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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 Anoph, Formas, grant number 2016-00364

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.

Mosquito-borne diseases (MBDs) are causing high morbidity and mortality for humans. Urban livestock keeping is still common in cities around the world. The animals may serve as reservoirs for zoonotic MBDs, which increase the risks for humans. Here we assess the knowledge and practices related to MBDs in households with livestock and without livestock and explore the perceptions of the health care sector about MBDs and livestock keeping in Hanoi city of Vietnam in a cross-sectional study. A quantitative survey was conducted including 513 households with and without livestock-keeping in six districts and complemented with qualitative surveys with four health staff from Hanoi Center of Disease Control and three district health centers. The quantitative survey indicated that the participants possessed basic knowledge on MBDs with an average score of 18.3 out of 35, of which non-livestock-keeping households had a better knowledge than households keeping livestock (p<0.05). Both household categories had low score, 3.5 out of 11, regarding preventive practices against MBDs. The negative binomial model showed that occupation and location of living were factors associated to the knowledge on MBDs. Farmers were likely to have better preventive practices as compared to office workers (p<0.05). Those who had better knowledge also had more adequate preventive practices against MBDs (p<0.001). The qualitative survey revealed that livestock keeping was determined as increasing risks of MBDs due to the increase of mosquito population. It is recommended that community campaigns to raise the awareness and change behavior on MBDs should be organized based on collaboration between the health sector and the veterinary sector for households with and without livestock living in central urban and peri-urban areas. Further studies are needed to confirm the association between urban livestock keeping and potential increasing risks of MBDs such as dengue and Japanese encephalitis.

In the updated NDC, Vietnam has allocated mitigation targets to energy, agriculture, industrial processes and product use (IPPU), land use, land use and forestry change (LULUCF) and waste in the period of 2021-2030. The establishment of a measurement, reporting and verification system (MRV) at national and sectoral levels is necessary to track the progress towards national and sectoral mitigation targets. However, at present very few studies on MRV indicators and remain fragmented. To meet that urgent need, this study was implemented to develop MRV indicators for mitigation actions to support the policy makers in tracking the NDC implementation. In this paper, a set of 85 MRV indicators divided into two categories: (i) 12 outcome indicators to track the national and sectoral mitigation targets, (ii) 72 progress indicators to track the implementation of mitigation options (including 40 for energy, 14 for agriculture, 7 for LULUCF, 4 for IPPU and 7 for waste) were developed based on relevant studies and expert consultation. The paper also tested the application of progress indicators in several mitigation options in the energy sector. The result showed that in energy sector, in 2014 the two mitigation options that have highest progress include: High efficiency residential refrigerators (0.85) and Introduction of CNG buses (0.75). Freight transport shift from road to railway and Cleaner cooking fuels had average values of progress indicators, 0.53 and 0.6, with respectively. The indicator values of the other tested mitigation options were all below 0.4 and hence greater efforts is needed to reach the mitigation targets.