Infectious Diseases Study Guide PDF

Infection Diseases Period 1 What is an infectious disease? ▪ An infectious disease is a disease that is caused when a pathogen is passed from one organism to another. Who cause an infectious disease? ▪ Pathogens are the cause of infectious disease...

Infection Diseases Period 1 What is an infectious disease? ▪ An infectious disease is a disease that is caused when a pathogen is passed from one organism to another. Who cause an infectious disease? ▪ Pathogens are the cause of infectious disease. ▪ Viruses ▪ Bacteria ▪ Protozoans ▪ Fungi ▪ Parasites Pathogens Cause Infectious Disease What do a cold and athlete’s foot have in common? They are both examples of an infectious disease Some but not all types of (bacteria, virus…) organisms are Pathogens. Many types doesn't cause infectious diseases. Our body benefits from organisms ,such as bacteria & protozoans live.. in intestinal on skin and (shafts of reproductive hair follicles) tracts These organisms keep pathogens from thriving and multiplying on body Germ theory and Koch’s experiments Before Microscope invention People though something passed from a sick person to a well person to cause an illness.  Germ theory and Koch’s experiments Nutrients solution Nutrients solution Louis Pasteur Demonstrated that microorganisms from the air are able to grow in nutrient solutions. Germ theory and Koch’s experiments With the knowledge gained from L.Pasteur and other discovers ,doctors and scientists develop the Germ germ theory. theory Germ theory states that some microorganism are pathogen Scientists were not able to clearly demonstrate Germ theory until Robert Koch developed his postulates What is type of bacteria did Koch study? R.Koch did his experiment on anthrax bacteria. ‫معلومة إثرائية‬ Koch’s experiments Robert Koch 1- was studying anthrax (a deadly disease) that effects cattle ,sheep and people. 2- he isolated bacteria from the blood of cattle that had died from anthrax, and growing the bacteria in laboratory. Koch’s Postulates ▪ Are rules for demonstrating that (suggest) organism cause a disease. Robert Koch used pure culture : artificial media contains the nutrients that bacteria need to survive and reproduce. Koch’s Postulates Robert Koch Developed series of guidelines still used today to identify pathogens that cause a specific disease: 1) Pathogen should be found in sick organism and not that of a healthy one 2) Pathogen must be isolated and grown in lab in pure culture 3) When purified pathogens placed in a new host, new host get same disease that infected original host 4) Injected pathogen isolated from the second host, should be identical to the original pathogen ▪ If the pathogen that was examined by Koch is virus instead of bacteria. ▪ Predict the result of the experiment? discuss  ▪ Explain some exceptions to Koch’s postulates do exist?. 1-Some pathogens cannot be grown in pure culture on artificial media. Such as bacteria that cause syphilis. 2-viruses cannot be grown in pure culture. Why?? Cultured cells are needed because viruses cannot be grown on artificial media. Select a disease with your colleague and type in report that contains: 1- the cause 2-symptoms 3-method of infection 4-treatment. 5- Period 2 Spread of Disease Large number of microorganisms coexist with humans Only a few cause disease (Pathogens) Some cause mild(light) diseases such as……… cold Some cause serious diseases such as……… meningitis How pathogens spread? cold ❖Discuss the role of reservoirs in disease dispersal ❖Analyse how diseases are transmitted Spread of Disease human reservoir animal Other(bacteria, water,food) Pathogens Direct contact Indirect transmission contact vectors Which is the source of the pathogen? How is the pathogen transmitted? Spread of Disease ▪ A disease reservoir is a source of the pathogen in the environment. ▪ Reservoirs might be: -animals - people - inanimate objects such as soil. 1- human 2- reservoir animal 3-Other(bacteria, water,food)  1-Human Reservoirs ▪ Humans are the main reservoir for pathogens that affect humans. ▪ Humans(reservoir) pass the pathogen directly or indirectly to other humans (host). ▪ Many pathogens past on to other host before the person knows he or she has disease. ▪ An individual that is symptom-free but capable of passing the pathogen is called a carrier. 