Asymptomatic Natural Human Infections With the Simian Malaria Parasites Plasmodium cynomolgi and Plasmodium knowlesi.
J Infect Dis
; 219(5): 695-702, 2019 02 15.
Article
en En
| MEDLINE
| ID: mdl-30295822
ABSTRACT
BACKGROUND:
In 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.METHODS:
Malariometric 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).RESULTS:
Asymptomatic 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.CONCLUSIONS:
Asymptomatic naturally acquired P. cynomolgi and P. knowlesi infections can both occur in humans. CLINICAL TRIALS REGISTRATION NCT01872702.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Plasmodium knowlesi
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Plasmodium cynomolgi
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Malaria
Tipo de estudio:
Observational_studies
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Prevalence_studies
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Risk_factors_studies
Límite:
Adolescent
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Adult
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Aged
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Animals
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
País como asunto:
Asia
Idioma:
En
Año:
2019
Tipo del documento:
Article