| Course | HS340 Epidemiology |
|---|---|
| Unit | Unit 9 |
| Paper type | Surveillance data review |
| Length | About 730 words, 5 pages double-spaced |
| Format | APA 7 student paper |
| School | Purdue University Global |
| Program | BS in Health Science |
| Updated | October 2026 |
Free sample paper for HS340 Unit 9
How Much of the Rise Was Disease? A Unit 9 Surveillance Data Review of Reported Campylobacteriosis in a Composite State
[Student Name]
Purdue University Global
HS340: Epidemiology
Unit 9 Surveillance Data Review
[Instructor Name]
[Date]
The state and its eight years of figures are composite; the surveillance guidelines, the review of culture-independent tests and the national foodborne report cited are real.
The Data
Eight years of state surveillance, each line giving reported cases, the rate per 100,000, the share of cases detected only by a culture-independent diagnostic test and the number of hospitalized cases:
Year 1: [560] cases, 18.1, [4] percent, [92] hospitalized. Year 2: [590] cases, 19.0, [6] percent, [95] hospitalized. Year 3: [610] cases, 19.7, [9] percent, [97] hospitalized. Year 4: [840] cases, 27.1, [31] percent, [99] hospitalized. Year 5: [910] cases, 29.4, [38] percent, [101] hospitalized. Year 6: [1,020] cases, 32.9, [44] percent, [104] hospitalized. Year 7: [1,240] cases, 40.0, [45] percent, [131] hospitalized. Year 8: [1,080] cases, 34.8, [50] percent, [104] hospitalized.
Rates use a constant population of [3.1] million for simplicity.
A Second Series: Culture-Confirmed Cases
Subtracting the cases found only by culture-independent tests gives the number confirmed by culture, the method used throughout the period:
Year 1, 538. Year 2, 555. Year 3, 555. Year 4, 580. Year 5, 564. Year 6, 571. Year 7, 682. Year 8, 540.
This series is nearly flat from Year 1 to Year 6, between 538 and 580, then jumps by about a fifth in Year 7 and falls back in Year 8.
Reported cases rose 82 percent from Year 1 to Year 6 while culture-confirmed cases rose 6 percent and hospitalizations 13 percent, so most of that rise came from finding infections differently, not from more infections.
Year 4: A Laboratory Switch
In Year 4 the state's largest health system replaced stool culture with a multiplex molecular panel that tests for many pathogens at once. Culture-independent tests are faster and often more sensitive, and they detect infections that culture would miss, but they also change what surveillance counts and leave no isolate for subtyping unless a laboratory cultures the specimen as well (Langley et al., 2015). Reported cases jumped 38 percent that year, from [610] to [840], while culture-confirmed cases and hospitalizations barely moved. The rise is an artifact of testing.
Year 6: A Reporting Change
In Year 6 the state began receiving electronic laboratory reports from two urgent care chains that had previously sent results only by fax, and some of those reports had been missed. Reported cases rose again, but culture-confirmed cases and hospitalizations did not. This is a change in completeness, one of the attributes surveillance evaluations are asked to assess (German et al., 2001).
Year 7: A Real Increase
Year 7 is different. Culture-confirmed cases rose from 571 to 682, hospitalizations from 104 to 131 and total reports from [1,020] to [1,240], while the share found only by new tests barely changed. When several independent series move together, and the testing mix stays steady, the most likely explanation is more infection. The state's outbreak log for that summer recorded two clusters linked to raw milk from one dairy, which accounts for part of the rise.
Year 8: Back Toward the Trend
Reports fell to [1,080], culture-confirmed cases to 540 and hospitalizations to 104, close to the Year 6 level. The Year 7 excess did not persist, consistent with an outbreak year rather than a new baseline.
What the State Should Report
The annual report should not describe Years 1 to 6 as a near doubling of Campylobacter infections. A fair summary is that reported cases rose mainly because of new tests and better reporting, that culture-confirmed cases were stable through Year 6, and that Year 7 saw a genuine increase partly explained by two outbreaks. National foodborne surveillance faced the same problem as culture-independent tests spread, and began reporting infections diagnosed by those tests separately from culture-confirmed ones (Marder et al., 2018).
Limits of the Review
Hospitalizations are a useful check because severe illness is less affected by testing changes, but they can shift with admission practices. The share of cases found only by new tests depends on laboratories reporting how each case was diagnosed, which may be incomplete. And a constant population slightly overstates rates in the later years if the state grew.
References
German, R. R., Lee, L. M., Horan, J. M., Milstein, R. L., Pertowski, C. A., & Waller, M. N. (2001). Updated guidelines for evaluating public health surveillance systems: Recommendations from the Guidelines Working Group. MMWR Recommendations and Reports, 50(RR-13), 1-35.
