scholarly journals Quantification of Site Layout and Filter Characteristics on Primary Filter Airflow Reduction on Commercial Swine Sites in Iowa

2019 ◽  
Vol 1 (2) ◽  
pp. 291-302
Author(s):  
Benjamin Smith ◽  
Steven Hoff ◽  
Jay Harmon ◽  
Daniel Andersen ◽  
Jeffrey Zimmerman ◽  
...  
Keyword(s):  
Influenza A ◽  
Energy Use ◽  
Reduction Rate ◽  
Disease Outbreaks ◽  
Respiratory Syndrome Virus ◽  
Positive Pressure ◽  
Row Crop ◽  
Site Layout ◽  
Crop Harvest ◽  
The Impact

Fresh air intake filtration is used on commercial swine breeding-gestation-farrowing farms to reduce the frequency of airborne infectious agents. For swine producers, porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus and Mycoplasma hyopneumoniae are considered the most economically challenging airborne pathogens. Reduced frequency of disease outbreaks has been attributed to retrofitting existing systems with filtration. Economic analysis of operating costs includes energy use, maintenance and replacement of filters. Filter replacement, the largest operational cost, is dependent on filter lifespan. However, limited data is available on filter lifespan and the rate of airflow reduction during the high dust-loading periods typically encountered for filtered swine building ventilation systems. Therefore, the objectives of this study were (1) estimate the average primary filter airflow reduction per day, (2) identify the impact of factors related to site layout, filter characteristics and weather on airflow reduction rates of filters in positive-pressure ventilated buildings and (3) determine methods for reducing average primary filter airflow reduction rate per day during row-crop harvest season. Both filter brand and the installed orientation of the filter significantly (p = 0.0314, p = 0.0419, respectively) impacted airflow reduction rates. All site layout factors were significant (driveway side, p = 0.001; dormer orientation, p = 0.0001; and dormer configuration, p = 0.0001). The materials tested significantly reduced the airflow reduction rate during row-crop harvest. The information obtained in this study will aid producers when planning for filtration, highlight details relevant to the purchase and installation of filters, identify factors that affect filter lifespan and identify methods for improving filter lifespan.

scholarly journals Live Poultry Market Closure and Avian Influenza A (H7N9) infection in cities of China, 2013-2017: An ecological study

2020 ◽  
Author(s):  
Ying Chen ◽  
Jian Cheng ◽  
Zhiwei Xu ◽  
Wenbiao Hu ◽  
Jiahai Lu
Keyword(s):  
Avian Influenza ◽  
Risk Reduction ◽  
Influenza A ◽  
Reduction Rate ◽  
Dominant Factor ◽  
Effective Measure ◽  
Partial Closure ◽  
Live Poultry ◽  
H7n9 Infection ◽  
The Impact

Abstract Background Previous studies have proven that the closure of live poultry markets (LPMs) was an effective intervention to reduce human risk of avian influenza A (H7N9) infection, but evidence is limited on the impact of scale and duration of LPMs closure on the transmission of H7N9. Method Five cities (i.e., Shanghai, Suzhou, Shenzhen, Guangzhou and Hangzhou) with the largest number of H7N9 cases in mainland China from 2013-2017 were selected in this study. Data on laboratory-confirmed H7N9 human cases in those five cities were obtained from the Chinese National Influenza Centre. The detailed information of LPMs closure (i.e., area and duration) was obtained from the Ministry of Agriculture. We used a generalized linear model with a Poisson link to estimate the effect of LPMs closure, reported as relative risk reduction (RRR). We used classification and regression trees (CARTs) to select and quantify the dominant factor of H7N9 infection. Results All five cities implemented the LPMs closure, and the risk of H7N9 infection decreased significantly after LPMs closure with RRR ranging from 0.80-0.93. Respectively, a long-term LPMs closure for 10-13 weeks elicited a sustained and highly significant risk reduction of H7N9 infection (RRR = 0.98). Short-time LPMs closure with 2 weeks in every epidemic did not reduce the risk of H7N9 infection (p>0.05). Partially closed LPMs in some suburbs contributed only 35% for reduction rate (RRR=0.35). Shenzhen implemented partial closure for first 3 epidemics (p>0.05) and all closure in the latest 2 epidemic waves (RRR=0.64). Conclusion Our findings suggest that LPMs all closure in whole city can be a highly effective measure comparing with partial closure (i.e. only urban closure, suburb and country remain open). Extend the duration of closure and consider permanently closing the LPMs will help improve the control effect. The effect of LPMs closure is greater than that of meteorology on H7N9 transmission.

