Binding Evolution of the Dengue Virus Envelope Against DC-SIGN: A Combined Approach of Phylogenetics and Molecular Dynamics Analyses Over 30 Years of Dengue Virus in Brazil.

The Red Queen Hypothesis (RQH), derived from Lewis Carroll's "Through the Looking-Glass", postulates that organisms must continually adapt in response to each other to maintain relative fitness. Within the context of host-pathogen interactions, the RQH implies an evolutionary arms race, wherein viruses evolve to exploit hosts and hosts evolve to resist viral invasion. This study delves into the dynamics of the RQH in the context of virus-cell interactions, specifically focusing on virus receptors and cell receptors. We observed multiple virus-host systems and noted patterns of co-evolution. As viruses evolved receptor-binding proteins to effectively engage with cell receptors, cells countered by altering their receptor genes. This ongoing mutual adaptation cycle has influenced the molecular intricacies of receptor-ligand interactions. Our data supports the RQH as a driving force behind the diversification and specialization of both viral and host cell receptors. Understanding this co-evolutionary dance offers insights into the unpredictability of emerging viral diseases and potential therapeutic interventions. Future research is crucial to dissect the nuanced molecular changes and the broader ecological consequences of this ever-evolving battle. Here, we combine phylogenetic inferences, structural modeling, and molecular dynamics analyses to describe the epidemiological characteristics of major Brazilian DENV strains that circulated from 1990 to 2022 from a combined perspective, thus providing us with a more detailed picture on the dynamics of such interactions over time.

Low CCL2 and CXCL8 Production and High Prevalence of Allergies in Children with Microcephaly Due to Congenital Zika Syndrome.

Congenital Zika Syndrome (CZS) is associated with an increased risk of microcephaly in affected children. This study investigated the peripheral dysregulation of immune mediators in children with microcephaly due to CZS. Gene expression quantified by qPCR in whole blood samples showed an increase in IFNγ and IL-13 transcripts in children affected with microcephaly compared to the control group. The microcephaly group exhibited significantly decreased CCL2 and CXCL8 levels in serum, quantified by CBA assay. An allergic profile questionnaire revealed a high prevalence of allergies in the microcephaly group. In accordance, elevated serum IgE level measured by the Proquantum Immunoassay was observed in children affected with microcephaly compared to the control group. Altogether, these findings show a persistent systemic inflammation in children with microcephaly due to CZS and suggest a possible impairment in leukocyte migration caused by low production of CCL2 and CXCL8, in addition to high levels of IgE associated with high prevalence of allergies. The dysregulation of inflammatory genes and chemokines underscores the importance of understanding the immunological characteristics of CZS. Further investigation into the long-term consequences of systemic inflammation in these children is crucial for developing appropriate therapeutic strategies and tailored vaccination protocols.

Innate immune response in patients with acute Chikungunya disease.

Chikungunya disease (CHIKD) is an arbovirose that presents with high morbidity, mainly due to arthralgia. Inflammatory mediators including IL-6, IL-1ß, GM-CSF and others have been implicated in the pathogenesis of CHIKD, whilst type I interferons can be associated with better outcomes. The role of pattern recognition receptors has been studied incompletely. Here, we evaluated the expression of RNA-specific PRRs, their adaptor molecules and downstream cytokines in acute CHIKD patients. Twenty-eight patients were recruited during the 3rd-5th day after the symptoms onset for clinical examination, peripheral blood collection and qRT-PCR analysis of PBMC to compare to the healthy control group (n = 20). We observed common symptoms of acute CHIKD, with fever, arthralgia, headache and myalgia being the most frequent. Compared with uninfected controls, acute CHIKV infection upregulates the expression of the receptors TLR3, RIG-I and MDA5, and also the adaptor molecule TRIF. Regarding cytokine expression, we found an upregulation of IL-6, IL-12, IFN-α, IFN-ß and IFN-γ, which are related directly to the inflammatory or antiviral response. The TLR3-TRIF axis correlated with high expression of IL-6 and IFN-α. Interestingly, greater expression of MDA5, IL-12 and IFN-α was related to lower viral loads in CHIKD acute patients. Together, these findings help to complete the picture of innate immune activation during acute CHIKD, while confirming the induction of strong antiviral responses. Drawing the next steps in the understanding of the immunopathology and virus clearance mechanisms of CHIKD should be of utter importance in the aid of the development of effective treatment to reduce the severity of this debilitating disease.

