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Dr Jo Lello


Dr Jo Lello

I started out as a junior medical laboratory scientist in microbiology at Liverpool PHLS, but returned to education undertaking an Applied Biology degree at Liverpool John Moores University. Following my degree I spent several years studying squirrel behaviour and disease before taking up a PhD in December 1999 at Stirling University under the guidance of Prof. Peter Hudson. It was there that my interest in coinfection began while studying the “Community Ecology of Rabbit (Oryctolagus cuniculus) Parasites”. After completion of the PhD in May 2006 I moved to Armidale (NSW, Australia), to take up a position as a Research Scientist in CSIRO Livestock Industries extending my coinfection research to examine the immune mechanisms mediating parasite interspecific interactions in sheep. Finally after three years down-under I returned to the UK and gained my position as a Lecturer here in Cardiff.

My research focuses on the over-arching question, ‘What are the consequences of coinfection for the spread and evolution of infectious disease?”. Within this broader question I explore three key areas:

  1. Detection – Developing statistical approaches to aid in determining the presence and form of interspecific parasite interactions in natural systems.
  2. Interaction Mechanisms – Elucidating the form of the interactions between the parasite species.
  3. Prediction – Examining the dynamic consequence of the parasite inter-specific interactions for both the hosts and parasites, with particular respect to parasite transmission and host-parasite evolution.


Position: Lecturer
Telephone:+44 (0)29 208 75885
Fax:+44 (0)29 208 74116
Location:Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX Room C6.13


Current and Developing Research

1.    How important is coinfection to human health?

We are all assaulted simultaneously by a plethora of different infectious organisms. This is especially true for people living in the developing world, where endemic infections are common and multiple infections are the norm. In recent work ( we demonstrated that infection with one species could alter the risk of being infected with another species. We continue to explore this question considering how coinfection may influence disease severity and infection and transmission processes. Our approach is to combine field studies with statistical methodologies to try gain a clearer understanding.

2.    What is the role of coinfection in the emergence, transmission and evolution of epidemic disease?

Gregarina blattarum mating pair inside the mid-gut of the cockroach host.

The German cockroach (Blattella germanica) is host to an endemic gut parasite, Gregarina blattarum. We use this model system to determine whether and how this endemic species alters the spread and evolution of an epidemic parasite species Steinernema carpocapsae. We have demonstrated that within host competition for resources between the endemic and epidemic parasites leads to a substantial reduction in transmission potential of the epidemic species ( In our ongoing work we are assessing whether these within host processes scale up to effect changes in epidemic spread through populations. We also aim to explore whether the within and / or between host processes result the evolution of greater virulence in either parasite species or in the evolution of host resistance mechanisms.

3.    Immune responses during coinfection

Merino sheep, hosts to the blood feeding worm Haemonchus contortus and intestinal browser Trichostrongylus colubriformis.

There are many different arms to the immune response and these different components often interact, up or down regulating one another. Therefore, the response of a host to one parasite species may have profound effects upon how that host responds to a second species. I am exploring this idea in both vertebrate and invertebrate systems. In past work with CSIRO I demonstrated that the blood feeding helminth Haemonchus contortus suppresses host immune response against a second helminth species Trichostrongylus columbriformis, in sheep (work in prep for publication). In my current work I am using the cockroach system to assess how macro- and micro-parasites may interact through differential host immune responses.

4.    Can we define coinfection functional groups?

In classical ecology we can define organisms in a particular environment by their effect upon and response to that environment – the functional group. Organisms can often be assigned to functional groups based on simple characteristics. Potential interactions between species can then be inferred by understanding how the functional groups interact rather having direct knowledge of the two species. If we can use this idea to group parasitess we can potentially predict how any two parasite species might interact ( Ongoing work using a variety of systems explores this concept, in particular with respect to the immune axis (i.e. using immune responses as a mechanism by which to group parasites).


Click here to see all publications

Link to ScopusTM Database

Selected Publications:

Randall J., Cable J., Guschina I. A., Harwood J. L., Lello J. (2013). Endemic infection reduces transmission potential of an epidemic parasite during co-infection. Proceedings of the Royal Society B: Biological Sciences 280(1769): 20131500.

Lello J. (2013). Coinfection: Doing the Math. Science Translational Medicine 5 (191): 191fs24.

Lello J., Knopp S., Mohammed K.A., Simba Khamis I., Utzinger J., Viney M.E. (2013). The relative contribution of co-infection to focal infection risk in children  Proceedings of the Royal Society B: Biological Sciences, 280 (1754): 1-7.

Lum E., Kimbi H. K., Mbuh J., Ndamukong-Nyanga J., Njunda A. L., Lello J. (2012). Co-infections of malaria and soil-transmitted helminths in localities with different levels of urbanisation in the Mount Cameroon region The Onderstepoort Journal of Veterinary Research, 79 (2): E1.

Hunt P. W., Lello J. (2012). How to make DNA count: DNA-based diagnostic tools in veterinary parasitology. Veterinary Parasitology 186 (1-2): SI101-108.

Fenton A., Viney M., Lello J. (2010). Detecting interspecific macroparasite interactions from ecological data: patterns and process. Ecology Letters 13(5): 606-615

Harwood JD; Phillips SW; Lello J.; et al. (2009). Invertebrate biodiversity affects predator fitness and hence potential to control pests in crops. Biological Control 51 (3): 499-506.

Lello J., Hussle T. (2008). Functional group/guild modelling of inter-specific pathogen interactions: A potential tool for predicting the consequences of co-infection. Parasitology 135 (7): 825-839.

Lello J., Norman R. A., Boag B., Hudson P. J., Fenton A. (2008). Pathogen interactions, population cycles and phase shifts. American Naturalist 171 (2): 176–182.

Fenton A., Lello J., Bonsall M. B. (2006). Pathogen responses to host immunity: the impact of time delays and memory on the evolution of virulence. Proceedings of the Royal Society B – Biological Sciences 273 (1597): 2083-2090.

Lello J., Boag B. & Hudson P. J. (2005). The effect of single and concomitant pathogen infections on condition and fecundity of the wild rabbit (Oryctolagus cuniculus). International Journal for Parasitology 35: 1509-1515.

Lello J., Boag B., Fenton A., Stevenson I. R., Hudson, P. J. (2004) Competition and mutualism among the gut helminths of a mammalian host. Nature 428: 840-844.

Paterson, S. & Lello, J. (2003). Mixed models: getting the best use of parasitological data. Trends in Parasitology 19 (8): 370-375.

Bown K. J., Ellis B. A., Birtles R. J., Durden L. A., Lello J., Begon M., Bennett, M. (2002). New World origins for haemoparasites infecting United Kingdom grey squirrels (Sciurus carolinensis), as revealed by phylogenetic analysis of Bartonella infecting squirrel populations in England and the United States. Epidemiology & Infection 129 (3): 647-653.

Boag B., Lello J., Fenton A., Tompkins D. M., Hudson P. J. (2001). Patterns of parasite aggregation in the wild European rabbit (Oryctolagus cuniculus). International Journal for Parasitology 31 (13): 1421-1428.