Related items
Showing items related by metadata.
-
ArticleWaterfowl Spring Migratory Behavior and Avian Influenza Transmission Risk in the Changing Landscape of the East Asian-Australasian Flyway
Frontiers Ecology and Evolution, Volume 6, Article 206
2018Also available in:
No results found.Avian influenza has advanced from a regional concern to a global health issue with significant economic, trade, and public health implications. Wild birds, particularly waterfowl (Anseriformes), are known reservoirs for low-pathogenic avian influenza viruses (AIV) and recent studies have shown their potential in the spread of highly pathogenic forms of virus. East Asia remains an epicenter for the emergence of novel strains of AIV, however, information on movement ecology of waterfowl, and subsequently a clearer understanding of disease transmission risks in this region has been greatly lacking. To address this, we marked two species of wild waterfowl, northern pintail (Anas acuta) and Eurasian wigeon (Anas penelope), with satellite transmitters on their wintering grounds in Hong Kong, China to study the northward spring migration in the East Asian Australasian Flyway in relation to disease transmission factors. Northern pintail were found to initiate migration 42 days earlier, travel 2,150 km farther, and perform 4.4 more stopovers than Eurasian wigeon. We found both species used similar stopover locations including areas along the Yangtze River near Shanghai, Bohai Bay and Korea Bay in rapidly developing regions of the Yellow Sea, and the Sea of Okhotsk where the species appeared to funnel through a migratory bottleneck. Both species appeared to exhibit strong habitat selection for rice paddies during migration stopovers, a habitat preference which has the potential to influence risks of AIV outbreaks as rapid land use and land cover changes occur throughout China. Both species had greatest association with H5N1 outbreaks during the early stages of migration when they were at lower latitudes. While Eurasian wigeon were not associated with outbreaks after the mean date of wintering ground departures, northern pintail were associated with outbreaks until the majority of individuals departed from the Yellow Sea, a migratory stopover location. Our results show species-level differences in migration timing and behavior for these common and widespread species, demonstrating the need to consider their unique temporal and spatial movement ecology when incorporating wild birds into AIV risk modeling and management. -
Book (series)Impact of mastitis in small scale dairy production systems 2014
Also available in:
No results found.Mastitis is the most prevalent production disease in dairy herds worldwide and it is well documented as disease with a heavy burden in developed countries, while very limited information is available for developing countries. This paper reviews the existing literature on the topic of mastitis to assist in the analysis of its occurrence in developing countries, focusing on small-scale farming systems and to provide information on the economic dimension of the disease in resource-poor environments . To the author’s knowledge, there are no pertinent published studies and so the purpose here is to summarize most of the data available on mastitis in resourcepoor environments, with a focus on small-scale producers. The papers reviewed show a significant prevalence of the disease throughout numerous herds in different countries in Africa and Asia, especially in its sub-clinical form. Economic estimates were limited to a few countries and conducted with disparate methodologies. Another issue hi ghlighted is the lack of awareness among farmers of the subclinical form of the disease, and this aspect is of fundamental importance because of the possibility of spreading infectious agents through the herd. The lack of medical treatment means, as demonstrated, an increase in the occurrence of mastitis cases on the farm, a consistent decrease in milk yield (up to 33% per quarter infected), a public health risk due to consumption of unsafe milk, and less efficient processing of milk. The data c ollected and organized can be used as a starting point to concentrate future efforts on the study and control of mastitis and its impact in developing countries, with a focus on its relevance for vulnerable small-scale farmer households. -
DocumentCommune-level Simulation Model of HPAI H5N1 Poultry Infection and Control in Viet Nam
Pro-Poor Livestock Policy Initiative: A Living from Livestock
2006Also available in:
No results found.This report describes a farm-based disease transmission model that approximates the dynamics of HPAI H5N1 outbreaks in Vietnam poultry farms. During model experimentation the impact of varying different sets of epidemiological parameters on the number of infected farms, the force of infection and on the net reproductive number within a commune were simulated. The average net reproductive number (secondary cases arising from one infected farm in a vaccinated population), Rn, in the most lenient c ontrol scenario was 2.26. Current disease control measures are predicted to significantly reduce disease transmission but do not completely eliminate the possibility for circulation of residual infection (Rn. = 1.05). A disease control optimization process which takes into account the differences in farm structure between geographical regions shows that optimal disease control policies differ, depending on local conditions. However, they also suggest that complete elimination of HPAI H5N1 from d omestic poultry in Vietnam requires high levels of vaccination coverage of S4 backyard farms, levels that are unlikely to be achievable. Therefore, more attention must be paid to early detection of infection and reduced response time.
Users also downloaded
Showing related downloaded files
No results found.