Biology and Natural History of Type 1 Diabetes Mellitus.

Type 1 diabetes mellitus is a clinical condition characterized by insufficient insulin production due to progressive loss of pancreatic islet ß-cells mediated by an autoimmune response. This deregulation of the immune system is caused by the action of genetic, epigenetic, and environmental factors in varying combinations for each individual. Although the inflammation of the islets with immune cell infiltration, known as insulitis, is an important element in pathogenesis, other factors are necessary for disease initiation. Associations with variants of HLA and other genes related to immune system function, mainly haplotypes HLA-DR3-DQ2 and HLA-DR4-DQ8, are more evident. The influence of polymorphisms and epigenetic modifications, as well as the microbiome, is convincing proof of the existence of a complex interaction between genetic, immune, and environmental factors in the etiology and pathogenesis of this metabolic disorder. Loss of selftolerance to autoimmunity is a critical point in the development of the disease, and regulatory T cells play a key role in this process. Thus, any failure of these cells, either due to an insufficient number or altered expression of cytokines and transcription factors, may be the trigger for the onset of the disease. The protective action of regulatory T cells is controlled by gene expression that is modulated by epigenetic modifications, including the dysregulation of noncoding RNAs. This review takes an updated approach to the natural history of type 1 diabetes, focusing on the factors involved in the etiology and pathogenesis.

The role of HPV-induced epigenetic changes in cervical carcinogenesis (Review).

Cervical cancer is associated with infection by certain types of human papillomaviruses (HPVs), and this affects women worldwide. Despite the improvements in prevention and cure of HPV-induced cervical cancer, it remains the second most common type of cancer in women in the least developed regions of the world. Epigenetic modifications are stable long-term changes that occur in the DNA, and are part of a natural evolutionary process of necessary adaptations to the environment. They do not result in changes in the DNA sequence, but do affect gene expression and genomic stability. Epigenetic changes are important in several biological processes. The effects of the environment on gene expression can contribute to the development of numerous diseases. Epigenetic modifications may serve a critical role in cancer cells, by silencing tumor suppressor genes, activating oncogenes, and exacerbating defects in DNA repair mechanisms. Although cervical cancer is directly related to a persistent high-risk HPV infection, several epigenetic changes have been identified in both the viral DNA and the genome of the infected cells: DNA methylation, histone modification and gene silencing by non-coding RNAs, which initiate and sustain epigenetic changes. In the present review, recent advances in the role of epigenetic changes in cervical cancer are summarized.

Biology and pathogenesis of human osteosarcoma.

Osteosarcoma (OS) is a bone tumor of mesenchymal origin, most frequently occurring during the rapid growth phase of long bones, and usually located in the epiphyseal growth plates of the femur or the tibia. Its most common feature is genome disorganization, aneuploidy with chromosomal alterations, deregulation of tumor suppressor genes and of the cell cycle, and an absence of DNA repair. This suggests the involvement of surveillance failures, DNA repair or apoptosis control during osteogenesis, allowing the survival of cells which have undergone alterations during differentiation. Epigenetic events, including DNA methylation, histone modifications, nucleosome remodeling and expression of non-coding RNAs have been identified as possible risk factors for the tumor. It has been reported that p53 target genes or those genes that have their activity modulated by p53, in addition to other tumor suppressor genes, are silenced in OS-derived cell lines by hypermethylation of their promoters. In osteogenesis, osteoblasts are formed from pluripotent mesenchymal cells, with potential for self-renewal, proliferation and differentiation into various cell types. This involves complex signaling pathways and multiple factors. Any disturbance in this process can cause deregulation of the differentiation and proliferation of these cells, leading to the malignant phenotype. Therefore, the origin of OS seems to be multifactorial, involving the deregulation of differentiation of mesenchymal cells and tumor suppressor genes, activation of oncogenes, epigenetic events and the production of cytokines.

