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| Year : 2004 | Volume
: 22
| Issue : 1 | Page : 68 |
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Evaluation of the direct acridine orange staining method for diagnosis of malaria
S Nandwani
Department of Microbiology, University College of Medical Sciences, New Delhi - 110 095, India
Correspondence Address:
Department of Microbiology, University College of Medical Sciences, New Delhi - 110 095, India
How to cite this article:
Nandwani S. Evaluation of the direct acridine orange staining method for diagnosis of malaria. Indian J Med Microbiol 2004;22:68 |
How to cite this URL:
Nandwani S. Evaluation of the direct acridine orange staining method for diagnosis of malaria. Indian J Med Microbiol [serial online] 2004 [cited 2021 Feb 25];22:68. Available from: https://www.ijmm.org/text.asp?2004/22/1/68/8070 |
Dear Editor,
Malaria causes 300 to 500 million infections and 1.5 to 2.7 million deaths each year worldwide.[1] Conventional Giemsa stained peripheral blood smear examination remains the gold standard for diagnosis of malaria in malaria endemic countries. However, the technique is labour intensive time consuming and may give poor results in cases with low parasitaemia.[2] In recent years numerous quick and new techniques for malaria diagnosis have been developed, one such being direct AO (acridine orange) staining technique, which was evaluated in this study.
A total of 310 blood samples were selected from patients presenting with pyrexia and/or atypical presentations. Giemsa and AO staining of peripheral blood smears for diagnosis of malaria were done simultaneously on all blood samples. AO staining was found to be 93.3% sensitive and 99.25% specific. Out of the 45 Giemsa smear positive cases (29 Plasmodium vivax, 15 Plasmodium falciparum and 1 mixed) AO staining was able to detect 42 cases. Out of the 265 Giemsa smear negative cases 2 were positive by AO staining. Comparing the examination of ordinary Giemsa thin blood film with the use of thick films, the thin film examination had a sensitivity of 71.1% and a specificity of 100%.
Our results demonstrated a higher sensitivity and rapidity of AO staining as compared to Giemsa stained thin blood films, confirming the results of other field studies.[3] Species differentiation was quite reliable with AO staining. It required only 10 minutes for reporting even at a low parasitaemia by AO staining method. Cost of each smear by AO was Rs.4 -5 per smear. We conclude that in terms of performance, speed, ease of use and reliability, the AO method would be ideal to support diagnosis of malaria. However, the cost of the microscope and special accessories need to be considered.
| ~ References | |  |
| 1. | World Health Organization. World malaria situation in 1994. Wkly Epidemiol Rec 1997;36:269-276; No. 37: 277-284; No.38, 285-292.  |
| 2. | Craig MH, Sharp BL. Comparative evaluation of four techniques for the diagnosis of P. falciparum infections. Trans R Soc Trop Med Hyg 1997;91:279-282. |
| 3. | Gay F, Traore' B, Zanoni J, et al. Direct acridine orange fluorescence examination of blood slides compared to current techniques for malaria diagnosis. Trans R Soc Trop Med Hyg 1996;90:516-518. |
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