International border malaria transmission in the Ethiopian district of Lare, Gambella region: implications for malaria spread into South Sudan

Abstract Background Despite notable progress in the control and prevention of malaria in the Horn of Africa, the disease continues to cause significant morbidity and mortality in various regions of Ethiopia, and elsewhere in the region. The transmission of malaria is affected by genetic, sociocultur...

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Bibliographic Details
Published in:Malaria Journal
Main Authors: Werissaw Haileselassie, Abebe Ejigu, Tesfahun Alemu, Sale Workneh, Mizan Habtemichael, Randy E. David, Kidane Lelisa, Wakgari Deressa, Guiyun Yan, Daniel M. Parker, Behailu Taye
Format: Article in Journal/Newspaper
Language:English
Published: BMC 2023
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Online Access:https://doi.org/10.1186/s12936-023-04479-5
https://doaj.org/article/534346e319ad471395d8fec5132d8772
Description
Summary:Abstract Background Despite notable progress in the control and prevention of malaria in the Horn of Africa, the disease continues to cause significant morbidity and mortality in various regions of Ethiopia, and elsewhere in the region. The transmission of malaria is affected by genetic, sociocultural, and ecological factors. Lare is an Ethiopian district adjacent to the Ethio-South Sudan border, in Gambella region. The region currently has the highest prevalence of malaria in Ethiopia. This study assesses the burden and spatiotemporal patterns of disease transmission, including the effect of climatic factors on the occurrence of malaria, across an international border crossing. This understanding can assist in crafting informed programmatic and policy decisions for interventions. Methods This study was conducted in Lare district, Southwest Ethiopia, a temperate zone. A retrospective descriptive analysis was conducted using clinical service data collected between 2011 and 2021 from the 9 health facilities of the district. Both clinically diagnosed patients and those identified using microscopy and rapid diagnostic testing (RDT) were included in the study. Additionally, climate data was incorporated into analyses. Examples of analyses include malaria burden, positivity rate, incidence, species frequency, and an ANOVA to assess inter-annual case number and meteorological factor variation. Results Between 2011 and 2021, a total of 96,616 suspected malaria cases were tested by microscopy or RDT, and 39,428 (40.8%) of these cases were reported as positive. There were 1276 patients admitted with 22 deaths recorded. There were further more significant fluctuations in positivity rates across years, the highest being 74.5% in 2021. Incidence varied from 18.0% in 2011 to 151.6% in 2016. The malaria parasite species most detected was Plasmodium falciparum, followed by a smaller proportion of Plasmodium vivax. The greatest proportions of P. falciparum cases were observed in 2018 and 2019, at 97.4% and 97.0% prevalence, ...