Retrospective Study Finds Persistent Malaria in Estie District, 2015–2022

An eight-year retrospective analysis found that malaria remained a persistent public-health problem in Estie District, Ethiopia, between 2015 and 2022 despite substantial fluctuations in reported incidence. Researchers reviewed laboratory records from Mekane Eyesus hospital and health center, identifying 7,674 microscopically confirmed malaria cases among 49,215 people who had been clinically suspected of having the disease. The confirmed cases represented 15.6% of the clinically suspected population examined.

The study was designed to describe patterns in malaria occurrence rather than measure population prevalence across the entire district. Its retrospective dataset came from peripheral blood-smear examinations documented in laboratory logbooks. The researchers used descriptive statistics to examine how confirmed infections varied by month, year, sex, age group, residential setting and season. Because the records covered people who sought care and were tested at one hospital and health center, the findings describe laboratory-confirmed disease in the study population rather than all malaria infections occurring in Estie District.

Confirmed malaria was distributed unevenly between sexes and residential settings. Males accounted for 81.9% of the positive cases, while females accounted for 18.1%, a difference reported at p less than 0.01. Rural residents represented 71.3% of confirmed infections, compared with 28.7% among urban residents, also with p less than 0.01. These proportions characterize the patients included in the retrospective analysis; they do not establish that malaria was more prevalent among every rural or male resident, nor do they identify the factors responsible for the observed differences.

Plasmodium falciparum was the most frequently identified malaria parasite, with its predominance reported at p less than 0.01. The study’s conclusion further described P. falciparum as the predominant species, followed by Plasmodium vivax, with both species reported in the rural population. The supplied results do not quantify the prevalence of mixed infections. Together, the findings show that the laboratory-confirmed burden involved more than one parasite species, while P. falciparum was the dominant one in the records analyzed.

Cases showed a marked seasonal concentration. The highest peak occurred among people aged 15 to 44 years during September, October and November. The investigators identified this three-month autumn period as the principal malaria-transmission season in Ethiopia following the heavy rains of July and August. This timing is an observed feature of the study’s monthly case pattern; the retrospective laboratory analysis did not itself establish how rainfall or any other environmental or biological factor produced the seasonal peak.

Across the full 2015–2022 observation window, malaria incidence fluctuated rather than following a uniform, continuous decline. The study’s conclusion warned that malaria could reappear between 2021 and 2022 and described this possibility as extremely concerning. The abstract does not provide a numerical year-by-year case series, so the magnitude or sharpness of any change during that interval cannot be quantified from the reported findings. What can be established is that malaria persisted through the end of the study period and remained capable of producing clinically suspected cases that were confirmed by microscopy.

The findings place the Estie data within the broader context of substantial reductions in malaria cases in Ethiopia over the preceding two decades, while showing that the district had not experienced a sustained disappearance of the disease. The authors called for existing intervention strategies in the study area to be reviewed and emphasized the need for uninterrupted malaria-control and prevention activities to reduce the local burden. They also stated that persistent malaria and renewed occurrence could hinder Ethiopia’s broader goal of malaria eradication.

As a district-level retrospective assessment, the research was not an evaluation of the effectiveness of a particular intervention, diagnostic test or treatment. It relied on clinical suspicions and blood-smear results recorded at a single hospital and health center over eight years. Such a design can reveal temporal, demographic and seasonal patterns among tested patients, but it cannot directly quantify community-wide incidence, infections missed by care-seeking or diagnostic services, or the independent effects of vector abundance, intervention coverage and other potential drivers. Within those limits, the study documents a continuing, seasonally concentrated malaria burden in Estie District dominated by P. falciparum, with P. vivax also present and rural residents accounting for most confirmed cases.

Subject of Research: Eight-year retrospective trends in laboratory-confirmed malaria among clinically suspected patients in Estie District, Ethiopia

Article Title: Eight-year malaria trend in Estie District, Ethiopia: implications for malaria elimination

Article References: Adugna, T. (2026). Eight-year malaria trend in Estie District, Ethiopia: implications for malaria elimination. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14332-0

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14332-0

Keywords: malaria, Estie District, Ethiopia, retrospective study, blood microscopy, Plasmodium falciparum, Plasmodium vivax, seasonal transmission, rural health, malaria surveillance, Eight-year, trend