Assessment of Malaria Parasite Rate and System Attributes in the Sentinel Surveillance Sites in Greater Accra Region

Abstract

Background Malaria remains a major public health problem in the world. In Ghana, the entire population of24.2 million is at risk of malaria infection. Malaria is end emic and perennial in all parts of the country, with seasonal variations that are more pronounced in the north. From 2010 to 2015, Ghana has reduced by 45% malaria deaths. Progress in reduction of malaria prevalence has been recorded in the routine surveillance system through Health Management Information System but unfortunately that data suffers from reliability from presumed malaria. Therefore, Ghana established the sentinel surveillance system in 2013, with the aim to monitor the prevalence of malaria in the country and minimizing the proportion of cases of presumed malaria. Since this establishment the sentinel surveillance system, the indicators generated by the system show a clear progression in the control of malaria. Nevertheless, there is no evidence about how effective the system is performing. This study seeks to evaluate the performance of the malaria sentinel surveillance system, by assessing its attributes in the Greater Accra region; and also, determine the prevalence of malaria during that same period. Methods: This study was cross-sectional and used secondary quantitative data and methods to derive malaria positivity rate in sentinel sites in the Greater Accra region. Data on malaria indicators were extracted from District Health Management Team e-database for January 2014 to December 2016. The data were analyzed to show both slide and RDT malaria positivity rate, proportion of suspected malaria case, and testing rate. Based upon CDC the Centre for Disease Control, Atlanta updated guideline for evaluating Public health surveillance system, keys system attributes were assessed and described. Epi info was used to generate frequencies, proportions, and chi square test at 5% confidence level. Results: In general, the rate of malaria positivity and the proportion of suspected cases of malaria prescribed with ACTs have decreased overtime. From 2014 to 2016, this decrease ranged from 25% to 12.2% for malaria positivity and from 61.4% to 29.6% for proportion of suspected malaria cases. There was also an increase of testing rate from 81.7 to 98 % over the study period. Data quality is particularly poor in the Qbom health center sentinel surveillance site. However, overall, the internal completeness of the surveillance system was satisfactory. Data from Sentinel sites was getting more and more accurate over time, when comparing with Noguchi Memorial Institute for Medical Research data. Positive predictive value ranged from 12.0010 to 20.4 % in 2014 to 2016, declining over time while Sensitivity increased leading to the increase of number of suspected cases since 2014. Conclusion: The testing rate in the malaria surveillance sites during the study period increased, resulting in a decrease in the use of ACTs. Majority of suspected cases were tested and classified according to outcomes. Malaria positivity rate also decreased significantly in the course of these three years. The data are generally of good quality, representing very well the community in terms of place and people. The application ofT3 (Test, Treat and Track) and case definition by the system, increased the systems sensitivity to the detriment of the positive predictive value.