Experts explain how to avoid getting sick when preparing food in the spring and summer.

Spring has arrived, and with it the hallowed ritual of the backyard barbecue. For an unlucky few there will be some serious aftereffects: the stomachaches, vomiting, or even hospitalization that can result from eating spoiled potato salad or an undercooked hamburger.

The CDC estimates that 325,000 hospitalizations and 5,000 deaths result from food-borne illness each year. The rate of illness tends to increase in the warmer months, in part due to picnics and barbecues, CDC researcher Elaine Scallan tells WebMD.

The good news this spring is a new study suggesting that Americans are wising up to the effects of eating risky foods. After conducting two national telephone surveys in 1998 and 2002 asking what people had eaten in the past week, researchers found that the percent eating one or more foods labeled "risky" in the past week declined from 31% in 1998 to 21% in 2002.

Media Campaigns

Researcher Erica Weis, MPH, of California's health services department, suggests that public health campaigns and media coverage of outbreaks may be responsible for the decline.

But there was room for improvement in certain groups. Among Asians and Pacific Islanders, the number eating risky foods was 32%. Research has found this group is more likely to eat raw fish or raw shellfish, Weis tells WebMD.

Risky-food consumption also appeared to be higher among children with compromised immune systems than among healthy children. The finding is worrying because an infection that could cause just a stomachache in a healthy person could hospitalize or even kill those with weakened immune systems.

The reason for this finding hasn't been studied. Perhaps sick kids want to eat the same things as their peers, Weis says. Or the finding may be due to the study design; parents answered surveys for their children, and the parents of sick children may keep closer tabs on what their children ate.

Risky Foods to Watch Out For

The researchers based their list of "risky" foods on studies of recent outbreaks. Here's the list:

* Pink hamburgers
* Pink ground beef
* Raw fresh fish
* Raw oysters
* Raw or unpasteurized milk
* Alfalfa sprouts
* Runny eggs

Undercooked eggs were the most commonly eaten risky food. That includes eggs served sunny-side up as well as raw eggs used in preparation of hollandaise sauce, meringue, Caesar salad dressing, and the like.

Food safety authorities have long steered people away from sunny-side-up, soft-boiled, or "over- easy" eggs, all of which carry the risk of salmonella. If you must eat runny eggs or use them in recipes, Weis suggests you buy pasteurized eggs, which have been briefly heated to destroy bacteria. They are available -- typically at a small premium -- at many supermarkets. If you're ordering sunny-side-up eggs at a restaurant, ask if they're pasteurized, she suggests.

Risky Take-Home Food

Food safety experts are keeping an eye on some worrying trends in food consumption. One is the growing preference for unprocessed "natural" foods available at farmers' markets. While many of these foods may be very healthy, unpasteurized dairy products and juices are more likely to carry a variety of nasty bacteria, experts say. "You can have fresh and locally-produced food that is also safe," Scallan says, "and safe food means pasteurized milk and juices."

Another trend: Buying prepared food from supermarkets and then bringing it home for the family. It's dangerous to leave perishable food at room temperature for more than two hours, notes Shelly Feist of the nonprofit Partnership for Food Safety Education. That window shortens considerably when temperatures are higher -- such as when a prepared meal is placed in a hot car. So be sure to eat prepared food soon after purchasing it, Feist says.

Food Safety in the Outdoors

The warm weather that makes springtime so inviting also creates an ideal breeding environment for bacteria and other pathogens found in food. Here's some advice from The Partnership for Food Safety Education on how to apply food-safety tips to the out-of-doors:

* Clean. Wash your hands --as well as utensils, cutting boards, and countertops -- in hot soapy water before and after preparing each food item. Also wash produce, which can carry harmful bacteria. As easy as these directives can be to ignore while in the kitchen, it's even easier when you're outside and playing with the dog, with the Frisbee, or with your baby niece, Feist notes. Don't drop your guard!

* Separate.Sure, it's tempting to pour that sauce you used to marinate raw burgers or chicken wings onto the cooked food. It's also tempting to place the cooked grub back onto the plate that held your raw meat. Don't give in! Always keep raw meat and its juices separate from cooked food. If you want to reuse that sauce, then boil it first.

* Cook.It's the best way to kill bad bugs. When grilling, preheat the coals on your grill for 20 to 30 minutes, or until the coals are lightly coated with ash. Use a meat thermometer to ensure that hamburgers and red meats are cooked to 160 degrees and ground poultry to 165 degrees. Poultry breast should be cooked to 170 degrees; dark meat (wings and thighs) should be cooked to 180 degrees. Poultry juices should run clear. Fish should be opaque and flaky.

* Chill.No, this doesn't refer to what you do after breaking open a Bud at the barbecue. Bacteria grow quickly at room temperature and even faster under the hot sun. So refrigerate meat while it marinates, and keep that potato salad in a cooler that's well-packed with ice or freezer packs.

