Question 19M.2.HL.TZ1.d
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.HL.TZ1.d |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Compare and contrast | Question number | d | Adapted from | N/A |
Ebola virus disease (EVD) is the disease in humans and other primates that is caused by the Ebola virus. Fruit bats are the reservoir for the virus and are able to spread the disease without being affected. Humans can become infected by contact with fruit bats or with people infected by the virus, their body fluids or equipment used to treat them.
The stacked bar graph shows the epidemiological data for the EVD cases in Conakry, the capital city of Guinea, surrounding suburbs and rural areas in Guinea from the beginning of January 2014 to the end of March 2015.
[Source: Adriana Rico, et al. “Epidemiology of Epidemic Ebola Virus Disease in Conakry and Surrounding Prefectures,
Guinea, 2014–2015.” Emerging Infectious Diseases 22.2 (2016): 178–183. PMC. Web. 23 Mar. 2017.
https://wwwnc.cdc.gov/eid/article/22/2/15-1304_article]
The table summarizes epidemiological data from Guinea during the Ebola outbreak in 2014. The data are based on figures supplied by Ebola treatment centres. The last column refers to people who died in places other than Ebola treatment centres.
[Source: Adriana Rico, et al. “Epidemiology of Epidemic Ebola Virus Disease in Conakry and Surrounding Prefectures,
Guinea, 2014–2015.” Emerging Infectious Diseases 22.2 (2016): 178–183. PMC. Web. 23 Mar. 2017.
https://wwwnc.cdc.gov/eid/article/22/2/15-1304_article]
Compare and contrast the data for Conakry with the data for the three suburbs.
[2]
differences:
a. Conakry has more cases than any of the suburbs
OR
more cases in total in the suburbs than in Conakry ✔
b. more male cases in Conakry whereas more female cases in suburbs ✔
c. higher «% of» fatal cases at Ebola treatment centers in suburbs than in Conakry ✔
similarity:
d. in both Conakry and suburbs «% of» fatal cases in treatment centers is higher than outside ✔
This was a timely question with Ebola epidemics again causing great problems in parts of Africa. Students were expected to have had some practice at analysing data relating to an epidemic because of this Skill in the programme: Analysis of epidemiological data related to vaccination programmes. It was assumed that candidates would understand terms such as ‘case’, ‘fatal case’, ‘infect’ and ‘treat’.
This was another question where the skill was in picking out significant trends. Differences between individual suburbs were not significant so all the answers accepted were either similarities or differences between the capital city and the suburbs generally. Most but not all candidates made two or more statements about the data that were significant enough to score marks. Some students treated percentages as though they were absolute numbers and for example added the percentage of fatal cases in and outside treatment centres together, which does not give a meaningful total.
