From 2004 to 2006, 658 patients with suspected dengue virus infections were enrolled in a clinical dengue cohort established in Recife, Pernambuco, located at the northeastern region of Brazil. A total of 2,364 blood samples were collected, and serum, plasma, and cells were cryopreserved. Among the suspected cases, 354 (54%) were confirmed as acute DENV-3 infection based on reverse transcription-polymerase chain reaction, virus isolation, and ELISA-IgM. According to WHO criteria, 29.4% of the positive acute cases were classified as dengue fever (DF) and 8.2% of the cases as dengue hemorrhagic fever (DHF), grade 1 or 2. The DHF cases represent 100% of those confirmed in Recife during the period of the study. The dengue cases that did not fulfill the definition of either DHF or DF were classified as DF complicated and accounted for 44.0% of the cases. All the acute cases were classified as either primary or secondary acute dengue virus infections. Secondary infection was predominant in patients with DF; however, there was no predominance of either primary or secondary infections in patients with DHF.

Although other studies have associated many newborn outcomes to ZIKV infection during pregnancy, these same adverse outcomes were rare or nonexistent in this study. The clinical presentation the newborns we studied was mild compared to other reports, suggesting that there is significant heterogeneity in congenital Zika infection.

Background São José do Rio Preto is one of the cities of the state of São Paulo, Brazil, that is hyperendemic for dengue, with the presence of the four dengue serotypes. Objectives: to calculate dengue seroprevalence in a neighbourhood of São José do Rio Preto and identify if socioeconomic and demographic covariates are associated with dengue seropositivity. Methods A cohort study to evaluate dengue seroprevalence and incidence and associated factors on people aged 10 years or older, was assembled in Vila Toninho neighbourhood, São José do Rio Preto. The participant enrolment occurred from October 2015 to March 2016 (the first wave of the cohort study), when blood samples were collected for serological test (ELISA IgG anti-DENV) and questionnaires were administrated on socio-demographic variables. We evaluated the data collected in this first wave using a cross-sectional design. We considered seropositive the participants that were positive in the serological test (seronegative otherwise). We modelled the seroprevalence with a logistic regression in a geostatistical approach. The Bayesian inference was made using integrated nested Laplace approximations (INLA) coupled with the Stochastic Partial Differential Equation method (SPDE). Results We found 986 seropositive individuals for DENV in 1322 individuals surveyed in the study area in the first wave of the cohort study, corresponding to a seroprevalence of 74.6% (95%CI: 72.2–76.9). Between the population that said never had dengue fever, 68.4% (566/828) were dengue seropositive. Older people, non-white and living in a house (instead of in an apartment), were positively associated with dengue seropositivity. We adjusted for the other socioeconomic and demographic covariates, and accounted for residual spatial dependence between observations, which was found to present up to 800 m. Conclusions Only one in four people aged 10 years or older did not have contact with any of the serotypes of dengue virus in Vila Toninho neighbourhood in São José do Rio Preto. Age, race and type of house were associated with the occurrence of the disease. The use of INLA in a geostatistical approach in a Bayesian context allowed us to take into account the spatial dependence between the observations and identify the associated covariates to dengue seroprevalence. Electronic supplementary material The online version of this article (10.1186/s12879-019-4074-4) contains supplementary material, which is available to authorized users.

Diagnostic tests for American tegumentary leishmaniasis were performed on blood samples of patients living in two endemic municipalities in the state of Pernambuco, Northeastern Brazil. DNA was extracted from 119 samples and used as template for polymerase chain reaction (PCR) analysis. The tests used primers specifi c for the kinetoplast mini-circle DNA (kDNA) of Leishmania braziliensis, a species circulating in Pernambuco, which amplify a 750 base pair target sequence. In total, 58 subjects (48.7%) showed positive PCR amplifi cation and 61 (51.3%) were negative. Of the PCR-positive samples, 37 (≅64%) were from treated, lesion-free subjects. In conclusion, the PCR technique is effi cacious at identifying Leishmania DNA in biopsy and venous blood samples.

Molecular techniques based on the detection of genomic sequences by reverse transcription (RT)-PCR, nested PCR, or real-time PCR have made possible the rapid diagnosis of dengue virus (DENV) infections, and these approaches have been accepted by clinical laboratories as the new standard method for the detection of dengue virus in acute-phase serum samples. One of these PCR-based assays, the two-step RT nested PCR (RT-NPCR) technique is used routinely in laboratories worldwide. In the present study, the two-step RT-NPCR as described by Lanciotti and collaborators (1992) was adapted to a novel single-tube nested PCR (STNPCR) format, which is less prone to cross-contamination and reduces reaction cost and time. When standards for each dengue serotype were tested, the detection limit of the STNPCR was at least 10 copies for DENV-1 and 100 copies for DENV-2 and DENV-3, whereas the detection limit for the two-step RT-NPCR was 100 copies for each serotype. Sera from 22 patients with confirmed DENV-3 infections and from 14 healthy individuals were then tested in the STNPCR format using the system described by Lanciotti as the reference standard. The results indicated a sensitivity of 75.9% (CI 95%,) and a specificity of 100% for the RT-STNPCR. Athough RT-STNPCR was less sensitive than the conventional twostep RT-NPCR for the detection of virus in serum samples, it was still adequately sensitive, and the advantages associated with a single-tube format may outweigh the somewhat lower assay sensitivity, making it useful for diagnosis in the field. Keywords nested PCR; diagnosis; dengue; single-tube Dengue virus is a mosquito-borne flavivirus and the most prevalent arbovirus in tropical and subtropical regions of Asia, Africa and Central and South America (Harris et al., 2000). There are four distinct serotypes, DENV-1, DENV-2, DENV-3 and DENV-4, all of which may cause an asymptomatic infection or a spectrum of diseases ranging from dengue fever (DF) to more * Corresponding author. Tel.: +; fax: +449. E-mail address: emarques@cpqam.fiocruz.br (E. T. A Marques). This manuscript is dedicated to the family and former students of Dr. Abath.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. severe clinical forms such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) (Guzman and Kouri, 2004). In recent years, dengue virus infection has emerged as a major public health problem, with expanding geographical distribution and increasing epidemic activity (Guha-Sapir and Schimmer, 2005). NIH Public AccessAlthough dengue virus infection confers protective immunity to the ho...