which show limited virus replication in the gut [67] may be also a feeding and infection source. 1:20 by PRNT90 from bats captured in the 3 sites of study in Costa Rica (Nicoya, Sarapiqu and Central Valley) during 2013C2014. (DOCX) pntd.0005537.s004.docx (18K) GUID:?978A5919-CF5E-4F48-B9A3-8034B7740D36 S4 Table: Information of DENV-2 sequences used in phylogenetic analysis. (DOCX) pntd.0005537.s005.docx (15K) GUID:?26314182-85A7-4D5B-B6EB-0250168EF7C9 S5 Table: Information of DENV-4 sequences used in phylogenetic analysis. (DOCX) pntd.0005537.s006.docx (16K) GUID:?27C61297-A037-4CDC-9E5D-CC6D0B58FAD9 Data Availability StatementAll Supporting Information files are available from the GenBank database (accession numbers KY461756-KY461776 and KY474382). Abstract 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 contamination. 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 contamination. Sera were analyzed by PRNT90 for a seroprevalence of 21.2% (51/241), Lactitol 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 from all positive organs or blood Rabbit Polyclonal to EDNRA was unsuccessful. Additionally, viral load analyses in positive blood samples by qRT-PCR showed virus concentrations under the minimal dose required for mosquito contamination. Simultaneously, 651 mosquitoes were collected using EVS-CO2 traps and analyzed for DENV and feeding preferences (bat cytochrome b). Only three mosquitoes were found DENV positive and none was positive for bat cytochrome b. Our results suggest an accidental presence of DENV in bats probably caused from oral ingestion of infected mosquitoes. Phylogenetic analyses suggest also a spillover event from humans to bats. Therefore, we conclude that bats in these urban environments do not sustain DENV amplification, they do not have a role as reservoirs, but function as epidemiological dead end hosts for this virus. Author summary Dengue is the most important Lactitol human vector-borne disease. Several studies have shown DENV presence in mammalian wildlife such as bats, thus considering them putative reservoirs or hosts. We aimed to elucidate if bats that cohabit in houses in close proximity with humans may be involved in a dengue transmission cycle. We sampled bats in low and high dengue incidence areas during the dry (low mosquito abundance) and wet (high mosquito abundance) seasons. We analyzed blood and several organs. As previously reported, we found DENV nucleic acid and neutralizing antibodies in a small percentage of blood samples, but virus detection in all organs was unfavorable. We were able to show that dengue found in all positive samples was in low concentration and thus virus isolation was unsuccessful. We found positive intestine samples which may suggest contamination through DENV-positive mosquito ingestion. Furthermore, mosquitoes sampled in close vicinity of bats roosting place were not feeding on these mammals. Virus sequence analysis from bats and humans show a spillover effect from humans to bats. Taken together, our results indicate that bats do not sustain sufficient virus amplification in order to function as reservoirs and exclude them as players in the dengue virus transmission cycle. Introduction Dengue is the most important arthropod-borne viral contamination of humans, it is established in the tropics worldwide, and its geographical expansion is expected to increase due to factors such as modern dynamics of climate change, globalization, travel, trade, poverty, unplanned urbanization, and viral evolution [1]. The World Health Organization (WHO) estimates that 2.5 billion people are at risk of infection, with 50C100 million infections per year [2]. Currently, two distinct Lactitol and impartial DENV transmission cycles occur: (i) Endemic DENV circulates among humans functioning as reservoirs and amplification hosts, transmitted mainly by.
