What are infectious diseases?
Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.
What are the different types of germs that cause infectious diseases?
There are four main types of germs:
- Bacteria are one-celled germs that multiply quickly. They may give off toxins, which are harmful chemicals that can make you sick. Strep throat and urinary tract infections are common bacterial infections.
- Viruses are tiny capsules that contain genetic material. They invade your cells so that they can multiply. This can kill, damage, or change the cells and make you sick. Viral infections include HIV and the common cold.
- Fungi are primitive plant-like organisms such as mushrooms, mold, mildew, and yeasts. Athlete's foot and yeast infections are common fungal infections.
- Parasites are animals or plants that survive by living on or in other living things. Malaria and head lice are infections that are caused by parasites.
How can you get infectious diseases?
There are many different ways that you can get an infectious disease:
- Through direct contact with a person who is sick. This includes kissing, touching, sneezing, coughing, and sexual contact. Pregnant people can also pass some germs along to their babies.
- Through indirect contact, when you touch something that has germs on it. For example, you could get germs if someone who is sick touched a door handle, and then you touch it.
- Through insect or animal bites.
- Through contaminated food, water, soil, or plants.
What are the symptoms of infectious diseases?
Infectious diseases can cause many different symptoms. Some are so mild that you may not even notice any symptoms, while others can be life-threatening.
What are the treatments for infectious diseases?There are treatments for some infectious diseases, such as antibiotic, antiviral, antifungal and anti-parasitic medicines. But for other infections, such as some caused by viruses, you can only treat your symptoms.
Can infectious diseases be prevented?
You can take steps to prevent many infectious diseases:
- Germs: Understand and Protect against Bacteria, Viruses, and Infections (Mayo Foundation for Medical Education and Research) Also in Spanish
- Infectious Diseases (Mayo Foundation for Medical Education and Research) Also in Spanish
- Coping with Stress during Infectious Disease Outbreaks (Substance Abuse and Mental Health Services Administration) - PDF Also in Spanish
- Taking Care of Your Behavioral Health: Tips for Social Distancing, Quarantine, and Isolation during an Infectious Disease Outbreak (Substance Abuse and Mental Health Services Administration) - PDF Also in Spanish
- Antibiotic Resistance: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Bacterial vs. Viral Infections: How Do They Differ? (Mayo Foundation for Medical Education and Research) Also in Spanish
- Port Health: Quarantine (Centers for Disease Control and Prevention)
- What's the Difference Between Infectious and Contagious? (Nemours Foundation) Also in Spanish
- From A to Zika: Understanding Emerging Diseases (National Institutes of Health) Also in Spanish
- Recurrent Infections May Signal Immunodeficiencies (American Academy of Allergy, Asthma, and Immunology) Also in Spanish
- Types of Neglected Tropical Diseases (National Institute of Allergy and Infectious Diseases)
Statistics and Research
- FastStats: Infectious Disease (National Center for Health Statistics)
- ClinicalTrials.gov: Communicable Diseases (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Article: Enhancing open clinical trials through blinded evaluations: an exploration with diabetic...
- Article: Use of the Pfizer Respiratory Syncytial Virus Vaccine During Pregnancy for...
- Article: Early Video-assisted Thoracoscopic Surgery or Intrapleural Enzyme Therapy in Pleural Infection:...
- Infectious Diseases -- see more articles