Dried blood spots to improve patient management in remote settings

The overall aim of the thesis was to assess the feasibility and utility of using blood collected on filter paper, dried blood spots (DBS), to improve patient management in remote settings. The use of DBS was evaluated for patient monitoring, quality assurance of point of care testing, and for surveillance to improve syndromic management. Systematic literature reviews, laboratory studies, and implementation of DBS based diagnostics were performed to answer these objectives. DBS is a feasible alternative to plasma in monitoring viral load in HIV patients on treatment. The type of filter paper, collection, storage and processing methods are critically important to obtain valid results for monitoring HIV. A DBS protocol was evaluated for syphilis serology, giving an adjusted sensitivity and specificity of 97.7% and 99.4% compared to plasma. DBS was implemented as quality assurance for Point-of-care test (PaCT), which showed that health worker proficiency varied significantly between clinics, stressing the importance of quality assurance. Laboratory evaluations revealed the possibility of obtaining adequate sensitivities to detect febrile illnesses; malaria, dengue, leptospira, B.bacilliformis, and chikungunya, but not for R. typhi and O.tsutsugamushi by DBS. When implemented in Peru, a local B.bacilliformis outbreak was identified which proved that DBS was more sensitive than the current surveillance method. The goal of this research was to determine whether DBS can improve patient management in remote settings. As new technologies are being developed rapidly, the use of simple and robust tools such as filter paper has continued to provide an affordable and reliable solution for clinical sample collection. While DBS is not the best sampling method, it is the simplicity and robustness that makes it useful in remote settings. This research showed that DBS can be used for monitoring HIV patient on antiretroviral therapy, the quality of syphilis diagnosis, and determining the major causes of fever in children to improve recommendations for syndromic management.