Self-Assessment Questions (SAQs) for Study Session 2

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering the questions below. Write your answers in your Study Diary and discuss them with your Tutor at the next Study Support Meeting. You can check your answers with the Notes on the Self-Assessment Questions at the end of this Module.

SAQ 2.1 (tests Learning Outcomes 2.1 and 2.2)

Tuberculosis (TB) is common in Ethiopia. Its main clinical manifestations include chronic cough and shortness of breath. Using this information, which classification of communicable diseases can you apply to TB and to which class does TB belong?


Using the given information, the classification could be based on the clinical manifestations of the disease (cough and shortness of breath); accordingly tuberculosis is classed as a respiratory disease.

SAQ 2.2 (tests Learning Outcomes 2.1 and 2.2)

How would you classify pulmonary tuberculosis using the epidemiologic method? What is the main importance of such classification?


Pulmonary tuberculosis is classified epidemiologically as an airborne disease. Such classification helps you in applying prevention and control measures against the disease.

SAQ 2.3 (tests Learning Outcomes 2.3, 2.4 and 2.5)

Suppose in a certain rainy season you diagnosed malaria in several people who came to you seeking treatment. Then, you undertook the following measures:

  • a.You treated each patient with the appropriate drug.
  • b.You mobilised the community to eradicate breeding sites of mosquitoes.
  • c.You gave health education on the proper use of bed nets.

Which factor in the chain of disease transmission are you targeting with each of the above measures?


  • a.Treatment of each patient targets the human reservoir.
  • b.Eradication of breeding sites targets the mode of transmission.
  • c.Bed net use targets the susceptible host.

SAQ 2.4 (tests Learning Outcomes 2.1, 2.3, 2.4 and 2.5)

Which of the following statements are true and which are false? In each case, explain your reasoning.

A  Isolation of the susceptible host is advised for the duration of the incubation period of a severe and easily transmitted disease.

B  Sterilisation refers to the destruction of all forms of micro-organisms by physical or chemical agents such as alcohol and chlorine.

C  Vaccination and vector control target the infected host so as to prevent transmission of infection.


A is false. It is true that isolation is applied for severe and easily transmitted diseases, but it is applied to the infected hosts (not the susceptible hosts) until the risk of transmission is reduced or stops.

B is true. Sterilisation kills all forms of micro-organisms, unlike disinfection which kills most but not all forms.

C is false. Vaccination mostly targets the susceptible host and vector control targets the mode of transmission.

SAQ 2.5 (tests Learning Outcome 2.6)

Suppose among the diseases you have identified in your community, two are malaria and ascariasis (infection by ascaris worms). Let’s say the prevalence rate of malaria is 90 per 1,000 population and the prevalence rate of ascariasis is 200 per 1,000 population.

  • a.If you need to prioritise activities to control one of these diseases, what other criteria should you consider?
  • b.Malaria is a more severe disease than ascariasis. Let’s say that interventions for both diseases are equally feasible, but the community and government are more concerned about malaria. So, considering all the factors, to which disease do you give higher priority for prevention and control?


  • a.The other criteria to be considered include the severity of the diseases, the feasibility of implementing effective interventions, and the concern of the community and the government.
  • b.Malaria has priority in two out of the five criteria: that is severity, community and government concern, whereas ascariasis has priority in only one criterion, which is the higher prevalence. Both diseases have equal priority in feasibility of implementing interventions. Therefore, malaria should be given higher priority for prevention and control.

Summary of Study Session 2