Second carcass-eating fly species cleared by FDA for maggot wound therapy
Second carcass-eating fly species cleared by FDA for maggot wound therapy
美国食品药品监督管理局批准第二种食腐蝇类用于蛆虫伤口疗法
The Food and Drug Administration this week cleared a second carcass-feasting fly species for use in maggot wound therapy, according to an announcement from Cuprina Holdings, a Singapore-based company that has dubbed its new therapeutic larvae MediFly Maggots. 据总部位于新加坡的 Cuprina Holdings 公司宣布，美国食品药品监督管理局（FDA）本周批准了第二种食腐蝇类用于蛆虫伤口疗法。该公司将其新型治疗性幼虫命名为“MediFly Maggots”。
With the clearance, Cuprina appears to be the only company to have FDA clearance to sell two species of fly larvae—and it’s abuzz with the potential to dominate the global maggot market. 获得此项批准后，Cuprina 似乎成为了唯一一家拥有 FDA 许可销售两种蝇类幼虫的公司，并有望在这一领域占据全球市场主导地位。
The new species is Lucilia cuprina, or Australian sheep blowfly. It’s a close relative of Lucilia sericata, or the common green bottle fly, which is the fly species most often used for wound therapy, often called biosurgery or maggot debridement therapy (MDT). 此次获批的新物种是丝光绿蝇（Lucilia cuprina），即澳洲绵羊绿蝇。它是丝光绿蝇（Lucilia sericata，即常见的铜绿蝇）的近亲，后者是目前伤口疗法中最常用的蝇种，这种疗法通常被称为生物外科手术或蛆虫清创疗法（MDT）。
L. sericata is the only other fly with FDA clearance, which the agency first granted in 2004 to Ronald Sherman, who is now Cuprina’s Medical and Scientific Director. 丝光绿蝇是此前唯一获得 FDA 批准的蝇种，该机构于 2004 年首次将其批准授予 Ronald Sherman，他目前担任 Cuprina 的医学与科学总监。
“We now hold FDA clearance for both species used in MDT, a position no other company holds,” Cuprina CEO David Quek said in a statement. “This anchors our wound-care platform in one of the world’s most demanding regulatory markets and gives us a defensible edge as we continue to build our portfolio.” Cuprina 首席执行官 David Quek 在一份声明中表示：“我们现在拥有 MDT 所用两种物种的 FDA 批准，这是其他任何公司都不具备的优势。这使我们的伤口护理平台在世界上监管最严格的市场之一站稳了脚跟，并为我们继续扩大产品组合提供了坚实的竞争优势。”
The company makes no claims of any significant therapeutic difference between the two maggot treatments. Rather, they are seen as fitting into different markets. L. sericata is more familiar in Western wound care, Cuprina says, while L. cuprina may have more recognition in Australia, Africa, Asia, and parts of the Americas. 该公司并未声称这两种蛆虫疗法在治疗效果上有显著差异。相反，它们被视为适用于不同的市场。Cuprina 表示，丝光绿蝇在西方伤口护理中更为人熟知，而澳洲绵羊绿蝇在澳大利亚、非洲、亚洲和美洲部分地区可能拥有更高的认可度。
For his part, Sherman, a long-time champion of wriggling remedies, cheered the clearance as a step forward for MDT generally. “Maggot debridement therapy has earned its place in modern wound care, and adding a second FDA-cleared species strengthens the entire field,” Sherman said. “Lucilia cuprina has a meaningful international track record, and bring[ing] it under US FDA clearance gives clinicians and their patients more flexibility in how this therapy is delivered.” 作为长期倡导这种“蠕动疗法”的专家，Sherman 对此次获批表示欢迎，认为这是 MDT 整体发展的一大进步。Sherman 说：“蛆虫清创疗法在现代伤口护理中已占有一席之地，增加第二个获 FDA 批准的物种加强了整个领域。澳洲绵羊绿蝇拥有重要的国际应用记录，将其纳入美国 FDA 的批准范围，为临床医生及其患者在实施该疗法时提供了更大的灵活性。”
Niche wigglers / 小众的“蠕动者”
The idea of allowing baby flies to help clean out wounds dates back centuries, but has yet to be embraced by modern medicine—for various reasons. The most obvious is the “ick” factor, which zaps enthusiasm from both patients and healthcare providers. This has led some larvae lovers to push for a rebrand, such as reframing larvae as adorable newborn flies, wee walruses, or maggies. 利用蝇类幼虫清理伤口的想法由来已久，但由于各种原因，至今尚未被现代医学完全接纳。最显而易见的原因是“恶心”因素，这削弱了患者和医护人员的热情。这促使一些幼虫爱好者推动品牌重塑，例如将幼虫重新包装为“可爱的新生蝇”、“小海象”或“小蛆蛆”。
It likely doesn’t help the effort that the L. curprina clearance lands as the US is facing an invasion of New World screwworm—a parasitic fly whose larvae feast on living flesh, causing horrific wounds on a wide variety of warm-blooded creatures and threatening millions of dollars in damage to the livestock industry. 此次澳洲绵羊绿蝇获批的时机可能并不理想，因为美国正面临新世界螺旋蝇的入侵——这是一种寄生蝇，其幼虫以活体组织为食，会在多种温血动物身上造成可怕的伤口，并对畜牧业造成数百万美元的潜在损失。
