As you read: Demonstrate evidence of a close reading by marking segments that are important, segments that are confusing, issues that your group should discuss. Common Core Reading Practice Article of the Week (Date: ) Brain-Eating Amoeba Turning Up in Northern Waters Source: By Scientific American, adapted by Newsela staff Sept. 05, 2014 https://newsela.com/articles/amoeba-brain/id/5056/ Before Reading Discuss: 1. We will read an informational text about a brain eating amoeba. Predict where it may be appearing and how dangerous it may be. Before Reading Address Challenging Vocabulary 1. Organism: a form of life considered as an entity; an animal, plant, fungus, protistan, or moneran. 2. Fatal: causing or capable of causing death; mortal; deadly 3. Epidemiologist: one who studies the branch of medicine dealing with the incidence and prevalence of disease in large populations and with detection of the source and cause of epidemics of infectious disease 4. Evade: to escape from by trickery or cleverness 5. Mucous membranes: a lubricating membrane lining an internal surface or an organ 6. Meningoencephalitis: Inflammation of the brain and its membranes. Also called cerebromeningiti, encephalomeningitis 7. Olfactory nerves: either one of the first pair of cranial nerves, consisting of sensory fibers that conduct to the brain the impulses from the mucous membranes of the nose 8. Immune cells: White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in defending the body against both infectious disease and foreign invaders 9. Respiratory failure: a condition in which the respiratory system is unable to provide an adequate supply of oxygen or to remove carbon dioxide efficiently 10. Remote: not likely 11. Sediment: the matter that settles to the bottom of a liquid; lees; dregs 12. Genome: a full set of chromosomes; all the inheritable traits of an organism During Reading: 1. Mark your confusions in the text and circle important facts. 2. Answer the following questions and then as a group discuss conclusions. (According to Common Core Expectations, students must offer textual evidence directly from the reading. It must be explicit which means it is very clear and complete. It should leave no doubt about the meaning. Students must quote specific phrases from the article) During and After Reading: 1. How does the beginning of the article shape the story? 2. Give evidence to support how dangerous the amoeba is. 3. How is Naegleria a mystery? 4. Describe how the amoeba eats the brain. 5. What symptoms do those infected have?
6. How does one eventually die from the amoeba? 7. What suggestions should one follow to avoid the amoeba 8. Why is it important that scientists have sequenced the amoeba s genome? After Reading discuss the following: 1. Based on the article, will you change any of your swimming habits? Why or Why not?
Brain-eating Amoeba Turning Up in Northern Waters Kali Hardig, 12, stands at the edge of the lake at Willow Springs Water Park near Little Rock, Arkansas, on Oct. 7, 2013. The park has been closed since the girl was sickened by a water-borne amoeba. Another girl, Hally Yust, 9, died from the rare brain-eating amoeba infection in July after swimming in a lake near her parent's home in Kansas. Photo: (AP Photo/Danny Johnston) Nine-year-old Hally Yust died in July after contracting a rare brain-eating amoeba infection while swimming near her family s home in Kansas. The organism responsible is called Naegleria fowleri. It dwells in warm freshwater lakes and rivers and usually targets children and young adults. Once in the brain it causes a swelling called primary meningoencephalitis. The infection is almost always universally fatal: it kills more than 97 percent of its victims within days. Although deadly, infections are exceedingly uncommon there were only 34 reported in the United States during the past 10 years but evidence suggests they may be increasing. Prior to 2010, more than half of the cases came from Florida, Texas and other Southern states. Since then, however, infections have popped up as far north as Minnesota. We re seeing it in states where we hadn t seen cases before, says Jennifer Cope, an epidemiologist and expert in amoeba infections at the U.S. Centers for Disease Control and Prevention, which is in charge of protecting America from health and safety threats. The expanding range of Naegleria infections could potentially be related to climate change, she adds, as the organism thrives in warmer temperatures. It s something we re definitely keeping an eye on.
It's Largely A Mystery When it comes to Naegleria there s a lot we don t know, Cope says. One of those things is why it chooses its victims. The amoeba has strategies to evade the immune system, and treatment options are meager partly because of how fast the infection progresses. But research suggests that the infection can be stopped if it is caught soon enough. So what happens during an N. fowleri infection? The microscopic amoebas can be suspended in water or nestled in soil. They enter the body when water goes up the nose. After attaching to the mucous membranes in the nasal cavity, N. fowleri burrows into the olfactory nerve, the structure that enables our sense of smell and leads directly to the brain. It probably takes more than a drop of liquid to trigger a Naegleria infection; infections usually occur in people who have been engaging in water sports or other activities that may force a lot of water up the nose diving, waterskiing, wakeboarding, and in one case a baptism dunking. Amoeba Really Does Eat The Brain It turns out that "brain eating" is actually a pretty accurate description for what the amoeba does. The amoeba moves to the the olfactory bulbs in the front of the brain. There, N. fowleri feasts on tissue using suction-cup-like structures on its surface. This destruction leads to the first symptoms loss of smell and taste about five days after the infection sets in. From there N. Fowleri moves to the rest of the brain, first gobbling up the protective covering that surrounds the central nervous system. When the body notices that something is wrong, it sends immune cells to combat the infection, causing the surrounding area to become inflamed. It is this inflammation, rather than the loss of brain tissue, that contributes most to the early symptoms of headache, nausea, vomiting and stiff neck. Neck stiffness in particular is linked to inflammation, as the swelling around the spinal cord makes it impossible to flex the muscles. As N. fowleri consumes more tissue and penetrates deeper into the brain, the secondary symptoms set in. They include seizures and mental symptoms such as confusion, seeing or hearing hallucinations, and trouble speaking and making sense. The frontal lobes of the brain, which are associated with planning and emotional control, tend to be affected most because of the path the olfactory nerve takes. But after that there s kind of no rhyme or reason all of the brain can be affected as the infection progresses, Cope says. Ultimately what causes death is not the loss of gray matter, but the extreme pressure in the skull from the inflammation and swelling related to the body s fight against the infection. Increasing pressure forces the brain down into where the brain stem meets the spinal cord, eventually severing the connection between the two. Most patients die from the resulting respiratory failure less than two weeks after symptoms begin. Treatments Are Just Within Reach The threat of contracting an N. fowleri infection is remote (many more people die every year from drowning), but you can take some measures to lower your risk even further. Cope recommends using nose plugs and not immersing your head fully under water when swimming. She also counsels against kicking up sediment, which can shake the amoeba loose. More effective treatments may be on the horizon. Last year, the U.S. Food and Drug Administration approved Miltefosine, a drug originally intended as an anti-cancer treatment. In 2013, two people in the United States survived N. fowleri when they took the drug (and others) soon after being infected.
And in June, scientists sequenced the amoeba s genome for the first time, figuring out the order of its DNA. Their insights may help us understand what makes it so deadly and point the way to better treatments. Until then, hold your nose.