The effectiveness of routine serological surveillance: case study of the 1997 epidemic of classical swine fever in the Netherlands

The authors describe the value of routine serological surveillance in detec ting the introduction of classical swine fever virus into a disease-free po pulation. The first investigation concerned the question of whether the epi demic of classical swine fever (CSF), which occurred from 1997 to 1998 in t he Netherlands, could have been detected using the existing monitoring syst em for notifiable diseases. The investigation used data from the CSF epidem ic of 1997/1998 and from the existing monitoring system. Secondly, the prob ability of detecting a case of CSF using routine serological surveillance w as modelled both for multiplier herds and for finishing herds, and then for different herd size categories. The first investigation concluded that the probability of detecting the epidemic at the current level of routine sero logical surveillance is very low. The second investigation concluded that e ven employing a sampling scheme of sixty blood samples per month, the proba bility of detecting an outbreak of CSF within forty days of the introductio n of the virus, is less than 40%.