Paperless registration during survey enumerations and large oral cholera mass vaccination in Zanzibar, the United Republic of Tanzania.

PROBLEM: Field trials require extensive data preparation and complex logistics. The use of personal digital assistants (PDAs) can bypass many of the traditional steps that are necessary in a paper-based data entry system. APPROACH: We programmed, designed and supervised the use of PDAs for a large survey enumeration and mass vaccination campaign. LOCAL SETTING: The project was implemented in Zanzibar in the United Republic of Tanzania. Zanzibar is composed of two main islands, Unguja and Pemba, where outbreaks of cholera have been reported since the 1970s. RELEVANT CHANGES: PDAs allowed us to digitize information at the initial point of contact with the respondents. Immediate response by the system in case of error helped ensure the quality and reliability of the data. PDAs provided quick data summaries that allowed subsequent research activities to be implemented in a timely fashion. LESSONS LEARNT: Portability, immediate recording and linking of information enhanced structure data collection in our study. PDAs could be more useful than paper-based systems for data collection in the field, especially in impoverished settings in developing countries.