Langley, G., Besser, J., Iwamoto, M., Lessa, F. C., Cronquist, A., Skoff, T. H., Chaves, S., Boxrud, D., Pinner, R. W., & Harrison, L. H. (2015). Effect of culture-independent diagnostic tests on future emerging infections program surveillance. Emerging Infectious Diseases, 21(9), 1582-1588. https://doi.org/10.3201/eid2109.150570
Marder, E. P., Griffin, P. M., Cieslak, P. R., Dunn, J., Hurd, S., Jervis, R., Lathrop, S., Muse, A., Ryan, P., Smith, K., Tobin-D'Angelo, M., Vugia, D. J., Holt, K. G., Wolpert, B. J., Tauxe, R., & Geissler, A. L. (2018). Preliminary incidence and trends of infections with pathogens transmitted commonly through food: Foodborne Diseases Active Surveillance Network, 10 U.S. sites, 2006-2017. Morbidity and Mortality Weekly Report, 67(11), 324-328. https://doi.org/10.15585/mmwr.mm6711a3
What the HS340 Unit 9 assignment asks for
The ninth unit typically supplies several years of surveillance data, sometimes with notes on testing or definitions, and asks you to judge whether a change in reported cases reflects a change in disease. Most reviews of this kind pair a table with a figure or two across a few pages. Instructors look for a second, independent series used as a check, such as hospitalizations or deaths, and for each artifact named precisely: a testing change, a definition change or a reporting change. Many sections reward a recommendation on how the trend should be described publicly. Describe what each figure shows in words. Cite surveillance evaluation guidelines and any source that explains the testing or definition change.
How this HS340 Unit 9 example is built
The review lists eight years of reported cases, rates, the share detected only by culture-independent tests and hospitalizations. A second series subtracts those cases to give culture-confirmed counts, and the highlighted sentence compares the three series from year one to year six. Separate sections explain year four as a laboratory switch, citing a review of how new tests affect surveillance, and year six as a reporting change in completeness, citing the evaluation guidelines. Year seven is read as a genuine increase because all series rise together, with outbreaks noted. Year eight returns toward trend. A section says what the state report should say, citing national foodborne surveillance, and a final section names three limits of the review.
Where the points sit in the HS340 Unit 9 rubric
Surveillance reviews are commonly graded on the use of independent checks, correct identification of artifacts, interpretation of genuine change, recommendations and presentation of data. Use of independent checks and identification of artifacts usually carry most of the marks, because the unit's purpose is to show that a reported count reflects both disease and the system that counts it. Interpretation earns credit when a real increase is recognized by several series moving together. Recommendations are rewarded when they tell the agency how to describe the trend honestly. Presentation covers a clear table, figures described in words and consistent rates. Citing evaluation guidelines and a source on the specific testing change strengthens every section.
Common HS340 Unit 9 mistakes, and how to avoid them
A typical error is describing every rise in reports as more disease, or every rise as an artifact, without testing either with a second series. Another is naming a testing change without showing its timing against the jump in cases. Some students calculate rates but never compare them with hospitalizations or deaths. Others overlook a definition or reporting change mentioned in the notes. Ending without advice on how the trend should be reported leaves the analysis unused. If your data cover another disease, perhaps pertussis, Lyme disease or a fungal infection, send the table and notes and we can help you find a check series and separate artifacts from real change.
Get an HS340 Unit 9 example written to your instructions
Point the desk to the series the HS340 Unit 9 review covers, attach the data or the report it comes from, then send the prompt alongside its rubric. A free first custom sample returns in 24-48 hours, describing that surveillance system before judging each change and naming the indicator used to check it. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
More HS340 papers and BS in Health Science samples
- HS340 Unit 1: Surveillance Discussion Post
- HS340 Unit 2: Rate Calculation Set
- HS340 Unit 3: Study Design Appraisal
- HS340 Unit 4: Two by Two Table
- HS340 Unit 5: Bias and Confounding Memo
- HS340 Unit 6: Outbreak Investigation Writeup
- HS340 Unit 7: Seminar Reflection on an Outbreak
- HS340 Unit 8: Screening Test Analysis
- HS340 Unit 10: Epidemiology Case Report
- HS315 Unit 9: Health Communication Piece
- HS305 Unit 9: Quasi-Experimental Article Critique
- HS292 Unit 9: Carried-Forward Diagnoses Reflection
- HS450 Unit 9: Stakeholder Communication Plan
HS340 Unit 9 questions, answered
Is a rise caused by more testing a false rise?
Not exactly. The extra cases are usually real infections that were previously missed, so the rise reflects better detection rather than more disease. The review describes it that way: year four found infections that earlier years did not see. What it cannot be read as is growing transmission, and a report that says so without dismissing the cases is being precise.
Where can data for a surveillance review be found?
State health departments publish annual reportable disease summaries, often with notes on definition changes, and the national notifiable disease system posts weekly and annual tables. Testing volume is harder to find and sometimes appears only in special reports. Where a prompt supplies composite data, as here, the review should still describe the system behind the numbers as if it were real.
Where can I find a free HS340 Unit 9 sample paper?
You can read the complete Unit 9 surveillance data review here, testing whether a doubling of reported Campylobacter cases was real.
What is a culture-independent diagnostic test?
A test, such as a multiplex molecular panel, that detects a pathogen's genetic material or antigens without growing it in culture. It is fast and sensitive but leaves no isolate unless culture is also done.
Why use hospitalizations as a check on a surveillance trend?
Severe cases tend to be tested and recorded in much the same way from year to year, so their count changes mainly when the amount of disease changes.