Tityus serrulatus Scorpion Venom Induces Apoptosis in Cervical Cancer Cell Lines.

Cervical cancer (CC) is classified as the fourth most common type of cancer in women worldwide and remains a serious public health problem in many underdeveloped countries. Human papillomavirus (HPV), mainly types 16 and 18, has been established as a precursory etiologic agent for this type of cancer. Several therapeutic attempts have been studied and applied, aiming at its control. However, not only do classical treatments such as chemotherapies and radiotherapies target tumor cells, but also they cause damage to several healthy cells. For these reasons, the search for new biologically active chemotherapeutic components is of great importance. In this study, we investigated the effect of Tityus serrulatus scorpion venom (TsV) on CC lines. There are very few studies exploring venom of scorpions, and, to our knowledge, no study has been conducted using the venom of the scorpion TsV for treatment of cervical cancer lines. After challenge with TsV, the MTT assay demonstrated cytotoxic effect on HeLa line. Similarly, the cell death process in HeLa analyzed by flow cytometry suggests death via caspase, since the pan-caspase inhibitor z-VAD-fmk significantly reduced the apoptotic response to the treatment. These results suggest that venom of TsV can be a potential source for the isolation of effective antiproliferative and apoptotic molecules in the treatment of CC.

Entomo-virological surveillance strategy for dengue, Zika and chikungunya arboviruses in field-caught Aedes mosquitoes in an endemic urban area of the Northeast of Brazil.

Aedes spp. are considered the main vectors of dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV) viruses in the world. Arbovirus detection in Aedes mosquitoes can alert authorities to possible outbreaks, reducing the impact of these diseases. The purpose of this study was to perform an operational strategy for virological surveillance of DENV, ZIKV and CHIKV in adult Aedes aegypti and Aedes albopictus mosquitoes captured at different key-sites in an endemic urban area of the Northeast Region of Brazil, with the prospect of discussing its role as part of an alert system for outbreaks in critical areas. Residential and non-residential premises located in areas of recent of transmission of these arboviruses were selected for adult mosquito collection in the rainy season (July) of 2018. A total of 1068 adult mosquitoes were collected: 946 Culex quinquefasciatus (88.6%), 118 Ae. aegypti (11.0%), two Ae. albopictus (0.2%) and two Aedes taeniorhynchus (0.2%). Among the premises surveyed, recycling points (N = 48, 40.7%), municipal schools (N = 36, 30.5%) and junkyards (N = 31, 26.2%) were the places with the highest frequency of adult Ae. aegypti. Health units (including primary health care facilities and one hospital) (N = 23; 19.5%) together with residential premises (N = 11; 9.3%) presented the lowest frequencies. Total RNAs of the samples were extracted from Aedes mosquitoes and a nested reverse transcription (RT) polymerase chain reaction (PCR) assay for detecting and typing DENV, ZIKV and CHIKV was performed. From the 37 Aedes spp. pools analyzed (35 Ae. aegypti, one Ae. albopictus and one Ae. taeniorhynchus), seven were positive for DENV-3, including three pools containing Ae. aegypti females, one containing an Ae. aegypti engorged female and three comprised of Ae. aegypti males. The positive pools were composed of mosquitoes collected in public schools, health units, junkyards, recycling points and residential premises. Our findings reinforce the importance of continuous virological surveillance in Aedes mosquitoes, as a useful tool for detecting arboviruses circulation in vulnerable areas, even in low infestation seasons.

Innate immune response in patients with acute Zika virus infection.