scholarly journals Live Poultry Market Closure and Avian Influenza A (H7N9) infection in cities of China, 2013-2017: An ecological study

2020 ◽  
Author(s):  
Ying Chen ◽  
Jian Cheng ◽  
Zhiwei Xu ◽  
Wenbiao Hu ◽  
Jiahai Lu
Keyword(s):  
Avian Influenza ◽  
Risk Reduction ◽  
Influenza A ◽  
Reduction Rate ◽  
Dominant Factor ◽  
Effective Measure ◽  
Partial Closure ◽  
Live Poultry ◽  
H7n9 Infection ◽  
The Impact

Abstract Background Previous studies have proven that the closure of live poultry markets (LPMs) was an effective intervention to reduce human risk of avian influenza A (H7N9) infection, but evidence is limited on the impact of scale and duration of LPMs closure on the transmission of H7N9. Method Five cities (i.e., Shanghai, Suzhou, Shenzhen, Guangzhou and Hangzhou) with the largest number of H7N9 cases in mainland China from 2013-2017 were selected in this study. Data on laboratory-confirmed H7N9 human cases in those five cities were obtained from the Chinese National Influenza Centre. The detailed information of LPMs closure (i.e., area and duration) was obtained from the Ministry of Agriculture. We used a generalized linear model with a Poisson link to estimate the effect of LPMs closure, reported as relative risk reduction (RRR). We used classification and regression trees (CARTs) to select and quantify the dominant factor of H7N9 infection. Results All five cities implemented the LPMs closure, and the risk of H7N9 infection decreased significantly after LPMs closure with RRR ranging from 0.80-0.93. Respectively, a long-term LPMs closure for 10-13 weeks elicited a sustained and highly significant risk reduction of H7N9 infection (RRR = 0.98). Short-time LPMs closure with 2 weeks in every epidemic did not reduce the risk of H7N9 infection (p>0.05). Partially closed LPMs in some suburbs contributed only 35% for reduction rate (RRR=0.35). Shenzhen implemented partial closure for first 3 epidemics (p>0.05) and all closure in the latest 2 epidemic waves (RRR=0.64). Conclusion Our findings suggest that LPMs all closure in whole city can be a highly effective measure comparing with partial closure (i.e. only urban closure, suburb and country remain open). Extend the duration of closure and consider permanently closing the LPMs will help improve the control effect. The effect of LPMs closure is greater than that of meteorology on H7N9 transmission.

scholarly journals 111 Common nutritional and infectious health challenges in nursery pigs

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 62-63
Author(s):  
Eric R Burrough ◽  
Nicholas K Gabler
Keyword(s):  
Influenza A ◽  
Diagnostic Testing ◽  
Clinical Signs ◽  
Enterotoxigenic Escherichia Coli ◽  
Detection Methods ◽  
Respiratory Syndrome Virus ◽  
Common Source ◽  
Poor Growth ◽  
Nursery Pigs ◽  
The Impact

Abstract Poor starting nursery pigs are a common source of frustration for pork producers due to suboptimal lean tissue production and failure to thrive. This is generally a multifactorial issue with potential nutritional, infectious and management contributors. Commonly encountered respiratory and enteric pathogens include porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), porcine enteric coronaviruses (TGEV/PEDV/PDCV), and group A, B, and C rotaviruses, as well as Salmonella typhimurium, enterotoxigenic Escherichia coli, Streptococcus suis, and Haemophilus parasuis. Infection with one or more of these agents can ultimately antagonize pig health and performance. However, while these specific pathogens may be causing an observed disease symptom, pigs may have been predisposed to infection due to various management, nutritional, and environmental risk factors. As many of these potential pathogens are endemic in production systems, it is important to remember that simply detecting a potential pathogen within a population is often not sufficient to assign cause for poor growth and production. To help fully interpret the impact of a detected agent, diagnostic efforts should focus on providing proof that the agent is actually causing disease. Molecular detection methods, such as PCR, are increasingly available for common pathogens and have high diagnostic sensitivity but lower diagnostic specificity. This paper will discuss the clinical signs and gross and microscopic lesions associated with common nursery pig pathogens, as well as proper sampling and diagnostic testing necessary to detect and confirm disease following infection with these agents.

