title: Influence of infection on malaria-specific antibody dynamics in a cohort exposed to intense malaria transmission in northern Uganda.
abstract: The role of submicroscopic infections in modulating malaria antibody responses is poorly understood and requires longitudinal studies. A cohort of 249 children ≤5 years of age, 126 children between 6 and 10 years and 134 adults ≥20 years was recruited in an area of intense malaria transmission in Apac, Uganda and treated with artemether/lumefantrine at enrolment. Parasite carriage was determined at enrolment and after 6 and 16 weeks using microscopy and PCR. Antibody prevalence and titres to circumsporozoite protein, apical membrane antigen-1 (AMA-1), merozoite surface protein-1 (MSP-119 ), merozoite surface protein-2 (MSP-2) and Anopheles gambiae salivary gland protein 6 (gSG6) were determined by ELISA. Plasmodium falciparum infections were detected in 38·1% (194/509) of the individuals by microscopy and in 57·1% (284/493) of the individuals by PCR at enrolment. Antibody prevalence and titre against AMA-1, MSP-119 , MSP-2 and gSG6 were related to concurrent (sub-)microscopic parasitaemia. Responses were stable in children who were continuously infected with malaria parasites but declined in children who were never parasitaemic during the study or were not re-infected after treatment. These findings indicate that continued malaria infections are required to maintain antibody titres in an area of intense malaria transmission.
authors.affiliation: Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Proietti
authors.forename: F
authors.initials: F
authors.lastname: Verra
authors.forename: M T
authors.initials: MT
authors.lastname: Bretscher
authors.forename: W
authors.initials: W
authors.lastname: Stone
authors.forename: B N
authors.initials: BN
authors.lastname: Kanoi
authors.forename: B
authors.initials: B
authors.lastname: Balikagala
authors.forename: T G
authors.initials: TG
authors.lastname: Egwang
authors.forename: P
authors.initials: P
authors.lastname: Corran
authors.forename: R
authors.initials: R
authors.lastname: Ronca
authors.forename: B
authors.initials: B
authors.lastname: Arcà
authors.forename: E M
authors.initials: EM
authors.lastname: Riley
authors.forename: A
authors.initials: A
authors.lastname: Crisanti
authors.forename: C
authors.initials: C
authors.lastname: Drakeley
authors.forename: T
authors.initials: T
authors.lastname: Bousema
mesh_terms: D000328:Adult; D000367:Age Factors; D000818:Animals; D000852:Anopheles / Q000276:immunology; D000906:Antibodies / Q000097:blood*; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D019476:Insect Proteins / Q000276:immunology; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology / Q000635:transmission; D008297:Male; D018512:Parasitemia / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015995:Prevalence; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000906:Antibodies; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D019476:Insect Proteins