Maria Elisa Siqueira Silva

Climate and acute/subacute paracoccidioidomycosis in a hyper-endemic area in Brazil

BACKGROUND Paracoccidioidomycosis (PCM) is Latin Americas most prevalent systemic mycosis, carrying an important social burden. Its agent, Paracoccidioides brasiliensis, has rarely been identified in nature. Studies characterizing acute/subacute PCM incidence and their relationship with climate variables are not available. This work analysed a series of acute/subacute cases that occurred in the Botucatu area, São Paulo State, Brazil, from 1969 to 1999, as an outcome of weather variability. METHODS Stepwise regression of annual data was applied to model incidence, calculated based on 91 cases, from lagged variables: antecedent precipitation, air temperature, soil water storage, absolute and relative air humidity, and Southern Oscillation Index (SOI). RESULTS Multiple regression analyses resulted in a model, which explains 49% of the incidence variance, taking into account the absolute air humidity in the year of exposure, soil water storage and SOI of the previous 2 years. CONCLUSIONS The correlations may reflect enhanced fungal growth after increase in soil water storage in the longer term and greater spore release with increase in absolute air humidity in the short term.

First description of a cluster of acute/subacute paracoccidioidomycosis cases and its association with a climatic anomaly.

Background Identifying clusters of acute paracoccidioidomycosis cases could potentially help in identifying the environmental factors that influence the incidence of this mycosis. However, unlike other endemic mycoses, there are no published reports of clusters of paracoccidioidomycosis. Methodology/Principal Findings A retrospective cluster detection test was applied to verify if an excess of acute form (AF) paracoccidioidomycosis cases in time and/or space occurred in Botucatu, an endemic area in São Paulo State. The scan-test SaTScan v7.0.3 was set to find clusters for the maximum temporal period of 1 year. The temporal test indicated a significant cluster in 1985 (P<0.005). This cluster comprised 10 cases, although 2.19 were expected for this year in this area. Age and clinical presentation of these cases were typical of AF paracccidioidomycosis. The space-time test confirmed the temporal cluster in 1985 and showed the localities where the risk was higher in that year. The cluster suggests that some particularities took place in the antecedent years in those localities. Analysis of climate variables showed that soil water storage was atypically high in 1982/83 (∼2.11/2.5 SD above mean), and the absolute air humidity in 1984, the year preceding the cluster, was much higher than normal (∼1.6 SD above mean), conditions that may have favored, respectively, antecedent fungal growth in the soil and conidia liberation in 1984, the probable year of exposure. These climatic anomalies in this area was due to the 1982/83 El Niño event, the strongest in the last 50 years. Conclusions/Significance We describe the first cluster of AF paracoccidioidomycosis, which was potentially linked to a climatic anomaly caused by the 1982/83 El Niño Southern Oscillation. This finding is important because it may help to clarify the conditions that favor Paracoccidioides brasiliensis survival and growth in the environment and that enhance human exposure, thus allowing the development of preventive measures.

VARIABILIDADE CLIMÁTICA – PROCESSOS FÍSICOS E DINÂMICOS NOS OCEANOS E ATMOSFERA

Climate presents significant importance on scientific studies due to its influence on life style and even on essential conditions to life. A presentation of climatic theories and the related physical and dynamical processes, underlying the inherent complexity to them, has motivated this revision. In this article, we put in evidence oceanic and climatic oscillation patterns that occur in association to the behavior of the atmosphere. We bring up the importance of heat sources over the Pacific Ocean that are responsible for different patterns (PNA), the South Pacific patterns (PSA), the North Atlantic (NAO) and the Antarctic Oscillation (SAM). The impact on air temperature and precipitation over South America due to the mentioned oscillations is also put in evidence.