EUHM Report: What is the etiology of Streptococcus anginosus?

The S anginosus group, often referred to as Streptococcus milleri , are commensals of the oropharyngeal, GI, and genitourinary microflora that can cause invasive  pyogenic infections in various sites. While more commonly associated with CNS, abdominal, head and neck, bloodstream, and thoracic infections, the three species that make up S anginosus have been associated with differing clinical manifestations.

Sunwoo, Bernie Y, and Wallace T Miller. “Streptococcus Anginosus Infections: Crossing Tissue Planes.” Chest. 146, no. 4 (2014): E121-125.

While more commonly associated with CNS, abdominal, head and neck, bloodstream, and thoracic infections, the three species that make up S anginosus have been associated with differing clinical manifestation.  The S anginosus group of organisms is known to be highly virulent and rapidly progressive, and it is not surprising that they might cross tissue planes.  Given the potential utility of radiographic extension across tissue planes in raising the differential of S anginosus , further research on the radiographic presentations of thoracic S anginosus is needed.

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EUH Krakow Conference: Review of Lemierre’s Syndrome

Bottom Line: Vijay and Fattah1 state that Lemierre’s syndrome typically presents in young adults who were previously healthy. In a case series of 222 patients who fit the “Lemierre’s syndrome case presentation, the median age was 19 years and 89% of patients were aged 10 to 35 years.”2 Its four key elements are “primary oropharyngeal infection within 4 weeks, suppurative thrombophlebitis of the internal jugular (IJ) vein, metastatic septic emboli, and [a] causal association with F necrophorum.” It should be “suspected in those with a recent history of oropharyngeal infection presenting with fever and rigors, with or without evidence of metastatic lesions, particularly respiratory symptoms (pleuritic chest pain, dyspnoea, haemoptysis).” Penicillin/beta-lactamase inhibitor, penicillin plus metronidazole, and carbapenem” are “appropriate empirical antibiotic regimens….There are no controlled trials to guide management, but most sources recommend between 2–6 weeks of antibiotics in total.” Review article provides four computed tomography pulmonary angiogram (CTPA) images with red arrows that indicate locations of multiple peripheral nodular lesions.

References:

1. Vijay V, Fattah Z. Lesson of the month 1: Lemierre‘s syndrome: a reminder of the ‘forgotten disease.’ Clin Med (Lond). 2018 Feb;18(1):100-102. doi:10.7861/clinmedicine.18-1-100.

2. Riordan T. Human infection with Fusobacterium necrophorum (Necrobacillosis), with a focuson Lemierre’s syndrome. Clin Microbiol Rev. 2007 Oct;20(4):622-59. doi:10.1128/CMR.00011-07.

EUHM Resident Report: Prevalence of Chagas disease in the United States.

The Bottom Line: In the United States, little evidence is available to document Chagas disease prevalence, assess congenital and vector-borne transmission risk, and quantify the clinical disease burden. Based on immigration estimates for the United States and prevalence estimates in Latin America, more than 300,000 persons with Chagas disease are living in this country; many of these persons do not know that they are infected. An estimated 63–315 babies acquire T. cruzi infection congenitally in the United States every year but most infections go undetected and untreated. Based on these estimates, chagasic cardiomyopathy, which can be prevented through early treatment, affects approximately 30,000–45,000 persons in the United States.

Montgomery, S. P., Starr, M. C., Cantey, P. T., Edwards, M. S., & Meymandi, S. K. (2014). Neglected Parasitic Infections in the United States: Chagas Disease. The American Journal of Tropical Medicine and Hygiene, 90(5), 814–818.

Although an estimated 300,000 persons with Chagas disease live in the United States, little is known about the burden of chagasic heart disease. It is not known how often congenital or vector-borne transmission of T. cruzi occurs in the United States, although it is known that infected mothers and infected vector bugs are found in this country

VA Resident Report: What is the distribution of arthritis associated with systemic infection?

The Bottom Line: Staphylococcus aureus is the main cause of septic arthritis involving native joints, although many other organisms are encountered also. In our center, neither the distribution nor the antibiotic susceptibility profiles of the causative organisms changed significantly over the last 30 years.

Table 1 Organisms responsible for septic arthritis.  Page 439

Dubost, J., Couderc, M., Tatar, Z., Tournadre, A., Lopez, J., Mathieu, S., & Soubrier, M. (2014). Three-decade trends in the distribution of organisms causing septic arthritis in native joints: Single-center study of 374 cases. Joint, Bone, Spine, 81(5), 438-440.

In this study, the distribution and antibiotic susceptibility profile of the organisms responsible for septic arthritis showed little change over the 30-year study period. Importantly, no significant increase in MRSA was noted, in keeping with a previous study. These findings do not support the use in our center of broader-spectrum antibiotics in patients for whom empirical antibiotic therapy is deemed necessary.

VA Resident Report: Review of Fournier’s gangrene

The Bottom Line: Fournier’s gangrene is a progressive necrotizing soft-tissue infection (NSTI) of the external genitalia and/or perineum. It is a urological emergency requiring prompt diagnosis and treatment — even with administration of parenteral broad-spectrum antibiotics and expedited aggressive surgical debridement, the disease can be fatal.

References: Hagedorn, J., & Wessells, H. (n.d.). A contemporary update on Fournier’s gangrene. Nature Reviews., 14(4), 205-214.

Summary: A high level of suspicion with prompt resuscitation and surgical intervention are the key for optimizing patient outcomes. For equivocal cases, several diagnostic tools, including laboratory tests and imaging, have been developed to be used in conjunction with physical examination findings. Most infections are polymicrobial, requiring broad-spectrum antibiotics and wide surgical debridement. Wound preparation with dressing changes and further debridements are essential for successful reconstruction once the local necrotic process and systemic infection has been treated.

VA Report: What are the most common clinical characteristics of Human Monocytic Erlichiosis?

Human monocytic ehrlichiosis commonly presents as a self-limited sickness with symptoms that most often include fever, headache, myalgias, nausea, arthralgias, and malaise. In rare cases, it manifests as a life-threatening illness with features of toxic shock-like syndrome and end-organ damage; this mostly occurs in the immunocompromised, geriatric, or pediatric populations. The most important determinant in the diagnosis of human monocytic ehrlichiosis is clinical suspicion. In addition to symptoms, pancytopenia is an important hematologic abnormality that is frequently associated with human monocytic ehrlichiosis. Thrombocytopenia is detected in 70-90% of patients over the course of the illness, leukopenia is observed within the first week in 60-70%, and anemia is noted within the first 2 weeks of presentation in 50% of patients. Elevated hepatic transaminases are present in almost 90% of patients

Hilal, T., & Snapp, W. (n.d.). The perils of country life: Human monocytic ehrlichiosis. The American Journal of Medicine, 128(8), 831-833.

The current recommended regimen for the treatment of human monocytic ehrlichiosis is doxycycline, 100 mg, twice daily for 5-14 days. Patients with a delay in treatment have a significantly increased rate of transfer to the intensive care unit, increased risk for mechanical ventilation, longer hospital stay, and longer duration of illness. Encephalopathy, acute renal failure, pulmonary infiltrates, and death have been reported in patients with severe human monocytic ehrlichiosis.