Contribution and Effectiveness of Event-Based Surveillance System in Disease Detection and Containment in Pakistan for Year 2017

Background: Event Based Surveillance (EBS) is the organized and rapid captures of information about events that are a potential risk to public health. Information can be about events related to occurrence of disease in humans or a potential exposure to a risk e.g. contaminated food,-chemicals or radio nuclear events. In Pakistan it is a recent phenomenon and is a compliment to Indicator Based Surveillance (IBS) which is traditionally going on in public sector health care facilities. Literature on effectiveness and contribution of EBS is scarce. Methodology: A cross sectional study was conducted based on retrospective record review of events reporting in Pakistan. For this purpose, Disease Surveillance and Response Units (DSRU) were identified and descriptive analysis of their reporting per epidemiological week was done. Results: Public sector health facilities were found the most frequent 75% (n=88) in reported events. Vector borne diseases 49% (n=58) were the most frequently reported event. In 85% (n=101) of events, WHO and/or CDC standard case definitions were used followed by operational cases definition 10% (n=12). System was found operational in all provinces and regions and was linked to laboratory based surveillance in all DSRUs. Median delay was found high in Vaccine Preventable Diseases (Measles and Diphtheria), eight days (range: 0-10 days) and Vector borne diseases (Dengue, Chikungunya and CL) six days (range: 0-8 days). Among all, 90% (n=105) response activities were establishment and/ or strengthening of surveillance system by training of local staff. All investigations were linked with public health laboratory investigation except for food/water borne outbreak 3% (n=4), where no laboratory confirmation of causative organism was found. Conclusion: Event based surveillance (EBS) should be strengthened as a compliment of IBS and its network should be expanded to regional and district levels. Frequent trainings of health care providers at health facilities and informal sources like media should be done to gather credible and timely information of events’ time place and persons involved. However, monitoring and evaluation should be integral part to improve event recording and hence targeted response.