Surveillance of patients with acute flaccid paralysis in Finland: report of a pilot study

WHO recommends that surveillance of patients with acute flaccid paralysis ( AFP) be used to demonstrate the eradication of wild poliovirus. In this art icle we report the results of a study to assess the frequency of AFP patien ts referred to Finnish hospitals and whether virological diagnostic coverag e could be improved by repeated reminders and active feedback. For this pur pose, we sent monthly questionnaires to all neurological and paediatric neu rological units in Finland, requesting retrospective reporting on investiga ted paralytic patients with defined clinically relevant diagnoses, rather t han AFP. Reminder letters included a pre-paid return envelope. Virological investigations were offered cost free. Of the 492 reporting forms sent, 415 (84%) were returned, evenly covering both the population and the study per iod (July 1997 to lune 1998). Of the 90 patients reported, 83 were evaluabl e. The apparent incidences of the diagnoses covered were 1.6 per 100 000 at any age, and 1.0 per 100 000 for under-15-year-olds. Guillain-Barre syndro me was the most common diagnosis (0.80 per 100 000). The two faecal specime ns required were virologically investigated in nine out of the 10 patients under 15 years of age, but in only 46% of all patients. Four adenovirus str ains, but no polioviruses or other enteroviruses, were isolated. We conclud e that a satisfactory monthly reporting system was readily established and that a sufficient number of patients with diagnoses resembling AFP are bein g referred to Finnish hospitals. Active feedback did not increase the propo rtion of virologically investigated patients to an acceptable level in all age groups. it is clear that other approaches must be used to quantify the circulation of poliovirus in Finland.