Self-Assessment Questions (SAQs) for Study Session 37

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering the following questions. 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 37.1 (tests Learning Outcomes 37.1, 37.2 and 37.5)

How many communicable diseases can you name that can be prevented by integrated vector control methods? (Think about all the vector-borne diseases you have learned about in this Module – not just in this study session!)

Answer

Malaria, relapsing fever, typhus, schistosomiasis, leishmaniasis, onchocerciasis and lymphatic filariasis are all vector-borne diseases prevented by integrated vector control methods. Did you remember all seven of these conditions?

SAQ 37.2 (tests Learning Outcomes 37.1 and 37.2)

Complete Table 37.1 by writing the common name of the vector in the second column beside the disease that it transmits.

Table 37.1  Four common vector-borne diseases and their vectors.

Vector-borne diseaseVector
Schistosomiasis                                  
Leishmaniasis                            
Onchocerciasis                               
Lymphatic filariasis                                   

Answer

The completed table appears below.

Table 37.1  Four common vector-borne diseases and their vectors.

Vector-borne diseaseVector
SchistosomiasisFreshwater snails
LeishmaniasisSandflies
OnchocerciasisBlackflies
Lymphatic filariasis Mosquitoes (Culex and Anopheline females)

SAQ 37.3 (tests Learning Outcomes 37.1, 37.2, 37.3, 37.4 and 37.5)

Imagine that you have been assigned to Humera and you see a 25-year-old man who has signs of severe weight loss, fever and a hugely enlarged abdomen.

  • a.What is your diagnosis?
  • b.What should you do for this patient?
  • c.What should you educate his family about the mode of transmission and how to protect themselves from this disease?

Answer

  • a.The signs of this disease strongly suggest that the patient is suffering from visceral leishmaniasis.
  • b.Inform the family that the disease is severe and life-threatening; immediately refer the patient to a higher health facility to confirm the diagnosis and begin treatment.
  • c.Educate the family about the mode of transmission of the disease by sandflies biting humans to take a blood meal. Advise them to destroy all rubbish heaps and rodent burrows around the house, and fill cracks in walls where sandflies like to breed. They should agree to their house being sprayed with insecticide and they should cover exposed skin and sleep under insecticide-treated bed nets to avoid sandfly bites.

SAQ 37.4 (tests Learning Outcomes 37.1, 37.3 and 37.4)

  • a.How could you tell the difference between the skin lesions of onchocerciasis and cutaneous leishmaniasis?
  • b.In addition to the physical consequences of the skin lesions, what impact can both these diseases have on the lives of affected people?

Answer

  • a.Cutaneous leishmaniasis is manifested by open skin ulcers, which may be large (see Figure 37.9). The skin lesions of onchocerciasis are characterized by changes in skin colour and the formation of large numbers of nodules (look back at Figure 37.15a).
  • b.In addition to the physical disabilities and pain caused by these conditions, the disfiguring appearance of onchocerciasis nodules and cutaneous leishmaniasis ulcers often results in stigmatization, discrimination and rejection of patients by their communities.

SAQ 37.5 (tests Learning Outcomes 37.1, 37.3 and 37.5)

  • a.Which regions of Ethiopia are most affected by schistosomiasis?
  • b.Why are children in affected communities particularly at risk of schistosomiasis, and what impact does the disease have on their lives, in addition to the pain and discomfort it causes?

Answer

  • a.Highland lakes and rivers in several parts of Ethiopia (e.g. Ziway, Hawassa, Bishoftu, Wonji, Haromay, Jimma, Bahir Dar, etc.) are affected by Schistosoma mansoni, which affects the intestines. Schistosoma haematobium, which mainly affects the bladder is limited to lowland swampy land and floodplains in the Awash and Wabe Shebele valleys and along the border with the Sudan.
  • b.Children are most at risk because they are more likely to go swimming in infected water, or stand in the water while fishing. They are also more likely than adults to stand in the water to urinate or defaecate. In addition to the pain caused by the disease, infected children are usually stunted in their growth and perform poorly at school.

Summary of Study Session 37