Biology subjects

De Jong, M. C. M.

Publications and source records attributed to De Jong, M. C. M..

4 recordsLinked to original sources

bioRxiv2026

Quantifying circulation and antibody cross-reactivity for co-circulating flaviviruses: the case of Usutu and West Nile virus in blackbirds

Serological testing is important for assessing past exposure and immunity, but interpretation can be complicated by antibody cross-reactivity between closely related viruses. We assess this challenge for Usutu virus (USUV) and West Nile virus (WNV), flaviviruses that recently emerged in Europe. We analysed samples from wild blackbirds collected in the Netherlands between 2016-2022. Samples (N=1742) were screened using an NS1-based protein micro-array, with positives confirmed by Focus Reduction Neutralization Tests (FRNT). We jointly estimated seroprevalence and antibody responses by fitting a Bayesian latent-variable model to FRNT values. Estimates of homologous and cross-reactive antibody responses were used to improve interpretation of observed titres for serosurveillance. Estimated seroprevalence varied across time and regions between 4.9% (95%CrI 3.5-6.7) to 18.5% (95%CrI 14.9-22.7) for USUV and between 2.4% (95%CrI 1.3-3.8) to 6.4% (95%CrI 3.9-9.6) for WNV. These were 1.5 (USUV) to 2.4 times (WNV) higher than estimates based on the current threshold-based algorithm. USUV induced a higher antibody response and was more likely to induce a cross-reactive response than WNV. Our classification algorithm informed by these estimates showed high sensitivity (WNV: 0.88, USUV: 0.97) and specificity (both: >0.99). Our results illustrate how quantitative frameworks can improve serological interpretation in settings with co-circulating pathogens.

ecology↗

bioRxiv2025

Implications of future change scenarios for mosquito-borne disease transmission in the Netherlands

BackgroundMosquito-borne virus transmission is shaped by its ecological context, including land use, climate, and population dynamics. Future changes in these factors may therefore affect the risk and intensity of Usutu virus (USUV) and West Nile virus (WNV) outbreaks in the Netherlands. Methodology & findingsWe compared a reference scenario to four future Shared Socio-economic Pathway scenarios developed for the Netherlands, which differed in land use, host distribution, mosquito distribution, and temperature. Temperature (between +1.0{degrees}C and +1.7{degrees}C) and mosquito abundance (between +5% and +10%) were predicted to increase during the transmission season across the scenarios. Scenario effects on hosts differed between species. We found that outbreak size and growth rate were expected to increase in all future scenarios for both USUV and WNV. These effects were most pronounced early in the season and in scenarios characterised by a high temperature increase and little concern about environmental change. Changes in outbreak risk differed between locations due to spatial variation in changes in host and vector abundance ConclusionsAcross a range of possible future scenarios, USUV and WNV outbreaks are expected to become larger, grow faster, and last longer. This is mostly driven by increased temperatures, highlighting the importance of climate mitigation measures to reduce disease outbreak risk and impact.

ecology↗

bioRxiv2024

Silent reservoirs are shaping disease emergence: the case of Usutu virus in the Netherlands

Disentangling contributions of different hosts to disease transmission is highly complex, but critical for improving predictions, surveillance, and response. This is particularly challenging in wildlife, with pathogens often infecting multiple species and data collection being difficult. Using the emergence of Usutu virus (USUV) in the Netherlands as a case study, we demonstrate the use of an Approximate Bayesian Computation framework on diverse data sources to uncover drivers of spatio-temporal wildlife disease emergence. We calibrated single- and multi-host mechanistic transmission models to five types of wildlife surveillance and research data, describing molecular and serological evidence of USUV in birds. Although Eurasian blackbirds, the primary target species for surveillance, were most severely affected, our models indicated that USUV could not persist in blackbirds alone. Our framework provided statistical support for additional, unobserved bird species to have contributed to transmission. This population of bird species is characterised by limited infection mortality, a longer lifespan, and likely further dispersal than blackbirds. Immunity in this population appears to have protected blackbirds from further USUV-related population decline. Our results underscore the importance of considering multiple host populations to understand outbreak dynamics. Neglecting the multi-host context of transmission can impact the reliability of predictions and projected impact of interventions.

ecology↗

bioRxiv2021

The SARS-CoV-2 reproduction number R0 in cats

Domestic cats are susceptible to SARS-CoV-2 virus infection and given that they are in close contact with people, assessing the potential risk cats represent for the transmission and maintenance of SARS-CoV-2 is important. Assessing this risk implies quantifying transmission from humans-to-cats, from cats-to-cats and from cats-to-humans. Here we quantified the risk of cat-to-cat transmission by reviewing published literature describing transmission either experimentally or under natural conditions in infected households. Data from these studies were collated to quantify the SARS-CoV-2 reproduction number R0 among cats. The estimated R0 was significantly higher than 1, hence cats could play a role in the transmission and maintenance of SARS-CoV-2. Questions that remain to be addressed are the risk of transmission from humans-to-cats and cats-to-humans. Further data on household transmission and data on virus levels in both the environment around infected cats and their exhaled air could be a step towards assessing these risks.

microbiology↗