Date | November 2014 | Marks available | 6 | Reference code | 14N.2.hl.12 |
Level | HL only | Paper | 2 | Time zone | |
Command term | Explain | Question number | 12 | Adapted from | N/A |
Question
The diagram shows some of the factors that affect the likely impacts of a disease on individuals and the community in which they live.
Identify two possible physical factors (A and B) that may affect the incidence and/or spatial extent of the disease.
Briefly outline how population distribution can affect the incidence of the disease.
Explain two management strategies that have been used to limit the spread of either one named water-borne disease or one named vector-borne disease.
“For all communities, the prevention of disease is at least as important as its treatment.” Discuss this statement, referring to one or more examples of disease.
Markscheme
Award [1 mark] for each factor. Possible responses include: relief and rivers, temperature, humidity, presence/absence of specific fauna such as mosquitoes, and occurrence of stagnant water. Accept other valid factors.
Award [1 mark] for any of the following:
- a concentrated distribution/high density of population may lead to higher rates of transmission/spread/diffusion/incidence in an area
- a dispersed population may mean lower rates of transmission/spread/diffusion/incidence in an area
- credit alternative statements provided they relate population distribution to incidence of a disease, rather than its spatial extent
- accept discussion of effects of the age distribution of a population.
Note that the question specifically excludes sexually transmitted diseases. Both strategies must relate to the same disease; if not, award up to a maximum of [3 marks].
For each strategy, award [1 mark] for identifying a management strategy (provided the strategy is relevant to the named disease) and [2 marks] for describing and explaining it. The strategy need not be located, but credit use of a located example if provided.
Possible strategies include: vaccination/inoculation, education, pest control/insect eradication, improvement of water quality, making effective treatment options readily available and affordable.
For example:
- “Drainage of land [1 mark] means mosquitoes lose their habitat so there is less malaria [1 mark] as seen in Italy’s Pontine marshes [1 mark].”
- “Avoiding mixing sewage with drinking water [1 mark] can be achieved by lining wells [1 mark]. This breaks the oral–fecal transmission route for cholera [1 mark].”
Credit all content in line with the markbands. Credit unexpected approaches wherever relevant.
The relative importance of policies of prevention/treatment of a disease will depend partly on the disease in question, and partly on any framework that is used to help shape the discussion eg comparing the importance of long-term eradication/mitigation with the short-term ethical imperative to help sufferers; or recognizing the resistance to contraception in some cultures.
Only one disease is required for the discussion. Therefore a range of geographic factors can feature in the answer, such as the economic, social, political, demographic characteristics of the community, country or region involved.
For band D, candidates must describe some ways in which one or more diseases can be both prevented and treated.
Band E should either provide greater exemplified detail of prevention and treatment options and the geographic factors that inform influence choices or offer some more sophisticated evaluation of the statement (eg discusses “important”, perhaps by contrasting a short-term and long-term view, or discusses the different viewpoints and perspectives of contrasting cultures).
At band F, expect both elements.
Examiners report
Many did not understand the term physical factors and cited human factors.
This was straightforward.
Management strategies were identified but further description and explanation were, at times, not fully supported. Unfortunately the use of Ebola in responses was not acceptable for this question as it is not water-borne or vector-borne.
There were some very good answers to this question; a range of diseases were considered (including the recent Ebola outbreak in Africa) and many were able to discuss the relative merits of prevention and treatment.