👉 Infections occur when pathogens, such as bacteria, viruses, fungi, or parasites, enter and multiply within a host's body, disrupting normal physiological functions and causing disease. The body's immune system typically responds by mounting an inflammatory reaction to contain and eliminate the invaders. However, if the infection is severe, widespread, or the immune response is compromised, it can lead to significant health issues. For instance, bacteria like Streptococcus pneumoniae can cause pneumonia, while viruses such as HIV can weaken the immune system itself. Effective prevention and treatment strategies, including vaccines, antibiotics, and antifungal medications, are crucial in managing infections and reducing their impact on human health.