Innate immunity receptors (Toll-like receptors/TLRs and RIG-like receptors/RLRs) are important for the initial recognition of Zika virus (ZIKV), modulation of protective immune response, and IFN-α and IFN-ß production. Immunological mechanisms involved in protection or pathology during ZIKV infection have not yet been determined. In this study, we evaluated the mRNA expression of innate immune receptors (TLR3, TLR7, TLR8, TLR9, melanoma differentiation-associated protein 5/MDA-5, and retinoic acid inducible gene/RIG-1), its adapter molecules (Myeloid Differentiation Primary Response Gene 88/Myd88, Toll/IL-1 Receptor Domain-Containing Adaptor-Inducing IFN-ß/TRIF), and cytokines (IL-6, IL-12, TNF-α, IFN-α, IFN-ß, and IFN-γ) in the acute phase of patients infected by ZIKV using real-time PCR in peripheral blood. Patients with acute ZIKV infection had high expression of TLR3, IFN-α, IFN-ß, and IFN-γ when compared to healthy controls. In addition, there was a positive correlation between TLR3 expression compared to IFN-α and IFN-ß. Moreover, viral load is positively correlated with TLR8, RIG-1, MDA-5, IFN-α, and IFN-ß. On the other hand, patients infected by ZIKV showed reduced expression of RIG-1, TLR8, Myd88, and TNF-α molecules, which are also involved in antiviral immunity. Similar expressions of TLR7, TLR9, MDA-5, TRIF, IL-6, and IL-12 were observed between the group of patients infected with ZIKV and control subjects. Our results indicate that acute infection (up to 5 days after the onset of symptoms) by ZIKV in patients induces the high mRNA expression of TLR3 correlated to high expression of IFN-γ, IFN-α, and IFN-ß, even though the high viral load is correlated to high expression of TLR8, RIG-1, MDA-5, IFN-α, and IFN-ß in ZIKV patients.

Th17 response in patients with cervical cancer.

Persistent infection by high-risk human papillomavirus (HR-HPV) is the main risk factor for uterine cervical cancer (UCC). However, viral infection alone is not sufficient for the development and progression of premalignant cervical lesions for cancer. In previous years it has been suggested that the adaptive immune response triggered by the differentiation of naïve helper T cells in Th17 cells may serve an important role in disease development. It has been hypothesized that Th17 cells may be involved in the promotion of UCC, as high levels of interleukin 17 (IL17) expression have been detected in the mucosa of the uterine cervix of patients affected by the disease. However, the role of Th17 cells in the tumor development and progression remains unclear. It is believed that the immune response of the Th17 type during persistent infection of the genital tract with HR-HPV triggers chronic inflammation with a long duration with the production of IL17 and other pro-inflammatory cytokines, creating a favorable environment for tumor development. These cytokines are produced by immune system cells in addition to tumor cells and appear to function by modulating the host immune system, resulting in an immunosuppressive response as opposed to inducing an effective protective immune response, thus contributing to the growth and progression of the tumor. In the present review, the latest advances are presented about the function of Th17 cells and the cytokines produced by them in the development and progression of UCC.

Macrophage Migration Inhibitory Factor (MIF): Biological Activities and Relation with Cancer.

Macrophage migration inhibitory factor (MIF) emerged in recent years as an important inflammation mediator, playing a prominent role in the pathogenesis of various types of malignant neoplasm. MIF is a glycoprotein that presents a wide spectrum of biological activities and exerts a complex interaction with various cellular signaling pathways, causing imbalance of homeostasis. Experimental and clinical studies show that high levels of MIF are found in almost all types of human cancers and are implicated in seemingly all stages of development of the tumors. The production of MIF is triggered through an autocrine signal emitted by tumor cells, and stimulates the production of cytokines, chemokines, and growth as well as angiogenic factors that lead to growth of the tumor, increasing its aggressiveness and metastatic potential. MIF is produced by virtually all types of human body cells, in response to stress caused by different factors, leading to pathological conditions such as chronic inflammation and immunomodulation with suppression of immune surveillance and of immune response against tumors, angiogenesis, and carcinogenesis. In this review, we present recent advances on the biological activity of MIF, the signaling pathways with which it is involved and their role in tumorigenesis.

