scholarly journals Transmission Dynamics of Corynebacterium spp. Within Two Danish Dairy Cattle Herds

2021 ◽  
Vol 8 ◽  
Author(s):  
Carsten Kirkeby ◽  
Tariq Halasa ◽  
Michael Farre ◽  
Galal Nazih Chehabi ◽  
Kaare Græsbøll
Keyword(s):  
Dairy Cattle ◽  
Transmission Rate ◽  
Cost Effective ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Effective Control ◽  
Indirect Transmission ◽  
The Mean ◽  
Cattle Herds ◽  
Danish Dairy

Intramammary infections (IMI) can cause mastitis, a prevalent and costly infectious disease in dairy cattle worldwide. The IMI is caused by a range of bacteria, including Corynebacterium spp. Knowledge of the transmission dynamics of pathogens is generally sparse but essential to support decision-making; such as input to bioeconomic models. In this observational study, we explored the transmission dynamics of Corynebacterium spp. in two different Danish dairy cattle herds by testing monthly quarter-level milk samples of all lactating cows for 1 year. We estimated the prevalence for herd 1 and 2 to 24 and 11.7%, respectively, and the mean quarter-level incidence to be 8 and 6.5% per month, respectively. We compared a model for indirect transmission via the environment with a model with the direct contagious transmission and found that the latter model best explained the data. We estimated the daily mean quarter-level transmission rate to be 0.016 and 0.018 cases/quarter-day for herd 1 and 2, respectively. The mean recovery rate was 0.012 and 0.016 for herd 1 and 2, respectively. Consequently, the basic reproduction number for herd 1 and 2 was 1.27 and 1.10, respectively. This study highlights that Corynebacterium spp. can be prevalent within a herd and transmit directly between cows. Thus, future studies should investigate cost-effective control measures against Corynebacterium spp.

scholarly journals Q fever infection in dairy cattle herds: increased risk with high wind speed and low precipitation

2015 ◽  
Vol 143 (15) ◽  
pp. 3316-3326 ◽  
Author(s):  
S. NUSINOVICI ◽  
J. FRÖSSLING ◽  
S. WIDGREN ◽  
F. BEAUDEAU ◽  
A. LINDBERG
Keyword(s):  
Wind Speed ◽  
Dairy Cattle ◽  
Protective Factor ◽  
Q Fever ◽  
Control Measures ◽  
Effective Control ◽  
High Wind ◽  
High Wind Speed ◽  
Increased Risk ◽  
Cattle Herds

SUMMARYRuminants are considered the main reservoir for transmission of Coxiella burnetii (Cb) to humans. The implementation of effective control measures against Cb in ruminants requires knowledge about potential risk factors. The objectives of this study were (i) to describe the spatial distribution of Q fever-infected dairy cattle herds in Sweden, (ii) to quantify the respective contributions of wind and animal movements on the risk of infection, while accounting for other sources of variation, and (iii) to investigate the possible protective effect of precipitation. A total of 1537 bulk milk samples were collected and tested for presence of Cb antibodies. The prevalence of test-positive herds was higher in the south of Sweden. For herds located in areas with high wind speed, open landscape, high animal densities and high temperature, the risk of being infected reached very high values. Because these factors are difficult to control, vaccination could be an appropriate control measure in these areas. Finally, the cumulated precipitation over 1 year was identified as a protective factor.

scholarly journals Transmission dynamics of Staphylococcus aureus within two Danish dairy cattle herds

2019 ◽  
Vol 102 (2) ◽  
pp. 1428-1442 ◽  
Author(s):  
C. Kirkeby ◽  
L. Zervens ◽  
N. Toft ◽  
D. Schwarz ◽  
M. Farre ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cattle ◽  
Transmission Dynamics ◽  
Cattle Herds ◽  
Danish Dairy

Water safety plans for small systems: a model for applying HACCP concepts for cost-effective monitoring in developing countries

2003 ◽  
Vol 47 (3) ◽  
pp. 215-220 ◽  
Author(s):  
G. Howard
Keyword(s):  
Risk Factors ◽  
Water Quality ◽  
Cost Effective ◽  
Control Measures ◽  
Effective Control ◽  
Performance Limits ◽  
Water Safety ◽  
Small Systems ◽  
Water Safety Plans ◽  
Contamination Events

