scholarly journals Serological Positivity against Selected Flaviviruses and Alphaviruses in Free-Ranging Bats and Birds from Costa Rica Evidence Exposure to Arboviruses Seldom Reported Locally in Humans

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 93
Author(s):  
Daniel Felipe Barrantes Murillo ◽  
Marta Piche-Ovares ◽  
José Carlos Gamboa-Solano ◽  
Luis Mario Romero ◽  
Claudio Soto-Garita ◽  
...  
Keyword(s):  
Costa Rica ◽  
Neutralizing Antibodies ◽  
Sylvatic Cycle ◽  
Histological Changes ◽  
Current Infection ◽  
Transmission Cycles ◽  
Free Ranging

Arboviruses have two ecological transmission cycles: sylvatic and urban. For some, the sylvatic cycle has not been thoroughly described in America. To study the role of wildlife in a putative sylvatic cycle, we sampled free-ranging bats and birds in two arbovirus endemic locations and analyzed them using molecular, serological, and histological methods. No current infection was detected, and no significant arbovirus-associated histological changes were observed. Neutralizing antibodies were detected against selected arboviruses. In bats, positivity in 34.95% for DENV-1, 16.26% for DENV-2, 5.69% for DENV-3, 4.87% for DENV-4, 2.43% for WNV, 4.87% for SLEV, 0.81% for YFV, 7.31% for EEEV, and 0.81% for VEEV was found. Antibodies against ZIKV were not detected. In birds, PRNT results were positive against WNV in 0.80%, SLEV in 5.64%, EEEV in 8.4%, and VEEV in 5.63%. An additional retrospective PRNT analysis was performed using bat samples from three additional DENV endemic sites resulting in a 3.27% prevalence for WNV and 1.63% for SLEV. Interestingly, one sample resulted unequivocally WNV positive confirmed by serum titration. These results suggest that free-ranging bats and birds are exposed to not currently reported hyperendemic-human infecting Flavivirus and Alphavirus; however, their role as reservoirs or hosts is still undetermined.

scholarly journals Serological Positivity against Selected Flavivirus and Alphavirus in Free-ranging Bats and Birds from Costa Rica Evidence Exposure to Arboviruses Seldom Reported Locally in Humans

2021 ◽  
Author(s):  
Daniel Felipe Barrantes Murillo ◽  
Marta Piche-Ovares ◽  
Jose Carlos Gamboa Solano ◽  
Luis Mario Romero ◽  
Claudio Soto-Garita ◽  
...  
Keyword(s):  
Costa Rica ◽  
Neutralizing Antibodies ◽  
Sylvatic Cycle ◽  
Histological Changes ◽  
Current Infection ◽  
Transmission Cycles ◽  
Free Ranging

Arboviruses have two ecological transmission cycles, sylvatic and urban. For some, the sylvatic cycle has not been thoroughly described in America. To study the role of wildlife in a putative sylvatic cycle, we sampled free-ranging bats and birds in two arbovirus endemic locations and analyzed them using molecular, serological, and histological methods. No current infection was detected, and no significant arbovirus-associated histological changes were observed. Neutralizing antibodies were detected against selected arboviruses. In bats, positivity in 34.95% for DENV-1, 16.26% for DENV-2, 5.69% for DENV-3, 4.87% for DENV-4, 2.43% for WNV, 4.87% for SLEV, 0,81% for YFV, 7.31% for EEEV, and 0.81% for VEEV was found. Antibodies against ZIKV were not detected. In birds, PRNT results were positive against WNV in 0.80%, SLEV in 5.64%, EEEV in 8.4%, and VEEV in 5.63%. An additional retrospective PRNT analysis was performed using bat samples from three additional DENV endemic sites resulting in a 3.27% prevalence for WNV and 1.63% for SLEV. Interestingly one sample resulted unequivocally WNV positive confirmed by serum titration. These results suggest that free-ranging bats and birds are exposed to not currently reported hyperendemic-human infecting Flavivirus and Alphavirus, however, their role as reservoirs or hosts is still undetermined.

scholarly journals Role of monkeys in the sylvatic cycle of chikungunya virus in Senegal

2016 ◽  
Author(s):  
Benjamin M. Althouse ◽  
Mathilde Guerbois ◽  
Derek A. T. Cummings ◽  
Ousmane M. Diop ◽  
Ousmane Faye ◽  
...  
Keyword(s):  
Host Species ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Sylvatic Cycle ◽  
Force Of Infection ◽  
One Step ◽  
Reservoir Hosts

