Study Guide

Infectious Diseases In the Real World

  • Ethics

    Tuskegee Syphilis Study

    In order to find a cure for infectious disease, the infectious disease must be studied. In research labs today, scientists use cell culture (different types of cells modified to grow in plastic plates) to study how pathogens affect cells. In order to know how it affects a whole body system, they must study the infectious disease in a real infection of a person or an animal.

    The ethics of using research animals is a debate for another day. Various animals are currently used in medical research, and safety protocols are very closely followed. After a long meticulous road, human subjects can be used when all of the risks have been minimized through previous tests.

    However, this was not always the case. There have been some real life "mad scientists" who have used unwilling human subjects to study infectious diseases. Did these studies provide valuable information? Yes. Were they deemed unethical? Absolutely.

    A famous case was the Tuskegee Syphilis Study. Between 1932 and 1972 a study was conducted by the United States Public Health Service to study the effects of syphilis. At the start of the study there was no effective drug against syphilis, and the study enrolled 600 black men, both with syphilis and without syphilis. They were observed and monitored in what began as a proper research study.

    However, when penicillin was discovered in the 1940's as an effective treatment for syphilis the patients were neither told that they had syphilis nor were they treated for it. This led many of them to eventually die of syphilis or complications of it. They also unknowingly passed the disease on to their wives and partners, and their children were born with congenital syphilis. The unethical behavior of the physicians and researchers in this trial led to further federal laws and regulations to protect human subjects in medical studies.

    History: Indigenous Populations Destroyed by Infectious Disease

    Although it is hard to know exactly what happened 500 years ago, most anthropologists agree that a large portion of the American indigenous population was decimated by infectious disease. These diseases were introduced to them by the Europeans arriving on their shores carrying European pathogens with them.

    The human immune system works better against things that it has already seen before. Remember, a person develops an army of antibodies and then leaves a small militia behind in case the disease returns. The indigenous people had no army and no militia; therefore, when they became infected with new pathogens they had little defense.

    Smallpox was the most deadly infectious disease, but it was likely a combination of several new pathogens at once that killed so many people. In addition since so many people were infected for the first time at the same time, not many healthy people were left were able to serve as caregivers, which likely raised the death toll. Some estimates say that millions of indigenous people, possibly 80-90% of the population, were wiped out by diseases introduced by the Europeans.

  • Policy

    Selecting the Influenza Vaccine Every Year

    Influenza causes 250,000-500,000 deaths each year worldwide. There is an effective vaccine to prevent or reduce the symptoms of influenza infection. However, because the influenza virus mutates rapidly, the major circulating strains are constantly changing. This means that the vaccine must also constantly change in order to remain effective against the most prevalent strains.

    The WHO has the 411 on the flu strains currently causing trouble in the world. Every year, they meet with the Global Influenza Surveillance and Response System (GISRS) to discuss the influenza strains currently making their rounds around the round world. These agencies then use their crystal balls (and important scientific data) to make predictions about which strains are likely to continue circulating. They use this info to make a recommendation about which strains should be included in the upcoming influenza vaccine.

    The vaccine prediction is usually accurate, but there have been several years where the circulating strains were different from the strains in the vaccine (making it useless). In 2009, when the H1N1 pandemic hit and spread around the world, the vaccine was ineffective because 2009 H1N1 was a completely new strain that was formed by a mix of several other viruses. In fact, they had to rush a new vaccine through production which was special for the 2009 H1N1 strain.

  • Pop Culture

    Infectious Diseases Movie Roundup

    There have been many movies about infectious diseases. Infectious diseases are scary, and scary makes for good movies. Never fear, here at Shmoop we have saved you the trouble of watching a bunch of movies. We watched them all for you, and collected them in this movie roundup.

    Don't worry, no spoilers here. Just some nail biting plots for you to consider for date night.

    Contagion (2011): The story of a novel mix between a pig virus and a bat virus which can infect humans. An unfortunate soul picks it up in Hong Kong. Some humans appear to have immunity to the virus. Other humans die within days. The infected population is quarantined and a breakdown of law and order ensues. The movie does a better job than most at explaining the science behind the scenes of combating deadly infectious disease, although things still happen a lot faster in Hollywood than they do in a real laboratory.

    Outbreak (1995): The story of an Ebola-like virus that causes a hemorrhagic fever. In this film, the virus was brought to the United States from Africa in a smuggled monkey. As the virus spreads, people are quarantined and there's a serious military cover-up. The plot thickens when the virus mutates into a strain that can be spread through coughs like influenza. Oh that sneaky virus…There is also a wild helicopter action scene at the end of the film. Overall, the science that they use to find a cure is questionable, and the speed that they produce the cure is even more unbelievable (literally).

    The Andromeda Strain (1971): In this classic film, a satellite crashes bearing a pathogen from another planet. An entire town is killed instantly by it, and a team of scientists is recruited to study its composition in a secret underground government lab. The scientific process is interesting although the "futuristic" technology is underwhelming 40 years later.

    The Stand (1994): A TV miniseries adapted from a Stephen King novel focusing more on the aftermath of a deadly superflu than on the disease itself. In this story, the superflu was accidentally released from a government lab. The virus wipes out 99.9% of humans in the United States. There is a special group of immune survivors who join one of two new communities to rebuild America.

    I am Legend (2007) and The Omega Man (1971) and The Last Man on Earth (1964): All adapted from a 1954 book, these films focus on the aftermath of a deadly infectious disease. The disease has wiped out nearly all people or turned them into evil mutant versions of themselves who live in the dark. The star of the film is an immune survivor of the virus who spends his lonely time trying to survive attacks from the mutants while searching for survivors and looking for a cure.

    28 Days Later (2002): A virus is released when a chimp is released from a research lab in the United Kingdom. The virus quickly spreads and kills most people. Those not killed are transformed into an angry mutant race. The few survivors band together and eventually find that they don't share the same goals for the future.