Spatial heterogeneity of malaria in Ghana: a cross-sectional study on the association between urbanicity and the acquisition of immunity. (December 2016)

• Record Type: Journal Article
• Authors: Frank, Clemens; Krumkamp, Ralf; Sarpong, Nimako; Sothmann, Peter; Fobil, Julius; Foli, Geoffrey; Jaeger, Anna; Ehlkes, Lutz; Owusu-Dabo, Ellis; Adu-Sarkodie, Yaw; Marks, Florian; Schumann, Ralf; May, Jürgen; Kreuels, Benno
• Is Part Of: Malaria journal. Volume 15:Number 1(2016)
• Page Start: 1
• Page End: 10
• Publication Date: 2016-12
• Subjects: Malaria -- Ghana -- Urbanization -- Semi-immunity -- Children; Malaria -- Periodicals; 616.9362
• DOI: 10.1186/s12936-016-1138-4
• Languages: English
• ISSNs: 1475-2875

Abstract

Abstract Background Malaria incidence has declined considerably over the last decade. This is partly due to a scale-up of control measures but is also attributed to increasing urbanization. This study aimed to analyse the association between malaria and urbanization and the effect of urbanicity on the acquisition of semi-immunity. Methods In 2012, children with fever presenting to St Michael's Hospital Pramso/Ghana were recruited. The malaria-positive-fraction (MPF) of fever cases was calculated on community-level to approximate the malaria risk. The mean age of malaria cases was calculated for each community to estimate the acquisition of semi-immunity. The level of urbanicity for the communities was calculated and associations between MPF, urbanicity and immunity were modelled using linear regression. Results Twenty-six villages were included into the study with a mean MPF of 35 %. A linear decrease of 5 % (95 % CI: 4–6 %) in MPF with every ten-point increase in urbanicity was identified. The mean age of malaria patients increased by 2.9 months (95 % CI: 1.0–4.8) with every ten-point increase in urbanicity. Discussion The results confirm an association between an increase in urbanicity and declining malaria risk and demonstrate that the acquisition of semi-immunity is heterogeneous on a micro-epidemiological scale and is associated with urbanicity.