Morogoro virus may affect survival of its natural host

Introduction: This is counterintuitive to expectations: a negative effect of the virus on its host potentially diminishes its own spreading capability. To understand and predict the spread of infectious diseases from animal hosts to humans, it is essential to know how parasite transmission relates to host density. Theory predicts that when host density drops below a critical threshold, parasites cannot spread quickly enough anymore in the population and will eventually disappear. Theoretically, parasite persistence would thus be impossible when population density regularly remains below the predicted persistence threshold. In contrast to this prediction, cases where host density is regularly low and parasites still persist, are frequently observed in naturally fluctuating host populations. In his research, Joachim Mariën ( Global Change Ecology Centre , research group Evolutionary Ecology ) investigates which mechanisms allow parasites to persist in fluctuating host populations. He uses Morogoro arenavirus and the multimammate mouse as study models.