World Malaria Day 2025

Sustaining malaria research gains and preparing for climate-driven disease threats in Manicaland, Zimbabwe

Reflecting on Zimbabwe’s malaria progress

World Malaria Day (25 April) is a moment to reflect on Zimbabwe’s public health achievements. Over the past two decades, malaria incidence declined by 84.5% between 2000 and 2016, prompting malaria elimination efforts in 20 of the country’s 47 districts. This success has been supported by long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), improved diagnostics, and case management.

However, these gains are increasingly under threat. Malaria transmission in Zimbabwe remains closely linked to rainfall and topography, with peak transmission during the rainy season (November to April) (scientific findings). Severe flooding in 2016/2017 resulted in widespread mosquito breeding and renewed outbreaks. In 2022, Zimbabwe reported approximately 366,000 malaria cases, concentrated in Mashonaland Central, Manicaland, and Masvingo provinces, according to the World Malaria Report 2023.

Despite the national decline in incidence—from 153 to 9 cases per 1,000 population between 2004 and 2022—malaria burden has fluctuated, due to climate variability, insecticide resistance, and disruptions to health service delivery.

New challenges: climate change and shifting disease ecology

Zimbabwe’s malaria landscape is being reshaped by climate change. Rising temperatures, erratic rainfall, and increased surface water are enabling malaria transmission to expand into highland zones previously considered low-risk. These shifts are particularly evident in ecologically diverse, topographically varied areas like Mutasa District in Manicaland Province (high-resolution malaria risk mapping).

The Honde Valley, located approximately 45 km northeast of Mutare , Zimbabwe’s third-largest city, is a critical zone of interest. This valley plunges from 1,800 to 800 meters above sea level over a short horizontal span, producing a natural altitudinal transect that drives microclimatic variation in temperature, humidity, and vector ecology. These gradients have a profound impact on the distribution and behavior of malaria vectors.

The valley’s proximity to the Mozambique border also heightens the risk of cross-border malaria importation (situational assessment, cross-border malaria, human movement patterns, risk factors). Reports of pyrethroid-resistant  necessitated a recent shift in IRS strategy from pirimiphos-methyl to DDT (scientific findings, World Malaria Report 2023), highlighting operational challenges. Moreover, malaria transmission is now being detected at higher altitudes, reflecting a troubling shift toward climate-facilitated transmission zones.

Beyond malaria: suspected arboviral emergence

Alongside this ecological shift in malaria transmission, persistent non-malarial febrile illnesses are being reported, especially during the rainy season. These cases are neither malaria-positive nor attributable to bacterial or respiratory infections, raising concerns about emerging arboviral diseases such as dengue and chikungunya (climate change and arboviruses, cascading risks, climate change impact, weather effects, vector-borne diseases, climate and malaria distribution). Misdiagnosed or untreated arboviral infections are suspected contributors, diverting health resources, causing school and work absenteeism, and driving antimicrobial resistance through inappropriate prescriptions.

Unlike malaria, which is transmitted by Anopheles mosquitoes, arboviruses are primarily spread by Aedes aegypti—a mosquito species that breeds in transient water containers and thrives in human-dominated landscapes (climate change and arboviruses, vector-borne diseases).This species is increasingly present in Manicaland, overlapping with Anopheles habitats and complicating differential diagnosis. A recent local seroprevalence study found 3–5% exposure to arboviruses in febrile patients yet no active arboviral surveillance exists to verify or respond to these findings.

Zimbabwe’s current disease surveillance system is largely passive and lacks high-resolution environmental data, such as temperature, rainfall, and vapor pressure variation across altitude. This limits the ability to detect early vector shifts and predict outbreak risk.

CLIMVEC alert: building a climate-sensitive surveillance future

In response, CLIMVEC Alert, a regional research collaboration—has been launched to build an adaptive vector-borne disease surveillance platform in climate-vulnerable areas like the Honde Valley.

Led by Stellenbosch University, the Manicaland Centre for Public Health Research, and regional partners including Africa University and the Ministry of Health and Child Care, CLIMVEC aims to detect and forecast climate-linked threats across both malaria and arboviral diseases.

Project objectives (2025–2030):

• Deploy real-time environmental sensors across ecological zones
• Conduct longitudinal community health and behavioral surveys
• Map and analyze Anopheles and Aedes vector ecologies with molecular tools
• Build early-warning models for disease outbreak prediction

This platform will support locally tailored, climate-smart health strategies in a region that represents both the opportunity and urgency of future-focused disease preparedness.

Tied to broader research: the NIH-funded IMPERATIVE Trial

CLIMVEC Alert builds on groundwork laid by the IMPERATIVE Trial (Improving Prevention and Engagement in Risk-Informed Approaches for Testing and Treatment in Vulnerable Populations), a NIH-funded initiative focused on HIV self-testing and peer-led PrEP access for men in Manicaland.

During the trial’s launch, Dr Wilfred Otambo, a postdoctoral fellow supervised by Prof Frank Tanser, visited the Honde Valley and convened with Ministry of Health officials, Africa University, and the Ministry of Health to explore synergies between climate, HIV prevention, malaria elimination, and emerging arboviral threats especially in climate-sensitive regions.

World Malaria Day: a call for funding and partnership

CLIMVEC Alert offers a high-return, high-impact opportunity for donors and development partners to: Sustain Zimbabwe’s malaria elimination gains, Prevent the emergence of new arboviral epidemics, Support scalable, climate-informed surveillance innovation

We are actively seeking funding partners and collaborators to pilot and scale this innovative platform across Manicaland and other high-risk regions.

To learn more or discuss partnership opportunities, please contact:

Dr Wilfred Otambo
Email: 28756622@sun.ac.za

Together, we can drive innovation in climate-linked disease surveillance and build resilient health systems for the future.

Further Reading

• World Malaria Report 2023 – A comprehensive overview of global malaria trends, including Zimbabwe’s progress and challenges.
• Malaria Transmission at The Zimbabwe–Mozambique Border – An observational study exploring parasitemia risks linked to travel and household location in Manicaland.
• Impact of Climate Change on Global Malaria Distribution – A scientific analysis of how climate shifts are altering malaria transmission zones worldwide.