An evaluation of the Zambia influenza sentinel surveillance system, 2011–2017

Simusika, Paul; Tempia, Stefano; Chentulo, Edward; Polansky, Lauren; Mazaba, Mazyanga Lucy; Ndumba, Idah; Mbewe, Quinn K.; Monze, Mwaka

Data for calculation of the indicators for data quality and completeness, timeliness, stability and utility were obtained from various sources including the main influenza sentinel surveillance database, the laboratory database, annual reports and other documents and records. In order to assess simplicity, acceptability, stability and utility, a selfadministered questionnaire as shown in additional file 1 below was designed targeting staff involved in surveillance at the sentinel sites. The questionnaire was designed to capture data based on staff perceptions of the program. Data collected from the surveillance system were also compared with WHO minimum data collection standards for ILI and SARI surveillance [6] . Each quantitative indicator was evaluated as the proportion (expressed as percentage) of the outcome of interest over the total. A scale from 1 to 3 was used to provide a score for each quantitative indicator as follows: < 60% (from the above calculation) scored 1 (weak performance); 60-79% scored 2 (moderate performance); ≥80% scored 3 (good performance). For indicators for which a proportion over a total could not be obtained (qualitative indicators) a score was assigned based on the same scale using expert consensus. The scores assigned to each indicator were averaged for all indicators evaluated for each attribute to provide a mean score for each surveillance attribute. An overall score for the surveillance system was obtained by averaging the scores of all evaluated indicators