PhD Life

The fight against African Trypanosomiasis…

Animal African Trypanosomiasis (AAT) is a devastating animal disease that leads to the death of millions of livestock, such as cattle, sheep, goats, and so on, in sub-Saharan Africa leaving several millions at risk. It also affects wild animals! Flagellated, unicellular organisms known as trypanosomes are the causative agents, and there are several species of them. Trypanosomes are transmitted by tsetse flies and mechanistically by some other blood-feeding flies.

Typically, trypanosomes are not supposed to be human-infective; this is because the human serum contains a particular component(s) known as “trypanolytic factor” which kills trypanosomes immediately as it encounters it. However, two species of trypanosomes (Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense) have undergone some adaptations that enable them to infect humans. These species cause human disease, called Human African Trypanosomiasis (HAT), with clinical manifestations which occur in two stages. In the early stage, the haemolymphatic system is affected; this is evidenced by intermittent fever, headaches and generally deteriorating health. The late stage (meningoencephalitic stage) is characterised by neurological complications because trypanosomes cross the blood-brain barrier to wreak havoc. As a result, the circadian cycle is disrupted hence HAT is fondly known as “sleeping sickness”.

Although the human disease is as devastating as the animal disease, there has been a massive decline in the number of recorded cases every year, and this has placed HAT in a class of diseases known as Neglected Tropical Diseases (NTDs). NTDs affect the poorest countries of the world, which include African countries. Considering how expensively tedious the process of drug discovery and development is (it technically costs billions of dollars and takes over a decade) as well as the small population and economic status of people affected by NTDs, there is a lack of incentive for profit-driven pharmaceutical companies to invest in interventions for NTDs. It is safe to assume that a condition that endangers about sixty-one million people is worth investing in – that is the population of people at risk of HAT. Well, that is a story for another day; I am currently interested in AAT!


My research interests…

AAT has a huge socio-economic impact. Millions of dollars are spent annually on drugs that are not satisfactory: their efficacy has been dulled by increasing levels of drug resistance and their unacceptable toxicity profiles (they literally kill the hosts in a bid to kill the parasites). Unfortunately, there has not been sufficient efforts towards the development of new drugs to tackle this disease. This is what makes my research highly relevant. I am interested in identifying compounds with trypanocidal activity and understanding how these compounds act. A thorough understanding of the effect(s) trypanocidal compounds have on trypanosomes and their hosts would translate to the development of new, effective treatments in the near future.


…and the PhD experience

While research in an essential component of my PhD, I also realise that the PhD programme by itself provides a beautiful opportunity to develop and gain mastery of transferable skills that would be relevant in my career and life in general. I aim to share my experience through this 4-year journey and hope you find the lessons I have learnt useful to you.

PhD experience

9 replies

  1. Very educative and mind blowing piece of work..good job here, my Pearl .


    • This is a good project — working on one of the most important but neglected tropical diseases, especially with emphasis on the economically important cattle. However, your little introduction to the research did not indicate how important the disease is to the cattle rearer and where and why prior efforts have not measured up. Jokingly though, I guess we can collaborate later on in silico drug discovery research with bias for veterinary products.


      • Thanks for your feedback, Adeniyi. Oh yeah, I did not mention the importance of AAT to the cattle-rearers because I probably felt that was intuitive. Admittedly, AAT is a wasting disease that leads to weight loss in the animals (this affects meat and milk production), decrease in farm power (as some of these animals are used for ploughing in the farms), abortion and infertility, and ultimately death. However, it is not only of importance to cattle-rearers but to everyone as well. These animals serve as reservoirs of the human-infective trypanosomes species. In terms of previous studies carried out, I did mention that some drugs are currently being used to control the disease but because of drug resistance and toxicity issues relating to those drugs, there is a need for new drugs. There is also the issue of cross-resistance where resistance of parasites to one drug confers resistance to another drug belonging to a similar class. That tells us that we need new classes of drugs. Being a neglected disease, there isn’t so much of studies carried out in this area. For the few studies that tow this line, the way the trypanocidal compounds act is vaguely understood. I believe that if only we better understood what these compounds target and how they bring about functional/structural changes in the trypanosomes without being detrimental to the livestock, we can develop better treatments for the disease. I hope I have explained myself more clearly now 😊


    • I’m glad you found it educative, Tobex. Thanks for reaching out.


      • Pearl, this your write is very exciting.I am particularly trilled by your interest in trpanosomosis, a disease of great economic importance in livestock industry, I hope you would also explore the zoonotic importance of the disease in human population in Ghana and the possibility of getting a vaccine for the disease in Africa.

        Best regards



        • Pearl, this your write up is very exciting.I am particularly trilled by your interest in trpanosomosis, a disease of great economic importance in livestock industry, I hope you would also explore the zoonotic importance of the disease in human population in Ghana and the possibility of getting a vaccine for the disease in Africa.

          Best regards



  2. I do understand that the reason for NTDs is not only economic but political: its therefore necessary to begin to look toward self-help and the starting point to self-help, I think, is building internal capacity. Thanks Prof for stepping in and please do remember to keep to your promise of making your solution available and affordable to the poor. Wish you best of luck.


    • You definitely have a point there, Joshua. The concept of being “neglected” arises when we do not feel something is important/relevant. With increased interest in NTDs these days and a new of generation of African scientists being equipped with the necessary training to profer solutions to our peculiar challenges, there is hope for the future. I aim to contribute my own quota to bring the change that is greatly desired.


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