Chapter 1 Questions

Esther Yoon

Chapter 1 Questions

1. Explain the statement that epidemiology is interdisciplinary.

Areas of study for epidemiology range from biostatistics, social and behavioral sciences, toxicology, pathology, virology, genetics, microbiology, and clinical medicine. Without observing all parts, a strong conclusion cannot be made and the best predictions will not be available. Because public health, and specifically epidemiology, work to better health in more than one way, it is important to consider all the factors, which is done by making sure all the above areas are looked at before describing, explaining, predicting, and attempting to control some health problem.

1. What are the characteristics that distinguish pandemic disease from epidemic and endemic disease? Identify some infectious diseases that could reach pandemic occurrence during the 21stcentury. What conditions do you believe exist at present that could incite the occurrence of pandemics?

Endemics are disease localized in certain geographic areas. One example of a past endemic would be malaria. An epidemic is when many are suddenly attacked by some illness. This spreads fairly rapidly. We often hear “outbreak” as well, which is a localized epidemic. Once this epidemic grows beyond the local area and into several other countries, the term changes to pandemic, because it is worldwide. In today’s world, travel is easy and fairly affordable, so any epidemic can turn into a pandemic if not contained. Diseases like HIV, SARS, and even bovine spongiform encephalopathy (BSE) could be potential pandemics this century. This is because travelers can take it to other countries and infect those people without knowing it. Also, this age brings great technology. If someone was to spread something, for example, anthrax, it is easy to transport and can travel through the air. This could be fatal to people quickly. With cleaner conditions, it is less likely that disease would spread by our pollution or by the water supply.

1. Why have public health officials been concerned about the emergence of new diseases such as “avian flu”: Speculate about what might happen to organized society and the health care system should an outbreak of pandemic influenza occur.
   Society would become very focused on treating the problem and health care would be swamped. What makes avian flu a big issue is that this virus in birds may be more easily transmissible to people. These birds can make the transmission and movement of the virus quicker.

There is also worry that because a pandemic is overdue, the next influenza pandemic will hit harder than expected. Since the Middle Ages, there have been several pandemics a century, and there has not been one since 1968 (New York State, 2011). The current virus has already been transmitted to other mammals and humans have become very ill. Roughly 50% of those with the virus have died (New York State, 2011). As the virus spreads to different species and around the world, it continues to change. The more it changes, the stronger and more resistant it can become. Researchers will have to work quickly to have effective treatments and even create a vaccine before the virus takes over. If the change of the avian flu is not closely observed, avian flu could really shake up the world.

Reference:
New York State Department of Health. (2011). Pandemic influenza frequently asked questions. Retrieved from

Chapter 2 Questions

2. Name three approaches for prevention (primary, secondary, and tertiary) of each of the following health problems/conditions:
a. motor vehicle accidents: 1 = driver’s education required for all learners under the age of 18. 2 = Building stronger medians so cars do not cross over to opposing traffic in an accident. 3 = educational classes for those who were in accidents so that they learn to become better drivers.
b. obesity: 1 = health lunch promoted at school and health enhancement classes geared towards life-long fitness. 2 = set a workout and diet plan individually. 3. Monitor consumption and type of consumption.
c. hepatitis A: 1 = get the vaccine. 2 = reduce the chances of fecal matter exchange. 3 = get medical attention and treat virus
d. hepatitis B and C: 1 = get the vaccine. 2 = educate on how hepatitis B and C are transmitted. 3 = treat it with medication and be aware of infecting others.
e. foodborne illness on cruise ships: 1 = follow all guidelines for food safety (fresh foods stored properly). 2 = immediately pinpoint food that seems to be the problem and remove it. 3 = Provide those affected with plenty of water and possibly medication.
f. mortality due to gang violence: 1 = break up gang activity by promoting education and better lifestyles. 2 = have people work with gangs to reduce violence, have areas of violence at high priority for law enforcement. 3 = start up programs for those trying to get out of gangs (protection, education opportunities, employment programs, etc.)

9. The following questions refer to Table 2A-1
a. Calculate the percentage decline in the death rate for all causes. What generalizations can be made about changes in disease rates that have occurred between 1900 and the present?

With the times, the death rate has gone down tremendously due to knowledge of how diseases travel and are transmitted. With better hygiene, medicine, and technology, people are not dying from diseases as often. More people are aware of the methods for prevention, so it is easier for public health officials to encourage cleanliness and immunizations. Also, technology has connected the world. Information is quickly shared with the world. If something comes up that might be dangerous, people all over the world can be notified and the situation can be brought under control in a reasonable amount of time. Over time, the types of illnesses that cause death have also changed.

b. Contrast the changes in death rates due to cancer, heart disease, and cerebrovascular disease. What additional information would be useful to specify better the changes in these conditions?

