Malaria over-diagnosis in Cameroon: diagnostic accuracy of Fluorescence and Staining Technologies (FAST) Malaria Stain and LED microscopy versus Giemsa and bright field microscopy validated by polymerase chain reaction
| Autor: | Alexander Shnyra, Eve Lofthus, Ying Liu, Carole McArthur, Carolyn J. Henry, Edward Friedlander, Aderosoye J. Adegbulu, Steven A. Gustafson, Sean M. Parsel, Nicole Parrish, Leo Ayuk, Charles Awasom, Syed A. Jamal |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Male Pathology Diagnostic accuracy Polymerase Chain Reaction Giemsa stain 0302 clinical medicine Prevalence Medicine Cameroon Child Coloring Agents Aged 80 and over Microscopy lcsh:Public aspects of medicine General Medicine Middle Aged Infectious Diseases Child Preschool Giemsa Female Research Article Adult medicine.medical_specialty Adolescent 030106 microbiology 030231 tropical medicine Stain Azure Stains lcsh:Infectious and parasitic diseases 03 medical and health sciences Young Adult Internal medicine parasitic diseases Humans lcsh:RC109-216 Aged Staining and Labeling business.industry Fluorescent microscopy Public Health Environmental and Occupational Health Infant lcsh:RA1-1270 Gold standard (test) medicine.disease Staining Malaria Tropical medicine Etiology business Nested polymerase chain reaction |
| Zdroj: | Infectious Diseases of Poverty Infectious Diseases of Poverty, Vol 6, Iss 1, Pp 1-9 (2017) |
| ISSN: | 2049-9957 |
| Popis: | Background Malaria is a major world health issue and its continued burden is due, in part, to difficulties in the diagnosis of the illness. The World Health Organization recommends confirmatory testing using microscopy-based techniques or rapid diagnostic tests (RDT) for all cases of suspected malaria. In regions where Plasmodium species are indigenous, there are multiple etiologies of fever leading to misdiagnoses, especially in populations where HIV is prevalent and children. To determine the frequency of malaria infection in febrile patients over an 8-month period at the Regional Hospital in Bamenda, Cameroon, we evaluated the clinical efficacy of the Flourescence and Staining Technology (FAST) Malaria stain and ParaLens AdvanceTM microscopy system (FM) and compared it with conventional bright field microscopy and Giemsa stain (GS). Methods Peripheral blood samples from 522 patients with a clinical diagnosis of “suspected malaria” were evaluated using GS and FM methods. A nested PCR assay was the gold standard to compare the two methods. PCR positivity, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. Results Four hundred ninety nine samples were included in the final analysis. Of these, 30 were positive via PCR (6.01%) with a mean PPV of 19.62% and 27.99% for GS and FM, respectively. The mean NPV was 95.01% and 95.28% for GS and FM, respectively. Sensitivity was 26.67% in both groups and specificity was 92.78% and 96.21% for GS and FM, respectively. An increased level of diagnostic discrepancy was observed between technicians based upon skill level using GS, which was not seen with FM. Conclusions The frequency of malarial infections confirmed via PCR among patients presenting with fever and other symptoms of malaria was dramatically lower than that anticipated based upon physicians’ clinical suspicions. A correlation between technician skill and accuracy of malaria diagnosis using GS was observed that was less pronounced using FM. Additionally, FM increased the specificity and improved the PPV, suggesting this relatively low cost approach could be useful in resource-limited environments. Anecdotally, physicians were reluctant to not treat all patients symptomatically before results were known and in spite of a negative microscopic diagnosis, highlighting the need for further physician education to avoid this practice of overtreatment. A larger study in an area with a known high prevalence is being planned to compare the two microscopy methods against available RDTs. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0251-0) contains supplementary material, which is available to authorized users. |
| Databáze: | OpenAIRE |
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