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Measuring ex vivo drug susceptibility in Plasmodium vivax isolates from Cambodia

Overview of attention for article published in Malaria Journal, September 2017
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  • Above-average Attention Score compared to outputs of the same age (62nd percentile)

Mentioned by

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6 tweeters
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1 Facebook page

Citations

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11 Dimensions

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22 Mendeley
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Title
Measuring ex vivo drug susceptibility in Plasmodium vivax isolates from Cambodia
Published in
Malaria Journal, September 2017
DOI 10.1186/s12936-017-2034-2
Pubmed ID
Authors

Suwanna Chaorattanakawee, Chanthap Lon, Soklyda Chann, Kheang Heng Thay, Nareth Kong, Yom You, Siratchana Sundrakes, Chatchadaporn Thamnurak, Sorayut Chattrakarn, Chantida Praditpol, Kritsanai Yingyuen, Mariusz Wojnarski, Rekol Huy, Michele D. Spring, Douglas S. Walsh, Jaymin C. Patel, Jessica Lin, Jonathan J. Juliano, Charlotte A. Lanteri, David L. Saunders

Abstract

While intensive Plasmodium falciparum multidrug resistance surveillance continues in Cambodia, relatively little is known about Plasmodium vivax drug resistance in Cambodia or elsewhere. To investigate P. vivax anti-malarial susceptibility in Cambodia, 76 fresh P. vivax isolates collected from Oddar Meanchey (northern Cambodia) in 2013-2015 were assessed for ex vivo drug susceptibility using the microscopy-based schizont maturation test (SMT) and a Plasmodium pan-species lactate dehydrogenase (pLDH) ELISA. P. vivax multidrug resistance gene 1 (pvmdr1) mutations, and copy number were analysed in a subset of isolates. Ex vivo testing was interpretable in 80% of isolates using the pLDH-ELISA, but only 25% with the SMT. Plasmodium vivax drug susceptibility by pLDH-ELISA was directly compared with 58 P. falciparum isolates collected from the same locations in 2013-4, tested by histidine-rich protein-2 ELISA. Median pLDH-ELISA IC50 of P. vivax isolates was significantly lower for dihydroartemisinin (3.4 vs 6.3 nM), artesunate (3.2 vs 5.7 nM), and chloroquine (22.1 vs 103.8 nM) than P. falciparum but higher for mefloquine (92 vs 66 nM). There were not significant differences for lumefantrine or doxycycline. Both P. vivax and P. falciparum had comparable median piperaquine IC50 (106.5 vs 123.8 nM), but some P. falciparum isolates were able to grow in much higher concentrations above the normal standard range used, attaining up to 100-fold greater IC50s than P. vivax. A high percentage of P. vivax isolates had pvmdr1 Y976F (78%) and F1076L (83%) mutations but none had pvmdr1 amplification. The findings of high P. vivax IC50 to mefloquine and piperaquine, but not chloroquine, suggest significant drug pressure from drugs used to treat multidrug resistant P. falciparum in Cambodia. Plasmodium vivax isolates are frequently exposed to mefloquine and piperaquine due to mixed infections and the long elimination half-life of these drugs. Difficulty distinguishing infection due to relapsing hypnozoites versus blood-stage recrudescence complicates clinical detection of P. vivax resistance, while well-validated molecular markers of chloroquine resistance remain elusive. The pLDH assay may be a useful adjunctive tool for monitoring for emerging drug resistance, though more thorough validation is needed. Given high grade clinical chloroquine resistance observed recently in neighbouring countries, low chloroquine IC50 values seen here should not be interpreted as susceptibility in the absence of clinical data. Incorporating pLDH monitoring with therapeutic efficacy studies for individuals with P. vivax will help to further validate this field-expedient method.

Twitter Demographics

The data shown below were collected from the profiles of 6 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 22 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 22 100%

Demographic breakdown

Readers by professional status Count As %
Researcher 9 41%
Student > Master 4 18%
Student > Bachelor 2 9%
Professor 1 5%
Student > Ph. D. Student 1 5%
Other 1 5%
Unknown 4 18%
Readers by discipline Count As %
Medicine and Dentistry 7 32%
Biochemistry, Genetics and Molecular Biology 5 23%
Nursing and Health Professions 2 9%
Agricultural and Biological Sciences 1 5%
Immunology and Microbiology 1 5%
Other 1 5%
Unknown 5 23%

Attention Score in Context

This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 04 December 2017.
All research outputs
#4,147,413
of 13,784,591 outputs
Outputs from Malaria Journal
#1,594
of 3,992 outputs
Outputs of similar age
#96,894
of 272,608 outputs
Outputs of similar age from Malaria Journal
#1
of 1 outputs
Altmetric has tracked 13,784,591 research outputs across all sources so far. This one is in the 49th percentile – i.e., 49% of other outputs scored the same or lower than it.
So far Altmetric has tracked 3,992 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.5. This one has gotten more attention than average, scoring higher than 51% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 272,608 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 62% of its contemporaries.
We're also able to compare this research output to 1 others from the same source and published within six weeks on either side of this one. This one has scored higher than all of them