Feasibility of a rapid dipstick antigen-capture assay for self-testing of travellers' malaria

Abstract

This open comparative study sought to determine whether, and with what level of instruction, travellers can successfully use and interpret the rapid whole blood malaria diagnostic test, ParaSight F. 160 visitors to the Zürich University Travel Clinic took part in the study. One group received written instructions only, while another group was given combined oral and written instructions on how to test their own blood for malaria infection and interpret a series of 5 prepared test strips. Each volunteer also completed a questionnaire targeted at assessing performance in using the diagnostic, interpretation of the results and acceptability of the concept of self-testing for malaria infection. The main outcome measures were successful performance of the test, correct interpretation of prepared test strips and acceptability of the test. In the group which received only written instructions, 60/80 (75%) were successful, whilst in the group which received written and oral instructions, 72/80 (90%) successfully performed the test (P < 0.02). Overall, 565 (70.6%) test strips were correctly and 165 (20.6%) incorrectly interpreted with 113 (14.1%) false negative interpretations. No prepared test strip was interpreted as false positive. Seventy (8.8%) test strips were not interpreted. Some 91. 9% of all candidates would use such a test if it were available. While it is possible for lay persons to successfully perform the test, interpretation of results poses a problem. In particular, the proportion of false negative interpretations is unacceptable. A combination of written and oral instructions leads to a significantly higher level of successful test performance. If such a test is to be made available to the general public, written instructions must be made concise and foolproof and the test endpoint clearly defined, as the currently available test is more suitable for trained laboratory personnel. In the meantime other candidate diagnostics have become available and these should now be assessed for their suitability in the context of travellers' malaria.