可以複習一下 Listeriosis
Listeria Outbreak Now 2nd Largest in
U.S. History
Daniel J. DeNoon
October 10, 2011 — The current listeria outbreak from
cantaloupes is now the second largest in U.S. history.
The toll now stands at 109 cases and 21 deaths. A pregnant
Iowa woman miscarried due to cantaloupe-linked listeria infection.
A person infected with listeria may take up to two months to
develop the serious illness known as listeriosis. It may be several weeks
before an illness is reported to the CDC, so cases that began after Sept. 11
may not yet be counted.
That count now has passed the 1998 listeria outbreak in hot
dogs and deli meats. That outbreak sickened 108 people. There were 14 deaths
and four miscarriages.
The largest U.S. listeria outbreak was in 1985, when 142
people became ill after eating Mexican-style cheese contaminated with
unpasteurized milk. Pregnant women were disproportionately affected. There
were 18 adult deaths, 20 miscarriages/stillbirths, and 10 deaths of newborns.
Pregnant women are at high risk of listeriosis. While the woman herself usually gets only flu-like
symptoms, listeria bacteria tend to infect the placenta. Infection of the
fetus often causes miscarriage or stillbirth. Infection of the newborn during
birth can result in death or permanent disability.
Also at risk are people over age 60, people with diabetes
or diseases that weaken immunity, and people taking immunity-suppressing drugs.
The current outbreak of listeria from cantaloupes isn't
over, even though it's very unlikely that any of the contaminated cantaloupes
are still in refrigerators or on grocery shelves. Melons from Jensen Farms'
Granada, Colo., packing plant were last shipped on Sept. 10. Cantaloupes
have only about a two-week shelf life.
Listeriosis Symptoms
Although listeriosis is a food-borne illness, when
symptoms appear it usually means the bacteria have escaped the digestive tract
and are spreading throughout the body. Listeriosis sometimes results in
fatal meningitis or encephalitis.
Listeriosis usually begins with diarrhea or other
intestinal symptoms. Patients soon develop fever and muscle aches. What
happens next depends on a person's risk factors:
- While pregnant women usually
get a mild flu-like illness,listeria infection can cause miscarriage,
stillbirth, premature delivery, or fatal infection of the newborn. - Other adults may develop headache,
stiff neck, mental confusion, loss of balance, and convulsions. - Symptoms may occur as soon as
soon as three days or as long as two months after infection. The usual
incubation period is thought to be one to three weeks.
Foods typically linked to listeriosis are deli meats, hot
dogs, and soft cheeses made with unpasteurized milk. Produce is less often
linked to outbreaks, although listeria occurs in soil and water. Listeria
bacteria are killed by cooking, but they can grow and multiply in
refrigerators.
In refrigerators where listeria-contaminated foods have been
stored, other foods often become contaminated. So does the refrigerator itself,
which should be thoroughly cleaned with soap and water and then wiped down with
a solution of diluted bleach.
SOURCES:
CDC web site.
FDA web site.
Iowa Department of Health web site.
Mead, P.S. Epidemiology and Infection, August 2006.
Linnan, M.J. The New England Journal of Medicine, Sept. 29,
1988.
WebMD Health News ©
2011 WebMD Inc.
This news article was written and produced by staff at WebMD Health and is
intended for a consumer audience. Questions or comments? Email newstip@webmd.net.
