Pulmonary Toxoplasmosis: A Review

Abstract

Toxoplasma pneumonia is being recognized with increased frequency, especially in patients with AIDS. We reviewed the English-, French-, and Spanish-language literature from January 1966 through February 1991 to identify cases of postnatally acquired pneumonia associated with Toxoplasma gondii. We identified two distinct clinical syndromes, one in immunocompetent patients and one in patients with defects in cell-mediated immunity. Shortness of breath and cough were the most common symptoms and fever and rales the most common signs in both groups of patients. Lymphadenopathy and hepatosplenomegaly were reported more frequently for immunocompetent patients. Chest roentgenographs usually revealed bilateral interstitial infiltrates, but a variety of other roentgenographic findings were reported. Serological findings were suggestive of active toxoplasmosis in immunocompetent but not in immunosuppressed patients. In early reports, identification of T. gondii as the etiologic agent of pneumonia was based on serology or autopsy findings. In more recent reports, open lung biopsy and especially bronchoalveolar lavage were used for diagnosis. Mortality among patients with toxoplasma pneumonia was 55%. However, in cases of T. gondii pneumonia diagnosed during life, mortality was 0 for immunocompetent patients and 40% for immunosuppressed patients. In immunosuppressed patients, improvement was associated with specific antitoxoplasma drug therapy. Unfortunately, relapses were common. We also reviewed data on series of patients with disseminated toxoplasmosis manifested predominantly in extrapulmonary sites and found that 33% of these patients had evidence of subclinical pulmonary involvement even though pneumonia had not been diagnosed clinically.

Bioluminescence Imaging of Toxoplasma gondii Infection in Living Mice Reveals Dramatic Differences between Strains

“…When this mouse was imaged again on day 18, a signal was no longer detected in the peritoneal cavity, but there was a signal from the thorax, head, and what seemed to be the eyes. By dissection of a similar mouse in another experiment, the thorax signal was determined to be due to extensive infection of the lungs, as expected (18). The lung signal was not detected on day 25 p.i.…”

l-Tryptophan-l-Kynurenine Pathway Metabolism Accelerated byToxoplasmagondiiInfection Is Abolished in Gamma Interferon-Gene-Deficient Mice: Cross-Regulation between Inducible Nitric Oxide Synthase and Indoleamine-2,3-Dioxygenase

“…Toxoplasma gondii, an intracellular protozoan parasite, is a major pathogen of opportunistic infectious disease and causes severe encephalitis, pneumonia, and retinochoroiditis in infants, during pregnancy, and in immunocompromised hosts, such as patients with AIDS or patients treated with immunosuppressive drugs (25,32,43). Previous studies indicated that various cytokines have important roles in the regulation of T. gondii replication.…”

Pulmonary Toxoplasmosis, a Rare but Severe Manifestation of a Common Opportunistic Infection in Late HIV Presenters: Report of Two Cases

“…The most common finding on chest radiographs is bilateral diffuse interstitial infiltrates [8,14,16]. The clinical and radiological appearance may be indistinguishable from the far more common P. jiroveci pneumonia.…”

“…Mortality in immunosuppressed patients with pulmonary toxoplasmosis is high: in the French survey 37% of HIV-infected patients with toxoplasma pneumonia died [14] and in a metaanalysis mortality among immunosuppressed persons with pulmonary toxoplasmosis was 40% [16]. As toxoplasma pneumonitis is clinically difficult do diagnose and is associated with a considerable mortality, it is necessary to force the diagnosis by microbiological examination of respiratory samples.…”