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Caracas, Venezuela

Diaz-Bello Z.,Central University of Venezuela | Thomas M.C.,Institute Parasitologia y Biomedicina Lopez Neyra | Lopez M.C.,Institute Parasitologia y Biomedicina Lopez Neyra | Zavala-Jaspe R.,Central University of Venezuela | And 3 more authors.
Epidemiology and Infection | Year: 2014

SUMMARY Trypanosoma cruzi I, a discrete typing unit (DTU) found in human infections in Venezuela and other countries of the northern region of South America and in Central America, has been recently classified into five intra-DTU genotypes (Ia, Ib, Ic, Id, Ie) based on sequence polymorphisms found in the spliced leader intergenic region. In this paper we report the genotype identification of T. cruzi human isolates from one outbreak of acute orally acquired Chagas disease that occurred in a non-endemic region of Venezuela and from T. cruzi triatomine and rat isolates captured at a guava juice preparation site which was identified as the presumptive source of infection. The genotyping of all these isolates as TcId supports the view of a common source of infection in this oral Chagas disease outbreak through the ingestion of guava juice. Implications for clinical manifestations and dynamics of transmission cycles are discussed. © Cambridge University Press 2013.

Lorenz C.,Instituto Butantan | Lorenz C.,University of Sao Paulo | Virginio F.,Instituto Butantan | Virginio F.,University of Sao Paulo | And 5 more authors.
Malaria Journal | Year: 2015

Background: Mosquitoes, Plasmodium parasites, and humans live in sympatry in some extra-Amazonian regions of Brazil. Recent migrations of people from Amazonia and other countries to extra-Amazonian regions have led to many malaria outbreaks. Lack of relevant expertise among health professionals in non-endemic areas can lead to a neglect of the disease, which can be dangerous given its high fatality rate. Therefore, understanding the spatial and temporal epidemiology of malaria is essential for developing strategies for disease control and elimination. This study aimed to characterize imported (IMP) and autochthonous/introduced (AU/IN) cases in the extra-Amazonian regions and identify risk areas and groups. Methods: Epidemiological data collected between 2007 and 2014 were obtained from the Notifiable Diseases Information System of the Ministry of Health (SINAN) and from the Department of the Unified Health System (DATASUS). High malaria risk areas were determined using the Local Indicator of Spatial Association. IMP and AU/IN malaria incidence rates were corrected by Local Empirical Bayesian rates. Results: A total of 6092 malaria cases (IMP: 5416, 88.9 %; AU/IN: 676, 11.1 %) was recorded in the extra-Amazonian regions in 2007-2014. The highest numbers of IMP and AU/IN cases were registered in 2007 (n = 862) and 2010 (n = 149), respectively. IMP cases were more frequent than AU/IN cases in all states except for Espírito Santo. Piauí, Espírito Santo, and Paraná states had high incidences of AU/IN malaria. The majority of infections were by Plasmodium falciparum in northeast and southeast regions, while Plasmodium vivax was the predominant species in the south and mid-west showed cases of dual infection. AU/IN malaria cases were concentrated in the coastal region of Brazil, which contains the Atlantic Forest and hosts the Anopheles transmitters. Several malaria clusters were also associated with the Brazilian Pantanal biome and regions bordering the Amazonian biome. Conclusion: Malaria is widespread outside the Amazonian region of Brazil, including in more urbanized and industrialized states. This fact is concerning because these highly populated areas retain favourable conditions for spreading of the parasites and vectors. Control measures for both IMP and AU/IN malaria are essential in these high-risk areas. © 2015 Lorenz et al.

Guzman M.G.,Institute Medicina Tropical
Nature reviews. Microbiology | Year: 2010

Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ∼50 million dengue infections and ∼500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future.

Lorenz C.,Instituto Butantan | Lorenz C.,University of Sao Paulo | Marques T.C.,University of Sao Paulo | Sallum M.A.M.,University of Sao Paulo | And 2 more authors.
Parasites and Vectors | Year: 2014

Background: In Brazil, the autochthonous transmission of extra-Amazonian malaria occurs mainly in areas of the southeastern coastal Atlantic Forest, where Anopheles cruzii is the primary vector. In these locations, the population density of the mosquito varies with altitude (5.263 m above sea level), prompting us to hypothesise that gene flow is also unevenly distributed. Describing the micro-geographical and temporal biological variability of this species may be a key to understanding the dispersion of malaria in the region. We explored the homogeneity of the An. cruzii population across its altitudinal range of distribution using wing shape and mtDNA gene analysis. We also assessed the stability of wing geometry over time. Methods: Larvae were sampled from lowland (5.20 m) and hilltop (81.263 m) areas in a primary Atlantic Forest region, in the municipality of Cananeia (State of Sao Paulo, Brazil). The right wings of males and females were analysed by standard geometric morphometrics. Eighteen landmarks were digitised for each individual and a discriminant analysis was used to compare samples from the hilltop and lowland. A 400-bp DNA fragment of the mitochondrial cytochrome oxidase gene subunit I (CO-I) was PCR-amplified and sequenced. Results: Wing shapes were distinct between lowland and hilltop population samples. Results of cross-validated tests based on Mahalanobis distances showed that the individuals from both micro-environments were correctly reclassified in a range of 54.96%. The wings of hilltop individuals were larger. The CO-I gene was highly polymorphic (haplotypic diversity = 0.98) and altitudinally structured (ΦUst = 0.085 and Jaccard = 0.033). We found 60 different haplotypes but only two were shared by the lowland and hilltop populations. Wing shape changed over the brief study period (2009.2013). Conclusions: Wing geometry and CO-I gene analysis indicated that An. cruzii is vertically structured. Wing shape varied rapidly, but altitude structure was maintained. Future investigations should identify the biotic/abiotic causes of these patterns and their implications in the local epidemiology of malaria. © 2014 Lorenz et al.; licensee BioMed Central.

Horstick O.,University of Heidelberg | Jaenisch T.,University of Heidelberg | Martinez E.,Institute Medicina Tropical | Kroeger A.,Community Medicine | And 4 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2014

The 1997 and 2009 WHO dengue case classifications were compared in a systematic review with 12 eligible studies (4 prospective). Ten expert opinion articles were used for discussion. For the 2009 WHO classification studies show: when determining severe dengue sensitivity ranges between 59-98% (88%/98%: prospective studies), specificity between 41-99% (99%: prospective study) - comparing the 1997 WHO classification: sensitivity 24.8-89.9% (24.8%/74%: prospective studies), specificity: 25%/100% (100%: prospective study). The application of the 2009 WHO classification is easy, however for (non-severe) dengue there may be a risk of monitoring increased case numbers. Warning signs validation studies are needed. For epidemiological/pathogenesis research use of the 2009 WHO classification, opinion papers show that ease of application, increased sensitivity (severe dengue) and international comparability are advantageous; 3 severe dengue criteria (severe plasma leakage, severe bleeding, severe organ manifestation) are useful research endpoints. The 2009 WHO classification has clear advantages for clinical use, use in epidemiology is promising and research use may at least not be a disadvantage. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.

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