Current and cumulative malaria infections in a setting embarking on elimination: Amhara, Ethiopia

Malaria Journal

Research

Chris Drakeley¹  Rebecca Dabbs¹  Kevin Tetteh¹  Caterina Guinovart²  Catherine Seneviratne²  Asefaw Getachew²  Gonzalo J. Domingo²  Richard W. Steketee²  Lindsay Yokobe²  Belendia A. Serda²  Berhane H. Tesfay²  Michael Kalnoky²  Sampa Pal²  Megan Littrell²  Pooja Bansil²  Woyneshet G. Yalew³  Belay B. Beyene³  Gregory S. Noland⁴ 

[1] Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, WCIE 7HT, London, UK;PATH, 2201 Westlake Avenue, Suite 200, 98121, Seattle, WA, USA;Regional Health Research Laboratory Center, Amhara National Regional State Health Bureau, P.O. Box 495, Bahir Dar, Ethiopia;The Carter Center, 453 Freedom Parkway, 30307, Atlanta, GA, USA;

关键词: Malaria;    Plasmodium falciparum;    Plasmodium vivax;    Seroconversion;    Seroprevalence;    Malaria transmission;   

DOI  :  10.1186/s12936-017-1884-y

 received in 2017-03-03, accepted in 2017-05-30,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundSince 2005, Ethiopia has aggressively scaled up malaria prevention and case management. As a result, the number of malaria cases and deaths has significantly declined. In order to track progress towards the elimination of malaria in Amhara Region, coverage of malaria control tools and current malaria transmission need to be documented.MethodsA cross-sectional household survey oversampling children under 5 years of age was conducted during the dry season in 2013. A bivalent rapid diagnostic test (RDT) detecting both Plasmodium falciparum and Plasmodium vivax and serology assays using merozoite antigens from both these species were used to assess the prevalence of malaria infections and exposure to malaria parasites in 16 woredas (districts) in Amhara Region.Results7878 participants were included, with a mean age of 16.8 years (range 0.5–102.8 years) and 42.0% being children under 5 years of age. The age-adjusted RDT-positivity for P. falciparum and P. vivax infection was 1.5 and 0.4%, respectively, of which 0.05% presented as co-infections. Overall age-adjusted seroprevalence was 30.0% for P. falciparum, 21.8% for P. vivax, and seroprevalence for any malaria species was 39.4%. The prevalence of RDT-positive infections varied by woreda, ranging from 0.0 to 8.3% and by altitude with rates of 3.2, 0.7, and 0.4% at under 2000, 2000–2500, and >2500 m, respectively. Serological analysis showed heterogeneity in transmission intensity by area and altitude and evidence for a change in the force of infection in the mid-2000s.ConclusionsCurrent and historic malaria transmission across Amhara Region show substantial variation by age and altitude with some settings showing very low or near-zero transmission. Plasmodium vivax infections appear to be lower but relatively more stable across geography and altitude, while P. falciparum is the dominant infection in the higher transmission, low-altitude areas. Age-dependent seroprevalence analyses indicates a drop in transmission occurred in the mid-2000s, coinciding with malaria control scale-up efforts. As malaria parasitaemia rates get very low with elimination efforts, serological evaluation may help track progress to elimination.

【 授权许可】

CC BY   
© The Author(s) 2017