scholarly journals Estimating the Effect of Respiratory Disease on Production Performance in Farrow-to-Finish Pig Farms

2020 ◽  
Author(s):  
Maria Rodrigues da Costa ◽  
Albert Rovira ◽  
Montserrat Torremorell ◽  
Rose Mary Fitzgerald ◽  
Josep Gasa ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Influenza A ◽  
Average Daily Gain ◽  
Disease Status ◽  
Production Performance ◽  
Respiratory Syndrome Virus ◽  
Feed Conversion ◽  
Pig Farms ◽  
Pig Performance ◽  
The Impact

Abstract Background Respiratory disease is one of the most important factors impacting pig production worldwide. However, the literature highlights the multitude of confounding factors complicating the clear attribution of growth impairment to respiratory disease, and the extrapolation of the effects of respiratory disease to a wider population has not been thoroughly researched. The objective of this study was to estimate the impact of respiratory disease on production performance in a subset of 56 Irish farrow-to-finish pig farms. Proxies for respiratory disease status such as serology for four major pathogens (influenza A virus, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae ), slaughter checks (pleurisy, pneumonia, lung abscesses, pericarditis and liver milk spots) and vaccination information were used as predictors for production performance. Results The models to estimate production performance from serology, slaughter checks, and vaccination were able to explain the variability of weaner and finisher mortality by 26 and 20%, respectively, and average daily feed intake (ADFI), average daily gain (ADG) and age at slaughter by 47, 40 and 41%, respectively. Feed conversion ratio and sow performance were not explained by the studied predictors. Conclusions The models fitted, especially those for ADFI, ADG and age at slaughter, emphasize the usefulness of sourcing information at different levels to understand the impact of farm health status on pig performance, and highlight the impact of respiratory disease on production performance.

scholarly journals Arterivirus molecular biology and pathogenesis

2013 ◽  
Vol 94 (10) ◽  
pp. 2141-2163 ◽  
Author(s):  
Eric J. Snijder ◽  
Marjolein Kikkert ◽  
Ying Fang
Keyword(s):  
Reverse Genetics ◽  
Function Analysis ◽  
Evolutionary Relationship ◽  
Disease Outbreaks ◽  
Equine Arteritis Virus ◽  
Respiratory Syndrome Virus ◽  
The Past ◽  
Protein Functions ◽  
The Usa ◽  
The Impact

Arteriviruses are positive-stranded RNA viruses that infect mammals. They can cause persistent or asymptomatic infections, but also acute disease associated with a respiratory syndrome, abortion or lethal haemorrhagic fever. During the past two decades, porcine reproductive and respiratory syndrome virus (PRRSV) and, to a lesser extent, equine arteritis virus (EAV) have attracted attention as veterinary pathogens with significant economic impact. Particularly noteworthy were the ‘porcine high fever disease’ outbreaks in South-East Asia and the emergence of new virulent PRRSV strains in the USA. Recently, the family was expanded with several previously unknown arteriviruses isolated from different African monkey species. At the molecular level, arteriviruses share an intriguing but distant evolutionary relationship with coronaviruses and other members of the order Nidovirales. Nevertheless, several of their characteristics are unique, including virion composition and structure, and the conservation of only a subset of the replicase domains encountered in nidoviruses with larger genomes. During the past 15 years, the advent of reverse genetics systems for EAV and PRRSV has changed and accelerated the structure–function analysis of arterivirus RNA and protein sequences. These systems now also facilitate studies into host immune responses and arterivirus immune evasion and pathogenesis. In this review, we have summarized recent advances in the areas of arterivirus genome expression, RNA and protein functions, virion architecture, virus–host interactions, immunity, and pathogenesis. We have also briefly reviewed the impact of these advances on disease management, the engineering of novel candidate live vaccines and the diagnosis of arterivirus infection.

scholarly journals Antibody responses to porcine reproductive and respiratory syndrome virus, influenza A virus, and Mycoplasma hyopneumoniae from weaning to the end of the finisher stage in fourteen groups of pigs in Ontario

