Today was my last day here in London. I have really enjoyed my week, especially seeing the process of chytrid swabbing from the very beginning, in the pet shop, right through the DNA extraction to the PCR and final analysis. I has been fascinating to be involved in the extraordinary world of research where everyone talks about papers and PhDs, the more papers to your name, the higher up you become. The devotion that the people I have met have to their is inspirational and I hope to one day do some research of my own, contributing a tiny drop to the sea of vast human knowledge. Yet from this week, I have learnt that every drop is powerful and has a huge impact on a small number of people, which turn has an impact on the wider society. For example, the research into chytridiomycosis will have a huge impact on pet shop owners, people with exotic pets and amphibian enthusiasts. These people will benefit from the learning about chytrid, how to prevent it and how to treat it so less of their animals will have chytrid. This will increase sales in pet shops, leading to greater profit which can be used to improve the conditions these pets are living, encouraging those who buy the pets to do likewise. Furthermore, if less amphibians are infected with chytrid, less will die and therefore less will be caught from the wild to be imported into England to supplement the deaths. This will reduce the sad impact which the pet trade often has on the environment, as it diminishes biodiversity. In addition to this, the research into chytrid can not only be applied to the pet trade but also amphibians in the wild. The greater our understanding of this disease, the more actions we can take to prevent wild animals being infected, preserving amphibian populations for generations to come and therefore maintaining ecosystems across the world.
Today, my cousin had lectures at the Royal Veterinary College as part of her MSc in Wild Animal Biology. This course is closely linked with the Wild Animal Health MSc, which is studies by vets wishing to specialise further into wild animals, therefore there were qualified vets in the lectures I attended. This was the first day of a new lecture series on epidemiology, with the introductory day consisting of 7 hours of lectures.
Introduction to Epidemiology – Dirk U. Pfeiffer
The first lecture introduced epidemiology as the study the incidence, distribution and control of diseases. Epidemiology pulls together many of the challenges facing veterinary medicine today which revolve around disease, from the complex multi-factorial relationships between animals disease, productivity and welfare to the control of new and emerging diseases and the impact human behaviour has on this. Imports and exports and improving transport along with an increasing population, allows for rapid spread of disease around the world, with Asia as the global hotspot. He picked up on ecosystems and how diseases emerge, first starting in the landscape of population growth and environmental change, spreading to the natural community of urbanisation and forest habitat alteration, finally focusing on host-pathogen dynamics. As well as this, epidemiology involves the idea of ‘One Health’ which is a popular concept within medicine considering the health of humans, animals and the environment as one. This has to be understood, considering the many different risk factors affecting disease in order to use the best approach for controlling disease spread and combining multiple pieces of knowledge inclusive of science and society. In this way, the emergence of disease can be tracked and controlled where possible, improving the way veterinary medicine deals with epidemiology.
Causality in Epidemiology – Dirk U. Pfeiffer
The next lecture considered the causes of disease, focusing on the knowledge needed on cause-and-effect relationships. He then talked about whether it was possible to eliminate causes and the effect this would have on the wider population, as well as the impact of multiple causes. He used lots of examples including the bTB badger culls. Here, badgers have been identified as a cause and therefore, efforts are being made to eliminate them. However, it only infected badgers which actually cause disease, so should they be screened? But it is the bacteria which are the underlying cause so should we be treating badgers with antibiotics? The deeper we go, the more complex the situation becomes and the decision has to made about at which level action should be taken.
Measures of Disease Frequency – Dirk U. Pfeiffer
The next lecture explained how it is important to quantify occurrence of disease in epidemiological research and this can be done by expressing the numbers of infected, diseased or dead animals as a proportion of the number of animals capable of experiencing infection, disease or death. This would calculate the probability, or risk, of populations becoming infected. Discrete data can be measured using ratios or proportions whilst continuous data can only be measured using rate. We could then take these measurements by considering incidence or survival time measures or prevalence measures. Prevalence is the probability of having the disease at a single point in time and therefore is not as useful as incidence measures which consider the effect of the disease across a period of time. After listening to this lecture, although a lot of it was not relevant for, I realised the importance of quantifying data, making it accessible and putting it into context to be compared to other diseases. Only then can we prioritise action which needs to be taken.
Epidemiological Studies – Julian Drewe
The final lecture was about the different types of study design used in epidemiology, and when each of them would be useful to use. The aim of using specific study designs is to enable the best method for defining cause and effect, considering the confounders (factors which may have an effect but may not be considered e.g. breed, age, gender) involved with the study and identifying the effects of individual factors, which can sometimes be hard to differentiate. Epidemiological studies may be descriptive (using case studies and surveys) or analytical. Analytical studies can be intervention/experimental, observational or systemic. Lots of very interesting case studies were highlighted during the lecture, with particular focus was on a survey of transmissible between baboons and humans in Cape Town, South Africa which was carried out by Julian Drewe. He explained that although it appeared that urban residential areas created the greatest risk for baboons having potential zoonoses, no true conclusions could be drawn because only 27 baboons were tested over 2 weeks. He was then able to relate to the importance of finding the balance in samples size, whatever study was being carried out.
I really enjoyed my day at the RVC, in this learning environment. During lunch I went into the small anatomy museum which was fantastic. I could have spent hours, even days in there, looking at the skeleton, bones and preserved body parts. I can’t believe that one day I might know what every one of these body parts is and what it does, and what to do when it goes wrong and I just can’t wait!
Thank you so much to my cousin, Felicity Wynne, who did so much to help me over the past week and also Emma Wombwell, who was brilliant in showing me everything she was doing for her PhD and even letting me get involved.