For each of the three major types of epi curves, give one characteristic of its histogram, and one characteristic of the outbreak itself that could cause that type of curve.
Common Source: A single, one-time exposure results in a single peak. Food-borne illness from a convention is one example.
Continuous: A constant exposure results in a plateau of cases. The 1854 London Cholera outbreak is one example.
Propagated: A host serves as a source of exposure for other susceptible hosts, resulting in a serious of growing peaks. A flu pandemic in which no one is initially immune would be one example.
Correct, your turn.
Re: Disease Detectives B/C
Posted: March 25th, 2017, 10:53 am
by yang573
A Minnesota health department enrolled 3,000 (healthy) individuals for 5 years to estimate the incidence rate of Hepatitis C in the Twin Cities metropolitan area. These people were called up annually, and the results are as follow:
After the 1st year, 2 individuals had a new diagnosis for hepatitis C, and 78 were lost to follow up
After the 2nd year, 0 individuals had been newly diagnosed with hepatitis C, and 90 were lost to follow up.
After the 3rd year, 5 individuals had been newly diagnosed with hepatitis C, and 155 were lost to follow up.
After the 4th year, 3 individuals had been newly diagnosed with hepatitis C, and 117 were lost to follow up.
After the 5th year, 6 individuals had been newly diagnosed with hepatitis C, and 49 were lost to follow up.
Calculate the incidence rate (in 1,000 person-years). Assume those lost to follow-up were disease-free for only half of the year.
Re: Disease Detectives B/C
Posted: March 27th, 2017, 7:44 am
by Unome
yang573 wrote:
A Minnesota health department enrolled 3,000 (healthy) individuals for 5 years to estimate the incidence rate of Hepatitis C in the Twin Cities metropolitan area. These people were called up annually, and the results are as follow:
After the 1st year, 2 individuals had a new diagnosis for hepatitis C, and 78 were lost to follow up
After the 2nd year, 0 individuals had been newly diagnosed with hepatitis C, and 90 were lost to follow up.
After the 3rd year, 5 individuals had been newly diagnosed with hepatitis C, and 155 were lost to follow up.
After the 4th year, 3 individuals had been newly diagnosed with hepatitis C, and 117 were lost to follow up.
After the 5th year, 6 individuals had been newly diagnosed with hepatitis C, and 49 were lost to follow up.
Calculate the incidence rate (in 1,000 person-years). Assume those lost to follow-up were disease-free for only half of the year.
Assuming I'm just suppose to halve the number lost to follow up and add it on: 0.0521
Re: Disease Detectives B/C
Posted: March 27th, 2017, 6:55 pm
by yang573
Unome wrote:
Assuming I'm just suppose to halve the number lost to follow up and add it on: 0.0521
I also got that answer. I added it up and ended up doing:
16 new cases in 13710 person-years for an incidence of 1.167 cases per 1000 person-years.
Ok, that makes a lot more sense. I had no idea what you meant by "assume those lost to follow-up are disease free for half of the year;" apparently I didn't need that?
Re: Disease Detectives B/C
Posted: March 30th, 2017, 5:54 am
by yang573
Unome wrote:Ok, that makes a lot more sense. I had no idea what you meant by "assume those lost to follow-up are disease free for half of the year;" apparently I didn't need that?
You still have to count them toward the person-years observed. I ended up with 13717.5 person-years. Ignoring them here just doesn't have much of an impact due to the number of participants. Feel free to PM me if you have anymore questions.
Your turn to pose a problem.
Re: Disease Detectives B/C
Posted: April 24th, 2017, 9:17 am
by Tailsfan101
The three types of disease transportation are _______borne, ___borne, and ______borne.
Re: Disease Detectives B/C
Posted: May 8th, 2017, 8:56 am
by The48thYoshi
Tailsfan101 wrote:The three types of disease transportation are _______borne, ___borne, and ______borne.
Airborne, Vehicleborne, Vectorborne
Re: Disease Detectives B/C
Posted: May 8th, 2017, 9:00 am
by Tailsfan101
The48thYoshi wrote:
Tailsfan101 wrote:The three types of disease transportation are _______borne, ___borne, and ______borne.