Listeria monocytogenes (單核球增生性李斯特菌)
l
A
Gram-positive coccobacillus。可引起listeriosis。
l
可在冷藏溫度(refrigeration temperatures)生長。
l
在各種動物﹑鳥類身上及土壤中。經未煮熟食物、乳酪、牛奶、coleslaw,等食物傳染。
l
潛伏期﹕3-70天﹐一般約三週
l
母子在尿液及陰道分泌液中排出細菌7-10天﹐但被感染者可能在糞便中排放細菌久達七﹑八個月。
病變﹕
l
感染孕婦及嬰兒 (經intrauterine infection=胎兒子宮內感染，或paranatal infection=經產道時感染)、或免疫不全病人(immunocompromised
patient)。
l
在新生兒及成人常呈現meningoencephalitis(腦膜腦炎) and/or
septicemia(敗血症)﹑在孕婦造成abortion(流產)。可能有endocarditis﹑肝臟及其他器官之granulomatous lesions(肉芽腫)或abscesses(膿瘍)﹐也可能有皮膚膿疹丘疹。正常人常只有輕微發燒。
l
母親可能無症狀﹐但新生兒可能會死產（still birth）﹑生下就有septicemia﹑或發生腦膜炎。
l
新生兒死亡率達30-50%﹐一般成人為35%﹐60歲以上者可達63%。
l
在一次由污染的牛奶引起的群突發中，經口食入大量(1011 CFU)細菌，引起腹瀉(79%)、發燒(72%)、畏寒(65%)、頭痛(65%)、肌痛(59%)、腹絞痛(55%)、噁心(47%)、嘔吐(26%)等症狀。潛伏期為20
(9~32)小時。得病率高達75%。腹瀉在天內自癒。Antibody to listeriolysin會昇高。60名受感染者中有三名得septicemia or brain abscess。
診斷﹕
l
靠血液及脊髓液之sheep blood agar細菌培養。有小的溶血圈。如先在4°C維持數日再加在培養劑則陽性率增加。
防治﹕
l
注意飲食安全衛生。動物來源之食物要經pasteurization(巴斯德低溫消毒)
(dairy products=牛奶製品)﹑輻射線處理(cheese=乳酪)﹑適當地煮熟。
l
處理死亡或生病之動物要小心﹐尤其是腦炎死亡之羊。
l
病患要胃腸道隔離(enteric precautions)。
l
Ampicillin
(50 mg/kg, iv q6h)加 aminoglycoside﹔TMP/SMZ(TMP 5.0 mg/kg, q6h, iv)﹔high dose penicillin。可在第一劑抗生素之前開始用dexamethasone
(0.4 mg/kg, q12h, 2 天)。
Listeria Outbreak Traced to Cantaloupe Packing Shed
By WILLIAM NEUMAN
Federal investigators said on Wednesday that a listeria outbreak that has killed at least 25 people across the country can be traced to bad sanitation at a cantaloupe packing shed used by a Colorado farm. Pooled water and poorly designed equipment allowed the deadly bacteria to spread throughout the facility, the government said.
“You’re rolling around cantaloupe on uncleanable equipment, and you’re getting it wet and you’re not cooling it. It provides the perfect environment for listeria growth and spread,” said James Gorny, a senior food safety advisor at the Food and Drug Administration.
The outbreak, the deadliest incident of foodborne illness in the last 25 years, has been traced to Jensen Farms in Holly, Colo., which grew and sold what are known as Rocky Ford cantaloupes, named for an area along the Arkansas River.
Officials said that tests found listeria in numerous areas of the farm’s open-air packing house, including a floor drain, a produce dryer and a conveyor belt.
They said that water had pooled on the ground and workers in the shed tracked it around and splashed it on equipment where melons were handled.
The farm had passed a food safety audit by an outside contractor just days before the outbreak began, but the auditor apparently failed to notice the flaws later identified by the F.D.A.
Eric Jensen, a member of the family that runs the farm, said in an e-mail message that the auditor gave the packing plant a score of 96 points out of 100.
F.D.A. officials did not criticize the auditor but they said the agency intended to establish standards for how auditors should be trained and how audits should be conducted.
It was not clear how listeria got into the packing plant to begin with. Listeria is frequently found in soil or manure but tests of the soil on the farm did not turn up the bacteria. Officials said that a dump truck used to take culled melons to a cattle farm was parked near the processing shed and could have carried bacteria to the facility.
Listeria can cause high fever and diarrhea and cases can be especially severe among older people or those with weakened immune systems. Most of the people who died in the outbreak were elderly. A total of 123 people in 26 states have been sickened in the outbreak, including those who died.
Herbert H. Stevens, 84, of Littleton, Colo., fell ill with a high fever on Aug. 24, a couple of weeks after eating a cantaloupe bought at a King Sooper grocery store. He has been in the hospital or a nursing home ever since.
His daughter, Jeni A. Exley, said she worried that he would no longer be able to take care of himself once he finally got to go home. “He’s surprised that he survived it, being that there’s so many deaths,” Ms. Exley said. “We should be able to trust the U.S. food supply but I don’t think you can right now.”
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