填空题
{{B}}Are Your Kids Making You Sick?{{/B}} Dr. Gerba is what
you might call a germ detective. A well-known authority on germs that make us
sick, he specializes in hunting down disease-causing microbes wherever they
hide. His investigations have taken him from private kitchens to public
restrooms to the food-export centers of South America. He seems to greet the
discovery of bacteria, viruses and parasites with the glee most of us reserve
for opening Christmas gifts. It's no wonder his job has earned him the nickname
Dr. Clean. Dr. Gerba is attending kindergarten today at the
request of Reader's Digest. We asked him to spend some time with the Kelley
family of Sarasota, Fla. --Bryan and Danielle and their two children,
six-year-old T.J. and two-year-old Shannon. The Kelleys seem constantly to be
passing around colds, flu and other viruses---which makes them like most
families with kids. "It's been shown that once you have
children, the number of colds per adult in the family at least doubles, "Gerba
says. {{U}} {{U}} 1 {{/U}} {{/U}}
Why? "It may be because children are going into day-care centers and into
school at a younger age," Gerba says. "So they're exposed to more germs earlier
on. We also take the children to large play areas, like playgrounds at fast-food
restaurants. Not to mention trips to the mall." {{U}}
{{U}} 2 {{/U}} {{/U}} We're about to find out. The
slim, bespectacled scientist sits in a kiddie-size chair at the back of the
classroom and sets out test tubes, swabs and chemicals--his ad hoe lab. With a
Q-Tip-like swab he dabs at a spot on the table's surface. "I'm going to look for
fecal bacteria, saliva, blood, mucus and a measure of general filth, "he
announces as he drops the swab into a test tube. {{U}}
{{U}} 3 {{/U}} {{/U}} Gerba dabs again at the same
spot, using a second swab, which he places in a separate tube. This test is for
coliform bacteria and E. coli, both present in fecal matter. The E. coli he's
testing for does not cause disease like the strain responsible for recent
outbreaks of food poisoning, but if this type is present, the other, more
dangerous variety may be as well. How might bacteria from feces find its way
onto these surfaces? Improper hand washing after going to the bathroom, says
Gerba. It will be about 24 hours before we'll have the
fecal-bacteria results. As he shakes the test tubes, I scan the
room. One child picks his nose, then wanders over to the supply shelves for a
bottle of paper paste. He handles a number of bottles before he decides on the
one he wants. Gerba also watches intently, then scurries over and swabs a paste
bottle, as well as several markers on the shelf. {{U}}
{{U}} 4 {{/U}} {{/U}} At each desk is a water
bottle with a pull-top; each is labeled with a child's name. Gerba swabs one
pull-top. When the children leave for the cafeteria, Dr. Gerba
examines the first set of test tubes. Gerba finds the heaviest concentrations of
bodily fluids on the computer mouse(the class's favorite object), the supply
shelves where paste, markers and crayons are stored, and the kids' favorite
puzzle. But what does this mean? Could T. J. Kelley pick up a
cold, flu or diarrhea from these objects. If somebody in the classroom had it,
of course, "says the germ detective. "If the surfaces are heavily contaminated
with such fluids as saliva or blood, then they're also heavily contaminated with
any germs growing in those fluids." {{U}} {{U}} 5
{{/U}} {{/U}} Later that afternoon we regroup outside the
Kelley home. Bryan Kelley is pitching balls to T. J. and a bunch of neighborhood
kids. They all use T. J. 's bat, so that's one of the first objects Gerba
swabs. Then we head for a favorite fast food restaurant, which
has a big playroom with plastic tunnels, pens and slides. Gerba is one step
behind curly-headed Shannon as she crawls through a curtain of clear vinyl
streamers into a blue padded playpen. One look at the vinyl strips and Gerba
knows he's hit pay dirt. "Gross! "he shouts, a little too enthusiastically for
my taste. "Every kid pushes through this with his face and wipes his nose on it
on the way in. "He also tests the blue pen behind the vinyl strips and one of
the tunnels. While we devour our fried food, the swabbed
samples develop. Within minutes, as Gerba guessed, we learn that the vinyl
shield is the most heavily contaminated with bodily fluids. The playpen and
tunnel are contaminated too. Those fries that I eagerly gobbled are suddenly not
sitting so well. A. Gerba points to the sample he took from the
sponge. The fluid is very yellow, as is the sample from the classroom
sink. B. So exactly what kind of germs are out there waiting
for out kids? And can we minimize our children's exposure by keeping certain
surfaces clean? C. Soon we're off to the playground, where T.
J. and his classmates enjoy exuberant fun before class resumes. Spoilsport that
he is, Gerba is right behind them, swabbing monkey bars, play tunnels and
slides. D. But annoying sniffles are the least of it. Many
microbiologists believe there has been a steady increase in the number of
infections in kids that lead to intestinal and stomach upset.
E. Through the morning, as the kids sing and play, Gerba swabs the surfaces they
touch most: toys, computer, play areas. He also checks a sponge on the sink
where the kids wash up before lunch. "A sponge is a great area for
microorganisms to grow, "Gerba says." So life is terrific in a sponge ff you're
a bacterium." F. If the liquid in the test tube turns dark in
the next ten minutes, bodily fluids are present. And if bodily fluids are
present, we know that germs could be present too. As there are hundreds of
possibilities--including viruses that cause colds, flu and diarrhea, and
bacteria such as Staphylococcus aureus (staph), strep and parasites--this test
doesn't look for specific microbes.