We report a case of mpox in a patient with a signal transducer and activator of transcription 1 gain-of-function mutation. Despite initial improvement with intravenous immune globulin and tecovirimat, severe symptoms developed and the patient died. This underscores the need for immune system optimization and effective virucidal treatments for mpox.

Tickborne infections are challenging to diagnose, particularly among solid organ transplant recipients. We report a US case of donor-derived ehrlichiosis from a living kidney donation that highlights how screening for living donors may miss tickborne infections. Clinicians should consider the epidemiology of the donor when screening donations and evaluating recipients for donor-derived infection.

A 59-year-old woman with newly diagnosed immune thrombocytopenia treated with steroids and rituximab presented with a cavitary lung lesion. Extensive work-up, including bronchoalveolar lavage and transthoracic lung biopsy, were unrevealing. Molecular testing on lung tissue ultimately diagnosed nonserogroup-1 Legionella pneumophila, underscoring the utility of advanced diagnostics in clinical conundrums. © 2025 Authors.

Rocky Mountain spotted fever (RMSF) is a tickborne disease endemic in areas of the Americas. Persistent high incidence of the disease exists in northern Mexico, perpetuated by local populations of brown dog ticks (Rhipicephalus sanguineus sensu lato) and free-roaming dogs. Six cases of RMSF caused by Rickettsia rickettsii, including three deaths, were reported to the California Department of Public Health during July 2023-January 2024. All six patients were eventually determined to have had exposure to R. rickettsii in Tecate, Mexico, a municipality on the U.S. border that had not been previously described as a high-risk RMSF area. Identification and reporting of the cases were complicated by challenges in diagnosis. The serious nature of the disease and delays in initiating appropriate treatment can result in life-threatening consequences. Epidemiologic collaborations among local, state, federal, and international public health agencies were essential to identifying Tecate as the location of exposure. Further collaborations will be important for directing future prevention measures. Increased health care provider awareness of RMSF is critical on both sides of the border to facilitate earlier diagnosis and initiation of appropriate treatment.

BACKGROUND: Borealpox virus (BRPV, formerly known as Alaskapox virus) is a zoonotic member of the Orthopoxvirus genus first identified in a person in 2015. In the six patients with infection previously observed BRPV involved mild, self-limiting illness. We report the first fatal BRPV infection in an immunosuppressed patient. METHODS: A man aged 69 years from Alaska's Kenai Peninsula was receiving anti-CD20 therapy for chronic lymphocytic leukemia. He presented to care for a tender, red papule in his right axilla with increasing induration and pain. The patient failed to respond to multiple prescribed antibiotic regimens and was hospitalized 65 days postsymptom onset for progression of presumed infectious cellulitis. BRPV was eventually detected through orthopoxvirus real-time polymerase chain reaction testing of mucosal swabs. He received combination antiviral therapy, including 21 days of intravenous tecovirimat, intravenous vaccinia immunoglobulin, and oral brincidofovir. Serial serology was conducted on specimens obtained posttreatment initiation. FINDINGS: The patient's condition initially improved with plaque recession, reduced erythema, and epithelization around the axillary lesion beginning one-week post-therapy. He later exhibited delayed wound healing, malnutrition, acute renal failure, and respiratory failure. He died 138 days postsymptom onset. Serologic testing revealed no evidence the patient generated a humoral immune response. No secondary cases were detected. CONCLUSION: This report demonstrates that BRPV can cause overwhelming disseminated infection in certain immunocompromised patients. Based on the patient's initial response, early BRPV identification and antiviral therapies might have been beneficial. These therapies, in combination with optimized immune function, should be considered for patients at risk for manifestations of BRPV.

A multinational outbreak of nosocomial fusarium meningitis occurred among immunocompetent patients who had undergone surgery with epidural anesthesia in Mexico. The pathogen involved had a high predilection for the brain stem and vertebrobasilar arterial system and was associated with high mortality from vessel injury. Effective treatment options remain limited; in vitro susceptibility testing of the organism suggested that it is resistant to all currently approved antifungal medications in the United States. To highlight the severe complications associated with fusarium infection acquired in this manner, we report data, clinical courses, and outcomes from 13 patients in the outbreak who presented with symptoms after a median delay of 39 days.

BACKGROUND: Pathology and monkeypox virus (MPXV) tissue tropism in severe and fatal human mpox is not thoroughly described but can help elucidate the disease pathogenesis and the role of coinfections in immunocompromised patients. METHODS: We analyzed biopsy and autopsy tissues from 22 patients with severe or fatal outcomes to characterize pathology and viral antigen and DNA distribution in tissues by immunohistochemistry and in situ hybridization. Tissue-based testing for coinfections was also performed. RESULTS: Mucocutaneous lesions showed necrotizing and proliferative epithelial changes. Deceased patients with autopsy tissues evaluated had digestive tract lesions, and half had systemic tissue necrosis with thrombotic vasculopathy in lymphoid tissues, lung, or other solid organs. Half also had bronchopneumonia, and one-third had acute lung injury. All cases had MPXV antigen and DNA detected in tissues. Coinfections were identified in 5/16 (31%) biopsy and 4/6 (67%) autopsy cases. DISCUSSION: Severe mpox in immunocompromised patients is characterized by extensive viral infection of tissues and viremic dissemination that can progress despite available therapeutics. Digestive tract and lung involvement are common and associated with prominent histopathological and clinical manifestations. Coinfections may complicate mpox diagnosis and treatment. Significant viral DNA (likely correlating to infectious virus) in tissues necessitates enhanced biosafety measures in healthcare and autopsy settings.