When Flesh-Eating Bacteria Meet Flesh-Eating Flies: A Rare Case of Necrotizing Fasciitis With Myiasis

Necrotizing fasciitis is one of the most feared diagnoses in medicine, a rapidly progressive infection that races along fascial planes, destroys soft tissue, and can claim a life within hours if surgical intervention is delayed. A new case report published in BMC Infectious Diseases by vascular and endovascular surgeon Wasim Al-Harethee of Ibn Sina Hospital in Sanaa, Yemen, adds a strikingly rare dimension to this already catastrophic disease: the coexistence of necrotizing fasciitis with myiasis, an infestation of living tissue by fly larvae. The report, published open access on 7 October 2026, documents the case of a 38-year-old diabetic patient whose blunt trauma injury spiraled into a life-threatening combination of bacterial tissue destruction and parasitic infestation, and it uses the case as a springboard for a minireview of how such complicated necrotizing skin and soft tissue infections should be recognized and managed.

The patient arrived with a clinical picture that would challenge any emergency department. Following blunt trauma, he had developed extensive skin necrosis, the systemic inflammatory response syndrome known as SIRS, diabetic ketoacidosis, and profound fluid and electrolyte imbalances. Each of these elements alone is dangerous; together they created a metabolic and hemodynamic storm. Diabetic ketoacidosis, in which the body breaks down fat at an uncontrolled rate because insulin is insufficient, compounded the hypovolemia caused by fluid shifts into damaged tissue. The combination of uncontrolled diabetes and necrotizing infection is particularly ominous, because hyperglycemia impairs immune cell function, microvascular perfusion, and wound healing, all of which give bacteria a decisive advantage in the subcutaneous battlefield.

Diagnosing necrotizing fasciitis early is notoriously difficult, because the external appearance of the skin often dramatically underrepresents the destruction occurring beneath it. In this case, the diagnosis was confirmed through a convergence of clinical assessment, laboratory findings, imaging studies, and the Laboratory Risk Indicator for Necrotizing Fasciitis, or LRINEC score. The LRINEC score is a widely used tool that assigns points based on six laboratory parameters, including C-reactive protein, total white blood cell count, hemoglobin, sodium, creatinine, and glucose, to help clinicians distinguish necrotizing infections from ordinary cellulitis. While no scoring system can replace surgical exploration and clinical judgment, the LRINEC score provides an objective anchor when the presentation is ambiguous, and its use in this case illustrates how structured risk assessment can support timely decision-making in resource-constrained settings.

Once the diagnosis was established, management proceeded along the well-established pillars of necrotizing soft tissue infection care: resuscitation, antibiotics, and surgery. A multidisciplinary team first stabilized the patient’s hypovolemic and metabolic status, correcting the fluid deficits and electrolyte derangements while addressing the diabetic ketoacidosis. Empirical broad-spectrum antibiotic therapy was initiated immediately and later refined according to the antibiogram, the laboratory report identifying which antibiotics the cultured bacteria were susceptible to. This stepwise approach, from empiric coverage to targeted therapy, reflects a central principle in severe infection management: early treatment cannot wait for microbiology results, but those results must ultimately steer therapy to maximize efficacy and minimize collateral damage to the patient’s microbiome and organs.

Multiple surgical debridements proved necessary. In necrotizing fasciitis, surgery is the definitive treatment, because antibiotics alone cannot penetrate tissue that has been devascularized by the infection’s thrombosis of small vessels. Debridement involves the serial removal of all necrotic and infected tissue, often requiring repeated returns to the operating room every 24 to 48 hours until the surgical team confirms that no further progression is occurring. Each operation is a delicate balance: removing too little tissue leaves the infection a foothold from which to spread, while removing too much sacrifices viable tissue and complicates later reconstruction. The fact that this patient required multiple procedures underscores the aggressive nature of the infection and the importance of vigilant reassessment between operations.