2020 ◽  
Author(s):  
Elana Raaphorst ◽  
Abdolvahab Farzan ◽  
Robert M. Friendship ◽  
Brandon N. Lillie
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Control Strategies ◽  
Serum Antibody ◽  
Swine Influenza ◽  
Mycoplasma Hyopneumoniae ◽  
Antibody Responses ◽  
Respiratory Syndrome Virus ◽  
Swine Farms ◽  
The Impact

Abstract Background Porcine reproductive and respiratory syndrome, swine influenza, and mycoplasmal pneumonia are some of the most prevalent respiratory diseases affecting swine farm productivity in Canada. Monitoring for the prevalence of the infectious agents associated with these diseases on farm may help to improve herd-specific control strategies and to minimize the impact of disease on commercial swine farms. The objectives of this study were to investigate antibody responses to porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and Mycoplasma hyopneumoniae ( M. hyopneumoniae ) from weaning to the end of the finisher stage on a subset of commercial swine farms in Ontario and to examine the effects of nursery diet on antibody responses. Results Serology found 8, 61, and 31% of pigs at weaning, 1, 31, and 22% at the end of nursery, 8, 38, and 18% at the end of grower, and 11, 48, and 25% at the end of the finisher stage tested seropositive for PRRSV, IAV, and M. hyopneumoniae, respectively. Of the groups tested for PRRSV, IAV, and M. hyopneumoniae, 3, 14, and 5 groups had > 20% of pigs that tested seropositive at least once over the course of production (“high seropositivity”). In general, seropositivity was more likely to be lower at the end of nursery compared to the other production stages for all three pathogens, and more likely to be higher for PRRSV and IAV at weaning, end of grower, and end of finisher. Pigs that were seropositive for PRRSV were more likely to be seropositive forM. hyopneumoniae (p < 0.001). Overall, pigs fed a low complexity diet during nursery were more likely to be seropositive for PRRSV (p < 0.001) and IAV (p = 0.04). Conclusions This study provides information regarding changes in serum antibody in pigs across different stages of production and highlights periods of vulnerability. Additionally, these findings may encourage further research into the effects of nursery diet complexity on disease susceptibility and immune response.

The Swine Flu Pandemic – Should We Be Concerned?

2021 ◽  
Vol 49 (1) ◽  
pp. 46-50
Author(s):  
Ross MacKenzie
Keyword(s):  
Life Insurance ◽  
Influenza A ◽  
Insurance Industry ◽  
Disease Outbreaks ◽  
Swine Flu ◽  
H1n1 Pandemic ◽  
Jigsaw Puzzle ◽  
Life Insurance Industry ◽  
Influenza A H1n1 ◽  
The Impact

As I write this review, we are in the midst of the 2009 influenza A (H1N1) pandemic. The extent and impact of this pandemic is still unknown. Although daily reports on confirmed cases and deaths provide a constant stream of detailed information, it is not possible to predict with any degree of precision the impact the outbreak will have in society in general or on the life insurance industry in particular.1 The epidemiology of such disease outbreaks has been likened to a jigsaw puzzle, and we are now at the stage where the picture is intriguing even if we are not sure what we are seeing.2

scholarly journals Live Poultry Market Closure and Avian Influenza A (H7N9) infection in cities of China, 2013-2017: An ecological study

2020 ◽  
Author(s):  
Ying Chen ◽  
Jian Cheng ◽  
Zhiwei Xu ◽  
Wenbiao Hu ◽  
Jiahai Lu
Keyword(s):  
Avian Influenza ◽  
Risk Reduction ◽  
Influenza A ◽  
Reduction Rate ◽  
Dominant Factor ◽  
Effective Measure ◽  
Partial Closure ◽  
Live Poultry ◽  
H7n9 Infection ◽  
The Impact