The role of the mediators of inflammation in cancer development.

Epigenetic disorders such as point mutations in cellular tumor suppressor genes, DNA methylation and post-translational modifications are needed to transformation of normal cells into cancer cells. These events result in alterations in critical pathways responsible for maintaining the normal cellular homeostasis, triggering to an inflammatory response which can lead the development of cancer. The inflammatory response is a universal defense mechanism activated in response to an injury tissue, of any nature, that involves both innate and adaptive immune responses, through the collective action of a variety of soluble mediators. Many inflammatory signaling pathways are activated in several types of cancer, linking chronic inflammation to tumorigenesis process. Thus, Inflammatory responses play decisive roles at different stages of tumor development, including initiation, promotion, growth, invasion, and metastasis, affecting also the immune surveillance. Immune cells that infiltrate tumors engage in an extensive and dynamic crosstalk with cancer cells, and some of the molecular events that mediate this dialog have been revealed. A range of inflammation mediators, including cytokines, chemokines, free radicals, prostaglandins, growth and transcription factors, microRNAs, and enzymes as, cyclooxygenase and matrix metalloproteinase, collectively acts to create a favorable microenvironment for the development of tumors. In this review are presented the main mediators of the inflammatory response and discussed the likely mechanisms through which, they interact with each other to create a condition favorable to development of cancer.

Link between chronic inflammation and human papillomavirus-induced carcinogenesis (Review).

Inflammation is a defense strategy against invading agents and harmful molecules that is activated immediately following a stimulus, and involves the release of cytokines and chemokines, which activate the innate immune response. These mediators act together to increase blood flow and vascular permeability, facilitating recruitment of effector cells to the site of injury. Following resolution of the injury and removal of the stimulus, inflammation is disabled, but if the stimulus persists, inflammation becomes chronic and is strongly associated with cancer. This is likely to be due to the fact that the inflammation leads to a wound that does not heal, requiring a constant renewal of cells, which increases the risk of neoplastic transformation. Debris from phagocytosis, including the reactive species of oxygen and nitrogen that cause damage to DNA already damaged by the leukotrienes and prostaglandins, has an impact on inflammation and various carcinogenic routes. There is an association between chronic inflammation, persistent infection and cancer, where oncogenic action is mediated by autocrine and paracrine signals, causing changes in somatic cells under the influence of the microbial genome or of epigenetic factors. Among the infectious agents associated with cancer, certain genotypes of human papillomavirus (HPV) stand out. HPV is responsible for virtually all cases of cervical cancer and a lower proportion of cancers of the vagina, vulva, anus, penis and a number of extragenital cancers. In the present review, recent advances in the mechanisms involved in the inflammatory response are presented with their participation in the process of carcinogenesis, emphasizing the role of chronic inflammation in the development of HPV-induced cervical cancer.

Genital tract infection with Chlamydia trachomatis in women attended at a cervical cancer screening program in Northeastern from Brazil.

PURPOSE: This cross-sectional study aimed to estimate the prevalence of Chlamydia trachomatis (CT) infection alone and in combination with human papillomavirus (HPV). Furthermore, the study investigates whether the CT infection increases the risk of contracting HPV and whether the presence of both pathogens is associated with a higher prevalence of cervical lesions. METHODS: Cervical samples of 1,134 asymptomatic women enrolled in a screening program for cervical cancer were analyzed. Two cervical specimens were collected from each patient, one for cytologic examination and the other for detection of CT by polymerase chain reaction (PCR), using a primer pair which amplifies a specific sequence of the DNA plasmid. RESULTS: The overall prevalence rate infection was 10.9%, being 10% in the women with normal cytology, 13.8% in those with atypical squamous cells of undetermined significance (ASC-US), and 25% with low-grade squamous intraepithelial lesion (LSIL). The infection by CT did not increase the risk of acquiring HPV infection. The higher prevalence of LSIL in women co-infected with HPV and CT is possibly due to HPV. CONCLUSION: CT infection was more prevalent in younger women aged up to 32 years, who had an early onset of reproductive activity and a history of having had multiple sexual partners lifelong may be at a greater risk of acquiring infection of the genital tract by C. trachomatis.

