Browsing by Author "Broecke, Bram Vanden"

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Arenavirus dynamics in experimentally and naturally infected rodents
(EcoHealth Alliance, 2017-06) Marien, Joachim; Borremans, Benny; Gryseels, Sophie; Broecke, Bram Vanden; Becker-Ziaja, Beate; Makundi, Rhodes; Massawe, Apia; Reijniers, Jonas; Leirs, Herwig
Infectious diseases of wildlife are typically studied using data on antibody and pathogen levels. In order to interpret these data, it is necessary to know the course of antibodies and pathogen levels after infection. Such data are typically collected using experimental infection studies in which host individuals are inoculated in the laboratory and sampled over an extended period, but because laboratory conditions are controlled and much less variable than natural conditions, the immune response and pathogen dynamics may differ. Here, we compared Morogoro arenavirus infection patterns between naturally and experimentally infected multimammate mice (Mastomys natalensis). Longitudinal samples were collected during three months of bi-weekly trapping in Morogoro, Tanzania, and antibody titer and viral RNA presence were determined. The time of infection was estimated from these data using a recently developed Bayesian approach, which allowed us to assess whether the natural temporal patterns match the previously observed patterns in the laboratory. A good match was found for 52% of naturally infected individuals, while most of the mismatches can be explained by the presence of chronically infected individuals (35%), maternal antibodies (10%), and an antibody detection limit (25%). These results suggest that while laboratory data are useful for interpreting field samples, there can still be differences due to conditions that were not tested in the laboratory.
Effects of forest disturbance on the fitness of an endemic rodent in a biodiversity hotspot
(Wiley, 2021) Ademola, Olaoluwa John; Broecke, Bram Vanden; Leirs, Herwig; Mulungu, Loth S.; Massawe, Apia W.; Makundi, Rhodes H.
Praomys delectorum occurs abundantly in both disturbed and intact forests in the Ukaguru Mountains within the Eastern Arc Mountains (EAM), Morogoro, Tanzania. While previous studies have reported that anthropogenic disturbances such as grazing, wood cutting, and harvesting have a positive effect on the population density of P. delectorum, the impact of habitat disturbance on its demographic traits is still unknown. We performed a capture–mark–recapture study in both disturbed and intact forests from June 2018 to February 2020 in order to investigate the effects of habitat disturbance on abundance and two demographic traits: survival and maturation of P. delectorum in the Ukaguru Mountains. We found no variation in abundance or maturation between intact and disturbed forests, but habitat type did affect survival. However, this effect was sex-dependent since female survival was higher in disturbed forests, while male survival remained similar across the two forest types potentially due to differences in predation pressure or food availability between the two habitats. Continuous demographic monitoring of P. delectorum in EAM is necessary given that the increasing human population surrounding the landscape is lead- ing to higher deforestation rates and expansion of the pine plantation in the forest reserve.
Relationship between population density and viral infection: a role for personality?
(Wiley, 2019) Broecke, Bram Vanden; Mariën, Joachim; Sabuni, Christopher Andrew; Mnyone, Ladslaus; Massawe, Apia W.; Matthysen, Erik; Leirs, Herwig
Conspecific density and animal personality (consistent among‐individual differences in behavior) may both play an important role in disease ecology. Nevertheless, both factors have rarely been studied together but may provide insightful information in understanding pathogen transmission dynamics. In this study, we investigated how both personality and density affect viral infections both direct and indirectly, using the multimammate mice (Mastomys natalensis) and Morogoro arenavirus (MORV) as a model system. Using a replicated semi‐natural experiment, we found a positive correlation between MORV antibody presence and density, suggesting that MORV infection is density‐dependent. Surprisingly, slower explorers were more likely to have antibodies against MORV compared to highly explorative individuals. However, exploration was positively correlated with density which may suggest a negative, indirect effect of density on MORV infection. We have shown here that in order to better understand disease ecology, both personality and density should be taken into account.