ArticleThe Journal of infectious diseases2019
Asymptomatic Natural Human Infections With the Simian Malaria Parasites Plasmodium cynomolgi and Plasmodium knowlesi.
Article in The Journal of infectious diseases, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01872702 (Targeted Chemo-elimination), which is not on this map. Cited by 114 papers, 12 of them syntheses that pooled it.
What it found
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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.
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.
Targeted Chemo-elimination (TCE) to Eradicate Malaria in Areas of Suspected or Proven Artemisinin Resistance in Southeast Asia and South Asia
Who cites it
114 citing papers in PubMed, 12 syntheses or guidelines pooled it, 163 citations in OpenAlex.
- Burden of malaria-HIV coinfection and associated adverse outcomes in Ethiopia: a systematic review and meta-analysis.BMC infectious diseases · 2026Pooled it
- Systematic review of Anopheles abundance and meta-analysis of nonhuman primate malaria infection in mosquitoes in Thailand.Parasites & vectors · 2026Pooled it
- Prevalence and determinants of zoonotic malaria in the Greater Mekong Subregion (GMS) and Malaysia: systematic review and meta-analysis.Malaria journal · 2025Pooled it
- The threat of increased transmission of non-Parasitology · 2023Pooled it
- Prevalence and proportion estimate of asymptomatic Plasmodium infection in Asia: a systematic review and meta-analysis.Scientific reports · 2023Pooled it
- A systematic review of asymptomatic Plasmodium knowlesi infection: an emerging challenge involving an emerging infectious disease.Malaria journal · 2022Pooled it
- The Role of Human Behavior inInternational journal of environmental research and public health · 2022Pooled it
- Prevalence and characteristics of malaria co-infection among individuals with visceral leishmaniasis in Africa and Asia: a systematic review and meta-analysis.Parasites & vectors · 2021Pooled it
- Quantification of the misidentification of Plasmodium knowlesi as Plasmodium malariae by microscopy: an analysis of 1569 P. knowlesi cases.Malaria journal · 2021Pooled it
- Preliminary review on the prevalence, proportion, geographical distribution, and characteristics of naturally acquired Plasmodium cynomolgi infection in mosquitoes, macaques, and humans: a systematic review and meta-analysis.BMC infectious diseases · 2021Pooled it
- Prevalence of severe Plasmodium knowlesi infection and risk factors related to severe complications compared with non-severe P. knowlesi and severe P. falciparum malaria: a systematic review and meta-analysis.Infectious diseases of poverty · 2020Pooled it
- How can interventions that target forest-goers be tailored to accelerate malaria elimination in the Greater Mekong Subregion? A systematic review of the qualitative literature.Malaria journal · 2019Pooled it
- Accurate and sensitive TaqMan real-time PCR assays to detect and quantify simian malaria parasites Plasmodium cynomolgi, Plasmodium inui and Plasmodium coatneyi.Malaria journal · 2026Article
- Zoonotic malaria in Southeast Asia's changing landscapes: vector complexity, challenges, and future strategies.Parasites & vectors · 2026Review
- Different clinical forms of Plasmodium vivax infection result in unique T cell epitope-specific immune responses.Journal of immunology (Baltimore, Md. : 1950) · 2026Article
- Epidemiology of malaria and leishmaniasis in Thailand (2004-2025): A systematic review.Current research in parasitology & vector-borne diseases · 2026Review
- Molecular Investigation ofVeterinary medicine international · 2026Article
- First molecular detection of zoonoticInternational journal for parasitology. Parasites and wildlife · 2025Article
- Caveola-vesicle complexes of Plasmodium vivax and Plasmodium cynomolgi: large-scale aggregation and structure of PHIST-positive vesicles in late schizont-infected red blood cells.Malaria journal · 2025Article
- Molecular and Microscopic Challenges in DetectingPathogens (Basel, Switzerland) · 2025Article
54 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
12 authors at 4 institutions in 3 countries.
Funding
Abstract
backgroundIn Southeast Asia, Plasmodium knowlesi, a parasite of long-tailed macaques (Macaca fascicularis), is an important cause of human malaria. Plasmodium cynomolgi also commonly infects these monkeys, but only one naturally acquired symptomatic human case has been reported previously.
methodsMalariometric studies involving 5422 subjects (aged 6 months to 65 years) were conducted in 23 villages in Pailin and Battambang, western Cambodia. Parasite detection and genotyping was conducted on blood samples, using high-volume quantitative PCR (uPCR).
resultsAsymptomatic malaria parasite infections were detected in 1361 of 14732 samples (9.2%). Asymptomatic infections with nonhuman primate malaria parasites were found in 21 individuals living close to forested areas; P. cynomolgi was found in 11, P. knowlesi was found in 8, and P. vivax and P. cynomolgi were both found in 2. Only 2 subjects were female, and 14 were men aged 20-40 years. Geometric mean parasite densities were 3604 parasites/mL in P. cynomolgi infections and 52488 parasites/mL in P. knowlesi infections. All P. cynomolgi isolates had wild-type dihydrofolate reductase genes, in contrast to the very high prevalence of mutations in the human malaria parasites. Asymptomatic reappearance of P. cynomolgi occurred in 2 subjects 3 months after the first infection.
conclusionsAsymptomatic naturally acquired P. cynomolgi and P. knowlesi infections can both occur in humans. CLINICAL TRIALS REGISTRATION: NCT01872702.
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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.