Evidence map›Paper›PMID 34906134›Full record

ArticleMalaria journal2021

Dynamic changes in genetic diversity, drug resistance mutations, and treatment outcomes of falciparum malaria from the low-transmission to the pre-elimination phase on the islands of São Tomé and Príncipe.

Ying-An Chen, Tsen-Ju Shiu, Lien-Fen Tseng, Chien-Fu Cheng, Wei-Liang Shih, Arlindo Vicente de Assunção Carvalho, Kun-Hsien Tsai

Open access · goldAbstract read
In one paragraph

Article in Malaria journal, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed, 1 pooled it
1.6field-weighted citation impact, top 16% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

8 citing papers in PubMed, 1 synthesis or guideline pooled it, 11 citations in OpenAlex.

  1. Pooled it
  2. Trajectory ofOpen forum infectious diseases · 2025
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  8. Genetic polymorphism ofAccess microbiology · 2022
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 3 institutions in 3 countries.

Ying-An ChenInstitute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan.
Tsen-Ju ShiuInstitute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Lien-Fen TsengTaiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe.
Chien-Fu ChengTaiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe.
Wei-Liang ShihInstitute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Arlindo Vicente de Assunção CarvalhoCentro Nacional de Endemias, Ministério da Saúde de São Tomé e Príncipe, São Tomé, São Tomé and Príncipe.
Kun-Hsien TsaiInstitute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan. kunhtsai@ntu.edu.tw.ORCID http://orcid.org/0000-0002-6154-113X
National Taiwan University · TWCentro Nacional de Endemias · STMinistry of Health and Welfare · KR

Funding

Ministry of Science and Technology Council (103-2314-B-002-036-MY2
6 · The paper itself

Abstract

backgroundWith effective vector control and case management, substantial progress has been made towards eliminating malaria on the islands of São Tomé and Príncipe (STP). This study assessed the dynamic changes in the genetic diversity of Plasmodium falciparum, the anti-malarial drug resistance mutations, and malaria treatment outcomes between 2010 and 2016 to provide insights for the prevention of malaria rebounding.

methodsPolymorphic regions of merozoite surface proteins 1 and 2 (msp1 and msp2) were sequenced in 118 dried blood spots (DBSs) collected from malaria patients who had visited the Central Hospital in 2010-2016. Mutations in the multi-drug resistance I (pfmdr1), chloroquine resistance transporter (pfcrt), and kelch 13 (pfk13) genes were analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing in 111 DBSs. A total of 7482 cases that completed a 28-day follow-up were evaluated for treatment outcomes based on the microscopic results. Regression models were used to characterize factors associated with levels of parasite density and treatment failures.

resultsParasite strains in STP showed significant changes during and after the peak incidence in 2012. The prevalent allelic type in msp1 changed from K1 to MAD20, and that in msp2 changed from 3D7/IC to FC27. The dominant alleles of drug-resistance markers were pfmdr1 86Y, 184F, D1246, and pfcrt 76 T (Y-F-D-T, 51.4%). The average parasite density in malaria cases declined threefold from low-transmission (2010-2013) to pre-elimination period (2014-2016). Logistic regression models showed that patients with younger age (OR for age = 0.97-0.98, p < 0.001), higher initial parasite density (log

conclusionsPlasmodium falciparum in STP had experienced changes in prevalent strains, and increased mutation frequencies in drug-resistance genes from the low-transmission to the pre-elimination settings. Notably, patients with younger age and receiving quinine treatment were more likely to show parasitological treatment failure during follow-up. Therapeutic efficacy should be carefully monitored to inform future treatment policy in STP.

Indexed as

Genetic VariationDrug ResistanceMalaria, FalciparumMutationPlasmodium falciparumSao Tome and PrincipeTreatment OutcomeAntimalarial drug resistance mutationsMalariaMerozoite surface proteinsPlasmodium falciparumRecurrenceSão Tomé and Príncipe

Identifiers

PMID34906134
PMCPMC8672503
OpenAlexW4200586005

What OpenQuestion holds

Textmetadata
LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.