Bat rabies surveillance and risk factors for rabies spillover in an urban area of Southern Brazil.

BACKGROUND: Bat rabies surveillance data and risk factors for rabies spillover without human cases have been evaluated in Curitiba, the ninth biggest city in Brazil, during a 6-year period (2010-2015). A retrospective analysis of bat complaints, bat species identification and rabies testing of bats, dogs and cats has been performed using methodologies of seasonal decomposition, spatial distribution and kernel density analysis. RESULTS: Overall, a total of 1003 requests for bat removal have been attended to, and 806 bats were collected in 606 city locations. Bat species were identified among 13 genera of three families, with a higher frequency of Nyctinomops in the central-northern region and Molossidae scattered throughout city limits. Out of the bats captured alive, 419/806 (52.0%) healthy bats were released due to absence of human or animal contacts. The remaining 387/806 (48.0%) bats were sent for euthanasia and rabies testing, which resulted in 9/387 (2.32%) positives. Linear regression has shown an increase on sample numbers tested over time (regression: y = 2.02 + 0.17×; p < 0.001 and r2 = 0.29), as well as significant seasonal variation, which increases in January and decreases in May, June and July. The Kernel density analysis showed the center-northern city area to be statistically important, and the southern region had no tested samples within the period. In addition, a total of 4769 random and suspicious samples were sent for rabies diagnosis including those from dogs, cats, bats and others from 2007 to 2015. While all 2676 dog brains tested negative, only 1/1136 (0.088%) cat brains tested positive for rabies. CONCLUSION: Only non-hematophagous bats were collected during the study, and the highest frequency of collections occurred in the center-northern region of the city. Rabies spillover from bats to cats may be more likely due to the registered exposure associated with cats' innate hunting habits, predisposing them to even closer contact with potentially infected bats. Although associated with a very low frequency of rabies, cats should always be included in rabies surveillance and vaccination programs.

Geographic distribution of patients affected by Cryptococcus neoformans/Cryptococcus gattii species complexes meningitis, pigeon and tree populations in Southern Brazil.

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.