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Es la biología molecular una mejor alternativa para el diagnóstico de la malaria que la microscopía? Comparación entre la microscopía, la detección de antígeno y las pruebas moleculares, en Kenia rural y Tanzania urbana
Author(s) -
Mens P.,
Spieker N.,
Omar S.,
Heijnen M.,
Schallig H.,
Kager P. A.
Publication year - 2007
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.2006.01779.x
Subject(s) - malaria , tanzania , rapid diagnostic test , nasba , diagnosis of malaria , diagnostic test , incidence (geometry) , polymerase chain reaction , medicine , biology , virology , immunology , plasmodium falciparum , veterinary medicine , genetics , nucleic acid sequence , dna , environmental science , physics , environmental planning , gene , optics
Summary Objective To assess the agreement of different diagnostic methods for the diagnosis and confirmation of the clinical suspicion of Plasmodium infection in children in Tanzania and Kenya. Method Blood samples were collected by the finger prick method from 338 children. Blood samples were collected from 338 children with the clinical suspicion of uncomplicated malaria in health clinics in Tanzania and Kenya. The presence of Plasmodium parasites was assessed with microscopy, rapid diagnostic tests (RDTs) and the molecular assays, quantitative nucleic acid sequence based amplification (QT‐NASBA) and polymerase chain reaction (PCR). The results were compared and analysed for agreement. Results There was a high degree of agreement (88.6–100%) between RDTs or molecular tests and microscopy. In rural Kenya, with a high incidence of malaria cases, the correlation coefficient ranged from 0.94 for RDTs to 0.76 for PCR. In urban Tanzania, where there was a low incidence of cases, R for RDTs was 1.0 but only 0.25 for PCR and 0.33 for NASBA. Conclusion Malaria is overestimated if the diagnosis is based solely on clinical signs. Therefore, laboratory confirmation is essential. Microscopy is a reliable method in rural areas where malaria is prevalent, but RDTs offer a good alternative with the advantage that it is an easy and rapid method. Molecular tests are more sensitive but difficult to implement in rural areas. In areas with lower incidence, molecular tests detect a significantly higher number of Plasmodium infections than RDTs or microscopy. Although implementation of molecular tools can be difficult, the prospect of an easy and cheap detection system makes them promising tools for the near future.