Rocky Mountain Spotted Fever
There's a silent killer stalking unsuspecting victims in the woodlands of North America. The killer is tiny-often small enough to fit on the head of a pin-but it packs a powerful punch. Who is this villain? It's a blood-sucking tick whose bite can cause Rocky Mountain spotted fever (RMSF) in humans.
RMSF is not actually caused by the tick itself. Rather, it can occur after the tick is infected with a pathogenic bacterium known as Rickettsia rickettsii. Thus, the tick is merely a vector, or carrier, of the disease-causing bacteria. Ticks that carry these bacteria are the most common source of infection. In order for the infection to be passed on from insect to human, an infected tick must attach itself to the skin for six to ten hours.
Many people who are infected with Rickettsia rickettsii bacteria become sick after about one week. Others, however, might not display any symptoms of RMSF for up to fourteen days. The initial signs and symptoms are nonspecific and can mimic those of other illnesses. These include high fever, chills, severe headache, achy muscles, nausea or vomiting, and general confusion. Three to five days after these initial symptoms occur, a distinctive non-itchy rash can appear. The rash-bright red spots about five millimeters across-usually first appears on the wrists and ankles, and then spreads outwards. Nonetheless, some people never develop these spots at all, making diagnosis tricky.
RMSF damages the lining of the body's smallest blood vessels, causing clots to form as well as leaks to occur. This, in turn, can cause other problems including inflammation of the brain, inflammation of the lungs, or kidney failure. In some cases, amputation of the fingers and toes may be necessary due to blood vessel damage. If left untreated, the disease can cause death. Historically, the death rate for the disease was as high as eighty percent.
With modern antibiotics, there is a sure cure for the disease. Doxycycline is the recommended antibiotic treatment for RMSF in adults and children of all ages. But you can decrease the chances of getting RMSF by taking a few simple precautions. First, always wear long pants and sleeves when you're out in the woods. Products containing DEET can often repel ticks. But more than anything else, check yourself for ticks from head to toe after being in a wooded or grassy area. Still, care must be taken because ticks can be tiny and easily overlooked. Taking this step has a distinct payoff. After all, an ounce of prevention is worth a pound of cure.
What is the meaning of the word "pathogenic," as used in the second paragraph?

Question

Quizplus · Accepted Answer

There are context clues in the second paragraph that suggest that pathogenic means "disease-causing" because it is used to describe the bacteria. For example, in the following sentence, we learn that the tick is "a vector for the disease-causing bacteria." In addition, the entire paragraph focuses on the causes of RMSF, a potentially fatal disease.
There is nothing in the context of the second paragraph that suggests that the bacterium is "slow-moving."
A bacterium is by definition an "extremely small" organism. Thus, it would be redundant to modify the word bacterium with a phrase like "extremely small."
There is nothing in the context of the second paragraph that suggests that the bacterium is "unusually shaped."