| 131. |
- Pham-Thanh, Long, et al.
(författare)
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Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam
- 2021
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4-74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.
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| 132. |
- Pham-Thanh, Long, et al.
(författare)
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Livestock Development in Hanoi City, Vietnam-Challenges and Policies
- 2020
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Ingår i: Frontiers in Veterinary Science. - : FRONTIERS MEDIA SA. - 2297-1769. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The rapid urban growth of Hanoi city requires a livestock production system that ensures both food security and the livelihoods of dwellers. This paper reviews the existing policies for livestock production of Hanoi city and the changes in livestock population between 2014 and 2018 and identifies major challenges for livestock development of the city. While a remarkable increase of the livestock population in recent years is evident, the dominance of small-scale farms, the presence of animal diseases, the slow progress of transiting farms out of urban areas, as well as the lack of analysis of climate change and gender impacts are major challenges that could affect the livestock development of Hanoi.
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| 133. |
- Pham-Thanh, Long, 1975-
(författare)
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The influence of urban livestock-keeping on the epidemiology of mosquito-borne zoonotic flaviviruses in Hanoi city of Vietnam
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In rapid urbanizing cities, the high density of livestock populations in close vicinity to humans, and high mosquito vector abundance have provided suitable conditions for transmission of mosquito-borne zoonotic flaviviruses, that cause several million cases of human disease annually. This thesis explores the urban livestock-keeping in Hanoi and its potential influence on the epidemiology of flavivirus infections. Four major components were investigated: livestock development of the city, knowledge and practices of local people on mosquito-borne diseases (MBDs), mosquito vector abundance, and risk factors for flavivirus exposure in animals.The analyses of the livestock development policy, animal data and key informant interviews showed that the livestock production system of Hanoi had increased in line with the governmental policy during 2014 to 2018. However, some major challenges were identified such as the high proportion of small-scale livestock farms, animal diseases, and a slow progress of translocation of livestock farms out of the urban areas.A cross-sectional study was conducted in 513 households in six districts of Hanoi (two urban, two peripheral, and two peri-urban). Knowledge and practices were evaluated; mosquitoes and larvae inside and outside the houses were collected and identified; blood samples of pigs and dogs were tested by a West Nile virus competitive enzyme-linked immunosorbent assay (cELISA), a kit that allowed for detection of antibodies against several flaviviruses of different animal species. JEV-specific antibodies were confirmed by plaque reduction neutralization test (PRNT). Logistic regression models using seropositivity of households as the outcome were built to identify significant risk factors.A low level of knowledge and preventive practices against zoonotic MBDs in community was indicated in the study. Among 12,861 adult mosquitoes and 2,427 larvae collected, Culex mosquitoes were the most abundant (93.01%), followed by Anopheles (3.82%), Mansonia (1.21%), Armigeres (1.18%) and Aedes mosquitoes (0.78%). In contrast, Aedes genus larvae were prominent at 87.02%, followed by Culex spp. (12.2%). There was a positive association between pig-keeping and Culex mosquitoes (p<0.001). In total, 475 dogs and 636 pigs were tested by a cELISA. The overall flavivirus seroprevalences in dogs and pigs were 70.7% and 88.5%, respectively. The PRNT results for a subset of 50 dog sera (34 positive, 6 doubtful and 10 negative samples by cELISA), and 50 pig sera (26 positive, 6 doubtful and 18 negative samples by cELISA) showed a lower proportion of JEV-specific antibodies (28 positives for dog samples, and 13 positives for pig samples). In conclusion, this thesis shows associations between livestock-keeping and risks of mosquito-borne zoonotic flavivirus infections to humans in Hanoi.
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| 134. |
- Pham-Thanh, Long, et al.
(författare)
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Zoonotic Flavivirus Exposure in Peri-Urban and Suburban Pig-Keeping in Hanoi, Vietnam, and the Knowledge and Preventive Practices of Pig Farmers
- 2022
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Ingår i: Tropical Medicine and Infectious Disease. - : MDPI. - 2414-6366. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- Mosquito-borne diseases (MBDs), including those caused by flaviviruses, remain human health problems for developing and urbanizing economies. This cross-sectional study examined risks of flavivirus exposure through a survey regarding knowledge and practices of pig farmers, and serological analysis of pigs in peri-urban and suburban Hanoi city. A total of 636 pig sera from 179 pig farms in 4 districts, namely, Chuong My, Dan Phuong, Ha Dong, and Bac Tu Liem, were analyzed by a competitive ELISA designed for flavivirus antibody detection. The results indicated a low level of awareness about MBDs among pig farmers, and a high seroprevalence in pigs at 88.5% (95%CI = 85.8-90.9%). Moreover, common practices of pig owners to prevent mosquitoes at home and farm did not show a significant reduction in flavivirus exposure in pigs. At animal level, significant associations between seropositive pigs and the farms with more than 60 pigs, and the district location were found. Farm-level multivariable analysis did not identify significant risk factors for flavivirus exposure. The study suggests that improving awareness of pig owners about MBDs in Hanoi city may be warranted to reduce the risk for MBD flavivirus infections in both humans and pigs.
