A financial cost-benefit analysis of eradicating virulent footrot.

In 2008, virulent footrot was detected in sheep in south-west Norway. Footrot is caused by Dichelobacter nodosus, and the outbreak was linked to live sheep imported from Denmark in 2005. A large-scale program for eradicating the disease was implemented as a joint industry and governmental driven eradication project in the years 2008-2014, and continued with surveillance and control measures by the Norwegian Food Safety Authority from 2015. The cost of the eradication program including surveillance and control measures until 2032 was assumed to reach approximately €10.8 million (NOK 90 million). A financial cost-benefit analysis, comparing costs in the eradication program with costs in two simulated scenarios, was carried out. In the scenarios, designated ModerateSpread (baseline) and SlowSpread, it was assumed that the sheep farmers would undertake some voluntary measures on their own that would slow the spread of the disease. The program obtained a positive NPV after approximately 12 years. In a stochastic analysis, the probabilities of a positive NPV were estimated to 1.000 and to 0.648 after 15 years and to 0.378 and 0.016 after ten years, for the ModerateSpread and SlowSpread scenarios respectively. A rapid start-up of the program soon after the detection of the disease was considered crucial for the economic success as the disease would have become more widespread and probably raised the costs considerably at a later start-up.

Cost-benefit analysis of management practices for ewes lame with footrot.

The aim of this study was to investigate the cost-benefit of different strategies to treat and control ovine footrot. In November 2006, 162 sheep farmers in England responded to a survey on prevalence and management of lameness. The costs of lameness per ewe per year (PEPY) were calculated for 116 flocks. Linear regression was used to model the overall cost of lameness PEPY by management method. Associations between farmer satisfaction and time and money spent managing lameness were investigated. The median prevalence of lameness was 5% (inter-quartile range, IQR, 4-10%). The overall cost of lameness PEPY in flocks with ≥10% lameness was UK £6.35 versus £3.90 for flocks with <5% lameness. Parenteral antibiotic treatment was associated with a significantly lower overall cost of lameness by £0.79 PEPY. Routine foot trimming and foot bathing were associated with significantly higher overall costs of lameness PEPY of £2.96 and £0.90, respectively. Farmers satisfied with time managing lameness spent significantly less time (1.46 h PEPY) than unsatisfied farmers (1.90 h PEPY). Farmers satisfied with money spent managing lameness had significantly lower treatment (£2.94 PEPY) and overall (£5.00 PEPY) costs than dissatisfied farmers (£5.50 and £7.60 PEPY, respectively). If the farmers in this study adopted best practice of parenteral antibiotic treatment with no routine foot trimming, and minimised foot bathing to treatment/prevention of interdigital dermatitis, the financial benefits would be approximately £4.65 PEPY. If these costs are similar on other farms the management changes would lead to significant economic benefits for the sheep industry.

Determination of prevalence and economic impact of ovine footrot in central Kashmir India with isolation and molecular characterization of Dichelobacter nodosus.

The present study determines the prevalence, economic impact of virulent footrot in central Kashmir, India, along with isolation and molecular characterization of Dichelobacter nodosus (D. nodosus) where so far no such work has been carried out. Over all 12.54% prevalence of footrot was recorded in central Kashmir with highest (15.84%) in district Srinagar, and least (10.89%) in district Budgam, while it was 13.28% in district Ganderbal. Overall economic impact of footrot was estimated to the tune of Rs 15.82 million annually to the sheep farming in central Kashmir. Out of 370 samples collected from footrot lesions of naturally infected sheep, 200 (54.05%) detected D. nodosus positive by polymerase chain reaction (PCR). Out of these, 132 (66.00%) samples carried serogroup B of D. nodosus, five (2.50%) serogroup E, one (0.50%) serogroup I, while, 53 (26.50%) had mixed infection of serogroups B and E, four (2.00%) of serogroups B and I, two (1.00%) of serogroups B and G and the remaining three (1.50%) samples harboured the mixed infection of serogroups B, E and I. Serogroup G was detected for the first time in India. Over all serogroup B was most frequent (97.0%) followed by E (30.5%), while serogoups I (4.0%) and G (1.0%) were least prevalent. A total of 265 D.nodosus strains were isolated out of which 194 (73.20%) were typed as serogroup B, 61 (23.01%) as serogroup E, eight (3.01%) as serogroup I and remaining two (0.75%) belonged to serogroup G. Out of 265 D. nodosus isolates, 164 (61.88%) possessed intA (integrase) gene, thus were considered as virulent strains. Serogroup wise intA gene was found in 121(62.37%) isolates of serogroup B, 36 (59.01%) of E, two (100%) of G and five (62.50%) of I. Out of 20 randomly selected isolates subjected to gelatin gel test, 16 isolates with intA gene produced thermostable protease while four isolates without intA gene revealed the production of thermolabile protease. This indicated a good co-relation between presence of intA gene and gelatin gel test in determination of the D. nodosus virulence. Thus the present investigation suggests the incorporation of serogroups B and E, based on their predominant prevalence, in the formulation of an effective bivalent vaccine to combat footrot in central Kashmir.

An economic evaluation of various treatments for contagious foot rot in sheep, using decision analysis.

Two decision analysis models were constructed to identify the cost-effectiveness of treatment and/or prevention regimens for ovine foot rot through a systematic evaluation approach of 2 consecutive phases. The first model evaluated the cost-effectiveness of examining the sheep for foot lesions and the use of 1 of 32 treatment regimens when lesions were present. The second model evaluated the 6 most cost-effective treatment regimens from the first model with or without a preventive measure (in this case, vaccination) to determine the most cost-effective approach to preventing/treating foot rot in a single year. Three prevalence levels of foot rot were used. In addition, 3 levels of reduced production attributable to foot rot were used. Threshold analysis, a form of sensitivity analysis, was used to evaluate allowable variations in the success rates and cost of treatments/prevention where the outcome of the models remains unchanged. Of the 32 treatment regimens tested in this model, the use of 10% zinc sulfate applied to the feet of sheep with foot rot was the most cost-effective regimen, regardless of the prevalence levels of the disease or its impact on productivity. In the second model, the use of vaccination with paring of the feet, as a preventive measure, followed by a treatment of the sheep that were still infected, was less cost-effective than to treat only the sheep with foot lesions and disregard prevention. This was true regardless of the prevalence levels of the disease or its impact on productivity.