Then came the unexpected finding. Histopathological examination of the debrided tissue revealed the presence of myiasis, the infestation of living vertebrate tissue by dipterous fly larvae. Myiasis occurs when flies deposit eggs on wounds, and the hatched larvae feed on the host’s necrotic or living tissue. While cutaneous myiasis is well documented in tropical and subtropical regions, particularly in settings with limited access to wound care, its coexistence with necrotizing fasciitis is described as extremely rare in the medical literature. The discovery was made not at the bedside but under the microscope, a detail that carries significant implications for how such cases are worked up.

This finding raises one of the most intriguing questions posed by the report: did the myiasis act as a primary trigger of the necrotizing process, or was it a secondary invader that colonized tissue already devastated by bacteria? The distinction is more than academic. If larvae inoculated or facilitated bacterial entry through broken skin, myiasis would represent a genuine initiating event, with implications for prevention in endemic areas. If, conversely, the larvae arrived after tissue necrosis had created an attractive substrate, they would be opportunistic colonizers, and the diagnostic and therapeutic focus would remain squarely on the bacterial infection. The author acknowledges that current guidelines do not resolve this question, and the case highlights genuine uncertainties in the existing evidence base.

Either way, the case argues powerfully for comprehensive diagnostic evaluation in complicated necrotizing soft tissue infections. The report emphasizes the value of histopathological and entomological assessment, disciplines that rarely feature in the standard workup of necrotizing fasciitis. Histopathology can reveal organisms, tissue invasion patterns, and inflammatory characteristics that cultures miss, while entomological identification of larvae to the species level can inform understanding of the infestation’s origin and its potential role in disease. For clinicians practicing in regions where wound myiasis is endemic, the message is that parasitic co-infection should at least be considered when the clinical course is atypical or when tissue examination yields surprises.

The broader context of this case is worth appreciating. Necrotizing fasciitis is predominantly of bacterial origin, typically involving Group A Streptococcus, Staphylococcus aureus including methicillin-resistant strains, or polymicrobial mixtures of aerobic and anaerobic organisms. The presence of Escherichia coli among the article’s keywords suggests that enteric organisms played a role in this patient’s infection, a pattern consistent with polymicrobial necrotizing infections that can arise when gut flora gain access to compromised tissue. In vulnerable patients, particularly those with diabetes, peripheral vascular disease, or immunosuppression, the consequences are dramatically worse, with higher rates of amputation and mortality. Yemen’s humanitarian and healthcare crisis adds another layer of severity, as delayed presentation and limited intensive care capacity are known to worsen outcomes in time-critical infections of this kind.

The clinical outcome in this case was, remarkably, both life- and limb-saving, a testament to the combined effect of early recognition, aggressive resuscitation, microbiology-guided antibiotics, and repeated surgical debridement. The report stands as a reminder that even in the most familiar of surgical emergencies, nature retains the capacity to surprise. It also underscores a practical lesson for clinicians worldwide: necrotizing soft tissue infections in vulnerable patients demand a low threshold for surgical exploration, disciplined use of risk scores such as LRINEC, and a willingness to pursue full histopathological workup when findings do not fit the expected pattern. As the author concludes, the coexistence of necrotizing fasciitis and myiasis poses significant diagnostic and therapeutic challenges, and cases like this one, documented in detail and shared openly, are precisely how the medical community begins to close the gaps in its guidelines.

Subject of Research: Coexistence of necrotizing fasciitis and myiasis in a diabetic patient following blunt trauma

Article Title: Complicated necrotizing skin and soft tissue infections and myiasis. A case report and minireview

Article References: Al-Harethee, W. (2026). Complicated necrotizing skin and soft tissue infections and myiasis. A case report and minireview. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14405-0

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14405-0

Keywords: necrotizing fasciitis, myiasis, necrotizing soft tissue infections, skin and soft tissue infections, diabetic ketoacidosis, LRINEC score, Escherichia coli, surgical debridement, histopathology, case report, BMC Infectious Diseases, Yemen