SMS-based smartphone application for disease surveillance has doubled completeness and timeliness in a limited-resource setting – evaluation of a 15-week pilot program in Central African Republic (CAR)

El-Khatib, Ziad; Shah, Maya; Zallappa, Samuel N; Nabeth, Pierre; Guerra, José; Manengu, Casimir T; Yao, Michel; Philibert, Aline; Massina, Lazare; Staiger, Claes-Philip; Mbailao, Raphael; Kouli, Jean-Pierre; Mboma, Hippolyte; Duc, Geraldine; Inagbe, Dago; Barry, Alpha Boubaca; Dumont, Thierry; Cavailler, Philippe; Quere, Michel; Willett, Brian; Reaiche, Souheil; de Ribaucourt, Hervé; Reeder, Bruce

The Argus app performs three operations: i) Alert, to provide an immediate notification of cases that may signal a potential outbreak; ii) Report, to transmit Weekly and Monthly surveillance reports, and iii) Archive, to review the status of previously submitted reports. Although the app functions optimally with a 3G cellular telephone network or greater, it requires only a GSM network to transmit basic disease data using a series of Short Message Service (SMS). For an Alert, the numbers of cases, hospitalized patients and deaths are submitted in an open text box format. In the Weekly Reports, the number of cases and deaths for each notifiable disease are submitted as a single SMS; hence a complete report requires a total of 20 SMS messages. Data transmission of the SMS messages occurs through a Universal Serial Bus (USB) modem connected to the laptop computer server maintained by the Director of Surveillance of the health district. The modem contains a Subscriber Identity Module (SIM) card that receives and transfers SMSs into a MySQL database, using Frontline SMS software [15] . After having submitting data to the server, users receive an acknowledgment on their smartphones for each disease notification successfully transmitted. In case of failure in delivery to the server, the app displays an error message on their smartphone screen. In this situation users are required to re-submit the messages.