Developing effective rodent control strategies to reduce disease risk in ecologically and culturally diverse rural landscapes

Diseases transmitted from rodents to humans are a serious threat to health, with the highest risk in low-income countries. The risk from rodent-borne infections (RBI) depends on the abundance of infected rodents, as well as how socio-cultural practices and beliefs influence human-rodent interactions. Many rodent species implicated in disease transmission are also pests that feed on crops and stored food, and consequently management to reduce rodent numbers could have a wide impact on health and well-being.

However, controlling rodent populations effectively is challenging. Breeding and movement from adjacent populations may rapidly cancel out the impact of control. Innovative approaches that exploit ecological understanding of where and when rodents breed have been developed in the agricultural sector, primarily in Asia, with communities working together to target control and significantly reduce crop damage.

However, such techniques are poorly developed in Africa, and their potential to reduce the risk from RBI is unknown. In some circumstances, changes to rodent movements following control could increase disease transmission and prevalence in rodent populations, potentially increasing risk to humans.

Ultimately, this project aims to reduce the risk from RBI in Africa by increasing the knowledge and expertise needed to develop holistic rodent management applicable for local conditions and communities. Working with communities in Tanzania and Madagascar, in the first stage of the project we will address specific unanswered questions, whilst in the second phase we will develop and test rodent management strategies.

Two questions we will address are: how do rodent movements change after localised control, and how does control influence the prevalence of RBI in rodent populations? To make sure our approach is widely relevant, we will work with rodent species and diseases that have large impacts and contrasting ecologies. We will focus on the multi-mammate mouse, a key pest species in Africa, and the black rat, a globally important invasive pest, and consider three RBI: plague, leptospirosis and rickettsioses, which differ in key aspects of their epidemiology.

We will combine field studies with sophisticated computer models to explore how control in different locations and at different times of the year impacts on rodent movement, abundance and the prevalence of RBI. The results will provide important insights into how ecological and epidemiological factors influence the impact of different control strategies on RBI and rodent damage.

We will also work with local communities using a range of approaches to address three further questions: how do communities perceive the health threat from rodents, how do communities currently interact with and manage rodents, and how feasible are different management strategies? As effective control strategies have to be accepted and sustainable for local communities, we need to understand local perceptions and practices.

For example, high labour requirements during specific key periods in the agricultural cycle may mean that some rodent control strategies are not feasible.

The insights from this research during the first phase of the project will be used to inform the development of community-led trials of rodent management strategies. The impact of these trials on rodent abundance and the prevalence of RBI will be monitored, and the results used to refine and test our computer models.

We will use this comparative study to identify common features that determine the effectiveness or uptake of a strategy. To ensure our research informs policies, we will conduct workshops with service providers involved in agriculture, health and the environment. Across these sectors we will explore current attitudes, policies and communication practices, and provide training in adaptive management approaches. Our project will also build research capacity through collaboration and training.