The two Lucilia species used in MDT are not considered parasitic. They mainly feast on carrion—though L. cuprina can cause a parasitic infestation in sheep called flystrike. In well-controlled MDT use, they feast only on dead and decaying tissue in wounds. 用于 MDT 的两种绿蝇并不被视为寄生虫。它们主要以腐肉为食，尽管澳洲绵羊绿蝇确实会在绵羊身上引起一种称为“蝇蛆病”的寄生感染。在严格控制的 MDT 应用中，它们只以伤口中的坏死和腐烂组织为食。
Perhaps the biggest reason MDT hasn’t taken off is that it’s not backed by solid evidence. While small, low-quality studies have indicated that maggot therapy is safe and effective at wound debridement, robust trials and evidence are lacking. As such, the treatment remains niche and is sometimes seen as a last resort for patients who refuse or are poor candidates for surgical or other standard debridement methods. MDT 未能普及的最大原因或许是缺乏坚实的证据支持。虽然一些小规模、低质量的研究表明蛆虫疗法在伤口清创方面是安全有效的，但缺乏强有力的临床试验和证据。因此，这种治疗方法仍然属于小众，有时被视为那些拒绝手术或其他标准清创方法，或不适合这些方法的患者的最后手段。
The hypothesis behind MDT is appealing if the maggots aren’t. To treat chronic, unhealing wounds, such as diabetic ulcers in the feet and legs, sterilized maggots are placed in the wound and secrete enzymes to liquify necrotic tissue. They then wiggle around to consume the slurry from all the nooks and crannies of a wound, which may be less painful and more efficient than surgical methods that try to slice out necrotic tissue. 如果撇开蛆虫本身不谈，MDT 背后的假设是很有吸引力的。为了治疗慢性、难以愈合的伤口（如足部和腿部的糖尿病溃疡），医生会将消毒后的蛆虫放置在伤口中，它们会分泌酶来液化坏死组织。随后，它们会四处蠕动，吞食伤口各个角落的腐烂物质。与试图切除坏死组织的手术方法相比，这种方式可能痛苦更小且效率更高。
The maggots are thought to secrete various antibacterial compounds to ward off pathogenic bacteria and block biofilms from forming, overall preventing secondary infection. Finally, the activity of the maggots may also stimulate tissue regrowth. 人们认为，蛆虫会分泌多种抗菌化合物来抵御病原菌并阻止生物膜的形成，从而整体上预防继发感染。最后，蛆虫的活动还可能刺激组织再生。
Interesting infestations / 有趣的感染案例
While the evidence for all of that remains slim, some researchers have reported benefits from unintentional maggots in wounds, which often go unreported in healthcare settings. In a 2018 report of two cases with accidental maggot infestation in unhealing wounds, researchers in Chicago noted that the maggots appeared helpful. 尽管上述所有结论的证据仍然有限，但一些研究人员报告了伤口中意外出现的蛆虫所带来的益处，这些情况在医疗环境中往往未被记录。在 2018 年关于两例伤口意外感染蛆虫的报告中，芝加哥的研究人员指出，这些蛆虫似乎起到了帮助作用。
“Accidental myiasis may have been a blessing in disguise because the maggots likely consumed the majority of necrotic tissue,” they reported. They also noted that maggots in a wound can be an early signal of cancer, given that “malignant wounds exude volatile metabolites, blood, and decaying tissues, which attract flies.” Both cases were found to have undiagnosed cancers. 他们报告称：“意外的蝇蛆病可能是一种因祸得福，因为蛆虫很可能吞噬了大部分坏死组织。”他们还指出，伤口中的蛆虫可能是癌症的早期信号，因为“恶性伤口会散发出挥发性代谢物、血液和腐烂组织，从而吸引苍蝇。”这两例患者最终都被发现患有未确诊的癌症。
While MDT is intended to be a well-controlled treatment with larvae closely monitored and carefully removed at timed intervals, accidental myiasis carries the risk of having the maggots run amok and becoming difficult to extract. When this happens, doctors in California provide a simple solution: using strips of uncooked bacon to entice the maggots out. 虽然 MDT 旨在成为一种受控良好的治疗方法，即对幼虫进行密切监测并在定时后小心移除，但意外的蝇蛆病存在蛆虫失控且难以提取的风险。当这种情况发生时，加利福尼亚州的医生提供了一个简单的解决方案：使用生培根条将蛆虫引诱出来。
This strategy worked for a woman with a poorly managed wound around her ear. After bacon strips were wrapped around her ear for 5 to 10 minutes, the maggots clung to the bacon and could be removed. The doctors note that they aren’t sure why it works—the bacon may block air, forcing the maggots to surface; the fats from the meat may increase their mobility; or the maggots just like bacon. 这一策略对一名耳部伤口处理不当的女性非常有效。在将培根条缠绕在她的耳朵上 5 到 10 分钟后，蛆虫附着在培根上，从而被成功移除。医生指出，他们不确定其原理——可能是培根阻断了空气，迫使蛆虫浮出表面；肉中的脂肪可能增加了它们的活动性；又或者，蛆虫只是单纯喜欢培根。
In all, they concluded that “Evidence suggests that maggot therapy prevents infection by bactericidal pathways and promotes wound healing by stimulating tissue growth stimulation.” But, they continued, if things go awry, “bacon therapy can provide a safe, cost-effective, noninvasive method for maggot extraction that avoids complications.” 总之，他们总结道：“证据表明，蛆虫疗法通过杀菌途径预防感染，并通过刺激组织生长促进伤口愈合。”但他们补充说，如果出现意外，“培根疗法可以提供一种安全、经济、无创的蛆虫提取方法，从而避免并发症。”