Natural history of pulmonary coccidioidomycosis: Further examination of the VA-Armed Forces Database.

There are still many limitations related to the understanding of the natural history of differing forms of coccidioidomycosis (CM), including characterizing the spectrum of pulmonary disease. The historical Veterans Administration-Armed Forces database, recorded primarily before the advent of antifungal therapy, presents an opportunity to characterize the natural history of pulmonary CM. We performed a retrospective cohort study of 342 armed forces service members who were diagnosed with pulmonary CM at VA facilities between 1955 to 1958, followed through 1966, who did not receive antifungal therapy. Patients were grouped by predominant pulmonary finding on chest radiographs. The all-cause mortality was low for all patients (4.6%). Cavities had a median size of 3-3.9 cm (IQR: 2-2.9-4-4.9 cm), with heterogeneous wall thickness and no fluid level, while nodules had a median size of 1-1.19 cm (Interquartile range [IQR] 1-1.9-2-2.9 cm) and sharp borders. The majority of cavities were chronic (85.6%), and just under half were found incidentally. Median complement fixation titers in both the nodular and cavitary groups were negative, with higher titers in the cavitary group overall. This retrospective cohort study of non-disseminated coccidioidomycosis, the largest to date, sheds light on the natural history, serologic markers, and radiologic characteristics of this understudied disease. These findings have implications for the evaluation and management of CM.

Coccidioidomycosis (CM), also known as San Joaquin Valley Fever, causes a variety of symptoms including pneumonia. This historical study investigates CM of the lungs in American soldiers with CM in the 1950s, prior to modern antifungals, to better understand the natural history.

Natural History of Disseminated Coccidioidomycosis: Examination of the Veterans Affairs-Armed Forces Database.

BACKGROUND: The natural history of non-central nervous system (non-CNS) disseminated coccidioidomycosis (DCM) has not been previously characterized. The historical Veterans Affairs (VA)-Armed Forces coccidioidomycosis patient group provides a unique cohort of patients not treated with standard antifungal therapy, allowing for characterization of the natural history of coccidioidomycosis. METHODS: We conducted a retrospective study of 531 VA-Armed Forces coccidioidomycosis patients diagnosed between 1955-1958 and followed to 1966. Groups were identified as non-DCM (462 patients), DCM (44 patients), and CNS (25 patients). The duration of the initial infection, fate of the primary infection, all-cause mortality, and mortality secondary to coccidioidomycosis were assessed and compared between groups. RESULTS: Mortality due to coccidioidomycosis at the last known follow-up was significantly different across the groups: 0.65% in the non-DCM group, 25% in the DCM group, and 88% in the CNS group (P < .001). The primary fate of pulmonary infection demonstrated key differences, with pulmonary nodules observed in 39.61% of the non-DCM group, 13.64% of the DCM group, and 20% of the CNS group (P < .001). There were differences in cavity formation, with 34.20% in the non-DCM group, 9.09% in the DCM group, and 8% in the CNS group (P < .001). Dissemination was the presenting manifestation or was concurrent with the initial infection in 41% and 56% of patients in the non-CNS DCM and CNS groups, respectively. CONCLUSIONS: This large, retrospective cohort study helps characterize the natural history of DCM, provides insight into the host immunologic response, and has direct clinical implications for the management and follow-up of patients.

Legionella pneumophila Is Directly Sensitive to 2-Deoxyglucose-Phosphate via Its UhpC Transporter but Is Indifferent to Shifts in Host Cell Glycolytic Metabolism.

Toll-like receptor (TLR) stimulation induces a pronounced shift to increased glycolytic metabolism in mammalian macrophages. We observed that bone marrow-derived macrophages (BMMs) increase glycolysis in response to infection with Legionella pneumophila, but the role of host macrophage glycolysis in terms of intracellular L. pneumophila replication is not currently understood. Treatment with 2-deoxyglucose (2DG) blocks L. pneumophila replication in mammalian macrophages but has no effect on bacteria grown in broth. In addition, we found that 2DG had no effect on bacteria grown in amoebae. We used a serial enrichment strategy to reveal that the effect of 2DG on L. pneumophila in macrophages requires the L. pneumophila hexose-phosphate transporter UhpC. Experiments with UhpC-deficient L. pneumophila revealed that mutant bacteria are also resistant to growth inhibition following treatment with phosphorylated 2DG in broth, suggesting that the inhibitory effect of 2DG on L. pneumophila in mammalian cells requires 2DG phosphorylation. UhpC-deficient L. pneumophila replicates without a growth defect in BMMs and protozoan host cells and also replicates without a growth defect in BMMs treated with 2DG. Our data indicate that neither TLR signaling-dependent increased macrophage glycolysis nor inhibition of macrophage glycolysis has a substantial effect on intracellular L. pneumophila replication. These results are consistent with the view that L. pneumophila can employ diverse metabolic strategies to exploit its host cells.IMPORTANCE We explored the relationship between macrophage glycolysis and replication of an intracellular bacterial pathogen, Legionella pneumophila Previous studies demonstrated that a glycolysis inhibitor, 2-deoxyglucose (2DG), blocks replication of L. pneumophila during infection of macrophages, leading to speculation that L. pneumophila may exploit macrophage glycolysis. We isolated L. pneumophila mutants resistant to the inhibitory effect of 2DG in macrophages, identifying a L. pneumophila hexose-phosphate transporter, UhpC, that is required for bacterial sensitivity to 2DG during infection. Our results reveal how a bacterial transporter mediates the direct antimicrobial effect of a toxic metabolite. Moreover, our results indicate that neither induction nor impairment of host glycolysis inhibits intracellular replication of L. pneumophila, which is consistent with a view of L. pneumophila as a metabolic generalist.