Abstract Background: Previous studies have proven that the closure of live poultry markets (LPMs) was an effective intervention to reduce human risk of avian influenza A (H7N9) infection, but evidence is limited on the impact of scale and duration of LPMs closure on the transmission of H7N9. Method: Five cities (i.e., Shanghai, Suzhou, Shenzhen, Guangzhou and Hangzhou) with the largest number of H7N9 cases in mainland China from 2013 to 2017 were selected in this study. Data on laboratory-confirmed H7N9 human cases in those five cities were obtained from the Chinese National Influenza Centre. The detailed information of LPMs closure (i.e., area and duration) was obtained from the Ministry of Agriculture. We used a generalized linear model with a Poisson link to estimate the effect of LPMs closure, reported as relative risk reduction (RRR). We used classification and regression trees (CARTs) model to select and quantify the dominant factor of H7N9 infection. Results: All five cities implemented the LPMs closure, and the risk of H7N9 infection decreased significantly after LPMs closure with RRR ranging from 0.80 to 0.93. Respectively, a long-term LPMs closure for 10-13 weeks elicited a sustained and highly significant risk reduction of H7N9 infection (RRR = 0.98). Short-time LPMs closure with 2 weeks in every epidemic did not reduce the risk of H7N9 infection (p>0.05). Partially closed LPMs in some suburbs contributed only 35% for reduction rate (RRR=0.35). Shenzhen implemented partial closure for first 3 epidemics (p>0.05) and all closure in the latest 2 epidemic waves (RRR=0.64). Conclusion: Our findings suggest that LPMs all closure in whole city can be a highly effective measure comparing with partial closure (i.e. only urban closure, suburb and rural remain open). Extend the duration of closure and consider permanently closing the LPMs will help improve the control effect. The effect of LPMs closure seems greater than that of meteorology on H7N9 transmission.

Impact of influenza virus during pregnancy: from disease severity to vaccine efficacy

2020 ◽  
Vol 15 (7) ◽  
pp. 441-453
Author(s):  
Ana Vazquez-Pagan ◽  
Rebekah Honce ◽  
Stacey Schultz-Cherry
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Pregnant Women ◽  
Disease Severity ◽  
Influenza A ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
Severe Influenza ◽  
The Impact

Pregnant women are among the individuals at the highest risk for severe influenza virus infection. Infection of the mother during pregnancy increases the probability of adverse fetal outcomes such as small for gestational age, preterm birth and fetal death. Animal models of syngeneic and allogeneic mating can recapitulate the increased disease severity observed in pregnant women and are used to define the mechanism(s) of that increased severity. This review focuses on influenza A virus pathogenesis, the unique immunological landscape during pregnancy, the impact of maternal influenza virus infection on the fetus and the immune responses at the maternal–fetal interface. Finally, we summarize the importance of immunization and antiviral treatment in this population and highlight issues that warrant further investigation.

scholarly journals The Effects of Social Distancing Policies on non-SARS-CoV-2 Respiratory Pathogens

2021 ◽  
Author(s):  
Jeff Nawrocki ◽  
Katherine Olin ◽  
Martin C Holdrege ◽  
Joel Hartsell ◽  
Lindsay Meyers ◽  
...  
Keyword(s):  
Public Health ◽  
Influenza A ◽  
Detection Rate ◽  
Respiratory Illness ◽  
Respiratory Pathogens ◽  
Public Health Response ◽  
Mixed Effect ◽  
Detection Rates ◽  
Social Distancing ◽  
The Impact

Abstract Background The initial focus of the US public health response to COVID-19 was the implementation of numerous social distancing policies. While COVID-19 was the impetus for imposing these policies, it is not the only respiratory disease affected by their implementation. This study aimed to assess the impact of social distancing policies on non-SARS-CoV-2 respiratory pathogens typically circulating across multiple US states. Methods Linear mixed-effect models were implemented to explore the effects of five social distancing policies on non-SARS-CoV-2 respiratory pathogens across nine states from January 1 through May 1, 2020. The observed 2020 pathogen detection rates were compared week-by-week to historical rates to determine when the detection rates were different. Results Model results indicate that several social distancing policies were associated with a reduction in total detection rate, by nearly 15%. Policies were associated with decreases in pathogen circulation of human rhinovirus/enterovirus and human metapneumovirus, as well as influenza A, which typically decrease after winter. Parainfluenza viruses failed to circulate at historical levels during the spring. Total detection rate in April 2020 was 35% less than historical average. Many of the pathogens driving this difference fell below historical detection rate ranges within two weeks of initial policy implementation. Conclusion This analysis investigated the effect of multiple social distancing policies implemented to reduce transmission of SARS-CoV-2 on non-SARS-CoV-2 respiratory pathogens. These findings suggest that social distancing policies may be used as an impactful public health tool to reduce communicable respiratory illness.

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