A rare cause of granulomatous hepatitis: Tularemia

Tularemia treatment: experimental and clinical data

Tularemia is a zoonosis caused by the Gram negative, facultative intracellular bacterium Francisella tularensis. This disease has multiple clinical presentations according to the route of infection, the virulence of the infecting bacterial strain, and the underlying medical condition of infected persons. Systemic infections (e.g., pneumonic and typhoidal form) and complications are rare but may be life threatening. Most people suffer from local infection (e.g., skin ulcer, conjunctivitis, or pharyngitis) with regional lymphadenopathy, which evolve to suppuration in about 30% of patients and a chronic course of infection. Current treatment recommendations have been established to manage acute infections in the context of a biological threat and do not consider the great variability of clinical situations. This review summarizes literature data on antibiotic efficacy against F. tularensis in vitro, in animal models, and in humans. Empirical treatment with beta-lactams, most macrolides, or anti-tuberculosis agents is usually ineffective. The aminoglycosides gentamicin and streptomycin remain the gold standard for severe infections, and the fluoroquinolones and doxycycline for infections of mild severity, although current data indicate the former are usually more effective. However, the antibiotic treatments reported in the literature are highly variable in their composition and duration depending on the clinical manifestations, the age and health status of the patient, the presence of complications, and the evolution of the disease. Many patients received several antibiotics in combination or successively. Whatever the antibiotic treatment administered, variable but high rates of treatment failures and relapses are still observed, especially in patients treated more then 2-3 weeks after disease onset. In these patients, surgical treatment is often necessary for cure, including drainage or removal of suppurative lymph nodes or other infectious foci. It is currently difficult to establish therapeutic recommendations, particularly due to lack of comparative randomized studies. However, we have attempted to summarize current knowledge through proposals for improving tularemia treatment which will have to be discussed by a group of experts. A major factor in improving the prognosis of patients with tularemia is the early administration of appropriate treatment, which requires better medical knowledge and diagnostic strategy of this disease.

Body Imaging of Bacterial and Parasitic Zoonoses: Keys to Diagnosis

Zoonotic infections, which are transmitted from animals to humans, have been a substantial source of human disease since antiquity. As the human population continues to grow and human influence on the planet expands, humans frequently encounter both domestic and wild animals. This has only increased as deforestation, urbanization, agriculture, habitat fragmentation, outdoor recreation, and international travel evolve in modern society, all of which have resulted in the emergence and reemergence of zoonotic infections. Zoonotic infections pose a diagnostic challenge because of their nonspecific clinical manifestations and the need for specialized testing procedures to confirm these diagnoses. Affected patients often undergo imaging during their evaluation, and a radiologist familiar with the specific and often subtle imaging patterns of these infections can add important clinical value. The authors review the multimodality thoracic, abdominal, and musculoskeletal imaging findings of zoonotic bacterial (eg, Bartonella henselae, Pasteurella multocida, Francisella tularensis, Coxiella burnetii, and Brucella species), spirochetal (eg, Leptospira species), and parasitic (eg, Echinococcus, Paragonimus, Toxocara, and Dirofilaria species) infections that are among the more commonly encountered zoonoses in the United States. Relevant clinical, epidemiologic, and pathophysiologic clues such as exposure history, occupational risk factors, and organism life cycles are also reviewed. Although many of the imaging findings of zoonotic infections overlap with those of nonzoonotic infections, granulomatous diseases, and malignancies, radiologists' familiarity with the imaging patterns can aid in the differential diagnosis in a patient with a suspected or unsuspected zoonotic infection. ^© RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Tularemia: A rare cause of pediatric lymph nodes adenitis

Adenopathy in pediatrics can have many different causes: infectious, tumoral, and inflammatory. We report the case of an 8-year-old patient with a febrile popliteal ulceration associated with an inflammatory satellite inguinal lymph node adenitis. Serological tests and polymerase chain reaction analyses confirmed the diagnosis of ulceroglandular tularemia. An appropriate antimicrobial therapy led to a full recovery. This case reminds us to consider tularemia as a potential emergent disease in children presenting with subacute to chronic lymphadenopathy and thereby to choose the correct diagnostic tool and appropriate antimicrobial therapy.

Challenging Mimickers in the Diagnosis of Sarcoidosis: A Case Study

Sarcoidosis is a systemic granulomatous disease of unknown cause characterized by a wide variety of presentations. Its diagnosis is based on three major criteria: a clinical presentation compatible with sarcoidosis, the presence of non-necrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. Many conditions may mimic a sarcoid-like granulomatous reaction. These conditions include infections, neoplasms, immunodeficiencies, and drug-induced diseases. Moreover, patients with sarcoidosis are at risk of developing opportunistic infections or lymphoma. Reliably confirming the diagnosis of sarcoidosis and better identifying new events are major clinical problems in daily practice. To address such issues, we present seven emblematic cases, seen in our department, over a ten-year period along with a literature review about case reports of conditions misdiagnosed as sarcoidosis.

Dangerous Pathogens as a Potential Problem for Public Health

Pathogens are various organisms, such as viruses, bacteria, fungi, and protozoa, which can cause severe illnesses to their hosts. Throughout history, pathogens have accompanied human populations and caused various epidemics. One of the most significant outbreaks was the Black Death, which occurred in the 14th century and caused the death of one-third of Europe's population. Pathogens have also been studied for their use as biological warfare agents by the former Soviet Union, Japan, and the USA. Among bacteria and viruses, there are high priority agents that have a significant impact on public health. Bacillus anthracis, Francisella tularensis, Yersinia pestis, Variola virus, Filoviruses (Ebola, Marburg), Arenoviruses (Lassa), and influenza viruses are included in this group of agents. Outbreaks and infections caused by them might result in social disruption and panic, which is why special operations are needed for public health preparedness. Antibiotic-resistant bacteria that significantly impede treatment and recovery of patients are also valid threats. Furthermore, recent events related to the massive spread of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an example of how virus-induced diseases cannot be ignored. The impact of outbreaks, such as SARS-CoV-2, have had far-reaching consequences beyond public health. The economic losses due to lockdowns are difficult to estimate, but it would take years to restore countries to pre-outbreak status. For countries affected by the 2019 coronavirus disease (COVID-19), their health systems have been overwhelmed, resulting in an increase in the mortality rate caused by diseases or injuries. Furthermore, outbreaks, such as SARS-CoV-2, will induce serious, wide-ranging (and possibly long-lasting) psychological problems among, not only health workers, but ordinary citizens (this is due to isolation, quarantine, etc.). The aim of this paper is to present the most dangerous pathogens, as well as general characterizations, mechanisms of action, and treatments.

Oculoglandular Tularemia From Crushing an Engorged Tick

We report on an unusual case of oculoglandular tularemia acquired after crushing a tick removed from a dog. As a droplet sprayed into the patient's eye the eyelids became inflamed, and on the fourth day, a high fever started. Prompt antibiotic treatment prevented serious complication.