Infectious Disease Control Methods and Transplantation Basics
Infectious Disease Control
Understanding the characteristics of infectious diseases and the nature of the agents that cause them is fundamental to prevention.
However, once a disease is declared, identifying the agent and making an early diagnosis are essential to implement the most appropriate treatment and, if necessary, isolation and reporting to the health authority.
Preventive Measures
Preventive measures to combat infectious diseases include:
- Disinfection of water supplies and wastewater treatment.
- Treatment of waste (urban, industrial, health-related).
- Sanitary control of food.
- Vaccination of the population.
Treatment Approaches
The treatment of infectious diseases is based on implementing procedures, techniques, and products that inhibit the activity of pathogens in living beings and their environment.
Treatment involves physical or chemical agents and antibiotics:
Physical or Chemical Agents
These are designed to remove or decrease the activity of microorganisms. The most important are heat and disinfectants, which allow the sterilization of objects (e.g., surgical instruments), and antiseptic substances, which combat pathogens on living tissue.
Antibiotics
Antibiotics are chemical substances that kill microorganisms or inhibit their growth, particularly bacteria. Many antibiotics are produced by certain microorganisms, such as various fungal species, while others are synthesized chemically.
The excessive use of antibiotics has led to the emergence of antibiotic-resistant microorganisms, requiring continuous research and the development of new antibiotics.
Donation and Transplantation of Cells, Blood, and Organs
A transplant is the replacement of a diseased or damaged organ or tissue in an individual with a healthy one from a donor.
Types of Transplants by Origin
Transplants can be classified based on their origin:
- Autologous transplant (autograft): Donor and recipient are the same individual. Used for tissues like skin, bone, or blood vessels.
- Syngeneic transplant: Donor is genetically identical to the recipient (occurs only between identical twins).
- Allogeneic transplant (homograft): Donor and recipient are different individuals of the same species. This is the most common type.
- Xenotransplantation (heterograft): Donor is an animal (e.g., using pig heart valves to replace human ones).
Commonly Transplanted Organs, Tissues, and Cells
- Organs: Heart, lung, liver, kidney, pancreas.
- Tissues: Bone, cornea, heart valves, skin, hair.
- Cells: Pancreatic islets, bone marrow stem cells, cord blood cells.
Types of Donors
There are two main types of donors:
- Living donor: An individual who can donate renewable tissues or cells (like skin, blood, bone marrow), an organ (like one kidney, as humans have two), or part of an organ that can regenerate (like the liver).
- Deceased or cadaveric donor: Generally, an individual who has been declared brain dead. Doctors maintain the viability of organs for transplant using artificial ventilation techniques and medications that keep the heart beating. Brain death occurs when all brain functions cease irreversibly, leading shortly to cardiac arrest if life support is withdrawn.
Transplant Rejection
One of the main challenges in organ transplantation is rejection, where the recipient’s immune system recognizes the transplanted organ as foreign and produces antibodies and lymphocytes that can destroy it. To prevent rejection, efforts are made to find the greatest possible compatibility (affinity or similarity) between the recipient’s and donor’s cells. Additionally, immunosuppressants—drugs that decrease or inhibit the patient’s immune response—are administered to prevent rejection.