Infectious Disease

Last updated date: 28-Aug-2023

Originally Written in English

Infectious Diseases

Infectious diseases are the most common conditions that frequently affect infants, young children, adults, and older adults. These infections vary depending on the agent's biochemical features, the size, and the manner of interaction with the human host. 

Infection control measures are essential are thus, essential to prevent these conditions. This minimizes the spread of infections from one host to another, including the patient to the healthcare provider and vice versa. Early diagnosis is also important since it helps identify the cause of the infection and develop an effective treatment plan. 


Defining Infectious Diseases 

Infectious diseases are the conditions that develop as a result of organism invasion in the body. These organisms include viruses, bacteria, parasites, and fungi. An infectious disease can range from simple infections that involve invasion and reproduction in the body and tissue reaction to the toxins produced. 

Basically, many organisms live and survive within the human body. Some of these organisms are usually harmless and can sometimes facilitate body functions like digestion. However, other organisms are harmful and react negatively to the body, causing various diseases. 


Types of Infectious Diseases 

How infections develop and alter a human body usually varies depending on the type of pathogen. The body consists of an immune system that acts as a defense mechanism against various infections. But sometimes, these pathogens can overpower the immune system, making it difficult to fight off. This results in a severe type of infection. 

Pathogens also vary in severity and intensity. Some release inflammatory content and toxins that result in negative responses and reactions. This also means that certain types of infections are minor and difficult to detect. However, others might be chronic and life-threatening or resistant to medication. 

In general, these are the main types of infections

Viral infections: 

Viral infection refers to the proliferation of harmful viruses within the body. Viruses are thus the small organisms that occur due to viral infections. They consist of small pieces of genetic content that are protected by the protein and fat molecules. Other viruses comprise of additional coating and different features on the surface.

A virus is parasitic, hence require the host cell to survive and conduct its usual life cycle. Therefore, if a virus gets into a host cell, it uses the cellular elements to live, reproduce and spread. With time, the virus overwhelms the host cell and can destroy or kill it. 

The common types of viral infections are;

  • Influenza or flu
  • Rabies 
  • Measles 
  • Common cold 
  • Polio 
  • Ebola 
  • Chickenpox 
  • Viral meningitis 
  • Viral hepatitis (hepatitis A, B, C, D, and E)


Fungal infections: 

Fungus consists of a wide group of organisms such as molds and yeasts. They are mainly found within the environment. For instance, in the soil, moist places such as the bathroom, and inside or outside a human body. 

Fungi can be small and invisible to the naked eye. However, others are relatively large and visible; for instance, you can notice pieces of large molds, especially in the bathroom. 

Although most of the fungi are harmless, others can cause fungal infections such as;

  • Ringworm
  • Thrush 
  • Vaginal yeast infections
  • Athlete’s foot 
  • Fungal meningitis 
  • Histoplasmosis
  • Aspergillosis 


Bacterial infections: 

Bacteria consist of single-celled microorganisms referred to as prokaryotes. They are highly diverse and take different shapes and sizes, including spiral shape, spherical, and rod-shaped. 

Bacteria can live and survive in different types of environments, including extremely hot or cold surroundings. They can as well survive under high temperatures and in radioactive exposure. 

Generally, there are many bacteria within our bodies that don’t usually cause any health condition. Instead, they play a vital role in the digestive system and helps with food digestion and absorption. 

In certain instances, the bacteria can get into the body and cause various bacterial infections such as;

  • Bacterial urinary tract infections 
  • Bacterial vaginosis 
  • Strep throat 
  • Cholera 
  • Tuberculosis 
  • Bacterial cellulitis 
  • Syphilis 
  • Gonorrhea 
  • Whooping cough 
  • Chlamydia 
  • Pneumonia 
  • Bacterial meningitis 
  • Tetanus 


Parasitic infections: 

Parasites mainly live inside or outside the host organism. It also acquires food and other vital nutrients from the host’s body. There are three main types of parasites that usually cause infections and illness. They include;

  • Helminthes: These are large organisms that include flatworm and roundworm
  • Protozoa: These are small single-celled organism 
  • Ectoparasites: These are organisms like fleas, lice, and ticks 

The common parasitic infections include;

  • Malaria 
  • Tapeworm infection 
  • Scabies 
  • Trichomoniasis 
  • Roundworm infection 
  • Liver blindness 
  • Toxoplasmosis 


