‘It’s only a virus.’ How often do those of us who are GPs utter these words in a typical day’s work? The poor virus becomes the default, the fall guy when we don’t know the diagnosis, but expect the patient to recover fully from their illness in a few days. Yet how many of us really understand the structure and function of viruses; how they exert their influence on the cell and the organism at large? Not many, perhaps. A quick random survey of my colleagues, registrars and medical students supports this assertion. They agree they know very little of such matters and were taught even less at an undergraduate level, especially in these days of case-based learning.
The word virus comes from the Latin for poison. The 1960 Nobel laureate and immunologist, Sir Peter Medawar, described the virus as ‘a piece of bad news wrapped in a protein’. Not all viruses are bad news, however, many function within, and interact with, their hosts without causing damage. Interestingly, in his book Genome1, Matt Ridley states that human endogenous retroviruses account for 1.3 per cent of the human genome. These have been incorporated into human DNA during its millenia of evolution. This is a more impressive fact when one notes that, at that time, proper genes were thought to only account for three per cent of our genome.
Why do viruses exist at all, one may ask? They are probably not even alive, certainly not in the sense that living tissue is. There is no doubt that they are population controllers; were it not for bacteriophages (bacterial viruses) our planet would have been overrun by bacteria. Viruses are fascinating: how they recognise their target cells, invade the cell, reproduce either in the nucleus or cytoplasm, reassemble and then egress from the cell in their tens to thousands to reinvade more cells could be the stuff of a story in a Boy’s Own annual.
As doctors, we are mainly interested in viruses that cause disease and particularly, as obstetricians and gynaecologists, those which are relevant to our specialty. It is these viruses that are covered in this issue of O&G Magazine. Viruses that cause infection (HSV, influenza, parvovirus, hepatitis B and C, CMV, HIV, rubella, varicella, dengue fever and the ever-so-topical Ebola) and neoplasia (Hepatitis B, hepatitis C, HPV, HIV, EBV) can be read about here.
Vaccines and immunisation have been the mainstay of management or, more correctly, prevention of viral diseases since the late 18th century. In 1798, Dr Edward Jenner started immunising people against smallpox by deliberately infecting them with cowpox, more than 100 years before it was known viruses even existed. Tobacco mosaic disease was found to be caused by a sub-bacterial particle in 1893, by Martinus Beijerinck (who coined the term virus), but it was not until 1935 that Wendell Meredith Stanley successfully crystalised it. The discovery of viruses grew from then on, especially with the development of the electron microscope, and a steady production of antiviral vaccines ensued throughout last century and continues today. Vitally, this issue covers topics on immunisation against important obstetric and gynaecological-relevant viruses.
We hope you enjoy this issue of O&G Magazine and please don’t think of it as forced learning because, when you really get into it, this micro-lilliputian world of virology is more interesting than you could have imagined.