77 research outputs found

    Searching for Digenic Inheritance in Deaf Brazilian Individuals Using the Multiplex Ligation-Dependent Probe Amplification Technique

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Mutations in the genes coding for connexin 26 (Cx26), connexin 30 (Cx30), and connexin 31 (Cx31) are the main cause of autosomal recessive nonsyndromic sensorineural hearing loss (AR-NSNHL). The 35delG mutation is the most frequent in the majority of Caucasian populations and may account for up to 70% of all GJB2 mutations. As a large number of affected individuals (10%-40%) with GJB2 mutations carry only one mutant allele, it has been postulated that the presence of additional mutations in the GJB6 gene (Cx30) explains the deafness condition found in these patients. In the present study, we screened the c. 35delG mutation in similar to 600 unrelated Brazilian patients, with moderate to profound AR-NSNHL. Other point mutations in the coding region of the GJB2 gene were screened by sequencing analysis as well as the IVS 1 + 1 G> A splice site mutation in the same gene. Digenic mutations including large deletions and duplications were investigated in the Cx26, 30, and 31 genes in monoallelic individuals for mutations in the GJB2 gene. Large deletions and duplications were assessed by multiplex ligation-dependent probe amplification. We found 46 patients with mutations in only one GJB2 allele. Different pathogenic mutations associated with c. 35delG were found in 13 patients. Two patients were identified with digenic heterozygous mutations. Our findings contributed to more accurate diagnosis and more appropriate genetic counseling in 28% of patients studied (13/46).1512849853Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Vulnerability of Brazilian municipalities to hantavirus infections based on multi‑criteria decision analysis

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    Background: Hantavirus infection is an emerging zoonosis transmitted by wild rodents. In Brazil, high case-fatality rates among humans infected with hantavirus are of serious concern to public health authorities. Appropriate preventive measures partly depend on reliable knowledge about the geographical distribution of this disease. Methods: Incidence of hantavirus infections in Brazil (1993–2013) was analyzed. Epidemiological, socioeconomic, and demographic indicators were also used to classify cities’ vulnerability to disease by means of multi-criteria decision analysis (MCDA). Results: From 1993 to 2013, 1752 cases of hantavirus were registered in 16 Brazilian states. The highest incidence of hantavirus was observed in the states of Mato Grosso (0.57/100,000) and Santa Catarina (0.13/100,000). Based on MCDA analysis, municipalities in the southern, southeastern, and midwestern regions of Brazil can be classified as highly vulnerable. Most municipalities in northern and northeastern Brazil were classified as having low vulnerability to hantavirus cardiopulmonary syndrome. Conclusions: Although most human infections by hantavirus registered in Brazil occurred in the southern region of the country, a greater vulnerability to hantavirus was found in the Brazilian Midwest. This result reflects the need to strengthen surveillance where the disease has thus far gone unreported

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

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    <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
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