Infection is very common in burn patients because they lose the primary barrier from microorganism invasion, the skin. While there are attempts to prevent infections, topical antimicrobials and systemic prophylaxis tend to lead to more resistant organisms. After the initial resuscitation, the most common cause of death is from sepsis and multiple organ dysfunction syndrome. The diagnosis is difficult in the burn population because the constant exposure from the open wound leads to an inflammatory response that leads to persistent hypermetabolism. This paper reviews the current understanding and treatment of infection and sepsis in burns.

Recent reclassification of the Klebsiella genus to include Klebsiella variicola, and its association with bacteremia and mortality, has raised concerns. We examined Klebsiella spp. infections among battlefield trauma patients, including occurrence of invasive K. variicola disease. Klebsiella isolates collected from 51 wounded military personnel (2009–2014) through the Trauma Infectious Disease Outcomes Study were examined using polymerase chain reaction (PCR) and pulsed-field gel electrophoresis. K. variicola isolates were evaluated for hypermucoviscosity phenotype by the string test. Patients were severely injured, largely from blast injuries, and all received antibiotics prior to Klebsiella isolation. Multidrug-resistant Klebsiella isolates were identified in 23 (45%) patients; however, there were no significant differences when patients with and without multidrug-resistant Klebsiella were compared. A total of 237 isolates initially identified as K. pneumoniae were analyzed, with 141 clinical isolates associated with infections (remaining were colonizing isolates collected through surveillance groin swabs). Using PCR sequencing, 221 (93%) isolates were confirmed as K. pneumoniae, 10 (4%) were K. variicola, and 6 (3%) were K. quasipneumoniae. Five K. variicola isolates were associated with infections. Compared to K. pneumoniae, infecting K. variicola isolates were more likely to be from blood (4/5 versus 24/134, p = 0.04), and less likely to be multidrug-resistant (0/5 versus 99/134, p<0.01). No K. variicola isolates demonstrated the hypermucoviscosity phenotype. Although K. variicola isolates were frequently isolated from bloodstream infections, they were less likely to be multidrug-resistant. Further work is needed to facilitate diagnosis of K. variicola and clarify its clinical significance in larger prospective studies.

Invasive fungal wound infection (FWI) after burn injury, while uncommon, is associated with significant morbidity and mortality. There are numerous risk factors for FWI, including large burn size and incomplete excision of burn wounds. FWI can be challenging to diagnose. Close attention to changes in the physical examination and, in particular, to the appearance of burn wounds leads the burn team to be suspicious of FWI. Once FWI is suspected, histopathological evaluation of an incisional biopsy provides definitive diagnosis, while tissue culture enables identification of the causative organism to the species level and facilitates targeted antifungal therapy. Management of FWI focuses largely on aggressive surgical intervention, in addition to adjunctive systemic and topical antifungals and nonpharmacologic therapies. Treatment of FWI involves a multifaceted approach, which requires expertise from the entire multidisciplinary burn team.

Non-tuberculous mycobacteria (NTM) cause a wide variety of clinical syndromes. Data guiding diagnosis and treatment of NTM skin and soft tissue infections (SSTI) and bone infections are limited. We sought to better understand SSTI and bone infections caused by NTM. All NTM clinical isolates recovered at Brooke Army Medical Center from 2012 to 2022 were screened; SSTI and bone isolates were included. Electronic health records were reviewed for epidemiologic, microbiologic, and clinical data. Infections were defined as recovery of one or more NTM isolate from skin, soft tissue, or bone cultures with a corresponding clinical syndrome. Forty isolates of skin, soft tissue, or bone origin from 29 patients were analyzed. Twenty (69 %) patients, majority female (14/20, 70 %), had infecting isolates, most commonly secondary to surgery (35 %) or trauma (35 %). Six of 20 (30 %) had bone infections. Time from symptom onset to isolate recovery was a median 61 days (IQR 43–95). Eight (40 %) had combined medical/surgical therapy, 8 (40 %) had surgery alone, and 4 (20 %) had medical therapy alone. M. abscessus was more frequently isolated from patients with true infections. Data supporting diagnosis and treatment decisions in NTM SSTI/bone infections is sparse. In this study the majority of NTM isolated were true infections. We confirm that surgery and trauma are the most common routes of exposure. The delay between symptom onset and directed therapy and the wide variety of treatment regimens highlight a need for additional studies delineating criteria for diagnosis and treatment.

Purpose of Review: 2024 saw the outbreak of a strain of highly pathogenic avian influenza with intermittent transmission to humans. This review will consider the landscape of avian influenza, the role migratory birds and cattle play in transmission, and our understanding of the current outbreak in humans. Recent Findings: While cases of human avian influenza have fortunately continued to be relatively low, the evidence that continued circulation in migratory and domestic poultry flocks combined with spillover into bovine herds support further efforts to understand this outbreak and develop mitigation strategies like vaccines and therapeutics. Summary: Highly pathogenic avian influenza is likely to remain a critical target for epidemiologic surveillance along with further development of new mitigation strategies.