BackgroundMalaria and dengue are the most prevalent vector-borne diseases worldwide and represent major public health problems. Both are endemic in tropical regions, propitiating co-infection. Only few co-infection cases have been reported around the world, with insufficient data so far to enhance the understanding of the effects of co-infection in the clinical presentation and severity.Methodology/Principal FindingsA cross-sectional study was conducted (2009 to 2011) in hospitalized patients with acute febrile syndrome in the Brazilian Amazon. All patients were submitted to thick blood smear and PCR for Plasmodium sp. detection, ELISA, PCR and NS1 tests for dengue, viral hepatitis, HIV and leptospirosis. In total, 1,578 patients were recruited. Among them, 176 (11.1%) presented P. vivax malaria mono-infection, 584 (37%) dengue fever mono-infection, and 44 (2.8%) were co-infected. Co-infected patients had a higher chance of presenting severe disease (vs. dengue mono-infected), deep bleeding (vs. P. vivax mono-infected), hepatomegaly, and jaundice (vs. dengue mono-infected).Conclusions/SignificanceIn endemic areas for dengue and malaria, jaundice (in dengue patients) and spontaneous bleeding (in malaria patients) should raise the suspicion of co-infection. Besides, whenever co-infection is confirmed, we recommend careful monitoring for bleeding and hepatic complications, which may result in a higher chance of severity, despite of the fact that no increased fatality rate was seen in this group.

Background TcSMUG L products were recently identified as novel mucin-type glycoconjugates restricted to the surface of insect-dwelling epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas disease. The remarkable conservation of their predicted mature N-terminal region, which is exposed to the extracellular milieu, suggests that TcSMUG L products may be involved in structural and/or functional aspects of the interaction with the insect vector.Methodology and Principal FindingsHere, we investigated the putative roles of TcSMUG L mucins in both in vivo development and ex vivo attachment of epimastigotes to the luminal surface of the digestive tract of Rhodnius prolixus. Our results indicate that the exogenous addition of TcSMUG L N-terminal peptide, but not control T. cruzi mucin peptides, to the infected bloodmeal inhibited the development of parasites in R. prolixus in a dose-dependent manner. Pre-incubation of insect midguts with the TcSMUG L peptide impaired the ex vivo attachment of epimastigotes to the luminal surface epithelium, likely by competing out TcSMUG L binding sites on the luminal surface of the posterior midgut, as revealed by fluorescence microscopy.Conclusion and SignificanceTogether, these observations indicate that TcSMUG L mucins are a determinant of both adhesion of T. cruzi epimastigotes to the posterior midgut epithelial cells of the triatomine, and the infection of the insect vector, R. prolixus.

Introduction: Human T-lymphotropic virus (HTLV) 1 and 2 infections can lead to neurological diseases, mainly in HIV/HTLV 1 coinfected. Furthermore, HTLV 1 infection in HIV/AIDS patients has also been associated with AIDS progression. Despite this, HTLV 1/2 infections are not of mandatory notification in Brazil. Here, we describe the prevalence of HTLV 1/2 in HIV/AIDS patients from Paraíba state, Brazil, as well as the sociodemographic characteristics of the coinfected individuals. Methodology: Information about HIV viral load and TCD4 lymphocyte count were obtained from patients’ records. Data on the patients’ sociodemographic characteristics were obtained by interview conducted after signing the informed consent form. The serological diagnosis for HTLV 1/2 was performed by Enzyme-Linked Immunosorbent Assay (ELISA) and Western Blot (WB). Results: A total of 401 HIV/AIDS patients participated in the study, of whom about 1.5% (6/401) were positive for antibodies against HTLV, specifically for HTLV 1, evaluated by both ELISA and WB. No risk factors were found associated with HIV/HTLV 1/2 coinfection. Conclusions: We report a 1.5% prevalence of HTLV 1 infection in HIV/AIDS patients from Paraíba state. Although we have not identified risk factors associated with HTLV 1, we describe the most observed sociodemographic characteristics in HIV/HTLV 1 coinfection.