it is branch of internal and preventive medicine that explain disorders caused by organisms -- such as bacteria, viruses, fungi or parasites. Many organisms live in and on animal bodies and our bodies. They're normally harmless or even helpful, but under certain conditions, with predisposing factors some organisms may cause disease.
Some infectious diseases can be passed from animal to animal and even human. Some are transmitted by bites from insects or animals. And others are acquired by ingesting contaminated food or water or being exposed to organisms in the contaminated environment.
Signs and symptoms vary depending on the organism causing the infection, but often include fever and fatigue. Mild complaints may respond to rest and home remedies, while some life-threatening infections may require immediate therapy and care .
Many infectious diseases, can be prevented by vaccines.
- معلم: Ihab Mahdi