Dengue Infection in Neotropical Forest Mammals

The American journal of tropical medicine and hygiene, 2014

During 2010 and 2011, the Loreto region of Peru experienced a dengue outbreak of unprecedented magnitude and severity for the region. This outbreak coincided with the reappearance of dengue virus-2 (DENV-2) in Loreto after almost 8 years. Whole-genome sequence indicated that DENV-2 from the outbreak belonged to lineage II of the southeast Asian/American genotype and was most closely related to viruses circulating in Brazil during 2007 and 2008, whereas DENV-2 previously circulating in Loreto grouped with lineage I (DENV-2 strains circulating in South America since 1990). One amino acid substitution (NS5 A811V) in the 2010 and 2011 isolates resulted from positive selection. However, the 2010 and 2011 DENV-2 did not replicate to higher titers in monocyte-derived dendritic cells and did not infect or disseminate in a higher proportion of Aedes aegypti than DENV-2 isolates previously circulating in Loreto. These results suggest that factors other than enhanced viral replication played a...

Acta Tropica, 2016

Dengue viruses are the most common arbovirus infection worldwide and are caused by four distinct serotypes of the dengue virus (DENV). In the present study, we assessed DENV transmission in São José do Rio Preto (SJRP) from 2010 to 2014. We analyzed blood samples from febrile patients who were attended at health care centers in SJRP. DENV detection was performed using multiplex RT-PCR, using flavivirus generic primers, based on the genes of the non-structural protein (NS5), followed by nested-PCR assay with species-specific primers. We analyzed 1549 samples, of which 1389 were positive for NS1 by rapid test. One thousand and eight-seven samples (78%) were confirmed as positive by multiplex RT-PCR: DENV-4, 48.5% (528/1087); DENV-1, 41.5% (449/1087); DENV-2, 9.5% (104/1087); and co-infection (5 DENV-1/DENV-4, 1 DENV-1/DENV-2), 0.5% (6/1087). Phylogenetic analysis of the DENV-4 grouped the isolates identified in this study with the American genotype and the showed a relationship between isolates from SJRP and isolates from the northern region of South America. Taken together, our data shows the detection and emergence of new dengue genotype in a new region and reiterate the importance of surveillance programs to detect and trace the evolution of DENV.

Japanese Journal of Infectious Diseases, 2015

Dengue fever (DF) is a mosquito-borne viral disease of great concern in tropical and subtropical regions of the world. One important cause of the increase in DF is rapid development and urbanization has led to proliferation of the Aedes aegypti mosquito, the vector responsible for transmission of the illness. Surveillance of dengue virus (DENV) infection in Brazil shows the predominance of DENV-1, DENV-2, and DENV-3 until 2010. This study reports the reappearance of DENV-4 in Brazil for the first time in 30 years. Serum samples were collected from individuals (n ＝ 214) exhibiting fever and muscular pain in Bahia, Brazil, during 2011-2012. These samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR)/nested PCR, which revealed that 82z of samples were positive for DENV-4; most were older age groups and exhibited a serological pattern consistent with a primary infection. The cocirculation of multiple DENV serotypes within the same city places the population at risk for a fatal form of the disease. Therefore, with the increasing incidence of severe DF cases, early diagnosis will be a priority for public health efforts in Brazil.

Dengue Bulletin

Roraima is the northernmost state of Brazil and its western and southern portion is covered by the Amazon rainforest. This region is one of the most affected by dengue viruses in Brazil. Reports from 1999 to 2011 pointed out a high incidence of dengue epidemics, and the state evolved from hypoendemic to hyperendemic. This led to the isolation and identification of the four dengue virus (DENV) serotypes with a substitution pattern of one serotype for another until 2010, when simultaneous circulation of the four serotypes was detected. In line with the increased risk of secondary infection and entry of new serotypes/genotypes, the number of severe cases increased in recent years. Roraima borders Venezuela and Guyana, where all four dengue serotypes are in circulation, and so it is considered an important port of entry for new genotypes into Brazil.

