# Case Report: Fatal Streptococcus pyogenes infection secondary to closed femoral fracture

## TL;DR

A patient with a closed femoral fracture developed a deadly Streptococcus pyogenes infection, highlighting the need for early detection and aggressive treatment.

## Contribution

This case report highlights the rare but severe complications of S. pyogenes infection following closed fractures and emphasizes the importance of early intervention.

## Key findings

- Streptococcus pyogenes can cause fatal necrotizing infections after closed fractures.
- Early fasciotomy and multidisciplinary care are critical for survival.
- Next-generation sequencing confirmed the infection and aided in diagnosis.

## Abstract

Invasive Streptococcus pyogenes infection is exceedingly rare in patients with closed fractures. However, it can precipitate life-threatening necrotizing soft-tissue infection and streptococcal toxic shock syndrome once it occurs. Early recognition and aggressive multidisciplinary management are essential for survival.

We presented a patient who sustained closed fracture of the upper segment of the left femur due to a traffic accident. He had a history of acute pharyngitis 10 days ago. The patient experienced fever on the second day after admission, with his body temperature ranging from 38.5 °C to 38.8 °C. He developed rapidly progressive swelling and severe pain at the fracture site on the third day, accompanied by high fever of 40.1 °C, tachypnea, and tachycardia, with mottled rash over the local skin, followed by hypotension, oliguria and a rise of serum creatinine. Emergent fasciotomy and decompression were performed, and the thigh musculature of patient was dusky-red and non-viable. Debridement was performed to remove the necrotic tissue. Subsequently, the patient rapidly developed to multiple organ dysfunction with profoundly elevated inflammatory markers. Thigh amputation surgery was undertaken to save his life. The wound secretion, blood culture, and plasma next-generation sequencing (NGS) all confirmed a diagnosis of streptococcal infection. The patient then underwent several times of debridement to remove necrotic tissue. Meanwhile, he took sensitive antibiotic therapy, aggressive fluid resuscitation and organ function support. Ultimately, his condition improved.

This case underscored the catastrophic potential of closed fractures complicated by necrotizing soft tissue infections caused by S. pyogenes, highlighting the critical need for heightened vigilance in patients with a recent history of Streptococcus exposure. Early and aggressive surgical intervention, along with multidisciplinary collaboration, is essential. Additionally, the role of prompt pathogen culture testing and advanced diagnostic techniques, such as NGS, in pathogen identification is emphasized.