Pathogens Part 3

Quick Check #1: 1. What is a pathogen? 2. Name five kinds of pathogens. 3. How are these five kinds of pathogens alike? 4. How are these five kinds of pathogens different? How Are Pathogens Spread? • Pathogens can enter the body through air, food, water, sexual interactions, skin contact, blood transfusions, etc. • The body’s reaction to an infection can vary from a mild discomfort to death. Pathogen Species Specificity I can transmit Brucellosis We can transmit lots of infectious agents including arena viruses and hantavirus. I can transmit Ebola virus! • Some infectious diseases of animals can be transferred to humans. • These are called zoonotic diseases. • All mammals can transmit rabies but raccoons and skunks are the most common carriers. Think about it: Where Do Pathogens Hide When Not Infecting People and Animals? The soil Bodies of water Surfaces like farm equipment The skin of people and animals In the air In body fluids Where are those pathogens? Do you know the difference between “infectious” and “contagious?” Infectious: pathogen can invade the body Contagious: pathogen can be spread from one animal to another. An animal that has a contagious condition will probably have to be isolated from other animals until it is determined that it is no longer contagious. Quick Check #2 1. How can pathogens get in the body to cause infection? 2. What is an infectious disease that can be transmitted from an animal to a human called? 3. Where are pathogens commonly found? 4. What’s the difference between being infectious and being contagious? Different infectious diseases require different approaches for prevention and control. But for any disease, there are three key steps for dealing with it. Three Key Steps reak the cycle of transmission ill the infectious agent ncrease host resistance Do you have some ideas on how to do these three things? Vaccination • Vaccination acts to increase the host’s resistance to a pathogen. • Vaccination is the administration of a material that stimulates adaptive immunity to a disease. • Although it is not possible to devise precise schedules for each vaccine, certain principles are common to all methods of active immunization. • Newborn animals are passively protected by maternal antibodies. • If stimulation of immunity is necessary at this stage, the mother may be vaccinated during late pregnancy. • Because the exact time of loss of maternal immunity cannot be predicted, young animals are often vaccinated at least twice to ensure successful immunization. Newborn animals acquire immunity from nursing colostrum, or the first milk produced by the mother. • The interval between vaccine doses depends on an animal’s immunologic memory. The duration of this memory depends on factors such as the nature of the antigen, the use of live or dead organisms, and the route of administration. • Modern vaccines may induce immunity that persists for an animal’s lifetime. Other vaccines may require boosting only once every 2-3 years. • Some vaccines, like Bordatella in dogs, are recommended to be given every 6 months. • Annual revaccination has been the rule because this approach is administratively simple and has the advantage of ensuring that an animal is regularly seen by a veterinarian. It is likely that this is more than sufficient for most vaccines. • The veterinarian in a local area will be most informed on protocols for vaccination. PLEASE NOTE: Sample schedule only. Check with your local veterinarian for a complete schedule for your area. Some Current Research Over-use of antibiotics has led to some bacteria developing resistance. This is a big problem. Scientists search for antibiotics that can replace current ones to which bacteria have evolved resistance. Delivery of nanoparticles to cells to kill drug-resistant bacteria • Nanoparticles are sized between 1 and 100 nanometers. Nanoparticles are 100 times smaller than bacteria. • Antibiotics bound with nanoparticles may be used one day to treat infections, especially those that are drug resistant. • One study will allow nanoparticles to be engineered as “small machines that will carry large numbers of antibiotic molecules to a single bacterial cell, then release and kill the cell.” Artist’s rendition of nanoparticles