Does emergency vaccination make sense as a supporting element in control of foot-and-mouth disease in Switzerland

The outbreak of foot and mouth disease (FMD) in Great Britain in 2001 let to discussions and especially emergency vaccination was deemed as an alternative to the culling of vast numbers of healthy animals. The project emergency vaccination for FMD in Switzerland was conducted to compare the effectiveness of conventional control strategies during a FMD outbreak alone and with ring vaccination of 3 km and 10 km, respectively. The results of this project showed that emergency vaccination conducted at the beginning of an epidemic was not favorable compared to conventional disease control strategy in Switzerland. In case of an advanced FMD epidemic, a 10 km ring vaccination could support the disease control in a positive way. However, the goal of emergency vaccination to save animal live can hardly be achieved due to actual legal basis and the consequent restriction measures within vaccination zones which will lead to welfare culling.

Bovine Tuberculosis Risk Factors for British Herds Before and After the 2001 Foot-and-Mouth Epidemic: What have we Learned from the TB99 and CCS2005 Studies?

Over the last couple of decades, the UK experienced a substantial increase in the incidence and geographical spread of bovine tuberculosis (TB), in particular since the epidemic of foot-and-mouth disease (FMD) in 2001. The initiation of the Randomized Badger Culling Trial (RBCT) in 1998 in south-west England provided an opportunity for an in-depth collection of questionnaire data (covering farming practices, herd management and husbandry, trading and wildlife activity) from herds having experienced a TB breakdown between 1998 and early 2006 and randomly selected control herds, both within and outside the RBCT (the so-called TB99 and CCS2005 case-control studies). The data collated were split into four separate and comparable substudies related to either the pre-FMD or post-FMD period, which are brought together and discussed here for the first time. The findings suggest that the risk factors associated with TB breakdowns may have changed. Higher Mycobacterium bovis prevalence in badgers following the FMD epidemic may have contributed to the identification of the presence of badgers on a farm as a prominent TB risk factor only post-FMD. The strong emergence of contact/trading TB risk factors post-FMD suggests that the purchasing and movement of cattle, which took place to restock FMD-affected areas after 2001, may have exacerbated the TB problem. Post-FMD analyses also highlighted the potential impact of environmental factors on TB risk. Although no unique and universal solution exists to reduce the transmission of TB to and among British cattle, there is an evidence to suggest that applying the broad principles of biosecurity on farms reduces the risk of infection. However, with trading remaining as an important route of local and long-distance TB transmission, improvements in the detection of infected animals during pre- and post-movement testing should further reduce the geographical spread of the disease.

Combined effect of a fluoride-, stannous- and chitosan-containing toothpaste and stannous-containing rinse on the prevention of initial enamel erosion-abrasion.

OBJECTIVES The aim of this study was to assess the preventive effect of a fluoride-, stannous- and chitosan-containing (F/Sn/chitosan-) toothpaste (TP) on initial enamel erosion and abrasion. METHODS In total, 150 human premolar enamel specimens were ground, polished and divided into 5 toothpaste/rinse groups (n=30): (G1) placebo-TP/tap water, (G2) sodium fluoride (NaF-) TP/tap water, (G3) F/Sn/chitosan-TP/tap water, (G4) F/Sn/chitosan-TP/Sn-rinse, (G5) NaF-TP/NaF-rinse. The 8-day erosion-abrasion cyclic treatment (one cycle/day) consisted of incubating the samples in artificial saliva (30min), then submitting the samples to toothbrush abrasion (2min incubation in toothpaste slurry; brushing with 20 toothbrush strokes) and rinsing (2min; 10ml) with the respective solution: tap water (G1-G3), Sn-rinse (G4) or NaF-rinse (G5). Afterwards, the samples were submitted to erosion (2min; 30ml 1% citric acid, pH=3.6). Surface microhardness (SMH) was measured initially and after every abrasion and erosion treatment. Enamel substance loss was calculated after each abrasion. Non-parametric ANOVA followed by Wilcoxon rank tests were used for analysis. RESULTS G1 presented the greatest SMH decrease, while G4 presented the least SMH decrease (p<0.001). G3 had a similar SMH decrease to G2 and G5. Substance loss was significantly lower in G4 than all other groups (p<0.05), closely followed by G3. Both G2 and G5 showed similar calculated enamel substance loss to G1. CONCLUSION The treatment with F/Sn/chitosan-TP and tap water provided a similar SMH decrease to both NaF-TP groups, but significantly lower substance loss. F/Sn/Chitosan-TP and Sn-rinse showed a better preventive effect, which promoted less SMH decrease and reduced substance loss. CLINICAL SIGNIFICANCE The toothpaste containing fluoride, stannous and chitosan shows promising results in reducing substance loss from erosion and abrasion. The combination of this toothpaste with the stannous-containing rinse showed even better prevention against erosion-abrasion.

Evidence for Emergency Vaccination Having Played a Crucial Role to Control the 1965/66 Foot-and-Mouth Disease Outbreak in Switzerland.

Foot-and-mouth disease (FMD) is a highly contagious disease that caused several large outbreaks in Europe in the last century. The last important outbreak in Switzerland took place in 1965/66 and affected more than 900 premises and more than 50,000 animals were slaughtered. Large-scale emergency vaccination of the cattle and pig population has been applied to control the epidemic. In recent years, many studies have used infectious disease models to assess the impact of different disease control measures, including models developed for diseases exotic for the specific region of interest. Often, the absence of real outbreak data makes a validation of such models impossible. This study aimed to evaluate whether a spatial, stochastic simulation model (the Davis Animal Disease Simulation model) can predict the course of a Swiss FMD epidemic based on the available historic input data on population structure, contact rates, epidemiology of the virus, and quality of the vaccine. In addition, the potential outcome of the 1965/66 FMD epidemic without application of vaccination was investigated. Comparing the model outcomes to reality, only the largest 10% of the simulated outbreaks approximated the number of animals being culled. However, the simulation model highly overestimated the number of culled premises. While the outbreak duration could not be well reproduced by the model compared to the 1965/66 epidemic, it was able to accurately estimate the size of the area infected. Without application of vaccination, the model predicted a much higher mean number of culled animals than with vaccination, demonstrating that vaccination was likely crucial in disease control for the Swiss FMD outbreak in 1965/66. The study demonstrated the feasibility to analyze historical outbreak data with modern analytical tools. However, it also confirmed that predicted epidemics from a most carefully parameterized model cannot integrate all eventualities of a real epidemic. Therefore, decision makers need to be aware that infectious disease models are useful tools to support the decision-making process but their results are not equal valuable as real observations and should always be interpreted with caution.

Palynological record and radiocarbon dates for sediment core T89-16, Congo River mouth

We present a high-resolution reconstruction of tropical palaeoenvironmental changes for the last deglacial transition (18 to 9 cal. kyr BP) based on integrated oceanic and terrestrial proxies from a Congo fan core. Pollen, grass cuticle, Pediastrum and dinoflagellate cyst fluxes, sedimentation rates and planktonic foraminiferal d18O ratios, uK37 sea-surface temperature and alkane/alkenone ratio data highlight a series of abrupt changes in Congo River palaeodischarge. A major discharge pulse is registered at around 13.0 cal. kyr BP which we attribute to latitudinal migration of the Intertropical Convergence Zone (ITCZ) during deglaciation. The data indicate abrupt and short-lived changes in the equatorial precipitation regime within a system of monsoonal dynamics forced by precessional cycles. The phases of enhanced Congo discharge stimulated river-induced upwelling and enhanced productivity in the adjacent ocean.