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Lacerda M.V.,Fundacao de Medicina Tropical Dr. Heitor Vieira Dourado | Lacerda M.V.,University of the State of Amazonas | Lacerda M.V.,University Nilton Lins | Mourao M.P.,Fundacao de Medicina Tropical Dr. Heitor Vieira Dourado | And 23 more authors.
Malaria Journal | Year: 2012

The resurgence of the malaria eradication agenda and the increasing number of severe manifestation reports has contributed to a renewed interested in the Plasmodium vivax infection. It is the most geographically widespread parasite causing human malaria, with around 2.85 billion people living under risk of infection. The Brazilian Amazon region reports more than 50% of the malaria cases in Latin America and since 1990 there is a marked predominance of this species, responsible for 85% of cases in 2009. However, only a few complicated cases of P. vivax have been reported from this region. A systematic review of the Brazilian indexed and non-indexed literature on complicated cases of vivax malaria was performed including published articles, masters' dissertations, doctoral theses and national congresses' abstracts. The following information was retrieved: patient characteristics (demographic, presence of co-morbidities and, whenever possible, associated genetic disorders); description of each major clinical manifestation. As a result, 27 articles, 28 abstracts from scientific events' annals and 13 theses/dissertations were found, only after 1987. Most of the reported information was described in small case series and case reports of patients from all the Amazonian states, and also in travellers from Brazilian non-endemic areas. The more relevant clinical complications were anaemia, thrombocytopaenia, jaundice and acute respiratory distress syndrome, present in all age groups, in addition to other more rare clinical pictures. Complications in pregnant women were also reported. Acute and chronic co-morbidities were frequent, however death was occasional. Clinical atypical cases of malaria are more frequent than published in the indexed literature, probably due to a publication bias. In the Brazilian Amazon (considered to be a low to moderate intensity area of transmission), clinical data are in accordance with the recent findings of severity described in diverse P. vivax endemic areas (especially anaemia in Southeast Asia), however in this region both children and adults are affected. Finally, gaps of knowledge and areas for future research are opportunely pointed out. © 2011 Lacerda et al; licensee BioMed Central Ltd.

Fratus A.S.B.,University of Sao Paulo | Cabral F.J.,University of Sao Paulo | Fotoran W.L.,University of Sao Paulo | Medeiros M.M.,University of Sao Paulo | And 6 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2014

In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infections; this presents an intriguing and underexplored area of research. In addition to the rapid access of infected persons to effective treatment, one cause of this phenomenon might be the recognition of cytoadherent variant proteins on the infected red blood cell (IRBC) surface, including the var gene encoded P. falciparum erythrocyte membrane protein 1. In order to establish a link between cytoadherence, IRBC surface antibody recognition and the presence or absence of malaria symptoms, we phenotype-selected four Amazonian P. falciparum isolates and the laboratory strain 3D7 for their cytoadherence to CD36 and ICAM1 expressed on CHO cells. We then mapped the dominantly expressed var transcripts and tested whether antibodies from symptomatic or asymptomatic infections showed a differential recognition of the IRBC surface. As controls, the 3D7 lineages expressing severe disease-associated phenotypes were used. We showed that there was no profound difference between the frequency and intensity of antibody recognition of the IRBC-exposed P. falciparum proteins in symptomatic vs. asymptomatic infections. The 3D7 lineages, which expressed severe malaria-associated phenotypes, were strongly recognised by most, but not all plasmas, meaning that the recognition of these phenotypes is frequent in asymptomatic carriers, but is not necessarily a prerequisite to staying free of symptoms.

da Costa A.G.,Federal University of Amazonas | dos Santos J.D.,Federal University of Amazonas | de Conceicao J.K.T.,Federal University of Amazonas | Alecrim P.H.,Federal University of Amazonas | And 3 more authors.
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2011

Introduction: Dengue is one of the most prevalent infectious diseases in Brazil and is a major public health problem worldwide. It is most prevalent in tropical and subtropical regions with 2.5 to 3 billion people at risk of becoming infected. Thus, this study sought to demonstrate the epidemiological characteristics of individuals affected by dengue, its prevalence and its epidemic process in the Middle Solimões region of Coari in the state of Amazonas between 2008 and 2009. Methods: Epidemiological data were obtained through epidemiological monitoring by the Municipal Health Facility of the city of Coari, AM. The variables analyzed were the month of notification, the number of confirmed cases, the cases' genders, the cases' ages and their neighborhoods of residence. Results: In total, 1,003 cases were reported (635 in 2008 and 368 in 2009), and 639 cases were diagnosed as positive. Of these, ±54% involved female subjects, and ±46% were male. The majority of the affected individuals were between 10 and 49 years of age, and the spatial distribution was concentrated in neighborhoods near streams, lakes and areas in which housing had recently been disrupted. Conclusions: We concluded that, during the period studied, there was an outbreak of dengue in the city of Coari, AM. However, it is possible that a dengue epidemic may have occurred earlier in Coari without proper diagnosis or follow-up and that previously infected individuals may have traveled to the capital of Amazonas (Manaus), where the virus has circulated since 1998.

Katsuragawa T.H.,Institute Pesquisas em Patologias Tropicais | Gil L.H.S.,Institute Pesquisas em Patologias Tropicais | Silva A.D.A.,Institute Pesquisas em Patologias Tropicais | Silva A.D.A.,Federal University of Rondonia | And 4 more authors.
PLoS ONE | Year: 2010

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. © 2010 Katsuragawa et al.

de Farias J.D.,Institute Pesquisas em Patologias Tropicais | de Farias J.D.,Federal University of Rondonia | Santos M.G.,Institute Pesquisas em Patologias Tropicais | Santos M.G.,Federal University of Rondonia | And 5 more authors.
Genetics and Molecular Biology | Year: 2012

Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants. We analyzed the frequency of the CCR5Δ32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in five sample sets from the population. Four were collected in Porto Velho, the state capital and the site of several waves of migration. Of these, two, from the Hospital de Base were comprised of HB Mothers and HB Newborns presenting allele frequencies of 3.5% and 3.1%, respectively, a third from the peri-urban neighborhoods of Candelária/Bate-Estaca (1.8%), whereas a fourth, from the Research Center on Tropical Medicine/CEPEM (0.6%), was composed of malaria patients under treament. The fifth sample (3.4%) came from the inland Quilombola village of Pedras Negras. Two homozygous individuals (CCR5Δ32/CCR5Δ32) were detected among the HB Mother samples. The frequency of this allele was heterogeneous and higher where the European inflow was more pronounced. The presence of the allele in Pedras Negras revealed European miscegenation in a community largely comprising Quilombolas. © 2012, Sociedade Brasileira de Genética.

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