Abstract

Coinfection by multiple parasites affects human health, parasite dynamics and the efficacy of infectious disease prevention and treatment. The capacity for different parasites (viruses, bacteria, fungi, protozoa, helminths) to interact is poorly understood. Interspecific interactions between coinfecting parasites could occur in many ways, either directly or indirectly with the host's immune system or bodily resources. We aimed to summarise connected resources, parasites and immune system components in coinfected humans using a network approach. The published literature contains thousands of records of coinfections in humans, associated immune responses, as well as parasite resource requirements. We used over 250 publications on human coinfection from 2009 to build an evidence-based parasite-immune system-resource network. We recorded the identity of coinfecting parasites, immune system components, host resources and the reported relationships between them. The network represents the potential for parasites to interact based on observation and theory found in recent coinfection literature. Results show the great taxonomic variety of coinfecting parasites, with particular involvement of viruses. Some parasites were reported in more coinfections, most notably HIV, suggesting that recent disease invasion and induced immunodeficiency may facilitate many parasite interactions. The network can also be used to generate numerous hypotheses for modelling work and suggestions for future observational and experimental research. The use of networks and other research tools to understand parasite interactions within coinfected hosts will help predict the potential for and consequences of disease invasions, as well as improve infectious disease interventions.