2026年8月5日 / 美国东部时间晚上8:01 / 哥伦比亚广播公司/美联社
美国卫生官员周三表示，目前已有15个州的环孢子虫感染病例与冰山生菜有关，此次持续的疫情又新增了6个受影响州。
今年全美范围内报告的环孢子虫感染病例至少已波及47个州，调查人员仍在持续追查有多少病例可能与同一污染来源有关。
美国疾病控制与预防中心（CDC）表示，与此次致命疫情相关的州数量已从9个增至15个。新增的阿肯色州、艾奥瓦州、密苏里州、内布拉斯加州、新罕布什尔州和北卡罗来纳州，加上此前已纳入名单的伊利诺伊州、印第安纳州、堪萨斯州、肯塔基州、密歇根州、俄亥俄州、俄克拉荷马州、宾夕法尼亚州和西弗吉尼亚州，构成了全部15个州。
调查人员最初将目标锁定在塔可贝尔餐厅供应的生菜上。联邦官员随后表示，他们正将泰勒农场作为此次疫情中生菜的来源地进行调查，该公司已召回在墨西哥中部种植的冰山生菜。
上月美国食品药品监督管理局（FDA）宣布一份来自泰勒农场的生菜样本环孢子虫检测结果为假阳性，引发了混乱。但FDA次日澄清，调查和证据“仍持续指向墨西哥中部地区泰勒农场门店生产的碎冰山生菜”。
哈特福德医疗保健首席流行病学家尤利西斯·吴博士上月对哥伦比亚广播公司新闻表示：“我认为我们还不能说疫情已得到控制。即便这种生菜被认定为感染源，也不意味着其他农产品不会被牵连其中。”
美国疾控中心此前曾表示，联邦和州级官员可能需要长达六周的时间才能确定一名患者是否属于某起疫情。密歇根州沃什特瑙县和利文斯顿县卫生部门医疗主任胡安·路易斯·马尔克斯博士表示，环孢子虫疫情的调查和控制难度颇高，原因有多个方面。
作为密歇根大学公共卫生兼职教授的马尔克斯指出，从人体接触寄生虫到出现症状可能需要数周时间；实验室中对该寄生虫的分析难度较大；此外，访谈所有病患并明确其共同暴露史需要耗费大量工作。
他还在一份声明中补充道：“此外，联邦、地方和州各级公共卫生部门都出现了人员裁减，因此总体可用的资源和能力都有所减少。”
据美国疾控中心介绍，环孢子虫是一种微小的球形寄生虫，通常会引发“频繁甚至爆发性水样腹泻”。疫情多发生在晚春和夏季。
这种喜热寄生虫会感染肠道，并通过粪便传播。由此引发的疾病称为环孢子虫病，其发病率低于沙门氏菌、大肠杆菌等其他病菌引发的食源性疾病。许多环孢子虫感染病例始终无法追溯到具体的食物或其他感染源。
美国有记录以来感染最严重的年份是2019年，全国共报告约4700例感染病例。今年的感染人数已远超该数字。仅密歇根州就报告了超过1.2万例感染病例，其中包括2例死亡病例。加上其他报告感染病例的州，全国总感染人数已超过2.5万。
据当地卫生官员透露，在密歇根州的1.2万多例病例中，截至7月30日已有193名患者接受住院治疗。密歇根州卫生与公众服务部表示，两名死者“患有严重的基础疾病”。
美国食品药品监督管理局表示，目前正在追踪五起独立的环孢子虫疫情。此次波及15个州的疫情是其中规模最大的。其余疫情包括一起已造成115人感染的案例，均未发现相关关联产品。
Cyclospora outbreak tied to iceberg lettuce now linked to 15 states, CDC says
August 5, 2026 / 8:01 PM EDT / CBS/AP
Cyclospora cases in 15 states have been linked to iceberg lettuce, U.S. health officials said Wednesday, adding six states with cases tied to the ongoing outbreak.
The parasite has been reported in at least 47 states total this year, and investigators have continued to probe how many could be linked to a common contaminated source.
The Centers for Disease Control and Prevention said the number of states tied to the deadly outbreak had grown from nine to 15. Arkansas, Iowa, Missouri, Nebraska, New Hampshire and North Carolina were added to a list that included Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.
Investigators initially narrowed in on the lettuce served at Taco Bell. Federal officials subsequently said they are focused on Taylor Farms as the source of the lettuce in the outbreak, and the company has recalled iceberg lettuce grown in central Mexico.
Confusion was sparked last month when the Food and Drug Administration announced that a sample of lettuce from Taylor Farms that had tested positive for cyclospora was a false positive. But the FDA clarified the next day that the investigation and evidence “continue to converge on shredded iceberg lettuce from Taylor Farms locations in central Mexico.”
“I don’t think we can say that this is under control yet,” Dr. Ulysses Wu, the chief epidemiologist for Hartford HealthCare, told CBS News last month. “Even if this lettuce was implicated, it doesn’t mean that other produce is not implicated as well.”
The CDC previously said it can take as long as six weeks for federal and state officials to determine if a sick person is part of an outbreak. There are several reasons cyclospora outbreaks can be hard to investigate and contain, said Dr. Juan Luis Marquez, medical director of the Washtenaw County and Livingston County health departments in Michigan.
It can take weeks between when someone is exposed to the parasite and when they come down with symptoms; it’s harder to analyze the parasite in laboratories; and it’s a lot of work to interview everyone who is sick and clearly identify common exposures, said Marquez, an adjunct public health professor at the University of Michigan.
Also, “there have been staffing cuts at all levels of public health — federal, local, state — so there are less resources and capacity generally available,” Marquez said in a statement.
Cyclospora is a microscopic, spherical parasite that commonly causes watery diarrhea “with frequent and sometimes explosive bowel movements,” according to the CDC. Outbreaks tend to occur most often in the late spring and summer.
The heat-loving parasite infects the bowels and spreads through feces. The illness, called cyclosporiasis, is less common than foodborne illnesses caused by other germs, including salmonella and E. coli. Many cyclospora cases are never linked to a specific food or other source.
The worst year in the U.S. for infections was 2019, when about 4,700 illnesses were reported nationally. This year has far surpassed that. Michigan alone has reported more than 12,000 cases — including two deaths. Adding in the other states that have reported cases, the national total stands at over 25,000.
Of the more than 12,000 cases in Michigan, 193 patients had received hospital treatment as of July 30, according to local health officials. The two people who died had “significant underlying health conditions,” the Michigan Department of Health and Human Services said.
The FDA says it is tracking five separate ongoing cyclospora outbreaks. The 15-state outbreak is by far the largest. No products have been linked to the other outbreaks, including one that has sickened 115 people.