Equinella – the infrmational system on equine infectious diseases in Switzerland

A proposed classification of veterinary epidemiosurveillance networks

“…However, one may distinguish between networks which use 'purely passive' data collection, i.e., in which the information is sent only if suspected cases have been noticed (e.g., the network for FMD in France), and networks which use 'passive-active' data collection, in which field observers must always send regular reports to the central unit, whether or not they have observed cases of disease, e.g., the Equinella network in Switzerland (28).…”

“…Such a sample, based on suspected cases, is often biased and not truly representative of all cases in the monitored population. Other networks based on non-random samples are those in which only volunteers take part (4,5,10,13,14,27,28,31).…”