Public Health Approaches to Infectious Disease

# Questions for the course

The following questions allow you to assess your understanding of the content of this course. Each one relates to one or more of the intended learning outcomes of the study.

If you are unable to answer a question, or do not understand the answer given, then reread the relevant section(s) of the course and try the question again.

## Question 1

(This question relates to course learning outcomes (LOs) 1–4.)

Suggest at least one example of a public health measure that can be taken to control malaria at each of the primary, secondary and tertiary levels of prevention.

## Answer

Primary prevention strategies against malaria include:

- chemoprophylaxis – taking drugs to protect against infection with malaria parasites before going into an endemic area, or at high-risk periods (e.g. during pregnancy)
- keeping skin covered, particularly from dusk to dawn
- use of insect-repellent chemicals on exposed skin
- routine use of insecticide-treated nets (ITNs) when sleeping
- spraying houses with insecticides against adult and larval mosquitoes
- use of curtains across doors and windows
- environmental engineering to prevent or destroy mosquito breeding sites
- putting surfactant on the surface of pools used by mosquitoes for breeding
- keeping water tanks covered.

Secondary prevention includes:

- providing education about the early signs of malaria and the need to seek treatment as soon as possible
- surveillance, screening and case finding of infected individuals in communities in endemic regions (e.g. by blood testing)
- administration of drugs to treat early cases of malaria.

Tertiary prevention refers to treatment of the life-threatening complications of malaria (e.g. cerebral malaria), usually with intravenously administered drugs and fluids.

## Question 2

(This question relates to course LOs 1–5 and the DOTS programme (directly observed treatment, short course: see Section 3.4) for the treatment of tuberculosis (TB). )

1. In what ways does the DOTS programme illustrate the importance of community action in the prevention and control of tuberculosis?
2. What is the main limitation of the DOTS approach as a strategy for preventing the transmission of TB?

## Answer

1. Even though the prime purpose of the DOTS programme is to ensure compliance with the drug regimen, it also supports individuals within their communities and involves many agencies (including community volunteers) in its delivery.
2. The main limitation of the DOTS approach in terms of TB prevention is that it cannot tackle the socio-economic conditions (e.g. poverty, lack of housing, poor nutrition) that increase the spread of TB.

## Question 3

(This question relates to course LOs 1, 3 and 5.)

Identify two similarities in the strategies used to control the spread of diarrhoeal diseases in the rural Health Extension Programme in Ethiopia (see Video 1) and C. difficile infection in English hospitals.

## Answer

You might have thought first of the common approach to increasing awareness of hand hygiene in both locations. The Ethiopian programme has promoted the installation of yellow plastic canisters of clean water near latrines to facilitate hand washing (ideally with soap); this is similar to the programme in English hospitals to install alcohol-based hand-hygiene stations in all wards and corridors.

Secondly, both of these initiatives require community mobilisation and the full participation of staff, patients and community members in order to reduce the incidence of infectious agents transmitted on the hands.

## Question 4

(This question relates to course LOs 1 and 6.)

Explain why the type of water source available is a key factor in determining the areas where guinea worms are endemic and the areas where they have spontaneously disappeared.

## Answer

Even in endemic countries, dracunculiasis does not occur in urban areas where piped water is supplied, and it is rare in rural communities where the principal sources of drinking water are fast-running streams or deep wells, because the intermediate host (cyclops) cannot survive in these environments. It inhabits still, shallow water, such as natural pools and step wells, where people are most likely to stand as they draw water, or seek relief from the burning pain of a guinea worm as it emerges.

OpenLearn - Public Health Approaches to Infectious Disease
Except for third party materials and otherwise, this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence, full copyright detail can be found in the acknowledgements section. Please see full copyright statement for details.