This week I attended the ISNTD Bites conference 2017 at the Institute of Child Health, London. I was really impressed with one of the talks given by Ailie Robinson on the work that she had conducted for her PhD at the London School of Hygiene and Tropical Medicine. Ailie has been investigating the influence of Plasmodium infection on the human volatile odour profiles in an endemic setting.
What caught my interest was something that I hadn’t previously considered with vector borne pathogenic diseases; which was how pathogens can affect its host in order to improve the likelihood of its host to be bitten by its vector and thus completing its life cycle.
Ailie presented her work where she had analysed the volatile odour profiles from three groups of participants with varying asymptomatic infections of malaria. The three groups investigated were: low density malaria (Plasmodium falciparum) infection, high density malaria infection or negative infection as a control.
Interestingly the gas-chromatographic-mass-spectrometry (GCMS) analysis of the volatile odour profiles from the people in the three groups showed that the high density infection group had significant increases in 3 organic compounds over the other 2 groups. To further investigate this interesting observation Ailie went on to present her work using gas-chromotography-electroantennography (GC-EAG); which is a technique that can be used to determine if the malaria causing mosquito (Anopheles gambiae) is attracted to a certain chemical; to show that all three of the observed molecules that were significantly increased in the high density infection group were highly attractive to the female mosquito. Inferring that the malaria parasite is by someway (either by expressing these chemicals itself or via a host response to infection) maximising its chances for reinfection.
Another interesting outcome from these experiments is the potential for the simple detection of asymptomatic malaria infection by using a breath test. See Ailie Robinson’s article here – (http://www.scidev.net/global/malaria/news/malaria-breath-test-CSIRO.html). I look forward to seeing her published data soon.
Blog written by Ryan West