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Size Matters: Measurement of Capsule Diameter in Cryptococcus neoformans
Published on: February 27, 2018
Geographic distribution of patients affected by Cryptococcus neoformans/Cryptococcus gattii species complexes
Tallulah Spina-Tensini1, Marisol Dominguez Muro2, Flávio Queiroz-Telles3
1Department of Neurology, Clinical Hospital of Universidade Federal do Paraná, Curitiba, Brazil.
Abstract:
Cryptococcal meningitis is mainly caused by members of the C. neoformans/C. gattii species complexes. The ecological niches of Cryptococcus species have extensively been studied, but its epidemiological relationship with meningitis cases is still unknown. In this study, we estimate the relationship between cryptococcal meningitis cases and tree and pigeon populations, the classical niches of members of C. neoformans/C. gattii sensu lato. We analysed the records of every patient whose cerebrospinal fluid culture yielded Cryptococcus spp. during the last 30 years at Clinical Hospital of Curitiba. Data about Curitiba's pigeon and tree distribution were obtained from Curitiba's Secretaries of Zoonosis and Environment archives. We used ArcGis9 software to plot the distribution of the pigeon and tree populations in this city as well as cryptococcal meningitis cases, distinguishing them according to the causal agent in C. neoformans or C. gattii s.l. In total, 489 cryptococcal cultures were documented, with 140 corresponding to patients eligible for this study (134 affected by C. neoformans s.l. and 6 by C. gattii s.l.). The map showed a relationship between C. neoformans s.l. patients and pigeon population. C. gattii s.l. patients were associated with neither tree nor pigeon populations, but lived close to large unbuilt, unforested areas.
Insights
Cryptococcal meningitis cases caused by Cryptococcus neoformans correlate with pigeon populations in Curitiba. Cryptococcus gattii cases were linked to unbuilt, unforested urban areas, not traditional ecological niches.
Area of Science:
- Environmental microbiology
- Medical mycology
- Epidemiology
Background:
- Cryptococcal meningitis is a serious fungal infection primarily caused by Cryptococcus neoformans and Cryptococcus gattii.
- While the ecological niches of these fungi are known, their direct epidemiological links to human meningitis cases remain unclear.
- Understanding these relationships is crucial for public health interventions and disease prevention strategies.
Purpose of the Study:
- To investigate the epidemiological association between cryptococcal meningitis cases and the distribution of known ecological niches (trees and pigeons) in Curitiba.
- To differentiate the spatial relationships of Cryptococcus neoformans and Cryptococcus gattii meningitis cases with environmental factors.
Main Methods:
- Analysis of 30-year cerebrospinal fluid culture records for Cryptococcus species at the Clinical Hospital of Curitiba.
- Acquisition of pigeon and tree distribution data for Curitiba from municipal archives.
- Geospatial analysis using ArcGis9 software to map fungal isolates, patient locations, and environmental data.
Main Results:
- A total of 140 eligible cryptococcal meningitis cases were identified (134 C. neoformans s.l., 6 C. gattii s.l.).
- Geospatial mapping revealed a significant correlation between Cryptococcus neoformans meningitis cases and pigeon population distribution.
- Cryptococcus gattii meningitis cases showed no association with tree or pigeon populations but were located near large unbuilt, unforested areas.
Conclusions:
- Pigeon populations may serve as a relevant environmental indicator for Cryptococcus neoformans meningitis risk in urban settings.
- Cryptococcus gattii meningitis epidemiology in this urban area is not linked to classical tree or pigeon niches, suggesting different environmental drivers.
- Further research into the specific environmental factors and urban habitats associated with Cryptococcus gattii is warranted.
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