专家解释如何在温暖的春季夏季准备食物时，避免其腐败和变质。

伴随着春季的来临，人们用后院的烧烤聚餐来庆祝它的到来。非常不幸的是烧烤可能带来严重的后遗症，比如腹痛，呕吐，甚至住院治疗等疾病，都可能是因为食用了变质马铃薯沙拉或一个未烹饪熟的汉堡包。

疾病预防控制中心研究员伊莱恩告诉记者，据该中心估计，每年有325000人因食物传染的疾病住院，其中5000人死亡。患病率在天气温暖的月份呈上升趋势。其中部分原因正是野餐和烧烤。

今年春天有一个好消息：一项新的研究表明，美国人正在降低使用“危险”食物的影响程度。在1998年和2002年进行的两次全国电话调查中，调查研究了人们过去一周中的饮食情况。研究人员从中发现，食用“危险”食物的比率由1998年的31 ％下降到年2002年的21 ％。

媒体宣传

加州卫生服务部的埃里卡维斯硕士研究员，表示面向公众的健康宣传活动和媒体报道的可能是上述概率下降原因。

但此类情况在某些群体还有改进的空间。比如，亚洲人和太平洋岛民，食用“危险”食品的概率为32 ％ 。研究发现，这组群体更可能食用到生鱼片或生贝类。

“危险”食物消费在免疫功能较弱的儿童群体食用比例要高于在健康儿童群体。令人担忧的研究显示，由“危险”食物带来的肠胃感染，可能给一个健康人带来的仅仅是腹部疼痛，而却有可能引发那些免疫功能较弱群体的住院治疗或者危及生命。

上述现象的原因还没有被科学证实。维斯研究员推测，有可能生病的孩子对“危险”食物并不排斥，或者发现与调查设计有关，由于孩子的父母代替孩子回答调查问题，或者父母密切关注他们的饮食。

“危险”食物的识别与提防

研究人员根据其对“危险食品”的研究，列出了最近容易暴发和常见的食物。清单如下：

* 未加工熟的汉堡包
* 未加工熟的牛排
* 生鲜鱼类
* 生鲜贝类
* 生鲜或未经高温消毒的牛奶
* 豆芽等发芽菜
* 未加工熟的流体状的鸡蛋

未加工的鸡蛋是最常见的食用风险。这些食品包括只煎一面的鸡蛋以及用生鸡蛋制作的酱油、蛋白、凯撒大帝沙拉酱等。

食品安全当局长期以来指导人们远离单面煎、软煮熟、“带生”鸡蛋等食品，所有这些鸡蛋食品都携带沙门氏菌的致病风险。如果你必须吃流状鸡蛋或使用其作为食谱，魏丝研究员建议你购买巴氏杀菌鸡蛋，这些鸡蛋已经简要加热并破坏了细菌。他们通常在很多超级市场都有小的溢价销售。如果您在一家餐厅点了单面煎蛋，请问他们是否有消毒处理。

外带食品的卫生安全风险

食品安全专家正在密切关注一些令人担忧的食品消费趋势。其中之一是人们越来越倾向于在农贸市场购买未处理未加工的“天然”食品。虽然许多这些食品可能会非常健康，但专家说它们（未经奶制品和果汁）更有可能携带各种细菌。“你可以把新鲜和当地生产的食品带回家，但安全的食物必须是巴氏奶和果汁”Scallan专家提醒。

另一个趋势是人们开始习惯购买已加工或已准备好的食品，把它带回家食用。我们在谢利法伊斯特非营利伙伴关系的食品安全教育提示中发现：易腐食品暴露在室温下超过两小时以上具有很高的食用致病风险，这类食品销售窗口忽视了温度较高情况下的食品保鲜——例如当外带饭菜放置在一个炎热的汽车内时。所以专家法伊斯特建议一定在准备食用食物时，再购买。

户外野餐的食品卫生安全

在温暖的春天，为室外饮食滋生细菌和其他病原体提供了气温条件和环境。下面是一些咨询意见，伙伴关系的食品安全教育，为您说明如何注意户外饮食的食品安全问题：

* 清洁。洗手-以及餐具，砧板，和台面-用热肥皂水在烹饪前和食用前后清洗上述每个物品。清洗各种可携带有害细菌的生鲜食物。法伊斯特提示，像在您厨房里一样不要忽视清洁，尤其是当您在外面玩狗、飞盘、或与您的宝宝侄女玩耍后。一定不要放弃你的卫生防护！

* 分离。酱油原料用来腌鸡翅膀汉堡包或熟食是诱人的美味。同样人们容易把煮熟的食物放回盛有生肉的盘子。不要混入！始终保持生肉及其果汁熟食分开。如果你想重复使用的酱油，然后再次食用它前要先煮熟一次。

* 烹调。这是最好的杀死细菌的方式。当烧烤时，预热炭煤20到30分钟，或直至煤是轻轻涂有炭灰。使用肉类温度计，以确保汉堡包和红肉煮熟到160度，家禽至165度。家禽乳腺癌病菌的完全杀灭应煮熟到170度；深色肉（翅膀和大腿）应煮熟至180度。家禽果汁应明确分开烹调。鱼应该烹调到不透明的片状。

* 冷却。这并非指你在开始烧烤后再去做什么。因为，细菌在室温条件下繁殖迅速，而在炎热的太阳下就更是如此。因此，冷藏肉类需要进行事先腌制 ，同时保持马铃薯沙拉在凉爽的挤满了冰或冷冻包装内储存。