Improvement of malaria diagnostic system based on acridine orange staining

Abstract

BackgroundRapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent.MethodsThe halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya.ResultsWithout staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard.ConclusionsConsistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.Electronic supplementary materialThe online version of this article (10.1186/s12936-018-2214-8) contains supplementary material, which is available to authorized users.

Development of a synthetic route towards N4,N9-disubstituted 4,9-diaminoacridines: On the way to multi-stage antimalarials

“…Its potential to treat Creutzfeld-Jakob disease was also investigated [11]. Interestingly, mepacrine has further gone through a ''drug to dye" move, being explored as a fluorescent biolabeling agent [12], while the well-known acridine orange dye is presently being reconsidered as a valuable tool for rapid malaria diagnosis [13].…”

Malaria therapeutics: are we close enough?

“…Since mature erythrocytes do not contain DNA or RNA, whereas the parasites do, fluorescent dyes such as acridine orange are used to detect the Plasmodium parasites. For this, the patient’s blood sample is incubated with acridine orange, staining the DNA and RNA of different developmental stages of Plasmodium [ 167 , 168 ]. The fluorescent parasites are then observed using a conventional fluorescence microscope or a fluorescence microscope based on LED [ 167 , 168 ].…”

Malaria distribution and performance of malaria diagnostic methods in Malaysia (1980–2019): a systematic review

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