The Dynamics of Transmission and Spatial Distribution of Malaria in Riverside Areas of Porto Velho, Rondônia, in the Amazon Region of Brazil

The study area in Rondônia was the site of extensive malaria epidemic outbreaks in the 19th and 20th centuries related to environmental impacts, with large immigration flows. The present work analyzes the transmission dynamics of malaria in these areas to propose measures for avoiding epidemic outbreaks due to the construction of two Hydroelectric Power Plants. A population based baseline demographic census and a malaria prevalence follow up were performed in two river side localities in the suburbs of Porto Velho city and in its rural vicinity. The quantification and nature of malaria parasites in clinical patients and asymptomatic parasite carriers were performed using microscopic and Real Time PCR methodologies. Anopheles densities and their seasonal variation were done by monthly captures for defining HBR (hourly biting rate) values. Main results: (i) malaria among residents show the riverside profile, with population at risk represented by children and young adults; (ii) asymptomatic vivax and falciparum malaria parasite carriers correspond to around 15% of adults living in the area; (iii) vivax malaria relapses were responsible for 30% of clinical cases; (iv) malaria risk for the residents was evaluated as 20–25% for vivax and 5–7% for falciparum malaria; (v) anopheline densities shown outdoors HBR values 5 to 10 fold higher than indoors and reach 10.000 bites/person/year; (vi) very high incidence observed in one of the surveyed localities was explained by a micro epidemic outbreak affecting visitors and temporary residents. Temporary residents living in tents or shacks are accessible to outdoors transmission. Seasonal fishermen were the main group at risk in the study and were responsible for a 2.6 fold increase in the malaria incidence in the locality. This situation illustrates the danger of extensive epidemic outbreaks when thousands of workers and secondary immigrant population will arrive attracted by opportunities opened by the Hydroelectric Power Plants constructions

Geographical distribution of American cutaneous leishmaniasis and its phlebotomine vectors (Diptera: Psychodidae) in the state of São Paulo, Brazil

<p>Abstract</p> <p>Background</p> <p>American cutaneous leishmaniasis (ACL) is a re-emerging disease in the state of São Paulo, Brazil. It is important to understand both the vector and disease distribution to help design control strategies. As an initial step in applying geographic information systems (GIS) and remote sensing (RS) tools to map disease-risk, the objectives of the present work were to: (i) produce a single database of species distributions of the sand fly vectors in the state of São Paulo, (ii) create combined distributional maps of both the incidence of ACL and its sand fly vectors, and (iii) thereby provide individual municipalities with a source of reference material for work carried out in their area.</p> <p>Results</p> <p>A database containing 910 individual records of sand fly occurrence in the state of São Paulo, from 37 different sources, was compiled. These records date from between 1943 to 2009, and describe the presence of at least one of the six incriminated or suspected sand fly vector species in 183/645 (28.4%) municipalities. For the remaining 462 (71.6%) municipalities, we were unable to locate records of any of the six incriminated or suspected sand fly vector species (<it>Nyssomyia intermedia</it>, <it>N. neivai</it>, <it>N. whitmani</it>, <it>Pintomyia fischeri</it>, <it>P. pessoai </it>and <it>Migonemyia migonei</it>). The distribution of each of the six incriminated or suspected vector species of ACL in the state of São Paulo were individually mapped and overlaid on the incidence of ACL for the period 1993 to 1995 and 1998 to 2007. Overall, the maps reveal that the six sand fly vector species analyzed have unique and heterogeneous, although often overlapping, distributions. Several sand fly species - <it>Nyssomyia intermedia </it>and <it>N. neivai </it>- are highly localized, while the other sand fly species - <it>N. whitmani, M. migonei, P. fischeri </it>and <it>P. pessoai </it>- are much more broadly distributed. ACL has been reported in 160/183 (87.4%) of the municipalities with records for at least one of the six incriminated or suspected sand fly vector species, while there are no records of any of these sand fly species in 318/478 (66.5%) municipalities with ACL.</p> <p>Conclusions</p> <p>The maps produced in this work provide basic data on the distribution of the six incriminated or suspected sand fly vectors of ACL in the state of São Paulo, and highlight the complex and geographically heterogeneous pattern of ACL transmission in the region. Further studies are required to clarify the role of each of the six suspected sand fly vector species in different regions of the state of São Paulo, especially in the majority of municipalities where ACL is present but sand fly vectors have not yet been identified.</p

SEASONAL DISTRIBUTION OF MALARIA VECTORS (DIPTERA: CULICIDAE) IN RURAL LOCALITIES OF PORTO VELHO, RONDÔNIA, BRAZILIAN AMAZON

We conducted a survey of the malaria vectors in an area where a power line had been constructed, between the municipalities of Porto Velho and Rio Branco, in the states of Rondônia and Acre, respectively. The present paper relates to the results of the survey of Anopheles fauna conducted in the state of Rondônia. Mosquito field collections were performed in six villages along the federal highway BR 364 in the municipality of Porto Velho, namely Porto Velho, Jaci Paraná, Mutum Paraná, Vila Abunã, Vista Alegre do Abunã, and Extrema. Mosquito captures were performed at three distinct sites in each locality during the months of February, July, and October 2011 using a protected human-landing catch method; outdoor and indoor captures were conducted simultaneously at each site for six hours. In the six sampled areas, we captured 2,185 mosquitoes belonging to seven Anopheles species. Of these specimens, 95.1% consisted of Anopheles darlingi, 1.8% An. triannulatus l.s., 1.7% An. deaneorum, 0.8% An. konderi l.s., 0.4 An. braziliensis, 0.1% An. albitarsis l.s., and 0.1% An. benarrochi. An. darlingi was the only species found in all localities; the remaining species occurred in sites with specific characteristics

Preoperative radiographic and histopathologic evaluation of central chondrosarcoma

BACKGROUND: Distinguishing grade 1 chondrosarcoma from grade 2 chondrosarcoma is critical both for planning the surgical procedure and for predicting the outcome. We aimed to review the preoperative radiographic and histologic findings, and to evaluate the reliability of preoperative grading. METHODS: We retrospectively reviewed the medical records of 17 patients diagnosed with central chondrosarcoma at our institution between 1996 and 2011. In these cases, we compared the preoperative and postoperative histologic grades, and evaluated the reliability of the preoperative histologic grading. We also assessed the preoperative radiographic findings obtained using plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI). RESULTS: Preoperative histologic grade was 1 in 12 patients, 2 in 4 patients, and 3 in 1 patient. However, 6 of the 12 cases classified as grade 1 before surgery were re-classified as grade 2 postoperatively. In the radiographic evaluation, grade 1 was suspected by the presence of a ring-and-arc pattern of calcification on plain radiography and CT and entrapped fat and ring-and-arc enhancement on MRI. Grades 2 and 3 were suspected by the absence of calcification and the presence of cortical penetration and endosteal scalloping on plain radiography and CT, as well as soft-tissue mass formation on MRI. CONCLUSION: Although the combination of radiographic interpretation and histologic findings may improve the accuracy of preoperative grading in chondrosarcoma, the establishment of a standard evaluation system with the histologic and radiographic findings and/or the development of new biologic markers are necessary for preoperative discrimination of low-grade chondrosarcoma from high-grade chondrosarcoma