Disease Detectives B/C

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I'm going to start this up again.

1. What is the ANOVA test?
2. In what situation would you use a t-test?
3. What causes Mad Cow Disease?
4. Why aren't viruses affected by antibiotics? (Semi-detailed answer please.)

Click to Show Answer

1) The ANOVA tests differences between two or more means.

2) When testing to see if the means of two populations are significantly different

3) A prion

4) Viruses have no cells, which is what antibiotics target and kill. Antibiotics are designed to kill the structures found in bacteria, and viruses have completely different structures.

[Nerd_Bunny]

I'm going to start this up again.

1. What is the ANOVA test?
2. In what situation would you use a t-test?
3. What causes Mad Cow Disease?
4. Why aren't viruses affected by antibiotics? (Semi-detailed answer please.)

Click to Show Answer

1) The ANOVA tests differences between two or more means.

2) When testing to see if the means of two populations are significantly different

3) A prion

4) Viruses have no cells, which is what antibiotics target and kill. Antibiotics are designed to kill the structures found in bacteria, and viruses have completely different structures.

Great answers! All correct! Your turn.

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What is a case definition? What are the three categories of a case and what constitutes each? Why might a person with the right symptoms not be considered a case? Why might a reported outbreak not really be an outbreak?

[Nerd_Bunny]

What is a case definition? What are the three categories of a case and what constitutes each? Why might a person with the right symptoms not be considered a case? Why might a reported outbreak not really be an outbreak?

Answers (Click to Show Hidden Text)

A case definition is a set of criteria that describe what a case would look like.
The three categories are: possible, probable, and confirmed. Possible: some factors point to diagnosis, but no lab verificiation, Probable: many factors point to diagnosis, but no lab verification, Confirmed: diagnosed by lab verification
A person with the right symptoms might not be considered a case because he doesn't have laboratory confirmation, or doesn't meet all the case definition requirements.
A reported outbreak might not really be an outbreak if there is no lab confirmation.

[UTF-8 U+6211 U+662F]

What is a case definition? What are the three categories of a case and what constitutes each? Why might a person with the right symptoms not be considered a case? Why might a reported outbreak not really be an outbreak?

Answers (Click to Show Hidden Text)

A case definition is a set of criteria that describe what a case would look like.
The three categories are: possible, probable, and confirmed. Possible: some factors point to diagnosis, but no lab verificiation, Probable: many factors point to diagnosis, but no lab verification, Confirmed: diagnosed by lab verification
A person with the right symptoms might not be considered a case because he doesn't have laboratory confirmation, or doesn't meet all the case definition requirements.
A reported outbreak might not really be an outbreak if there is no lab confirmation.

Yep, although I was going for these answers for questions three and four (Click to Show Hidden Text)

3) The person might have the same disease but not be linked to the outbreak (different place, different time, did not participate in an event that all of the other ill people did, etc.)
4) There might not be more cases than expected. The cases might not be all related. The increased number of cases might be because of better surveillance and tests.
Also n.b. that a case can be confirmed by being epidemiologically linked to a confirmed case.

Your turn!

[Nerd_Bunny]

1. What is one of the most common food sources of botulism?
2. Give an example of observer bias.
3. Which one of Hill's Criteria for Causation is the most important? (For lack a better phrase...) Why?
4. Give an example of volunteer bias.

[Killboe]

1. Improperly canned food, Home canned foods with low acidity, smoked or salted fish, and potatoes baked in aluminum foil. 2. An example would be if a doctor thought that shorter kids that drank coffee would never grow so they give them probiotic/hormone growther when they shouldn't. 3. I'm not too sure what you mean exactly 4.A volunteer research thinks that boys have a weaker immune system than girls. This might lead to deviation from the true results.

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1. What is one of the most common food sources of botulism?
2. Give an example of observer bias.
3. Which one of Hill's Criteria for Causation is the most important? (For lack a better phrase...) Why?
4. Give an example of volunteer bias.

My answers (Click to Show Hidden Text)

1. Same as killboe
2. If an experimenter thought that males smoked more often and unconsciously picked a biased sample or ignored data that did not support his hypothesis.
3. Not sure here too, all 9 of them are important. Maybe consistency to eliminate the impact of random chance?
4. People that have more severe signs and symptoms may be more willing to take the experimental drug than the control drug, creating bias against the experimental drug.

[Nerd_Bunny]

My answers (Click to Show Hidden Text)

1. Same as killboe
2. If an experimenter thought that males smoked more often and unconsciously picked a biased sample or ignored data that did not support his hypothesis.
3. Not sure here too, all 9 of them are important. Maybe consistency to eliminate the impact of random chance?
4. People that have more severe signs and symptoms may be more willing to take the experimental drug than the control drug, creating bias against the experimental drug.

1. Improperly canned food, Home canned foods with low acidity, smoked or salted fish, and potatoes baked in aluminum foil. 2. An example would be if a doctor thought that shorter kids that drank coffee would never grow so they give them probiotic/hormone growther when they shouldn't. 3. I'm not too sure what you mean exactly 4.A volunteer research thinks that boys have a weaker immune system than girls. This might lead to deviation from the true results.

Answers: 1. Correct.
2. Both are good examples.
3. Temporal relationship. This one is considered the absolutely essential criterion to determine causation because without the cause being before the outcome, nothing else would come from it. This one was a bit tricky.
4. Both are good examples. EDIT: Whoever wants to post the next question can.

[Nerd_Bunny]

Ok, I guess I'll post the next questions.

1. List 4 types of direct transmission and 4 different types of indirect transmission.
2. What is a good treatment for botulism?
3. Give an example of healthy worker effect.
4. What is the formula for chi-squares?