Search

Abstract Background Accurate diagnosis is essential for prompt and appropriate treatment of malaria. While rapid diagnostic tests (RDTs) offer great potential to improve malaria diagnosis, the sensitivity of RDTs has been reported to be highly variable. One possible factor contributing to variable test performance is the diversity of parasite antigens. This is of particular concern for Plasmodium falciparum histidine-rich protein 2 (PfHRP2)-detecting RDTs since PfHRP2 has been reported to be highly variable in isolates of the Asia-Pacific region. Methods The pfhrp2 exon 2 fragment from 458 isolates of P. falciparum collected from 38 countries was amplified and sequenced. For a subset of 80 isolates, the exon 2 fragment of histidine-rich protein 3 (pfhrp3) was also amplified and sequenced. DNA sequence and statistical analysis of the variation observed in these genes was conducted. The potential impact of the pfhrp2 variation on RDT detection rates was examined by analysing the relationship between sequence characteristics of this gene and the results of the WHO product testing of malaria RDTs: Round 1 (2008), for 34 PfHRP2-detecting RDTs. Results Sequence analysis revealed extensive variations in the number and arrangement of various repeats encoded by the genes in parasite populations world-wide. However, no statistically robust correlation between gene structure and RDT detection rate for P. falciparum parasites at 200 parasites per microlitre was identified. Conclusions The results suggest that despite extreme sequence variation, diversity of PfHRP2 does not appear to be a major cause of RDT sensitivity variation.

Two studies involving a total of six 5 and 6-year olds demonstrated that it is possible to increase specified components of children's creative behaviors using a verbal self-instructional procedure. A social validation procedure indicated that drawings high in representational diversity were ranked as significantly more creative than baseline drawings, although this effect was not repeated for the stories. (CL)

Author(s): Joanne Baker [1] A Short Bright Flash: Augustin Fresnel and the Birth of the Modern Lighthouse Theresa Levitt W. W. Norton: 2013 [illus. 1] At a remote lighthouse on [...]

The Edge of Physics: A Journey to Earth's Extremes to Unlock the Secrets of the Universe/Dispatches from the Frontiers of Cosmology by Anil Ananthaswamy Houghton Mifflin Harcourt/Gerald Duckworth: 2010. 336 [...]

Charles Darwin's ideas speak to the essence of what it is to be human. Different cultures have absorbed and expressed this in different ways. His impact on science and culture [...]

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-8500.2007.00533_6.x Byline: Joanne Baker (1) Author Affiliation: (1)James Cook University