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| 135. |
- Plyusnin, Alexander, et al.
(författare)
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Validation of an antigenic site targeted by monoclonal antibodies against Puumala virus
- 2023
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Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 104:10
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Tidskriftsartikel (refereegranskat)abstract
- Identification of B-cell epitopes facilitates the development of vaccines, therapeutic antibodies and diagnostic tools. Previously, the binding site of the bank vole monoclonal antibody (mAb) 4G2 against Puumala virus (PUUV, an orthohantavirus in the Hantaviridae family of the Bunyavirales order) was predicted using a combination of methods, including pepscan, phage-display, and site-directed mutagenesis of vesicular stomatitis virus (VSV) particles pseudotyped with Gn and Gc glycoproteins from PUUV. These techniques led to the identification of the neutralization escape mutation F915A. To our surprise, a recent crystal structure of PUUV Gc in complex with Fab 4G2 revealed that residue F915 is distal from epitope of mAb 4G2. To clarify this issue and explore potential explanations for the inconsistency, we designed a mutagenesis experiment to probe the 4G2 epitope, with three PUUV pseudoviruses carrying amino acid changes E725A, S944F, and S946F, located within the structure-based 4G2 epitope on the Gc. These amino acid changes were able to convey neutralization escape from 4G2, and S944F and S946F also conveyed escape from neutralization by human mAb 1C9. Furthermore, our mapping of all the known neutralization evasion sites from hantaviral Gcs onto PUUV Gc revealed that over 60 % of these sites reside within or close to the epitope of mAb 4G2, indicating that this region may represent a crucial area targeted by neutralizing antibodies against PUUV, and to a lesser extent, other hantaviruses. The identification of this site of vulnerability could guide the creation of subunit vaccines against PUUV and other hantaviruses in the future.
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| 136. |
- Puckett, Emily E., et al.
(författare)
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Genomic analyses reveal three independent introductions of the invasive brown rat (Rattus norvegicus) to the Faroe Islands
- 2020
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Ingår i: Heredity. - : NATURE PUBLISHING GROUP. - 0018-067X .- 1365-2540. ; 124:1, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Population genomics offers innovative approaches to test hypotheses related to the source and timing of introduction of invasive species. These approaches are particularly appropriate to study colonization of island ecosystems. The brown rat is a cold-hardy global invasive that has reached most of the world's island ecosystems, including even highly isolated archipelagoes such as the Faroe Islands in the North Atlantic Ocean. Historic records tell of rats rafting to the southern island of Suouroy in 1768 following a shipwreck off the coast of Scotland, then expanding across the archipelago. We investigated the demographic history of brown rats in the Faroes using 50,174 SNPs. We inferred three independent introductions of rats, including to Suouroy, the islands of Borooy and Viooy, and onto Streymoy from which they expanded to Eysturoy and Vagar. All Faroese populations showed signs of strong bottlenecks and declining effective population size. We inferred that these founder events removed low frequency alleles, the exact data needed to estimate recent demographic histories. Therefore, we were unable to accurately estimate the timing of each invasion. The difficulties with demographic inference may be applicable to other invasive species, particularly those with extreme and recent bottlenecks. We identified three invasions of brown rats to the Faroe Islands that resulted in highly differentiated populations that will be useful for future studies of life history variation and genomic adaptation.
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| 137. |
- Puckett, Emily E., et al.
(författare)
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Global population divergence and admixture of the brown rat (Rattus norvegicus)
- 2016
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 283:1841
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Tidskriftsartikel (refereegranskat)abstract
- Native to China and Mongolia, the brown rat (Rattus norvegicus) now enjoys a worldwide distribution. While black rats and the house mouse tracked the regional development of human agricultural settlements, brown rats did not appear in Europe until the 1500s, suggesting their range expansion was a response to relatively recent increases in global trade. We inferred the global phylogeography of brown rats using 32 k SNPs, and detected 13 evolutionary clusters within five expansion routes. One cluster arose following a southward expansion into Southeast Asia. Three additional clusters arose from two independent eastward expansions: one expansion from Russia to the Aleutian Archipelago, and a second to western North America. Westward expansion resulted in the colonization of Europe from which subsequent rapid colonization of Africa, the Americas and Australasia occurred, and multiple evolutionary clusters were detected. An astonishing degree of fine-grained clustering between and within sampling sites underscored the extent to which urban heterogeneity shaped genetic structure of commensal rodents. Surprisingly, few individuals were recent migrants, suggesting that recruitment into established populations is limited. Understanding the global population structure of R. norvegicus offers novel perspectives on the forces driving the spread of zoonotic disease, and aids in development of rat eradication programmes.
