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Rio de Janeiro, Brazil

de Araujo A.P.O.,Instituto Oswaldo Cruz Fiocruz | Telleria E.L.,Instituto Oswaldo Cruz Fiocruz | Dutra J.M.F.,Instituto Oswaldo Cruz Fiocruz | Dutra J.M.F.,Laboratorio Of Paleoparasitologia | And 2 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2012

Lutzomyia longipalpis is the most important vector of visceral leishmaniasis in Brazil. When female sandflies feed on blood, a peritrophic matrix (PM) is formed around the blood bolus. The PM is secreted by midgut cells and composed of proteins, glycoproteins and chitin microfibrils. The PM functions as both a physical barrier against pathogens present in the food bolus and blood meal digestion regulator. Previous studies of mosquitoes and sandflies have shown that the absence of a PM, resulting from adding an exogenous chitinase to the blood meal, accelerates digestion. In the present study, we analysed biological factors associated with the presence of a PM in L. longipalpis females. Insects fed blood containing chitinase (BCC) accelerated egg-laying relative to a control group fed blood without chitinase. However, in the BCC-fed insects, the number of females that died without laying eggs was higher and the number of eggs laid per female was lower. The eggs in both groups were viable and generated adults. Based on these data, we suggest that the absence of a PM accelerates nutrient acquisition, which results in premature egg production and oviposition; however, the absence of a PM reduces the total number of eggs laid per female. Reduced fecundity in the absence of a PM may be due to inefficient nutrient conversion or the loss of the protective role of the PM. Source


Valverde J.G.,Instituto Oswaldo Cruz | Gomes-Silva A.,Instituto Oswaldo Cruz | de Carvalho C.J.M.,Instituto Oswaldo Cruz | de Souza D.L.,Federal University of Fluminense | And 6 more authors.
Annals of Tropical Medicine and Parasitology | Year: 2011

This survey aims to estimate the prevalence of intestinal parasitic infections in Santa Isabel do Rio Negro, Amazonian Brazil, through three distinct techniques, correlating the prevalence rates with family income and age groups as well as assessing the household clustering of infections. Prevalence rates were assessed through Graham (n=113), Baermann-Moraes (n=232) and Ritchie (n=463) methods. The Graham method was adopted only for children under 5 years old, 15% of whom were positive for Enterobius vermicularis. By the Baermann-Moraes technique, 5.6% of the samples were positive for Strongyloides stercoralis larvae. The Ritchie technique disclosed the following results: Ascaris lumbricoides (26%), Trichuris trichiura (22.5%), hookworms (9.5%), Entamoeba histolytica/ Entamoeba dispar (25.3%), Giardia lamblia (12.5%) and E. vermicularis (0.6%). Children aged 5-14 years presented the highest prevalence for pathogenic parasites. Giardiasis and hookworm infection rates were inversely related to family income. The presence of positive contacts in the same household substantially increased the risk of infection by enteric parasites: odds ratio (OR)=2.70, 95% confidence interval (CI)=1.69-4.29 for ascariasis; OR=2.17, 95% CI=1.34-3.51 for trichuriasis; OR=2.13, 95% CI=1.08-4.17 for hookworm disease; OR=3.42, 95% CI=1.86-6.30 for giardiasis; and OR=2.16, 95% CI=1.35-3.47 for amoebiasis, supporting infection clustering in the home. Intestinal parasitoses are extremely frequent in the studied area, and routine methods for diagnosis may underestimate the prevalence of enterobiasis and strongyloidiasis. © W. S. Maney & Son Ltd 2011. Source


Bianucci R.,University of Turin | Bianucci R.,University of Oslo | Bianucci R.,Laboratoire dAnthropologie Bio culturelle | Araujo A.,Laboratorio Of Paleoparasitologia | And 2 more authors.
Acta Tropica | Year: 2015

The comprehensive analyses of human remains from various places and time periods, either by immunological or molecular approaches, provide circumstantial evidence that malaria tropica haunted humankind at least since dynastic ancient Egypt. Here we summarize the "actual state-of-the-art" of these bio-molecular investigations and offer a solid basis for the discussion of the paleopathology of malaria in human history. © 2015 Elsevier B.V. Source


Camacho M.,Laboratorio Of Paleoparasitologia | Pessanha T.,Laboratorio Of Paleoparasitologia | Leles D.,Federal University of Fluminense | Dutra J.M.F.,Laboratorio Of Paleoparasitologia | And 3 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2013

Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz's spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis. Source


Bianucci R.,University of Turin | Bianucci R.,University of Oslo | Bianucci R.,Laboratoire dAnthropologie Bio culturelle | Lopes Torres E.J.,State University of Rio de Janeiro | And 12 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2015

Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition. © 2015, Fundacao Oswaldo Cruz. All rights reserved. Source

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