The development of water safety plans (WSPs) for small systems should be based on a thorough understanding of the relationships between risk factors and contamination events. This can be achieved through the use of well-designed assessments of water quality that provide better evidence to support the identification of control measures, performance limits, monitoring parameters and verification procedures. Training of community operators is critical to the success of the WSP and the understanding gained from the assessments provides a sound basis for addressing these needs. The WSP approach provides for more effective control of water quality and the use of targeted assessments is cost-effective in improving the design of WSPs.

scholarly journals Development of a Sanitation Safety Plan for improving the sanitation system in peri-urban areas of Iringa, Tanzania

2017 ◽  
Vol 7 (2) ◽  
pp. 340-348 ◽  
Author(s):  
M. Domini ◽  
G. Langergraber ◽  
L. Rondi ◽  
S. Sorlini ◽  
S. Maswaga
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Control Measures ◽  
Effective Control ◽  
Safety Plan ◽  
First Results ◽  
Assessment Matrix ◽  
Planning Methodology ◽  
The Given

The Sanitation Safety Planning methodology is implemented within a cooperation project in Iringa, Tanzania. The study presents the methodology and its adaptation and use for the given context, in order to assess risks and to support stakeholders in improving the current sanitation system and validate the design of an improved one. First results of the application of the methodology, obtained in one of the four peri-urban wards of Iringa, demonstrated its efficacy and utility in prioritising risks and identifying cost-effective control measures. Risks were assessed by the use of a semi-quantitative approach, and a simplified risk assessment matrix was developed for the case study. A sensitivity analysis was carried out in order to evaluate criteria for prioritising control measures to be selected for the development of an achievable improvement plan.

scholarly journals Modeling the Novel Coronavirus (SARS-CoV-2) Outbreak in Sicily, Italy

2020 ◽  
Vol 17 (14) ◽  
pp. 4964 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Sebastiano Battiato ◽  
Antonella Agodi
Keyword(s):  
Transmission Rate ◽  
Control Measures ◽  
Transmission Dynamics ◽  
The Novel ◽  
Epidemic Spread ◽  
Transmission Rates ◽  
Contact Precautions ◽  
Travel Restrictions ◽  
Novel Coronavirus ◽  
Reported Data

Italy was the first country in Europe which imposed control measures of travel restrictions, quarantine and contact precautions to tackle the epidemic spread of the novel coronavirus (SARS-CoV-2) in all its regions. While such efforts are still ongoing, uncertainties regarding SARS-CoV-2 transmissibility and ascertainment of cases make it difficult to evaluate the effectiveness of restrictions. Here, we employed a Susceptible-Exposed-Infectious-Recovered-Dead (SEIRD) model to assess SARS-CoV-2 transmission dynamics, working on the number of reported patients in intensive care unit (ICU) and deaths in Sicily (Italy), from 24 February to 13 April. Overall, we obtained a good fit between estimated and reported data, with a fraction of unreported SARS-CoV-2 cases (18.4%; 95%CI = 0–34.0%) before 10 March lockdown. Interestingly, we estimated that transmission rate in the community was reduced by 32% (95%CI = 23–42%) after the first set of restrictions, and by 80% (95%CI = 70–89%) after those adopted on 23 March. Thus, our estimates delineated the characteristics of SARS-CoV2 epidemic before restrictions taking into account unreported data. Moreover, our findings suggested that transmission rates were reduced after the adoption of control measures. However, we cannot evaluate whether part of this reduction might be attributable to other unmeasured factors, and hence further research and more accurate data are needed to understand the extent to which restrictions contributed to the epidemic control.

scholarly journals Increased incidence rate of undesired early heifer departure in Mycoplasma bovis-antibody positive Danish dairy cattle herds

2019 ◽  
Vol 166 ◽  
pp. 86-92 ◽  
Author(s):  
Mette Bisgaard Petersen ◽  
Annette Kjær Ersbøll ◽  
Kaspar Krogh ◽  
Liza Rosenbaum Nielsen
Keyword(s):  
Dairy Cattle ◽  
Incidence Rate ◽  
Mycoplasma Bovis ◽  
Cattle Herds ◽  
Danish Dairy

scholarly journals Control Strategies for the Third wave of COVID-19 infection in India: A Mathematical Model Incorporating Vaccine Effectiveness