2-Animal Reservoirs ▪ Animals also are reservoirs of pathogens that can be passed to humans, such as:Influenza and Rabies Influenza can infect various types of birds Affected respiratory system Animal Reservoirs Rabies found in many wild animals such as bats ,foxes , skunks and racoons. Spread by animal bite MCQ Spot Check For a pathogen to spread, it must have both a reservoir and a way to spread. A. True B. False Rabies is found in domestic dogs and many wild animals, such as bats, foxes, skunks, and raccoons. Rabies can be transmitted from……….. A. animal reservoir B. contaminated water C. soil D. insects 3-Other Reservoirs ▪ Some bacteria found in the soil, such as tetanus bacteria can cause disease in humans ▪ tetanus bacteria -it contaminates a deep wound in the body. Affected nervous system 3-Other Reservoirs ▪ Contaminated Water and food is another reservoir of pathogens for human disease. ▪ Contaminated Water -What was the main purposes of sewage treatment plants ? The safe disposal of human feces which prevents contamination of the water by pathogens. ▪ Contaminated water used in growing or preparing food can transfer pathogen. ▪ Contaminated Food Contact with humans or insects such as flies. Transmission of pathogen 1-Direct contact -with other humans. -major modes of transmission of pathogens, such as: cold 2.Indirectly contact by air When person with an infectious disease sneeze or coughs , pathogens can be passed along with the mucus droplets 3.Indirectly contact by touching contaminated objects Organisms survive on objects handled by humans. How to prevent the spread of these diseases? Cleansing of dishes, utensils, and countertops with detergents as well as careful hand-washing. 4. vectors Organism that carry pathogens Arthropods which include biting insects such as mosquitoes and ticks  Cause protozoan Vector mosquito  Vector mosquitoes Cause virus Flies can transmit pathogens by landing in infected materials such as feces then landing on materials handled or eaten by humans.  Identify four kinds of pathogens. What is the difference between a pathogen and disease?. Compare between Giardia , Hepatitis B and Chicken pox.(use table 1) An individual that is symptom-free but capable of passing the pathogen is called a …... A. holder B. transmitter C. carrier D. passenger Lyme disease, malaria, and West Nile virus are diseases that are passed to humans by ……… A. direct contact B. indirectly through the air C. indirectly through touching contaminated objects D. organisms called vectors that carry pathogens. Period 3 What did you learn last lesson? 1 thing you learnt from last lesson? 1 question you had from last lesson that wasn’t answered? What will we learn today? ❖Explain different ways pathogens can cause diseases including viruses, bacteria and fungi. ❖Differentiate between diseases patterns to include endemic, epidemic and pandemic.  Why do you feel aches and pains, and why do you cough and sneeze? SYMPTOM The pathogen, such as an influenza virus or bacteria, has invaded some of the cells of your body. RASH FEVER VOMIT Symptoms of Disease When are symptoms of disease receive? The pathogenic has invaded host cells Virus (ex:Influenza) Bacteria Symptoms of Disease Virus (ex:Influenza) Multiplies in the host cells Then leaves the host cells Exocytotosis Causing the cell to burst Damage tissues or kills some cells  How the viruses leaves the host cells? Causing the cell to burst Exocytotosis Symptoms of Disease Bacteria Produce Harmful chemicals Toxins Carried throughout the body via the bloodstream Damage various part of the body ▪ Toxins produced by pathogens affect organ systems. Pathogens Way to ling Produce Effect in the body Tetanus Contaminates Potent Spasms in bacteria a deep wound toxin the in the body voluntary muscles Botulism Consumes toxin Paralyzes bacteria (eat)food nerves which Related image bacteria grown Disease Patterns As outbreaks of diseases spread Certain patterns are observed. Why it is impertinent to monitor disease patterns? To help control the spread of diseases. Type agencies observe the spread of disease patterns? The Centers for Disease Control and Prevention (CDC), and the World Health Organization (WHO) monitor disease patterns. What is the role of these agencies ? Publish reports about the incidence of specific disease to help control the spread of diseases patterns. Disease Patterns  Disease Patterns Endemic diseases Epidemic Pandemic Continually are A large outbreak Widespread found in small in an area and throughout a large amount within the afflict many region such as country population. people ,continent and the entire globe Such as cold  Period 4 ❖Differentiate between antibiotics and antiviral drugs as treatments for infectious diseases ❖Differentiate between bacterial sensitivity and resistance to antibiotics ❖Analyze the increase in the occurrence of antibiotic-resistant bacteria  Virus vs. Bacteria Influenza virus -Colds and influenza are caused by viruses. -Viruses are non-living particle that contains genetic material and attack cells to reproduce. -Viruses cannot be “killed” with antibiotics. -Bacteria are living organisms that have a metabolism, have DNA, and can reproduce on their own. -Bacteria can be killed with antibiotics because these substances target key processes in bacteria, such as production of the bacterial cell