diseases are with the help of medications. There are different types of medications based on the type of infection. These medications include:
- Antibacterial (for bacterial infections)
- Antiviral (for viral infections)
- Anthelmintics (for parasitic infections)
- Antifungal (for fungal infections)
These medications can be given:
- Orally in form of tablets, capsules, powder, syrups
- Applied topically in form of creams, gels, powder
- Intravenous antibiotics
- In form of injections
There are many infectious diseases that cause havoc in the world in the form of endemics and pandemics. Some of these include Swine flu that still causes many deaths around the world. Infections such as HIV/AIDS have countries invest millions to find a cure. Many countries around the world are fighting a battle to get rid of the nasty polio virus that ruins the lives of thousands of children. There are different ways to prevent infections that includes vaccinations. Any sign of fever, chills or rashes, one should speak to a doctor. Prevention of the key to avoid infectious diseases.
Written by: Saptakee sengupta
Date last updated: March 15, 2015