Infectious Diseases
What Is Infectious Diseases ?
Infectious diseases are illnesses caused by harmful microorganisms, such as bacteria, viruses, fungi, or parasites, that enter the body, multiply, and cause an infection. These diseases can be spread, directly or indirectly, from one person to another, through contact with an infected person, animal, or object, or by consuming contaminated food or water.
Some common infectious diseases include the flu, tuberculosis, HIV/AIDS, malaria, and COVID-19. Symptoms vary widely depending on the specific disease but can range from mild, like a cold, to severe, like pneumonia or sepsis.
What are the types of infectious diseases?
Infectious diseases can be caused by viruses, bacteria, fungi, parasites, or a rare group known as transmissible spongiform encephalopathies (TSEs).
Viral infections: Viruses are small pieces of genetic material (DNA or RNA) enclosed in a protein shell called a capsid. Since they cannot reproduce on their own, viruses invade your cells and hijack their machinery to replicate.
Bacterial infections: Bacteria are single-celled organisms with genetic instructions stored on a small strand of DNA. Many bacteria are harmless or beneficial, but some release toxins that can cause illness.
Fungal infections: Fungi, like bacteria, are present both on and inside the body. However, an overgrowth of certain fungi or the entry of harmful fungi through the mouth, nose, or skin can lead to infection.
Parasitic infections: Parasites live and reproduce by using other organisms as hosts. Common parasites include worms (helminths) and single-celled organisms known as protozoa.
Transmissible spongiform encephalopathies (TSEs): TSEs, or prion diseases, are caused by faulty proteins called prions. These defective proteins trigger other proteins, often in the brain, to malfunction. The body cannot break down or remove these faulty proteins, leading to illness. Prion diseases are rare but serious.
What are the symptoms of infectious diseases?
- Fever
- Chills
- Congestion
- Cough
- Fatigue
- Muscle aches and headaches
- Gastrointestinal issues (diarrhea, nausea, vomiting)
How do infectious diseases spread?
Infectious diseases can spread in various ways, depending on the type of infection. Fortunately, most infections can be prevented through simple measures.
Pathogens often enter the body through the mouth, nose, or cuts in the skin. Common ways diseases spread include:
- Person-to-person transmission through coughing or sneezing, with droplets sometimes lingering in the air.
- Close contact, such as kissing or engaging in oral, anal, or vaginal sex.
- Sharing utensils, cups, or other personal items.
- Touching contaminated surfaces like doorknobs, phones, or countertops.
- Contact with the feces of an infected person or animal.
- Bug bites, such as from mosquitoes or ticks, or animal bites.
- Eating or drinking contaminated or improperly prepared food or water.
- Handling contaminated soil or sand, such as while gardening.
- Transmission from a pregnant person to their fetus.
How are infectious diseases treated?
Infectious diseases can spread in various ways, depending on the type of infection. Fortunately, most infections can be prevented through simple measures.
Pathogens often enter the body through the mouth, nose, or cuts in the skin. Common ways diseases spread include:
- Person-to-person transmission through coughing or sneezing, with droplets sometimes lingering in the air.
- Close contact, such as kissing or engaging in oral, anal, or vaginal sex.
- Sharing utensils, cups, or other personal items.
- Touching contaminated surfaces like doorknobs, phones, or countertops.
- Contact with the feces of an infected person or animal.
- Bug bites, such as from mosquitoes or ticks, or animal bites.
- Eating or drinking contaminated or improperly prepared food or water.
- Handling contaminated soil or sand, such as while gardening.
- Transmission from a pregnant person to their fetus.