Strengthening early warning function of surveillance in the Republic of Serbia: lessons learned after a year of implementation.

The Republic of Serbia, with WHO support, has implemented an early warning system (ALERT) for priority communicable diseases, to complement the routine surveillance system which notifies individual confirmed cases. The results of its evaluation, conducted one year after implementation is presented here. ALERT relies on notification of 11 syndromes by primary care facilities. Data is analysed weekly at district level and transmitted to national epidemiologists. ALERT is perceived to be a simple and flexible tool. Acceptability is higher at national level than at district level. Some districts perceive ALERT as a parallel system poorly connected to control measures. Sensitivity of ALERT in detecting cases of meningitis is 93%, and 37% for cases of hepatitis. Retrospective analysis of ALERT data identified 9 outbreaks, 5 of which had been recognized by epidemiologists. ALERT was the timeliest system for detecting 4 outbreaks identified by both systems. ALERT was useful for triggering timely investigation and control of outbreaks of hantavirus and salmonellosis and for detecting the start of the influenza season. However, ALERT did not detect clusters of brucellosis and tularaemia targeted by the unexplained fever syndrome. This evaluation underlined the need for a global review of surveillance activities when implementing new components such as ALERT. While control measures based on notification of individual confirmed cases are well understood and implemented, the investigation and verification process that should result from an increase in ALERT syndromes is not fully understood. Field epidemiology training programmes, such as the EPIET programme, are best suited to bring about this change of perspective.