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This case study introduces students to the complex field of immunology and the wide variety of host-pathogen interactions that drive evolutionary change.  The case begins with a basic overview of the phases of the immune response and how each contributes to host defense against an invading pathogen.  In order to delve deeper into each phase, students explore the metaphor of a battle in which a host and pathogen are locked in combat in order to understand the individual components of the immune response.  Once students successfully understand how the immune system works in general, they are then asked to think creatively about how a pathogen that wants to survive could evolve to evade the immune response, and to find concrete examples in the literature.  The overall goal is for students to gain a deeper understanding of the immune response and how host-pathogen interactions drive coevolution of both host immune components and the pathogen itself. The case was originally designed for an introductory biology course, but can easily be adapted for use in a variety of different courses and levels.

Which pathogens play a major role in causing infection? Just recently, the Robert Koch-Institute prepared a list of 127 pathogens by ranking them in terms of frequency, spread and burden of disease.   Considering this prioritisation, we extended our search tool by bacteria, viruses and fungi accordingly. In the list, you will find both the clinically relevant pathogens and the spectrum of effect necessary for disinfectants to inactivate them.

Scientists have confirmed that the pathogen that causes Lyme Disease -- unlike any other known organism -- can exist without iron, a metal that all other life needs to make proteins and enzymes. Instead of iron, the bacteria substitute manganese to make an essential enzyme, thus eluding immune system defenses that protect the body by starving pathogens of iron.

The table below displays the list of human viral pathogens, with transmission and general facts about associated pathologies.

Around the world, disease-carrying mosquitoes are advancing at speed, taking viruses such as dengue and Zika, plus a host of lesser-known ills such as chikungunya and St. Louis encephalitis, into new territories from Europe to the Pacific. "The concern is that we have these species spreading everywhere. Today the focus is on Zika but they can carry many different viruses and pathogens," said Anna-Bella Failloux, head of the department that tracks mosquito viruses at France's Institut Pasteur.

Lyme disease, Ebola and malaria all developed in animals before making the leap to infect humans. Predicting when such a 'zoonotic' disease will spark an outbreak remains difficult, but a new study suggests that artificial intelligence could give these efforts a boost. A computer model that incorporates machine learning can pinpoint, with 90% accuracy, rodent species that are known to harbour pathogens that can spread to humans, researchers report this week in the Proceedings of the National Academy of Sciences1. The model also identified more than 150 species that are likely to be disease reservoirs but have yet to be confirmed as such.

Why did you get the flu this winter, but your co-workers didn't? The answer, according to a new study of twins, may have less to do with your genes and more to do with your environment-including your past exposure to pathogens and vaccines. Our immune system is incredibly complex, with diverse armies of white blood cells and signal-sending proteins coursing through our veins, ready to mount an attack on would-be invaders. Everyone's immune system is slightly different-a unique mixture of hundreds of these cells and proteins. But the main driver of this variation is unclear. Although scientists know that our immune system can adapt to our environment-that's why vaccines work, for instance-it is also built by our genes.

If thinking about the billions of bacteria taking up residence in and on your body gives you the willies, you probably won't find it comforting that humans are also full of viruses. These maligned microbes are actually intertwined in the very fibers of our being-about 8 percent of our genetic material is made up of absorbed forms of retroviruses, the viral family to which HIV, the pathogen that causes AIDS, belongs.

"This case study uses a PowerPoint presentation to guide students through two activities designed to teach them about the basics of coronavirus diagnosis and transmission. The first activity involves a set of five "clicker questions" that students answer using either a personal response system, online polling application, or show of hands as they consider symptoms and test results of a hypothetical patient. The second activity is an outbreak simulation in which students consider the spread of a pathogen in various geographical settings and from different perspectives. Students work together to draft a list of precautions that could be taken to limit the spread of the disease and minimize healthy individuals' risk of contracting it. The simulation is designed for a biology lesson pertaining to outbreaks. Although coronavirus is used as the model, the concepts of disease transmission and prevention covered in this case are relevant to many diseases."