Virology …, 2011

Background: In Brazil dengue has been a major public health problem since DENV-1 introduction and spread in 1986. After a low or silent co-circulation, DENV-1 re-emerged in 2009 causing a major epidemic in the country in 2010 and 2011. In this study, the phylogeny of DENV-1 strains isolated in RJ after its first introduction in 1986 and after its emergence in 2009 and 2010 was performed in order to document possible evolutionary patterns or introductions in a re-emergent virus. Findings: The analysis of the E gene sequences demonstrated that DENV-1 isolated during 2009/2010 still belong to genotype V (Americas/Africa) but grouping in a distinct clade (lineage II) of that represented by earlier DENV-1 (lineage I). However, strains isolated in 2011 grouped together forming another distinct clade (lineage III). Conclusions: The monitoring of DENV is important to observe the spread of potentially virulent strains as well to evaluate its impact over the population during an outbreak. Whether explosive epidemics reported in Brazil caused mainly by DENV-1 was due to lineage replacement, or due the population susceptibility to this serotype which has not circulated for almost a decade or even due to the occurrence of secondary infections in a hyperendemic country, is not clear. This is the first report of multiple lineages of DENV-1 detected in Brazil.

2003

Prior to 2000, only DEN-1 and the American genotype DEN-2 viruses were isolated in Peru. D uring the dengue outbreak from May 2000 to May 2001 in the North-west departments of Peru, clinical data and blood samples were obtained from 1,652 patients who presented clinical manifestations comparable with those of dengue. Virus genome isolations were made from 278 (16.8%) of the samples. Serotype-specific monoclonal antibodies and polymerase chain reaction (PCR) were used to type isolations. The genotype of the majority of the DEN-2 isolations was determined by the restriction fragment length polymorphism (RFLP) analysis. Members of each serotype and two genotypes of DEN-2 virus were isolated: DEN-1 (n = 93); Asian genotype DEN-2 (n = 104); American genotype DEN-2 (n = 1); DEN-2 genotype not determined (n = 53); DEN-3 (n = 25); and DEN-4 (n = 2). Representatives of each serotype, and genotype for DEN-2, were confirmed by partial sequence analysis. D engue antibodies as determined by Plaque Reduction N eutralization Test (PNT) were present in the acute serum from the single D H F Grade-II patient, in 19 of 31 (61%) acute sera from patients with D H F Grade-I and in 3 of 45 (7%) acute sera of D F patients, suggesting an association between pre-existing dengue antibody and disease severity.

Emerging Infectious Diseases, 2009

Emerging Infectious Diseases, 2022

Emerging Infectious Diseases, 2011

To study the evolution of dengue virus (DENV) serotype 2 in Puerto Rico, we examined the genetic composition and diversity of 160 DENV-2 genomes obtained through 22 consecutive years of sampling. A clade replacement took place in 1994-1997 during a period of high incidence of autochthonous DENV-2 and frequent, short-lived reintroductions of foreign DENV-2. This unique clade replacement was complete just before DENV-3 emerged. By temporally and geographically defi ning DENV-2 lineages, we describe a refuge of this virus through 4 years of low genome diversity. Our analyses may explain the long-term endurance of DENV-2 despite great epidemiologic changes in disease incidence and serotype distribution. E pidemic dengue fever (DF) and the emergence of dengue hemorrhagic fever (DHF) in the Americas are associated with increased endemicity and cocirculation of the 4 dengue virus (DENV) serotypes, 1-4 (1). These increases have been particularly evident in Puerto Rico, where transmission increased during the past 25 years (2-4). The fi rst DHF epidemics in the Americas occurred in the 1980s and were caused by the Asian/American genotype of DENV-2, then new to the region, which rapidly replaced the American genotype (5-7). This replacement has been linked to a potential to cause higher viremia and severe illness (8-10). Introduction of DENV-3 in the mid 1990s and increased human population and travel further fostered larger and more frequent DF and DHF epidemics in the region (11-13).

PLoS neglected tropical diseases, 2017

Several studies have shown Dengue Virus (DENV) nucleic acids and/or antibodies present in Neotropical wildlife including bats, suggesting that some bat species may be susceptible to DENV infection. Here we aim to elucidate the role of house-roosting bats in the DENV transmission cycle. Bats were sampled in households located in high and low dengue incidence regions during rainy and dry seasons in Costa Rica. We captured 318 bats from 12 different species in 29 households. Necropsies were performed in 205 bats to analyze virus presence in heart, lung, spleen, liver, intestine, kidney, and brain tissue. Histopathology studies from all organs showed no significant findings of disease or infection. Sera were analyzed by PRNT90 for a seroprevalence of 21.2% (51/241), and by PCR for 8.8% (28/318) positive bats for DENV RNA. From these 28 bats, 11 intestine samples were analyzed by RT-PCR. Two intestines were DENV RNA positive for the same dengue serotype detected in blood. Viral isolation...