Martina Eldh1, Ulf Hammar2, David Arnot3, Hans-Peter Beck4,5, André Garcia6,7, Anne Liljander8, Odile Mercereau-Puijalon9, Florence Migot-Nabias6, Ivo Mueller9, Francine Ntoumi10,11, Amanda Ross5,12, Thomas Smith5,12, Klara Sondén1,13, Manijeh Vafa Homann1, Victor Yman1, Ingrid Felger4,5, Anna Färnert1,13. 1. Division of Infectious Diseases, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden. 2. Unit of Biostatistics, Department of Epidemiology, Institute for Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. 3. Zhejiang-Edinburgh Institute, Zhejiang University Medical School, International Campus of Zhejiang University, Haining, People's Republic of China. 4. Molecular Diagnostics, Medical Parasitology and Infection Biology, Swiss Tropical Institute, Basel, Switzerland. 5. University of Basel, Basel, Switzerland. 6. MERIT, IRD, Université Paris 5, Sorbonne Paris Cité, Paris, France. 7. Cerpage, Cotonou, Bénin. 8. International Livestock Research Institute, Nairobi, Kenya. 9. Institut Pasteur, Parasites and Insect Vectors Department, Paris, France. 10. Fondation Congolaise pour la Recherche Médicale and Faculty of Sciences and Technology University Marien Ngouabi Brazzaville, Republic of Congo. 11. Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany. 12. Department of Epidemiology and Public Health, Swiss Tropical Institute, Basel, Switzerland. 13. Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.
Abstract
BACKGROUND: The malaria parasite Plasmodium falciparum holds an extensive genetic polymorphism. In this pooled analysis, we investigate how the multiplicity in asymptomatic P. falciparum infections-that is, the number of coinfecting clones-affects the subsequent risk of clinical malaria in populations living under different levels of transmission. METHODS: A systematic search of the literature was performed to identify studies in which P. falciparum infections were genotyped in asymptomatic individuals who were followed up prospectively regarding the incidence of clinical malaria. Individual participant data were pooled from 15 studies (n = 3736 individuals). RESULTS: Multiclonal asymptomatic infections were associated with a somewhat increased subsequent risk of clinical malaria in the youngest children, followed by an initial declining risk with age irrespective of transmission intensity. At approximately 5 years of age, the risk continued the gradual decline with age in high-transmission settings. However, in older children in moderate-, low-, and seasonal-transmission settings, multiclonal infections were either not significantly associated with the risk of subsequent febrile malaria or were associated with an increased risk. CONCLUSIONS: The number of clones in asymptomatic P. falciparum infections is associated with different risks of subsequent clinical malaria depending on age and transmission intensity.
BACKGROUND: The malaria parasitePlasmodium falciparum holds an extensive genetic polymorphism. In this pooled analysis, we investigate how the multiplicity in asymptomatic P. falciparum infections-that is, the number of coinfecting clones-affects the subsequent risk of clinical malaria in populations living under different levels of transmission. METHODS: A systematic search of the literature was performed to identify studies in which P. falciparum infections were genotyped in asymptomatic individuals who were followed up prospectively regarding the incidence of clinical malaria. Individual participant data were pooled from 15 studies (n = 3736 individuals). RESULTS: Multiclonal asymptomatic infections were associated with a somewhat increased subsequent risk of clinical malaria in the youngest children, followed by an initial declining risk with age irrespective of transmission intensity. At approximately 5 years of age, the risk continued the gradual decline with age in high-transmission settings. However, in older children in moderate-, low-, and seasonal-transmission settings, multiclonal infections were either not significantly associated with the risk of subsequent febrile malaria or were associated with an increased risk. CONCLUSIONS: The number of clones in asymptomatic P. falciparum infections is associated with different risks of subsequent clinical malaria depending on age and transmission intensity.
Authors: Elangwe M Sarah-Matio; Emilie Guillochon; Antoine Berry; Isabelle Morlais; Sandrine E Nsango; Luc Abate; Christelle M Ngou; Gaelle A Bouopda; Lionel B Feufack-Donfack; Albert N Bayibéki; Majoline Tchioffo Tsapi; Arthur Talman; Alejandro Marin-Menendez; Lawrence Ayong; Antoine Claessens; Thierry Lefèvre Journal: Antimicrob Agents Chemother Date: 2022-07-06 Impact factor: 5.938
Authors: Lawrence S Redmond; Martin D Ogwang; Patrick Kerchan; Steven J Reynolds; Constance N Tenge; Pamela A Were; Robert T Kuremu; Nestory Masalu; Esther Kawira; Isaac Otim; Ismail D Legason; Herry Dhudha; Leona W Ayers; Kishor Bhatia; James J Goedert; Sam M Mbulaiteye Journal: Malar J Date: 2020-07-28 Impact factor: 2.979
Authors: Sally Peprah; Martin D Ogwang; Patrick Kerchan; Steven J Reynolds; Constance N Tenge; Pamela A Were; Robert T Kuremu; Walter N Wekesa; Nestory Masalu; Esther Kawira; Isaac Otim; Ismail D Legason; Leona W Ayers; Kishor Bhatia; James J Goedert; Ruth M Pfeiffer; Sam M Mbulaiteye Journal: Infect Agent Cancer Date: 2021-06-07 Impact factor: 2.965