The scientists are from the Centers for Disease Control and Prevention, and they have embarked on this watery journey to solve a decades-old mystery about a rare and fatal disease: monkeypox. A cousin to the deadly smallpox virus, the monkeypox virus initially infects people through contact with wild animals and can then spread from person to person. The disease produces fever and a rash that often turns into painful lesions that can feel like cigarette burns. It kills up to 1 in 10 of its victims, similar to pneumonic plague, and is particularly dangerous in children. Monkeypox is on the U.S. government list of pathogens such as anthrax and Ebola with the greatest potential to threaten human health. There is no cure.

This directed case study was developed in order to present genomic data to students, allow them to interpret the impact of genetic variations on phenotype, and to explore precision medicine. Students are introduced to "Josie," a college sophomore who decides to have her genome sequenced after learning about genome-wide association studies (GWAS) in class. As students work  through the case, they learn about the different technologies that can be used in GWAS studies and interpret Josie's results for a subset of genetic markers that affect a range of traits from pharmacogenetics to disease risk alleles and non-pathogenic traits. Students are confronted with ethical issues such as duty to inform, actionable results, and variants of unknown significance (VUS). Students are also asked to reflect on their feelings about getting genomic testing for themselves. An optional activity for advanced students (included in the teaching notes) involves using the Gene database at NCBI to explore variants of the CYP2C9 gene. The case study is appropriate for use in undergraduate genetics or molecular biology classrooms.

This interactive module introduces the anatomy of the immune system and walks through the timeline of a typical immune response.  The timeline includes the differences between the first time a pathogen is encountered versus subsequent infections, including an explanation of how vaccines work. Different tabs, videos, images, questions, and a detailed glossary of terms allow this resource to be explored at varying levels of depth depending on the class. Refer to the "Educator Resources" tab in the Click & Learn for implementation suggestions. 

One common virus takes a sneaky route to success. It doesn't kill its leafy hosts. Instead, it makes infected plants smell more attractive to bees. That ensures this germ will have a new generation of the plants to host it in the future.

This case study examines the molecular methods that were used to reverse engineer the 1918 influenza virus strain in order to try and solve the mystery of why it was so deadly. The story starts in the 1950s with the unsuccessful attempts to culture the influenza virus and follows scientists through to the turn of the century when cutting edge molecular tools enabled scientists to finally resurrect the 1918 virus through reverse genetics. The history and methods involved in resurrecting this deadly virus are reviewed in class with a PowerPoint presentation containing clicker questions (answered with a personal response system) and discussion questions (answered in small groups). This "clicker case" is suitable for high school biology and lower division undergraduate biology classes for non-majors. It could also be used in any lower division non-major class focused on human disease and the history of human disease.

It starts with a tickle in your throat that becomes a cough. Your muscles begin to ache, you grow irritable, and you lose your appetite. It's official: you've got the flu. It's logical to assume that this miserable medley of symptoms is the result of the infection coursing through your body - but is that really the case? Marco A. Sotomayor explains what's actually making you feel sick.

list of infectious viral and bacterial disease, Rhode Island Dept of Health

Scientists and healthcare professionals initially exhibited little concern over the Zika virus even after evidence of human infection was first identified in 1952; Zika appeared to be both rare and unassociated with morbidity or mortality. Around 2015 all of this changed as journalists, scientists, public health officials, and laypeople scrambled to learn about its varied modes of transmission and devastating consequences (e.g., birth defects and autoimmune disorders). Although research continues to rapidly evolve, this case study directs students to reliable scientific sources (e.g., Centers for Disease Control and World Health Organization) that will likely continue to provide the most current information in order to explore questions such as: Where did the virus come from? How does it spread? What can we do to prevent it? Students will also consider the public health challenges and possible solutions associated with emerging infectious diseases. The case was originally written for an upper-level biology or public health course in which students already have some basic background knowledge regarding viruses, vaccines, and infectious disease.