Self-Assessment Questions (SAQs) for Study Session 6

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering these 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 6.1 (tests Learning Outcomes 6.1 and 6.3)

Imagine that the relative humidity of your village is 40% in February and 80% in September. Describe how this could affect malaria transmission in your village. Start by explaining the effect of humidity on the vector.

Answer

There will be malaria transmission in September, but not in February. At 40% humidity, mosquitoes cannot live long enough to transmit malaria in February.

SAQ 6.2 (tests Learning Outcome 6.2)

Imagine that the average daily temperature in your village is 12°C and you rarely see malaria cases. Describe the reason why there is no malaria transmission in your village.

Answer

A daily average temperature of 12˚C is not enough for the parasites to develop inside the mosquito vector. It is too cold.

SAQ 6.3 (tests Learning Outcomes 6.2 and 6.3)

Imagine that your village is located at 1,000 metres above sea level and is covered with vegetation throughout the year. Several new malaria cases are occurring every month. What could be the factors causing the high malaria rate in your village?

Answer

  • Located at 1,000 metres above sea level, your village will have favourable temperatures for mosquito growth and parasite development.
  • High vegetation coverage increases humidity and high humidity helps the vector to live longer; malaria is transmitted by long-living vectors.

SAQ 6.4 (tests Learning Outcome 6.4)

Most of the malaria cases in your village come in the two months following the rainy season. Very few cases occur in the dry season. Explain the reason why so many cases occur after the rainy season.

Answer

The rains create several vector breeding grounds; many vector breeding sites produce many vectors; more vectors mean more malaria transmission.

SAQ 6.5 (tests Learning Outcome 6.5)

Anopheles arabiensis prefers to bite humans more than animals. Another Anopheles mosquito, An. pharoensis, feeds more on animals than humans. Which one of them will be a better vector of malaria and why?

Answer

  • An. arabiensis will be a better vector of malaria.
  • Mosquitoes that prefer to feed on humans have a better chance of picking up the parasite from an infected person and transmitting it to another person.

SAQ 6.6 (tests Learning Outcome 6.5)

In village A, most of the malaria cases are due to falciparum malaria. In village B, vivax malaria is more common than falciparum malaria. Which village will have more deaths due to malaria and why?

Answer

  • Village A will have more deaths due to malaria than village B.
  • Falciparum malaria is the more dangerous form of malaria that often causes deaths; people very rarely die of vivax malaria.

Summary of Study Session 6