One way computers have helped Kenya's healthcare system is the use of portable "personal digital assistants (PDAs)" computers which have enabled medical records professionals to collect data on patients tested for tuberculosis and HIV rather than using paper forms. The data is then transferred to the provincial health office where it will be examined for surveillance and research purposes. The PDA has been proven to save time and improve productivity, allowing for an effective and efficient system. However, there have been reports of missing data from the PDA and computer viruses, so the PDA will need to be constantly monitored and updated to improve the software. Some health centers have preferred the paper format because it is more reliable than the PDA and because some professionals may have found it difficult to use the system or because they do not prefer to change a system that already works. For computers to be effective in healthcare systems, the device infrastructure must be fit for purpose without any hitches (Piloting the use of personal digital assistant for tuberculosis and human immunodeficiency virus interview, Kenya, 2007,