For cancer, it did not make the top 10 causes of death back in 1900. This makes it difficult to compare and contrast the changes in today’s age. My assumption would be that people did not live long enough to get cancer and there were other causes that were thought to have caused the death. The more visible symptoms were probably what the thought of cause of death was listed as.
Disease of the heart increased over this time. When considering the lifestyle changes and longer lifespan, it is understandable. The food we eat today is high in high fructose corn syrup, sodium, sugar, and calories. More processed foods are being consumed as well. With our bodies not changing as fast as our diets, vessels are getting clogged and the heart is having to work harder as people become more obese.
Cerebrovascular disease has decreased from 106.9 to 41.9 per 100,000 since 1900. The technology has probably made it easier to monitor high risks.
These three specific causes of death show the three different changes possible. One was not even considered as a cause of death, one increased in incidences, and the last decreased. The causes of these disease are all different. One might think that it is crazy that incidences are on the increase because the knowledge of medicine and better technology should be moving us to becoming healthier. However, it is not the case. If this table was able to add in major causes of the diseases, I think it would be clearer why the trend is the way it is. Also, showing the individual disease in a line graph would show all the fluctuations. When lining the graph up to big events that happened between 1900 and now, those sudden spikes or decreases could be explained.

c. Note the decline in mortality for the four communicable disease since 1900 (1, 2, 3, and 10). With the exception of pneumonia and influenza, these are no longer among the 10 leading causes of death. Can you speculate regarding how much of each is due to environmental improvements and how much to specific preventative and curative practices?

Because of how quickly and easily tuberculosis spreads, it was vital to have a control plan. Clearly, the plan was successful since it is now not considered a leading cause of death. For TB, it seems like preventative and curative practices should receive the most credit. Knowing how quickly the bacteria can spread, those working in the health care field were targeted as at-risk and monitored closely. Still today, if anyone wants to work in the hospital or around children, it is very common to go and get a TB skin test done. I personally had to get x-rays because my skin test was too close to be sure. There is also a vaccine, which I received as a baby, which is a preventative practice. There have not been many environmental improvements, that I am aware of, that has aided in the rate decrease.
Unlike TB, the removal of diarrhea from the top 10 is probably more of a mix of both environmental improvements and preventative practices. Some causes of diarrhea are viruses, bacteria, and parasites (Mayo Clinic, 2013). When clean drinking water was not a priority, many bacteria and viruses lived in the water. When the water was consumed, symptoms were common. When traveling to other countries, people are warned about the drinking water. Even South Korea, a developed country doing very well, does not drink tap water. They boil their water or purchase it because of possible contamination (Mayo Clinic, 2013). A preventative practice has been to be aware of food. If it has been sitting out, there is a chance of bacteria growth. Even raw fruits and vegetables can cause diarrhea if they are not clean. Washing work stations when working with different types of food is important as well because there could be transmission of germs. Besides food, people are more aware of spreading their germs. Hand sanitizers are common everywhere. Signs are often in the bathrooms to wash your hands thoroughly with soap before returning to the workplace.
For diphtheria, the vaccine makes the preventative and curative practices more important in the not recordable causes of death. About 97% of children who receive the vaccine, which includes a vaccine for pertussis and tetanus, are protected against diphtheria (CDC, 2013). With it being a more common bacteria in children, having clean environments are important, but it is also important to act with preventative measures.
References:
Centers for Disease Control and Prevention [CDC]. (2013, July 8). Diphtheria fact sheet for parents. Retrieved from
Mayo Clinic. (2013). Diarrhea. Retrieved from

d. Among the 10 leading causes of death in 2009 were chronic lower respiratory diseases (44.7 per 100,000 – rank 3), diabetes (22.3 per 100,000 – rank 7), Alzheimer’s disease (25.7 per 100,000 – rank 6), ad suicide (11.9 per 100,000 – rank 10). (Note: Data are not shown in Table 2A-1.) In 1900, these were not among the 10 leading causes of death. How do you account for these changes?

Our change of lifestyle would be one reason that the top 10 list is changing. More people live and work in the city, most people have cars, jobs are safer, there are more people at higher levels of stress, and our diet is much different. On top of all those changes, medicine and technology have improved life by having better methods of catching diseases and having vaccines and medication that will prevent illnesses. Through the medical knowledge we now have, public health can go and work with the people by educating and providing resources. The work done by all these people makes changes in the government so that there are better regulations.

