Dermatological aspects of tularaemia: a study of 168 cases

Targeting Tularemia: Clinical, Laboratory, and Treatment Outcomes From an 11-year Retrospective Observational Cohort in Northern Sweden

BACKGROUND

Tularemia is an important reemerging disease with a multimodal transmission pattern. Treatment outcomes of current recommended antibiotic regimens (including ciprofloxacin and doxycycline) remain unclear. In this retrospective cohort study, we report clinical, laboratory, geographical, and treatment outcomes of laboratory-confirmed tularemia cases over an 11-year period in Northern Sweden.

METHODS

Data from reported tularemia cases (aged >10 years at time of study) in Norrbotten county between 2011 and 2021 were collected through review of electronic medical records and participant questionnaires; 415 of 784 accepted participation (52.9%). Of these, 327 were laboratory-confirmed cases (serology and/or polymerase chain reaction). A multivariable logistic regression model was used to investigate variables associated with retreatment.

RESULTS

Median age of participants was 54 years (interquartile range [IQR], 41.5-65) and 49.2% were female. Although ulceroglandular tularemia was the predominant form (n = 215, 65.7%), there were several cases of pulmonary tularemia (n = 40; 12.2%). Inflammatory markers were largely nonspecific, with monocytosis frequently observed (n = 36/75; 48%). Tularemia was often misdiagnosed on presentation (n = 158, 48.3%), with 65 (19.9%) receiving initial inappropriate antibiotics and 102 (31.2%) retreated. Persistent lymphadenopathy was infrequent (n = 22, 6.7%), with 10 undergoing surgical interventions. In multivariable analysis of variables associated with retreatment, we highlight differences in time until receiving appropriate antibiotics (8 [IQR, 3.25-20.75] vs 7 [IQR, 4-11.25] days; adjusted P = .076), and doxycycline-based treatment regimen (vs ciprofloxacin; adjusted P = .084), although this was not significant after correction for multiple comparisons.

CONCLUSIONS

We comprehensively summarize clinical, laboratory, and treatment outcomes of type B tularemia. Targeting tularemia requires clinical awareness, early diagnosis, and timely commencement of treatment for an appropriate duration.

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.

Emerging infectious diseases of the skin: a review of clinical and histologic findings

Emerging infectious diseases are of great importance to public health and clinical practice. This review aims to characterize the clinical and histopathologic features of emerging infectious diseases with cutaneous manifestations in order to increase awareness of these entities among dermatologists, pathologists, and dermatopathologists.

Parinaud's Oculoglandular Syndrome: A Case in an Adult with Flea-Borne Typhus and a Review

Parinaud's oculoglandular syndrome (POGS) is defined as unilateral granulomatous conjunctivitis and facial lymphadenopathy. The aims of the current study are to describe a case of POGS with uveitis due to flea-borne typhus (FBT) and to present a diagnostic and therapeutic approach to POGS. The patient, a 38-year old man, presented with persistent unilateral eye pain, fever, rash, preauricular and submandibular lymphadenopathy, and laboratory findings of FBT: hyponatremia, elevated transaminase and lactate dehydrogenase levels, thrombocytopenia, and hypoalbuminemia. His condition rapidly improved after starting doxycycline. Soon after hospitalization, he was diagnosed with uveitis, which responded to topical prednisolone. To derive a diagnostic and empiric therapeutic approach to POGS, we reviewed the cases of POGS from its various causes since 1976 to discern epidemiologic clues and determine successful diagnostic techniques and therapies; we found multiple cases due to cat scratch disease (CSD; due to Bartonella henselae) (twelve), tularemia (ten), sporotrichosis (three), Rickettsia conorii (three), R. typhi/felis (two), and herpes simplex virus (two) and single cases due to tuberculosis, paracoccidioidomycosis, Yersinia enterocolitica, Pasteurella multocida, Chlamydia trachomatis, Epstein-Barr virus, and Nocardia brasiliensis. Preauricular lymphadenopathy is a common clinical clue for POGS and is unusual in viral and bacterial conjunctivitis. For POGS, the major etiological consideration is B. henselae, which is usually diagnosed by the indirect immunofluorescence serologic technique. Although CSD POGS is usually self-limited, oral azithromycin may hasten resolution. However, other possible etiologies of POGS may also arise from cat or cat flea contact: sporotrichosis, tularemia, Pasteurella multocida, or FBT. If there is no cat contact, other epidemiologic and clinical findings should be sought, because several of these conditions, such as tularemia, paracoccidioidomycosis, and tuberculosis, may have grave systemic complications. Although there are usually no long-term ocular sequelae if POGS is properly diagnosed, it still may cause prolonged ocular discomfort and require multiple physician contacts.