2022 ◽  
Author(s):  
Ashutosh Mahajan ◽  
Namitha Sivadas ◽  
Pooja Panda
Keyword(s):  
Transmission Rate ◽  
Control Strategies ◽  
Control Measures ◽  
Disease Spread ◽  
Effective Control ◽  
Third Wave ◽  
Social Distancing ◽  
Vaccination Rates ◽  
New Variant ◽  
The Future

The waning effectiveness of the COVID-19 vaccines and the emergence of a new variant Omicron has given rise to the possibility of another outbreak of the infection in India. COVID-19 has caused more than 34 million reported cases and 475 thousand deaths in India so far, and it has affected the country at the root level, socially as well as economically. After going through different control measures, mass vaccination has been achieved to a large extent for the highly populous country, and currently under progress. India has already been hit by a massive second wave of infection in April-June, 2021 mainly due to the delta variant, and might see a third wave in the near future that needs to be controlled with effective control strategies. In this paper, we present a compartmental epidemiological model with vaccinations incorporating the dose-dependent effectiveness. We study a possible sudden outbreak of SARS-CoV2 variants in the future, and bring out the associated predictions for various vaccination rates and point out optimum control measures. Our results show that for transmission rate 30% higher than the current rate due to emergence of new variant or relaxation of social distancing conditions, daily new cases can peak to 250k in March 2022, taking the second dose effectiveness dropping to 50% in the future. A combination of vaccination and controlled lockdown or social distancing is the key to tackling the current situation and for the coming few months. Our simulation results show that social distancing measures show better control over the disease spread than the higher vaccination rates. <br>

MODELING CHOLERA TRANSMISSION UNDER DISEASE CONTROL MEASURES

2020 ◽  
pp. 1-26
Author(s):  
MARGARET BROWN ◽  
MIKO JIANG ◽  
CHAYU YANG ◽  
JIN WANG
Keyword(s):  
Disease Control ◽  
Disease Transmission ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Threshold Dynamics ◽  
Education Programs ◽  
Multiple Control ◽  
Indirect Transmission ◽  
Transmission Pathways ◽  
The Impact

We present a new mathematical model to investigate the transmission dynamics of cholera under disease control measures that include education programs and water sanitation. The model incorporates the impact of education programs into the disease transmission rates and that of water sanitation into the environmental pathogen dynamics. We conduct a detailed analysis to the autonomous system of the model and establish the local and global stabilities of its equilibria that characterize the threshold dynamics of cholera. We then perform an optimal control study on the general model with time-dependent controls and explore effective approaches to implement the education programs and water sanitation while balancing their costs. Our analysis and simulation highlight the complex interaction among the direct and indirect transmission pathways of the disease, the intrinsic growth of the environmental pathogen and the impact of multiple control measures, and their roles in collectively shaping the transmission dynamics of cholera.

Ecology of the maize stalk borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae)

1987 ◽  
Vol 77 (2) ◽  
pp. 255-269 ◽  
Author(s):  
J. B. J. Van Rensburg ◽  
M. C. Walters ◽  
J. H. Giliomee
Keyword(s):  
Plant Development ◽  
Busseola Fusca ◽  
Cost Effective ◽  
Control Measures ◽  
Effective Control ◽  
Planting Dates ◽  
Plant Parts ◽  
New Information ◽  
Repeated Sampling ◽  
Definite Pattern

AbstractNew information on the intraseasonal progression of larval infestations of Busseola fusca (Fuller) in South Africa was obtained through repeated sampling in maize plantings of different planting dates over various seasons. Due to the occurrence of distinct periods of moth flight, variation in planting date had a marked influence on levels of larval infestation. Also, plants were found to be most attractive as sites for oviposition between three and five weeks after emergence, resulting in a definite pattern in the time distribution of different larval instars in different plant parts. In the pre-tassel stage of plant development, most larvae occurred in localized groups within the whorls, reaching maximum numbers eight weeks after plant emergence. The emergence of the tassel forced some larvae to migrate to adjacent plants, resulting in an increase of internally damaged plants without an increase in larval numbers. It is shown that scouting for eggs over a limited period of plant development can lead to better timing of spray applications and thus to more cost-effective control measures.

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