wall. E. coli  Treating and Fighting Diseases Drug to help the body fight a disease An antibiotic Chemical agents Antiviral drugs a substance that Used in the Used to treat can kill or inhibit treatment of infections and the growth of other protozoan and influenza in the microorganisms fungal disease elderly(old) Such as: Penicillium Erythromycin Neomycin Most viral disease are handled Gentamicin by the body’s built-in defense system- the immune system ▪ Penicillin is chemical substances and secreted by the fungus Penicillium ▪ Penicillin kill competing bacteria that grow on the fungal food sources. Connection to Health What is the effect of the widespread use of antibiotics? Many bacteria become resistant to particular antibiotics Natural selection The process by which organisms better adapted to their environment tend to survive and produce more offspring. Bacteria in a population might have a trait that enables them to survive when a particular antibiotic is present. Bacteria reproduce quickly and pass trait on the variation. The number of antibiotic-resistant bacteria in a population can increase quickly too. Antibiotic resistance of bacteria has presented the medical community with some problems with treating certain diseases. For example: *Penicillin was used effectively for many years to treat some diseases. Image result for pneumonia Staphylococcal disease : -acquired in high-density living condition -infection in skin, pneumonia, or meningitis -Difficult to treat because bacteria has resistant to many antibiotics. W You wake up one morning with a stuffy nose, O slight fever, and fatigue. Do you have a cold or R the flu? Or are they the same? K Should you go to your doctor for an antibiotic? Why or why not? T O G E T H E R Drag each disease patterns to the appropriate bin Endemic Epidemic Pandemic Match Disease pattern ( ) Widespread throughout a large Endemic diseases region such as country ,continent and the 1 such as cold entire globe ‫أمراض مستوطنة‬ ( )Small amounts within the population 2 Epidemic ‫وباء‬ ( )A large outbreak in an area and Pandemic 3 afflict many people ‫وباء منتشر‬ ▪ Expect what will happen to blue bacteria? MCQ Spot Check For a pathogen to spread, it must have both a reservoir and a way to spread. A. True B. False Rabies is found in domestic dogs and many wild animals, such as bats, foxes, skunks, and raccoons. Rabies can be transmitted from……….. A. animal reservoir B. contaminated water C. soil D. insects An individual that is symptom-free but capable of passing the pathogen is called a …... A. holder B. transmitter C. carrier D. passenger Lyme disease, malaria, and West Nile virus are diseases that are passed to humans by ……… A. direct contact B. indirectly through the air C. indirectly through touching contaminated objects D. organisms called vectors that carry pathogens. There are different ways for a pathogen to transmit from its reservoir to human, which can be through……. A. direct contact B. indirectly through the air C. indirectly through touching contaminated objects D.organisms called vectors that carry pathogens. E. all of the above The virus infections lead to tissues damage and even kills some cells. The virus multiplies inside the cell and leaves by…………….. A. exocytosis B. causing the cell to burst C. degrading cell nucleus D. both A and B When pathogenic bacteria invade the body, beside to the cell damage that can occur, bacteria cause harm through……………. A. degrading cell membrane B. secreting toxins C. dehydrating the cell D.non of the above The toxin from the botulism bacteria can cause disease in humans even when no bacteria are present. A. True B. False All types of bacteria, all protozoans, and all viruses invade and live inside cells, causing damage. A. True B. False Diseases that are continually are found in small amounts within the population is called ……. A. Epidemic B. Endemic C. Pandemic D.All of the above An antibiotic is a substance that can kill or inhibit the growth of bacteria only. A. True B. False Fungus Penicillium secretes a chemical to kill competing bacteria that grow on the fungal food source. This chemical is called …... A. Penicillin B. Erythromycin C. Neomycin D. gentamicin. Some antiviral drugs are used to treat herpes infections, influenza in the elderly, and HIV infections. Most viral diseases are handled by…….. A. Lymphatic system B. Antibiotic C. Digestive system D. Immune system All antibiotics are produced from fungal secretion. A. True B. False Bacteria in a population might have a trait that enables them to survive when a particular antibiotic is present. These bacteria can reproduce quickly and pass on the variation. This has caused the bacteria to develop………. A. antibiotic tolerance B. antibiotic side effect C. antibiotic resistance Biology Department 11AD-2021/2022 Federal Entity | ‫هيئة اتحادية‬