Nguyen Hoan Phu who had an enormous wealth of clinical experience treating these tropical infections, worked with us and were able to teach me about tropical infections: how to diagnose and treat them.
That convinced me that I wanted to make a full career in tropical medicine research.
Nick is also a member of the Cambridge Infectious Diseases steering committee.
What led you to become interested in your area of research?
If the resistance mechanism is active site specific then these types of drugs won’t work, but if it’s a pump that for example pumps the drug out of the cells, which is the mechanism of action of chloroquine resistance, then it may be very sensitive to the overall shape of the molecule.
In that case a molecule with a different backbone but the same active site may be effective. Vast amounts of money have been poured into malaria vaccine research over the past 50 years, and given how much money has been invested, the progress has been woeful.
However, in the last 2-3 years in Cambodia/Thai border we have identified strains of P.falciparum which appear to be at least partially resistant to the artemisinins: parasite clearance rates are much slower than usual.
If these resistant strains spread, particularly to Africa, then it will lead to a major public health disaster. For a number of reasons, South East Asia is the home to the most resistant malaria parasites in the world.
A great deal of news footage has been written in the last few years about the prospects of not just malaria control, but eradication: artemisinin resistance is a major threat to this.
With the increased resources available from governments, and large funding organisations, we may well be able to get on top of P. But then we have a new challenge, which is to get rid of P.vivax. vivax and it looks like it will more difficult to eliminate because unlike P.falciparum, P.vivax hides in the liver in the form of the hypnozoite, so that years later you can get relapses of vivax malaria, and standard anti-malarial drugs don’t touch it.
There is also the risk of an emerging pandemic of an infectious disease, most likely viral infection, along the lines of a highly virulent form of influenza virus, or SARS.
Even if you isolate the parasite there is no in vitro test that can differentiate a resistant parasite from a sensitive one.
The only way to tell whether malaria is resistant is to take patients with malaria, give them the drug, and then carefully follow the parasite counts and see whether the counts fall rapidly, as they should, or slowly, if resistant.So from the age of about 12, I wanted to become a doctor, and to study tropical medicine.