Health

• Infection is a condition in which pathogens such as bacteria, viruses, fungi, and protozoans enter the body and multiply
• Viruses are single-celled microorganisms that cause diseases such as strep throat, tuberculosis, gonorrhea, and syphilis
• Bacteria are more complex than viruses and cause diseases like malaria and dysentery
• Protozoa and Rickettsia are pathogens smaller than bacteria but multiply like viruses. Typhus is caused by Rickettsia
• Fungi are single-celled or multi-celled organisms that feed on organic materials and cause skin and lung diseases like ringworm, athlete's foot, and nail infections
• Pathogens may not always lead to disease; they can kill cells, multiply rapidly, or produce toxins that paralyze cells
• Fever should not be disregarded as it might be a sign of a more serious disease, signaling the presence of an infection
• The stages of infection are:

  • Incubation stage: time between exposure to a pathogen and appearance of symptoms
  • Prodromal stage: signs and symptoms start to appear, lasting about a day or two
  • Acute stage: disease is at its peak, signs and symptoms can be clinically used for diagnosis
  • Declining stage: symptoms start to subside, severity of the disease declines
  • Convalescent stage: symptoms fade, patient recovers health and strength