Genital infection with herpes simplex virus types 1 and 2 in women from natal, Brazil.

Objective. To evaluate the prevalence of HSV-1 and HSV-2 in pregnant and nonpregnant women, testing the correlation between DNA of the viruses with colposcopic and/or cytological changes, and evaluate association with sociodemographic characteristics and sexual activity. Methods. Included in this study were 106 pregnant and 130 nonpregnant women treated at primary health care units of Natal, Brazil, in the period 2010-2011. The patients were examined by colposcopy, and two cervical specimens were collected: one for cytology examination and another for analysis by PCR for detection of HSV-1 and HSV-2. Results. HSV-1 alone was detected in 16.0% of pregnant and 30.0% of nonpregnant women. For HSV-2, these rates were 12.3% and 15.5%, respectively. HSV-2 had a higher correlation with cytology and/or colposcopy changes than HSV-1 did. Genital HSV-1 infection was not associated with any of the variables tested, whereas HSV-2 infection was associated with ethnicity, marital status, and number of sexual partners. Conclusions. The prevalence of HSV-1 was higher than that observed for HSV-2 in both pregnant and nonpregnant women. The genital infection by HSV-2 was higher in women with changed colposcopy and/or cytology, and it was associated with ethnicity, marital status, and number of sexual partners.

Knowledge about HPV and Screening of Cervical Cancer among Women from the Metropolitan Region of Natal, Brazil.

Objective. The purpose of this study was to assess the knowledge level about HPV and screening of cervical cancer in women from the metropolitan region of Natal, Brazil. Materials and Methods. A descriptive cross-sectional study involving sexually active women was conducted. The participants were submitted to a face-to-face interview, using a structured questionnaire that permitted the quantification of data and opinions of the respondents. Results. Most participants (70.9%) had poor knowledge about HPV and also the Pap test (53.0%). The high level of knowledge about HPV was associated with age, education, marital status, household income, and pregnancy, while the high level of knowledge about the Pap test proved to be associated only with education and household income. Conclusion. The results highlight the need for performing educational campaigns emphasizing the role of HPV in the etiology of cervical lesions of different degrees, including cervical cancer, as well as the importance of having a Pap test regularly to prevent these diseases.

Virological surveillance for early warning of dengue epidemics in the State of Rio de Janeiro, Brazil.

BACKGROUND: The state of Rio de Janeiro has been important since 1986 as a portal for the introduction of dengue virus (DENV) into Brazil and dissemination of the virus throughout the country. This study describes an active surveillance of DENV in the state of Rio de Janeiro from 2004 to 2008. METHOD: A total of 14 408 samples from patients suspected to be infected with DENV were tested by virus isolation, and nested reverse transcriptase (RT)-PCR assay or anti-DENV dengue IgM antibody capture ELISA (MAC-ELISA), or both. RESULTS: By the use of these different methods, a total of 2324 (16.1%) cases were confirmed as dengue infection. The study covers an inter-epidemic period (2004-2005), the DENV-3 circulation in 2006, the re-emergence of DENV-2 in 2007 and the severe epidemic caused by DENV-2 in the summer of 2008. During the period, 69 dengue fatal cases were reported, 14 (20.2%) deaths being attributable to DENV-3 and 55 (79.7%) to DENV-2. CONCLUSION: Our results emphasize the role of the laboratory in the early detection of dengue virus transmission and provide information on the dynamics of DENV introduction and spread, important for the assessment of intervention strategies.

Origin and evolution of dengue virus type 3 in Brazil.