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| 138. |
- Rissanen, Ilona, et al.
(författare)
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Molecular rationale for antibody-mediated targeting of the hantavirus fusion glycoprotein
- 2020
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Ingår i: eLIFE. - : eLife Sciences Publications, Ltd. - 2050-084X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The intricate lattice of Gn and Gc glycoprotein spike complexes on the hantavirus envelope facilitates host-cell entry and is the primary target of the neutralizing antibody-mediated immune response. Through study of a neutralizing monoclonal antibody termed mAb P-4G2, which neutralizes the zoonotic pathogen Puumala virus (PUUV), we provide a molecular-level basis for antibody-mediated targeting of the hantaviral glycoprotein lattice. Crystallographic analysis demonstrates that P-4G2 binds to a multi-domain site on PUUV Gc and may preclude fusogenic rearrangements of the glycoprotein that are required for host-cell entry. Furthermore, cryoelectron microscopy of PUUV-like particles in the presence of P-4G2 reveals a lattice-independent configuration of the Gc, demonstrating that P-4G2 perturbs the (Gn-Gc)(4) lattice. This work provides a structure-based blueprint for rationalizing antibody-mediated targeting of hantaviruses.
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| 139. |
- Sevencan, Funda, et al.
(författare)
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Serologic Investigation of Hantavirus Infection in Patients with Previous Thrombocytopenia, and Elevated Urea and Creatinine Levels in an Epidemic Region of Turkey
- 2015
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Ingår i: Japanese journal of infectious diseases (Print). - 1344-6304 .- 1884-2836. ; 68:6, s. 488-493
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Tidskriftsartikel (refereegranskat)abstract
- The first cases of Hantavirus infection in Turkey were reported in early 2009 in the Zonguldak and Bartin provinces. The aim of this study was to investigate the presence of Hantavirus antibodies in patients who had clinical and laboratory findings that were potentially associated with Hantavirus infection prior to the epidemic in Bartin in 2009. After screening 314,577 medical records from between 2007 and 2009, the clinical and laboratory data for 442 patients meeting the criteria of coexistent thrombocytopenia, and elevated urea and creatinine levels were transferred to a statistical program. Home visits were made to 170 patients, 84 of whom consented to participate in the study. The participants completed a questionnaire and provided a blood sample. Commercial anti-Hantavirus IgG and IgM ELISA and immunoblotting assays were used, with seropositive samples being confirmed by focus reduction neutralization tests (FRNT). ELISA and/or immunoblotting assays detected 10 positive samples; however, only 7 of these were recorded as positive by FRNT. FRNT positivity was significantly associated with female sex, the presence of a barn near to the house, and working in a forest (P < 0.05). In a Hantavirus endemic region, physicians must keep in mind that thrombocytopenia, and elevated urea and creatinine levels may indicate Hantavirus infection.
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| 140. |
- Sharma, Garima, et al.
(författare)
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Antibiotic use, knowledge, and practices of milk vendors in India's informal dairy value chain
- 2022
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Ingår i: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Milk vendors play an important role in India's dairy value chain; however, their food safety practices are poorly understood. From the standpoint of milk safety, vendor behavior is significant because it has the potential to affect both consumer and producer behavior. This study investigates vendors' hygienic knowledge and practices toward milk safety, and antimicrobial resistance (AMR)Methods: A cross-sectional study was conducted in the states of Assam and Haryana (India). In selected villages, all the milk vendors identified at the time of the visit were interviewed. A questionnaire was used to assess the knowledge and practices on antibiotics, milk safety, and hygiene. The milk samples were tested for the presence of antibiotic-resistant bacteria using antibiotic susceptibility testing.Results: A total of 2444 milk vendors were interviewed during the survey. Out of these 156 (59.8%) of the vendors traded in raw milk while 40.2% traded in pasteurizes milk. Vendors were categorized depending on whom they supplied milk. Five categories were identified: (a) those who sold at grocery shops; (b) those who sold on the roadside; (c) those who sold from door to door; (d) those who sold to sweet makers/tea stalls; (e) those who sold from own home/other entity. The level of training among vendors on milk hygiene was non-existent and the knowledge related to antibiotics was low. Most of them (86.07%) agreed that boiled milk is always safer than raw milk but almost half (48.77%) of them admitted that sometimes they drink milk without boiling it. Most vendors believed that they could identify whether milk is safe or not for consumption just by its appearance and smell. Out of 124 milk samples collected from surveyed milk vendors and tested for the presence of antibiotic-resistant bacteria, 80 (64.52%) tested positive.Conclusion: This study highlights the low levels of knowledge regarding food safety among milk vendors. It shows the predominance of informal milk businesses in the surveyed states and the prevalence of AMR bacteria in milk traded by them. Training may be a beneficial strategy for addressing the issue.
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