Causes of Infectious Diseases

Infections can develop and spread in different ways. They also differ in terms of shape, size, genetic content, functions, and body reaction. Some of the common causes of infectious health conditions include; 

  • Bacteria or the single-celled organisms that cause illness 
  • Viruses that invade healthy cells and multiply 
  • Parasites that live in the body of the host, causing illness 
  • Fungi, including different forms of fungus causing a range of infections 
  • Direct contact with a person or animal that has an infection. It can spread from person to person, animal to person, or mother to the unborn baby. 
  • Indirect contact where you get the disease by touching objects or things belonging to a person who has an infection. 
  • Insect bites; carriers such as mosquitoes, ticks, fleas, and lice can transmit infections from one person to another. 
  • Food contamination; you can as well acquire an infection by consuming contaminated food or water. 


Signs and Symptoms of Infectious Diseases

Signs and Symptoms of Infectious Diseases

The signs and symptoms of infectious diseases usually vary based on the primary cause. While some infections are mild and treatable with home remedies, others may be chronic or life-threatening and require medical care. 

The common signs and symptoms that might indicate infectious health conditions include; 

  • Fever and chills 
  • Extreme fatigue 
  • Severe diarrhea 
  • Prolonged coughing 
  • Headache and muscles aches 
  • Dehydration 
  • Nausea and vomiting 


When to See a Physician 

The severity and intensity of infectious diseases vary from one person to another, depending on various underlying factors. Some infectious conditions are minor, while others are chronic and require immediate medical attention to prevent more complications. 

You should, therefore, see a health care provider if you are experiencing the following;

  • Prolonged and recurring symptoms 
  • Breathing difficulties 
  • Severe headache associated with high fever 
  • Symptoms that worsen even under home care treatment 
  • Development of rashes 
  • Animal or insect bite 
  • Unexplainable swelling 


Diagnosing Infectious Diseases 

Health care providers usually conduct a number of tests and examinations. This helps them determine the cause of a particular infection and the underlying symptoms. Some of the prevalent diagnostic tests include; 

Laboratory tests: 

Most infectious diseases have the same signs and symptoms. Therefore, physicians often perform different lab tests to identify the type of condition. These tests include;

  • Blood tests 
  • Stool test to check for parasites and other organisms 
  • Urine tests 
  • Throat swabs 
  • Spinal tap or lumbar puncture 


A biopsy involves extracting a small sample of tissues from the internal organ to tests for the infectious disease. For instance, doctors can perform a biopsy of the lungs to examine fungi, causing pneumonia. 

Imaging scans: 

Imaging scans

Doctors use various imaging procedures to diagnose the infectious disease and determine the other health issues causing the symptoms. Some of the common imaging procedures include;

  • Computerized tomography (CT scan)
  • Magnetic resonance imaging (MRI)
  • X-rays 


Treatment Options for Infectious Diseases 

Accurate diagnosis of the type of infection makes it easy for the doctor to administer appropriate treatment. The treatment forms can, however, range from;

Antiviral drugs: 

Antiviral drugs are designed to treat and manage certain viruses. They can’t, however, permanently cure all types of viral infections. Instead, doctors can treat other types of infection through supportive therapies, including intake of fluids and enough rest. 

Overall, antiviral can be used to address conditions such;

  • Herpes 
  • Influenza 
  • Hepatitis B and C


Antibiotics are drugs designed to kill and prevent the growth of bacteria and other organisms. Therefore, if a bacterium is the cause of the infection, the doctor can administer antibiotics to help destroy the bacteria and cure the disease. 


Small parasites usually cause parasitic infections such as malaria. Anti-parasitic drugs are thus used to treat the condition. However, certain types of parasites have become resistant to medication hence require other treatment forms. 


Antifungal medication helps treat parasitic and fungal infections. Chronic fungal infections of the internal organs, especially for people with a weak immune system, can require intravenous antifungal drugs. 



Infectious diseases are health conditions caused by an agent, particularly a microorganism that can alter a person’s overall health. These agents include viruses, bacteria, fungi, and parasites. In most cases, these infections spread from one person to another, either directly or indirectly. 

To address infectious conditions, CloudHospital has opted for the latest innovative diagnostic techniques. These help determine the infection's actual cause and administer an effective treatment that suits a person’s requirements.