The incidence of dengue fever and dengue hemorrhagic fever in Brazil experienced a significant increase since the emergence of dengue virus type-3 (DENV-3) at the early 2000s. Despite the major public health concerns, there have been very few studies of the molecular epidemiology and time-scale of this DENV lineage in Brazil. In this study, we investigated the origin and dispersion dynamics of DENV-3 genotype III in Brazil by examining a large number (n=107) of E gene sequences sampled between 2001 and 2009 from diverse Brazilian regions. These Brazilian sequences were combined with 457 DENV-3 genotype III E gene sequences from 29 countries around the world. Our phylogenetic analysis reveals that there have been at least four introductions of the DENV-3 genotype III in Brazil, as signified by the presence of four phylogenetically distinct lineages. Three lineages (BR-I, BR-II, and BR-III) were probably imported from the Lesser Antilles (Caribbean), while the fourth one (BR-IV) was probably introduced from Colombia or Venezuela. While lineages BR-I and BR-II succeeded in getting established and disseminated in Brazil and other countries from the Southern Cone, lineages BR-III and BR-IV were only detected in one single individual each from the North region. The phylogeographic analysis indicates that DENV-3 lineages BR-I and BR-II were most likely introduced into Brazil through the Southeast and North regions around 1999 (95% HPD: 1998-2000) and 2001 (95% HPD: 2000-2002), respectively. These findings show that importation of DENV-3 lineages from the Caribbean islands into Brazil seems to be relatively frequent. Our study further suggests that the North and Southeast Brazilian regions were the most important hubs of introduction and spread of DENV-3 lineages and deserve an intense epidemiological surveillance.

Evaluation of a generic RT-nested-PCR for detection of flaviviruses in suspected fatal cases of dengue infection, Rio de Janeiro, Brazil.

Flaviviruses are significant causes of disease worldwide and can be classified serologically into several antigenic complexes. The purpose of the present study was to evaluate the effectiveness of a generic RT-nested-PCR for detection of flavivirus during a dengue outbreak in Brazil in 2008. A total of 105 serum samples were collected from patients with fatal outcome and examined by generic RT-PCR, conventional RT-PCR, and IgM serology. The generic RT-PCR confirmed 19 of 105 (18%) cases. Conventional RT-PCR performed on 105 serum samples detected 45 (42.8%) dengue virus infections. The IgM serology confirmed 44 of 102 (43.1%) cases. The infecting serotype was identified by generic RT-PCR in 19 cases (18 DENV-2 and 1 DENV-3) and by conventional RT-PCR in 45 cases (40 DENV-2 and 5 DENV-3). In addition, we analyzed the performance of the generic and conventional RT-PCRs and IgM serology on serum samples stratified by the day of onset of symptoms. Our results indicate that different methods should be included in flavivirus surveillance programs, including virological and serological approaches.

Human papillomavirus prevalence in women with normal cytology and with cervical cancer in Natal, Brazil.

This study analyzed the prevalence of human papillomavirus (HPV) in cervical specimens obtained from women with normal cytology and with cervical cancer, in order to evaluate their correlation with health status and demographic characteristics, as well as sexual and reproductive activity in women treated at a cancer reference hospital in Natal, Northeast Brazil. A total of 158 women were divided into 2 groups according to their health status: group I comprised 110 women with normal cytology, and group II comprised 48 women with cervical cancer. Cervical smears were analyzed by cytological or histopathological examination for the detection of cytological alterations, and by PCR for HPV DNA detection using MY09/11 primers, followed by HPV genotyping by dot blot hybridization. Results showed overall HPV prevalence to be 24.5% in group I, with 19.1% of patients having single infection and 5.4% double infection. The HPV prevalence in group II was 85.4%, with 79.2% of patients having single and 6.2% double infection. We identified 10 different HPV genotypes, most with high oncogenic potential. HPV 16 was the most prevalent genotype in the two studied groups, followed by HPV 58 and HPV 18. High-risk HPV genital infection, chronological age, ethnicity, early onset of sexual and reproductive activities, multiple sexual partners and smoking increased the risk for cervical cancer.