AbstractAthropod-borne viruses (arboviruses) pose the greatest risk of spillover into humans of any class of pathogens. Such spillover may occur as a one-step jump from a reservoir host species into humans or as a two-step jump from the reservoir to a different amplification host species and thence to humans. Despite the widespread havoc wreaked by emerging arboviruses, little is known about their transmission dynamics in reservoir and amplification hosts. Here we used serosurveillance and mathematical modeling to elucidate the role of monkeys in the sylvatic, enzootic cycle of chikungunya virus (CHIKV). Over three years, 219 African green monkeys, 78 patas monkeys, and 440 Guinea baboons were captured in the region surrounding Kedougou, Senegal. The age of each animal was determined by anthropometry and dentition, and exposure to CHIKV was determined by detection of neutralizing antibodies. We estimate age-specific CHIKV seroprevalence, force of infection (FoI), and basic reproductive number (R0) in each species. Among the different species, CHIKV Fol ranged from 0.13 to 1.12 (95% CI, 0.81–2.28) and R0 ranged from 1.5 (95% CI, 1.3–1.9) to 6.6 (95% CI, 5.1–10.4). CHIKV infection of infant monkeys was detected even when the virus was not detected in a concurrent survey of primatophilic mosquitoes and when population seropositivity, and therefore immunity, was too high for monkeys themselves to support continuous CHIKV transmission. We therefore conclude that monkeys in this region serve primarily as amplification rather than reservoir hosts of CHIKV. Additional efforts are needed to identify other vertebrate hosts capable of supporting continuous circulation.

scholarly journals Blocking the GITR-GITRL pathway to overcome resistance to therapy in sarcomatoid malignant pleural mesothelioma

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Malignant Pleural Mesothelioma ◽  
Neutralizing Antibodies ◽  
Pleural Mesothelioma ◽  
Spheroid Formation ◽  
Resistance To Therapy ◽  
Sarcomatoid Mesothelioma

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.

scholarly journals Helminth Interactions with Bacteria in the Host Gut Are Essential for Its Immunomodulatory Effect

2021 ◽  
Vol 9 (2) ◽  
pp. 226
Author(s):  
Milan Jirků ◽  
Zuzana Lhotská ◽  
Lucia Frgelecová ◽  
Oldřiška Kadlecová ◽  
Klára Judita Petrželková ◽  
...  
Keyword(s):  
Protective Effect ◽  
Intestinal Inflammation ◽  
Hymenolepis Diminuta ◽  
Clinical Parameters ◽  
Th2 Response ◽  
Histological Changes ◽  
Immunological Markers ◽  
Bacterial Microbiota ◽  
Inflammatory Effect

Colonization by the benign tapeworm, Hymenolepis diminuta, has been associated with a reduction in intestinal inflammation and changes in bacterial microbiota. However, the role of microbiota in the tapeworm anti-inflammatory effect is not yet clear, and the aim of this study was to determine whether disruption of the microflora during worm colonization can affect the course of intestinal inflammation. We added a phase for disrupting the intestinal microbiota using antibiotics to the experimental design for which we previously demonstrated the protective effect of H. diminuta. We monitored the immunological markers, clinical parameters, bacterial microbiota, and histological changes in the colon of rats. After a combination of colonization, antibiotics, and colitis induction, we had four differently affected experimental groups. We observed a different course of the immune response in each group, but no protective effect was found. Rats treated with colonization and antibiotics showed a strong induction of the Th2 response as well as a significant change in microbial diversity. The microbial results also revealed differences in the richness and abundance of some bacterial taxa, influenced by various factors. Our data suggest that interactions between the tapeworm and bacteria may have a major impact on its protective effect.

scholarly journals Creating Ecotourism in Costa Rica, 1970–2000

2016 ◽  
Vol 18 (1) ◽  
pp. 146-183 ◽  
Author(s):  
GEOFFREY JONES ◽  
ANDREW SPADAFORA
Keyword(s):  
Costa Rica ◽  
Knowledge Spillovers ◽  
Critical Role ◽  
Environmentally Sustainable ◽  
National Image ◽  
Positive Externalities ◽  
Resource Endowment ◽  
The Government ◽  
New Industry

Between the 1970s and the 2000s, Costa Rica became established as the world’s leading ecotourism destination. This article argues that although Costa Rica benefited from biodiversity and a pleasant climate, the country’s preeminence in ecotourism requires more than a natural resource endowment explanation. While previous literature has emphasized the efforts of the government and nongovernment organizations, this article demonstrates the critical role of small entrepreneurs in the co-creation of the industry. Making extensive use of oral history, the article explores the role of tour companies in drawing affluent Western ecotourists to the country, and of the creators of ecolodges and other forms of accommodation in providing them with somewhere to stay. Clustering created positive externalities, drawing new entrepreneurs into the industry who could also learn from knowledge spillovers. There were downsides to the new industry. The creation of the national image of a natural paradise enabled many businesses which were not environmentally sustainable to free ride on the green image.

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