Tomographic findings of acute pulmonary toxoplasmosis in immunocompetent patients

Abstract

BackgroundToxoplasmosis is one of the most common human zoonosis, and is generally benign in most of the individuals. Pulmonary involvement is common in immunocompromised subjects, but very rare in immunocompetents and there are scarce reports of tomographic findings in the literature. The aim of the study is to describe three immunocompetent patients diagnosed with acute pulmonary toxoplasmosis and their respective thoracic tomographic findings. Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology.Case presentationFrom 2009 to 2013, three patients were diagnosed with acute respiratory failure secondary to acute toxoplasmosis. The patients were two female and one male, and were 38, 56 and 36 years old. Similarly they presented a two-week febrile illness and progressive dyspnea before admission. Laboratory tests demonstrated lymphocytosis, slight changes in liver enzymes and high inflammatory markers. Tomographic findings were bilateral smooth septal and peribronchovascular thickening (100%), ground-glass opacities (100%), atelectasis (33%), random nodules (33%), lymph node enlargement (33%) and pleural effusion (66%). All the patients improved their symptoms after treatment, and complete resolution of tomographic findings were found in the followup.ConclusionThese cases provide a unique description of the presentation and evolution of pulmonary tomographic manifestations of toxoplasmosis in immunocompetent patients. Toxoplasma pneumonia manifests with fever, dyspnea and a non-productive cough that may result in respiratory failure. In animal models, changes were described as interstitial pneumonitis with focal infiltrates of neutrophils that can finally evolve into a pattern of diffuse alveolar damage with focal necrosis. The tomographic findings are characterized as ground glass opacities, smooth septal and marked peribronchovascular thickening; and may mimic pulmonary congestion, lymphangitis, atypical pneumonia and pneumocystosis. This is the largest series of CT findings of acute toxoplasmosis in immunocompetent hosts, and the diagnosis should be considered as patients that present with acute respiratory failure in the context of a subacute febrile illness with bilateral and diffuse interstitial infiltrates with marked peribronchovascular thickening. If promptly treated, pulmonary toxoplasmosis can result in complete clinical and radiological recovery in immunocompetent hosts.

Pulmonary Toxoplasmosis Diagnosed on Transbronchial Lung Biopsy in a Mechanically Ventilated Patient

“…It can also affect other organ systems such as liver, pancreas, bone marrow, lymph nodes, kidney, spleen, and skin. Respiratory manifestations of acute toxoplasmosis are usually described in transplant recipients and patients with HIV infection [10,14,15]. Pulmonary toxoplasmosis accounted for 4% of all cases of pneumonia in the HIVinfected patients in the pre-highly active antiretroviral therapy (HAART) era and is uncommon in the HAART era [9,10].…”

“…Pulmonary toxoplasmosis commonly presents as a subacute febrile illness with cough and dyspnea [10,16]. Radiographic abnormalities predominantly comprise two patterns: bilateral, diffuse, fine to medium reticulonodular opacities, such as those seen in PJP, and a bilateral, predominantly coarse, nodular pattern more commonly seen in tuberculosis, histoplasmosis, and coccidioidomycosis [15][16][17]. Given the nonspecific nature of symptoms and radiological tests, and the significant overlap with other etiologies, the diagnosis of pulmonary toxoplasmosis can be challenging.…”

A rare case of pulmonary toxoplasmosis in a patient with undifferentiated inflammatory arthritis on chronic methotrexate and corticosteroid therapy

“…Acute presentations of pulmonary toxoplasmosis may mimic a viral upper respiratory tract infection 9. CT findings of ground-glass opacities and peribronchovascular thickening may mimic other pulmonary conditions of atypical pneumonia, pneumocytosis and methotrexate lung disease 10. Thus, patients with pulmonary toxoplasmosis may escape detection or are misdiagnosed, delaying proper antiparasitic treatment and leading to significant morbidity and mortality.…”

“…Samples from BAL should be cultured, undergo GMS staining and undergo PCR amplification for Toxoplasma 16. Chest radiographs are variable and may demonstrate reticulonodular infiltrates, nodular opacities and/or coalescence opacities 10. CT findings may include diffuse interstitial infiltrates and ground-glass opacities with thickening of the interlobular septa that may be comparable to Pneumocystis jirovecii pneumonia 10…”

Toxoplasma gondii Pneumonia in an Immunocompetent Individual

“…Two cases of such patients have been reported. 3 , 4 The patient had not come into contact with any cats, dogs, pigs or other mammals, was not on immunosuppressants, had no history of immunosuppressive diseases and her living environment was healthy; although she was diagnosed with T gondii infection, the mechanism of which requires further study. The clinical manifestations of the toxoplasmosis complex, often due to injury of different organs, are varied.…”