Evidence map›Paper›PMID 41856656›Full record

Observational studyBMJ global health2026

Pandemic-associated disruption of seasonal mortality patterns in Lusaka, Zambia.

Avulundiah Edwin Phiri, Muleya Siakabeya, Veronica Mtonga

Abstract readObservational Study
In one paragraph

Observational study in BMJ global health, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

3 authors.

Avulundiah Edwin PhiriMathematics, The Copperbelt University School of Mathematics and Natural Sciences, Kitwe, Zambia edwin@aims.ac.za.ORCID 0000-0001-9794-5438
Muleya SiakabeyaSchool of Business, University of Lusaka, Lusaka, Zambia.
Veronica MtongaSchool of Business, University of Lusaka, Lusaka, Zambia.ORCID 0009-0009-4529-6080

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionClimate-sensitive mortality in rapidly urbanising tropical Africa is poorly characterised, and how pandemics disrupt established seasonal patterns remains underexplored. We analysed long-term all-cause mortality in Lusaka, Zambia, to quantify pre-COVID-19 seasonality and examine pandemic-associated deviations.

methodsWe conducted an observational, exploratory longitudinal time-series analysis of routinely collected monthly all-cause mortality data from Lusaka, Zambia (January 2013 to December 2023; n=180 276). Seasonal dynamics were assessed using classical decomposition and Kruskal-Wallis tests. Structural breaks were identified using Bai-Perron and cumulative sum control chart (CUSUM) analyses. A parsimonious Seasonal Autoregressive Integrated Moving Average (SARIMA) model, selected via Akaike information criterion-based automated procedures and validated using rolling-origin cross-validation, was used to benchmark pre-pandemic forecast performance. Analyses were based on aggregated mortality counts in a population with a high paediatric mortality burden.

resultsPre-pandemic mortality exhibited two seasonal peaks: the rainy season (November to March), 22% above the annual mean (95% CI 15% to 29%) and the cool-dry season (June to July), 18% above (95% CI 12% to 24%). Two structural breakpoints temporally aligned with pandemic onset (March 2020) and a subsequent transition toward more stable post-pandemic patterns (May 2022). During the pandemic period, cold-season mortality increased by 41% (95% CI 32% to 50%), while rainy-season mortality declined by 28% (95% CI -35% to -21%). Overall seasonality weakened after 2020 (p=0.14 vs pre-pandemic p=0.05). The SARIMA model showed good pre-pandemic accuracy (root mean square error (RMSE)=245; MAPE=9%) but underestimated mortality during pandemic surges.

conclusionsCOVID-19 coincided with substantial disruption and attenuation of established seasonal mortality patterns in Lusaka. These observational findings highlight the value and limitations of routine mortality surveillance and forecasting for situational awareness and preparedness in rapidly urbanising, resource-constrained settings.

Indexed as

COVID-19MortalityPandemicsSeasonsHumansLongitudinal StudiesSARS-CoV-2ZambiaCOVID-19EpidemiologyMathematical modelling

Identifiers

PMID41856656
PMCPMC13007078

What OpenQuestion holds

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LicenceCC BY-NC
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.