What to know about infections
Chain of Infection: An infection occurs when a microorganism – such as bacteria, fungi, or a virus – enters a person’s body and causes harm. The effects of infections occur due to the immune system’s attempt to get rid of the invading organism.
In many cases, the immune system can stop these pathogens from multiplying in the body. If not, serious damage can result.
The microorganism uses that person’s body to sustain itself, reproduce, and colonize. These infections microscopic organisms are known as pathogens, and they can multiply quickly.
They can spread in several different ways, including through:
- skin contact
- the transfer of bodily fluids
- contact with feces
- ingesting contaminated food or water
- inhaling airborne particles or droplets
- touching an object that a person carrying the pathogen has also touched
In this article, we explain the different types of infections, how to reduce the risk of infection, and what symptoms they cause.
Types
Chain of Infection:How an infection spreads and it’s effects on the human body depend on the type of pathogen.
The immune system is an effective barrier against infectious agents. However, pathogens may sometimes overwhelm the immune system’s ability to fight them off. At this stage, an infection becomes harmful.
Some pathogens have little effect at all. Others produce toxins or inflammatory substances that trigger negative responses from the body. This variation means that some infections are mild and barely noticeable, chain of infection while others can be severe and life threatening. Some pathogens are resistant to treatment.
Infection can spread in a variety of ways.
Bacteria, viruses, fungi, and parasites are different types of pathogens. They vary in several ways, including:
- size
- shape
- function
- genetic content
- how they act on the body
For example, Chain of Infection viruses are smaller than bacteria. They enter a host and take over cells, whereas bacteria can survive without a host.
Treatment will depend on the cause of the infection. This article will focus on the most common and deadly types of infection: bacterial, viral, fungal, and prion.
Viral infection
Viral infection occur due to infection with a virus. Millions of different viruses may exist, but researches have only identified about 5000 types to date. Chain of Infection Viruses contain a small piece of genetic code, and a cost of protein and lipid (fat)molecules protects them.
Viruses invade a host and attach themselves to a cell. As they enter the cell, Chain of Infection they release their genetic material. This material forces the cell to replicate the virus, and the virus multiplies. When the cell dies, it releases new viruses, which infect new cells.
Not all viruses destroy their host cell, however. Some of them change the function of the cell.Chain of Infection Some viruses, such as human papillomavirus (HPV) and Epstein Barr virus (EBV), can lead to cancer by forcing cells to replicate in an uncontrolled way.
A virus can also target certain age groups, such as infants or young children.
Viruses may remain dormant for a period before multiplying again. The person with the virus can appear to have fully recovered, but they may get sick again when the virus reactivates.
Viral infections include:
- the common cold, which mainly occurs due to rhinovirus, coronavirus, and adenovirus
- encephalitis and meningitis, resulting from enteroviruses and the herpes simplex virus (HSV), as well as West Nile Virus
- warts and skin infections, for which HPV and HSV are responsible
- gastroenterritis, which norovirus causes
- COVID-19, a respiratory disease that develops after a novel coronavirus infection that is currently causing a global pandemic
Other viral conditions include:
- Zika virus
- HIV
- hepatitis C
- polio
- influenza (flu), including H1N1 swine flu
- Dengue fever
- Ebola
- Middle East respiratory syndrome (MERS-CoV)
Antiviral medications can help relieve the symptoms of some viruses while the diseases passes. They can either prevent the virus from reproducing or boost the host’s immune to counter the effects of the virus.
Antibiotics are not effective against viruses. Chain of Infection These drugs will not stop the virus, and their use increases the risk of antibiotic resistance.
Most treatment aims to relieve symptoms while the immune system combats the virus without assistance from medication.
Bacterial infections
Bacterial are single celled microorganisms, also known as prokaryotes.
Experts estimate that there are at least 1 nonillion bacteria on Earth. A nonillion is a 1 followed by 30 zeros. Much of the Earth’s biomass comprises bacteria.
Bacteria take three main shapes:
- Spherical: These are known as cocci.
- Rod-shaped: These have the name bacilli.
- Spiral: Coiled bacteria are known as spirilla. If the coil of a spirillum is particularly tight, scientists call it a spirochete.
Chain of Infection Bacteria can live in almost any type of environment, from extreme heat to intense cold, and some can even survive in radioactive waste.
There are trillions of strains of bacteria, and few cause diseases in humans. Chain of Infection Some of them live inside the human body, such as in the gut or airways, without causing harm.
Some “good” bacteria attack “bad” bacteria and prevent them from causing sickness. However, some bacterial diseases can be deadly.
These include:
- cholera
- diphtheria
- dysentery
- bubonic plague
- tuberculosis
- typhoid
- typhus
Some examples of bacterial infections are:
- bacterial meningitis
- otitis media
- pneumonia
- tuberculosis
- upper respiratory tract infection (although this is usually viral)
- gastritis
- food poisoning
- eye infections
- sinusitis (again, more often viral)
- urinary tract infections (UTIs)
- skin infections
- sexually transmitted infections (STIs)
A doctor can treat bacterial infections with antibioics. However, some strains become resistant and can survive the treatment.
Causes
The cause of an infection is which ever type of organism has entered the body. Chain of Infection A specific virus, for example, will be the cause of a viral infection.
The effects of an infection, such as swelling or a runny nose, occur due to the immune system’s attempt to get rid of the invading organism.
A wound fills with pus, for example, when white blood cells rush to the site of an injury to combat foreign bacteria.