10. The following questions refer to Figure 2-3.

a. List and describe the trends in death rates by the five leading causes of death.

1. Disease of the Heart
It has kept fairly steady but with a slight decline since 1958. There are no spikes or sudden drops in the shown range.

2. Malignant Neoplasms
This is a very straight line. There has been no changes at all. Even when looking at the line markers, there is barely any change.

4. Cerebrovascular Disease
The trend is downwards. There was a sharper drop between 1974 and 1985. After that, it continued to decrease, but not as quickly.

5. Accidents (unintentional injuries)
Overall, there has been a decrease in death rates due to accidents. However, when looking closely, there has been a slight increase since about 1992, which brings the rates back to around the early 1980s.

6. Alzheimer’s Disease
Alzheimer’s was not a cause of death until 1979 so the rate looks much different from the others on the chart. The biggest surge was from 1979 – 1987, then another small spike occurred between 1997 and 1999. Since then, the rate has held steady.

b. Describe the trend for hypertension and Parkinson’s disease. Can you suggest an explanation for the trends in hypertension and Parkinson’s disease deaths?
Hypertension’s trend had a steady decrease until about 1990 and then it has increased at a slow pace since then. My assumption would be that the change of lifestyle and diet to more processed foods has caused this change in trend. Some risk factors for hypertension are lack of physical activity, being obese or overweight, too much sodium, not enough vitamin D, too much alcohol, and stress (Mayo Clinic, 2012). More people are becoming obese and overweight in this country and that will increase blood pressure, which leads to hypertension. Symptoms often do not show until much later, but it is treatable. It is important to catch it early to prevent the symptoms from worsening.
Parkinson’s disease had a steady rate up until the 1980s when it started, and still is, increasing. An explanation would be the same as Alzheimer’s. The disease has become more understood over the years and physicians are more likely to accurately diagnose a patient with it. The National Parkinson’s Foundation’s website still says that there is still no one way to diagnose a patient, which makes it difficult (National Parkinson’s Foundation, 2013). It is diagnosed through a variety of diagnostic tests and observing symptoms (NPF, 2013). Because Parkinson’s is a neurodegenerative brain disorder, it took time and a lot of research to see what is happening to the brain cells. With better and more accurate technology, a diagnosis is found much quicker than it used to. This explains the rate increase for Parkinson’s over the years.

Reference:
Mayo Clinic. (2012). High blood pressure (hypertension). Retrieved from
National Parkinson’s Foundation [NPF]. (2013). What is Parkinson’s Disease? Retrieved from

c. Does the curve for accidental deaths correspond to our expectations from various publicity reports?
Yes. However, I would have assumed that the rate would be lower than that. There has been a push for worker’s safety and that would bring the rates down. Several major organizations, unions, states, and even the employers have departments devoted to the safety of workers. Outside of the work place, there have also been a decrease thanks to publicity and better safety knowledge. Knowing not to leave your vehicle on in enclosed places or being aware around firearms protects everyone.

d. What is the trend for Alzheimer’s disease? Can you offer an explanation?
Alzheimer’s was not considered a disease, so never thought of as a cause of death, until 1979. As people learned about it and physicians began diagnosing it, there was a huge increase in the cause of death rate. Even though we know now that it is not a normal form of aging, it could have been thought that before there was research and knowledge about Alzheimer’s. With more research, more people were accurately diagnosed and there was a good reason for certain people’s odd loss of memory.

Go to. Select a specificrace,adult age group(10-year age groupbetween 25-65), andsexand download the leading causes of death reports for 1983, 1995, and 2007. Answer the following questions:

1. List and describe the trends in death rates by the 10 leading causes of death for the three years. Suggest an explanation for these trends.

Chronic lower respiratory disease has stayed on the list in #9, #7, and #7. The research that proved how bad smoking was for the lungs probably brought people to stop smoking, but there are still people that do. It would be interesting to see where it stands now, especially with the indoor smoking bans.

Perinatal period was only on the 1983 top 10. Most likely because there were better methods, cleaner births, and better knowledge of prenatal health care. In the US, facilities and prenatal check-ups are highly encouraged and have experience in successful pregnancies.

Nephritis was only on the 1995 and 2007 lists. The explanation would be that there was a better classification for something that has been around for years. There are several types of nephritis with varying symptoms. With more research and knowledge of what is happening to the body, nephritis was a diagnosis that could explain why there was inflammation. This goes for Alzheimer’s and Hypertension. It started to become something that physicians could diagnose because they were knowledgeable about it and more information for it was available. Hypertension also increased because of the stressful lifestyle and change in diet.