Transmission and Age Impact the Risk of Developing Febrile Malaria in Children with Asymptomatic Plasmodium falciparum Parasitemia.
Plasmodium falciparum
age
asymptomatic
immunity
transmission
Journal
The Journal of infectious diseases
ISSN: 1537-6613
Titre abrégé: J Infect Dis
Pays: United States
ID NLM: 0413675
Informations de publication
Date de publication:
23 02 2019
23 02 2019
Historique:
received:
06
06
2018
accepted:
10
10
2018
pubmed:
12
10
2018
medline:
9
1
2020
entrez:
12
10
2018
Statut:
ppublish
Résumé
Plasmodium falciparum infections lead to febrile illness unless the host has sufficient immunity, in which case infection may cause no immediate symptoms (ie, "asymptomatic parasitemia"). Previous studies are conflicting on the role of asymptomatic parasitemia in determining the risk of developing febrile malaria. We monitored 2513 children (living in Kilifi, Kenyan Coast) by blood smears in 17 cross-sectional surveys to identify asymptomatic parasitemia and used active surveillance over 11325 child-years of follow-up to detect febrile malaria. We evaluated the interaction between transmission intensity, age, and asymptomatic parasitemia in determining the risk of developing febrile malaria. In the moderate and high transmission intensity settings, asymptomatic parasitemia was associated with a reduced risk of febrile malaria in older children (> 3 years), while in the lower transmission setting, asymptomatic parasitemia was associated with an increased risk of febrile malaria in children of all ages. Additionally, the risk associated with asymptomatic parasitemia was limited to the first 90 days of follow-up. Asymptomatic parasitemia is modified by transmission intensity and age, altering the risk of developing febrile episodes and suggesting that host immunity plays a prominent role in mediating this process.
Sections du résumé
BACKGROUND
Plasmodium falciparum infections lead to febrile illness unless the host has sufficient immunity, in which case infection may cause no immediate symptoms (ie, "asymptomatic parasitemia"). Previous studies are conflicting on the role of asymptomatic parasitemia in determining the risk of developing febrile malaria.
METHODS
We monitored 2513 children (living in Kilifi, Kenyan Coast) by blood smears in 17 cross-sectional surveys to identify asymptomatic parasitemia and used active surveillance over 11325 child-years of follow-up to detect febrile malaria. We evaluated the interaction between transmission intensity, age, and asymptomatic parasitemia in determining the risk of developing febrile malaria.
RESULTS
In the moderate and high transmission intensity settings, asymptomatic parasitemia was associated with a reduced risk of febrile malaria in older children (> 3 years), while in the lower transmission setting, asymptomatic parasitemia was associated with an increased risk of febrile malaria in children of all ages. Additionally, the risk associated with asymptomatic parasitemia was limited to the first 90 days of follow-up.
CONCLUSIONS
Asymptomatic parasitemia is modified by transmission intensity and age, altering the risk of developing febrile episodes and suggesting that host immunity plays a prominent role in mediating this process.
Identifiants
pubmed: 30307567
pii: 5127001
doi: 10.1093/infdis/jiy591
pmc: PMC6386809
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
936-944Subventions
Organisme : Medical Research Council
ID : G1002624
Pays : United Kingdom
Organisme : Wellcome Trust
ID : 107769/Z/10/Z
Pays : United Kingdom
Organisme : Wellcome Trust
ID : 107568/Z/15/Z
Pays : United Kingdom
Informations de copyright
© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America.
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