A Study Suggests that Mosquitoes Develop Resistance to Bed Nets

September 16, 2011

Unlocking Word Meanings
Read the following words/expressions found in today’s article. 

1. malaria (n.) [muh-lair-ee-uh] – a disease caused and transmitted by infected mosquitoes
Example: Many people in tropical countries like the Philippines suffer from malaria.

2. incidence (n.) [in-si-duhns] – the frequency in which something happens or takes place
Example: Incidence of common colds during winter season is high.

3. immunity (n.) [ih-myoo-ni-tee] – a body's ability to resist or withstand the attack of a certain disease or illness
Example: Vitamin C increases the body’s immunity to influenza.

4. exposure (n.) [ik-spoh-zher] – the experience of coming into contact with something
Example: Long exposure to polluted air may damage the lungs.

5. validate (v.) [val-i-deyt] – to confirm or establish the truthfulness or accuracy of something
Example: Our manager validates the sales report to check if it is correct. 

Read the text below.

Over the last few years, insecticide-treated bed nets have been distributed throughout Africa to prevent malaria infection. But a study from Senegal suggests that mosquitoes have developed resistance to chemicals used in the said bed nets.

The study focused on the malaria incidence in one small village in Senegal both before and after the introduction of bed nets in 2008.

In the first three weeks, the number of malaria cases fell to 13 times lower than before the nets were used. However, in the last four months, the number of malaria cases returned to higher levels, particularly among older children and adults. In addition, researchers observed the growing number of mosquitoes able to withstand the chemicals used in the bed nets.

Researchers think that the bed nets may have reduced the immunity people developed through exposure to mosquito bites. This suggests that the bed nets brought more harm than good.

On the contrary, some experts argue that it is impossible to draw wider conclusions about the long-term effectiveness of nets from a study that only covered one specific village. Dr. Joseph Keating of Tulane University advised the extension of the study to two more years to validate if the results represent a general trend in the whole African continent.

Viewpoint Discussion
Enjoy a discussion with your tutor.

Discussion A

·         How does your city or community maintain cleanliness?
·         What other measures can be done in order to prevent diseases?

Discussion B

·         Have you ever read research reports or studies before? What were these studies all about?
·         Do you think it is important to validate information or results from studies? Why or why not?

September 16, 2011