Doctors suspected man had brain cancer. He actually had worms.
Doctors suspected man had brain cancer. He actually had worms.
医生曾怀疑男子患有脑癌，结果竟是寄生虫感染
A 60-year-old man in Spain went to the doctor complaining of a headache that he couldn’t shake. It had started two weeks prior and was only getting worse. He also said he had noticed subtle changes in his behavior. 西班牙一名 60 岁的男子因头痛难忍前往医院就诊。这种头痛始于两周前，且症状不断加重。他还表示，自己察觉到行为上出现了一些细微的变化。
In a neurological exam, doctors found he had a mild delay in his movements, but no other deficits. His blood work was generally normal except for elevated IgE, a signal of immune responses linked to allergies, autoimmune disease, and parasitic infections. 在神经系统检查中，医生发现他的动作反应略有迟缓，但没有其他功能障碍。他的血液检查结果基本正常，唯独 IgE 指标升高，这通常是与过敏、自身免疫性疾病和寄生虫感染相关的免疫反应信号。
The doctors did a computed tomography (CT) scan of his head and saw much more obvious evidence of a problem: There were multiple lesions distributed throughout his brain accompanied by swelling. 医生对他进行了头部计算机断层扫描（CT），结果发现了更明显的病灶：他的大脑中分布着多处病变，并伴有肿胀。
In a case report in Emerging Infectious Diseases, the doctors reported working through the possible conditions that could explain all the findings. They noted that the man was not immunocompromised and had never traveled internationally. Their top suspicion was metastatic cancer. 在《新发传染病》（Emerging Infectious Diseases）杂志发表的一份病例报告中，医生们记录了他们排查所有可能病因的过程。他们指出，该男子免疫功能正常，且从未出国旅行。他们最初最怀疑的是癌症转移。
For his headache, the doctors put him on an anti-inflammatory corticosteroid, and he finally got some relief. They then began an extensive series of tests to look for the cancer they thought had spread to his brain. This included a whole-body, contrast-enhanced CT scan, a colonoscopy, and a hybrid positron emission tomography/CT scan often used to map cancer. But the tests didn’t reveal any malignancies. 为了缓解头痛，医生为他开了抗炎皮质类固醇药物，他的症状终于有所好转。随后，医生开始进行一系列广泛的检查，试图寻找他们认为已经扩散到大脑的癌症。检查包括全身增强 CT 扫描、结肠镜检查以及常用于癌症定位的 PET/CT 联合扫描。但这些检查均未发现任何恶性肿瘤。
The doctors did another brain scan, this time with a magnetic resonance imaging (MRI) scan to get a better look at the lesions. With the more detailed imaging, they saw clearly that the lesions weren’t tumors; they were encapsulated tapeworm larvae. On the MRI, the doctors could see the worms’ heads, called scolexes. 医生又进行了一次脑部扫描，这次使用了磁共振成像（MRI）以更清晰地观察病灶。通过更详细的影像，他们清楚地看到这些病灶并非肿瘤，而是被包裹的绦虫幼虫。在 MRI 影像上，医生甚至能看到绦虫的头部，即头节。
The finding surprised the doctors since tapeworms aren’t endemic to Spain and he said he hadn’t traveled. However, the man may have been exposed during his work. Until 10-years prior, when he retired, he had worked in construction, often working alongside people who had migrated from regions where pork tapeworms (Taenia solium) are endemic. The parasitic worms can spread through the fecal-oral route. His doctors speculated his infection might have been a rare case of cryptic transmission from sharing meals and bathrooms with his coworkers, one of whom apparently had a tapeworm infection. 这一发现令医生感到惊讶，因为绦虫在西班牙并非地方性流行病，且该男子声称自己从未出国。然而，他可能在工作中接触到了寄生虫。在 10 年前退休之前，他一直从事建筑工作，经常与来自猪肉绦虫（Taenia solium）流行地区的移民一起工作。这种寄生虫可以通过粪口途径传播。医生推测，这可能是一起罕见的隐匿性传播病例，源于他与同事共用餐食和卫生间，而其中一名同事显然患有绦虫感染。
Sneaky worms
狡猾的寄生虫
Taenia solium can infect people in two ways: by eating cysts in undercooked meat or ingesting eggs through fecal contamination. The parasite infects pigs, and when they ingest eggs from feces, the worms hatch in the pigs’ guts, bore through the intestines, get into the bloodstream, and migrate into a variety of tissues and muscles. There, they form into encapsulated larvae called cysticerci. 猪肉绦虫可以通过两种方式感染人类：食用未煮熟肉类中的囊尾蚴，或通过粪便污染摄入虫卵。这种寄生虫会感染猪，当猪摄入粪便中的虫卵后，虫卵会在猪的肠道内孵化，钻入肠壁，进入血液循环，并迁移到各种组织和肌肉中。在那里，它们会形成被包裹的幼虫，即囊尾蚴。
If a person eats undercooked meat containing cysticerci, the larvae will develop into adult tapeworms in the person’s intestinal tract and live there, possibly for years. Meanwhile, those infected people will be shedding eggs in their feces. If those eggs get spread around from poor hygiene and sanitation—into water, food, etc.—and make it into a person’s mouth, they do what they do in pigs. The eggs hatch, burrow into the bloodstream, and then go wandering around, embedding in various tissues, muscles, and organs, including the brain. 如果人食用了含有囊尾蚴且未煮熟的肉类，幼虫会在人体肠道内发育成成虫，并可能在那里存活多年。同时，这些感染者会通过粪便排出虫卵。如果这些虫卵因卫生条件差而传播到水、食物等处，并被人摄入，它们就会像在猪体内一样：虫卵孵化、钻入血液，然后在体内游走，嵌入各种组织、肌肉和器官，包括大脑。
When cysticerci enter a person’s central nervous system, it’s a disease called neurocysticercosis (NCC), which is the diagnosis the doctors in Spain gave the man. Testing after his MRI revealed his immune system had made antibodies against Taenia solium, confirming the infection. 当囊尾蚴进入人的中枢神经系统时，就会引发一种称为“神经囊尾蚴病”（NCC）的疾病，这正是西班牙医生对该男子的诊断。MRI 后的检测显示，他的免疫系统产生了针对猪肉绦虫的抗体，从而证实了感染。
NCC can be serious, causing seizures, significant neurological deficits, cognitive decline, stroke, and other problems. But it can also be asymptomatic. The severity depends on where in the brain the worms settle. Luckily for the man, the effects were relatively mild. Doctors prescribed him two anti-parasitic drugs, and he recovered. 神经囊尾蚴病可能很严重，会导致癫痫、严重的神经功能缺损、认知能力下降、中风及其他问题。但它也可能无症状。病情的严重程度取决于寄生虫在大脑中的寄生位置。幸运的是，该男子的症状相对较轻。医生为他开了两种抗寄生虫药物，他最终康复了。
“Our case emphasizes that the absence of travel history should not preclude NCC from the differential diagnosis of multiple ring-enhancing brain lesions, even in regions where metastatic cancer is statistically much more likely,” they concluded. If they had caught onto the worms sooner, it would have prevented “unnecessary invasive oncologic procedures and lead to prompt, targeted antiparasitic therapy.” “我们的病例强调，即使在统计学上转移性癌症可能性大得多的地区，缺乏旅行史也不应将神经囊尾蚴病排除在多发性环状强化脑病变的鉴别诊断之外，”他们总结道。如果他们能早点发现寄生虫，就能避免“不必要的侵入性肿瘤检查，并能及时进行针对性的抗寄生虫治疗。”