PARACORT · The role of macroPARAsite COinfection in Rodent-borne microparasite Transmission

The role of macroPARAsite COinfection in Rodent-borne microparasite Transmission

Summary and Objectives Rodent-borne microparasitic diseases (e.g. Lymphochoriomeningitis virus and Hantavirus), are of increasing public health concern due to rising prevalences worldwide. Additionally, rodents are themselves a threat to food security because they damage agricultural crops and food stores. To effectively control rodent-borne emerging and re-emerging diseases, and the rodent hosts themselves, we need to fully understand the relationship between these rodent hosts and their parasites. Importantly, a high proportion of wild rodents carry endemic macroparasites (e.g. ticks, mites, intestinal worms) but little is known about how these infections change the spread and emergence of the important human transmissable diseases or the dynamics and demography of their rodent hosts. There are good reasons to believe that macroparasites could alter the transmission of microparasitic disease. Firstly, macroparasites alter the host immune response, generally stimulating what is known as a T-helper II response. This is important because a type II response down-regulates the T-helper I response, which is broadly responsible for control of microparasites. It is possible therefore, that rodents that are infected with macroparasites could have less resistance to infection with a range of microparasites. Secondly, a frequent characteristic of macroparasite species is that they can alter the demography and dynamics of host populations. As all parasite dynamics are integrally linked to the dynamics of their host populations, any change in rodent dynamics (e.g. by altering survival or fecundity) due to macroparasites may alter the dynamics of coinfecting microparasites. The key objective of this research was to determine the potential for macroparasites of wild rodents to control host demographics and to alter the transmission of important human transmissible diseases and to assess the implications of these findings for rodent and infection control. Specifically the project had 5 objectives: 1) To determine whether there were any direct interspecific relationships between the macro- and macroparasites in the two most prevalent forest rodents in the Autonomous Province of Trentino, in Northern Italy. 2) To determine the role macroparasites and microparasites play in controlling host demographic parameters. 3) To determine the community dynamics (of both hosts and parasites) that result from the combination of these interspecific parasite interactions and host demographic influences. 4) To assess how changing host or parasite numbers (e.g. via rodent or parasite control strategies) would affect host demography and parasite transmission, given the interplay between the components of the system. 5) To provide advice on co-ordinated control of hosts and parasites, which complement the needs of key local stakeholders

Data: CORDIS, © European Union