David Simons

Short presentation

I study how rodents and the viruses they carry are shaped by the landscapes people build. Having trained as a medical doctor before moving into disease ecology, my work spans Lassa fever in West Africa and rodent-borne viruses in Fennoscandia. I am currently a Birgitta Sintring Fellow in the Videvall group at Uppsala University, using the gut microbiome of bank voles as a high-resolution proxy to measure how animals connect to one another and to their environment.

Keywords

• disease ecology
• zoonoses
• rodent-borne pathogens
• gut microbiome
• Lassa fever
• arenavirus
• hantavirus
• One Health
• spatial epidemiology
• Bayesian modelling
• open science

Biography

I initially studied biodiversity and conservation at Leeds before entering medicine. The pivot was driven by a simple premise: a community's health depends fundamentally on the health of its environment, and treating the two as separate disciplines misses most of what matters. After qualifying at King's College London, I worked as a doctor in London, including a stint at the Hospital for Tropical Diseases.

Ultimately, I wanted to work closer to the source, to understand the ecological mechanisms that allow these infections to reach people in the first place. That took me into research via a master's at LSHTM, followed by a PhD jointly run between the Royal Veterinary College, UCL, and LSHTM, focusing on rodent ecology and Lassa fever spillover in Sierra Leone. I have been pretending to be an ecologist ever since and hoping nobody looks too closely, though spatial epidemiology and disease ecology are where I am genuinely at home.

Since 2023, I have been a postdoctoral scholar at Pennsylvania State University, working on the SCAPES project in Nigeria. Managing the field surveillance of Lassa virus in people and rodents has meant dedicating significant time to protocol design, training field and laboratory teams, and ensuring the resulting data holds utility beyond a single study. I am also a Fellow-in-Residence at the VERENA Institute, co-leading Project ArHa, a global synthesis of rodent sampling for arenaviruses and hantaviruses. I also serve as an external expert for the ECDC on the environmental determinants of communicable disease. Alongside this, I am an academic editor at PLOS Neglected Tropical Diseases and help organise the Rodent-Borne Zoonotic Diseases workshop series.

I now live in Stockholm and joined Uppsala in September 2026 on a Birgitta Sintring Fellowship. After several years investigating rodent-borne disease in West Africa, it is a pleasure to conduct fieldwork somewhere slightly colder. Outside of work, I spend my time outdoors, hiking with my partner and our Boxer, Simcoe, and swimming in as many of the lakes around Stockholm as the season allows.

Research

My research is ultimately about people. It rarely looks like that, given how much time I spend thinking about rodents, but you cannot understand a zoonotic disease without triangulating three things: where the hosts occur, what pathogens they carry, and how often susceptible people come into contact with those hosts or their contaminated environments. Occurrence, hazard, and risk. Miss any one of them, and the epidemiological picture is incomplete.

Transmission heterogeneity. Transmission does not spread evenly, a few individuals, places, and moments account for most of it. I am interested in why. On the rodent side, this means identifying which species thrive around human settlement, as the species that do well alongside us are frequently the ones carrying the viruses we care about. On the human side, it means asking why one person's infection is mild while another's is severe, and why one village faces substantial exposure while its neighbour has almost none. These questions are as much about human behaviour and spatial dynamics as they are about virology.

Observation bias. There is a persistent bias in whose diseases get studied. We tend to investigate infections when they cause outbreaks, and we invest the most when those outbreaks threaten wealthier countries or urban centres. Consequently, the evidence base is heavily weighted towards places that were already well-resourced, while the rural communities "at the end of the road"—who carry the highest burden—are studied the least. That bias dictates what we know, which interventions are developed, and who ultimately benefits from them.

Network structures via the microbiome. At Uppsala, I am interrogating the fundamentals beneath these transmission dynamics. Can contact between wild animals be measured using what they carry, a pathogen, or better, a harmless commensal? Because bacteria move between animals that meet and those that share ground, the similarity between two individuals' gut communities holds quantifiable data about their connectivity. If this signal can be read reliably, it offers a transferable method to measure contact structure in wild populations without requiring prior knowledge of a specific pathogen. If successful, this approach will illuminate how zoonotic pathogens physically move through host populations, allowing us to pinpoint where interventions - like rodent vaccination or fertility control - would be most effective in a network. This project combines fieldwork on bank voles in Finnish Lapland and central Sweden with 16S rRNA sequencing and Bayesian modelling.

Lassa fever. Through the SCAPES project, I co-lead the longitudinal surveillance of Lassa virus in southern Nigeria, tracking rodents, human behaviour, and land use simultaneously. My earlier work in Sierra Leone examined how rodent communities shift across land-use gradients, and how those ecological shifts dictate where spillover hazard sits.

Data synthesis and open tools. A massive amount of rodent sampling has been conducted globally, yet very little of it is interoperable across studies. Project ArHa is an attempt to rectify this for arenaviruses and hantaviruses by forcing scattered datasets into a unified framework. I build most of my analytical tools openly, releasing them for public use. I firmly believe that data and insight must outlive the project that funded them. Someone else will inevitably have questions about my data that I could not have conceived of during collection, and the architecture should be there to let them ask.

Media

Personal website

https://www.dsimons.org