The Development of the Virus Concept as Reflected in Corpora of Studies on Individual Pathogens. 1. Beginnings at the Turn of the Century

Abstract

DuRING THE last quarter of the nineteenth century bacteriology emerged as a separate discipline. A number of pathogenic bacteria were isolated and described, and it proved possible to grow them in culture on artifical media. At the same time, there were diseases which were being studied in great detail, but for which no infectious agent could be found.One such example was rabies. Although the number of victims was limited, its manifestations and manner of spread were striking and caused much public concern. When Pasteur achieved the development of a vaccine, and saved the life of a young boy who would otherwise certainly have succumbed to the disease, the emotional impact and the professional response were considerable. Yet, in spite of much painstaking work, Pasteur failed to isolate a causal organism. All the evidence suggests that although Pasteur may have conceived of a causal agent so small that it eluded detection by the light microscope, he did not suspect that it differed essentially from the pathogenic micro-organisms so far observed.Then, in the last decade of the century, work on two very different conditions yielded unexpected results. In 1892, Ivanovski, a young Russian botanist, published his report' of a study of the mosaic disease of the tobacco plant, carried out on tobacco plantations in different parts of Russia, and in the laboratories of the Academy of Sciences in St. Petersburg. Ivanovski found that when he passed the sap of infected tobacco plants through bacteria-proof filters, the clear filtrate remained infectious when inoculated into healthy plants. This did not surprise him, since he suspected the presence of a bacterial toxin and saw the result as support for his theory. The Russian journal in which the paper was published does not appear to have had a wide distribution outside Russia at the time,2 and Ivanovski's results passed largely unnoticed.

Time to Say Goodbye to Bronchiolitis, Viral Wheeze, Reactive Airways Disease, Wheeze Bronchitis and All That

“…By the beginning of the twentieth century it was widely recognized that a variety of bacteria appeared to play an important role in upper and lower airway infections. However, the concept of viruses was far from established despite the extraordinary insightful work and interpretation of the Dutch botanical microbiologist Beijerinck who published his work on the mosaic disease of the tobacco plant in 1896 (24). More than 30 years later the existence of viruses as a class of organism that were too small to see under the microscope and that required living host cells in order to replicate was still not universally accepted though a number of diseases such as rabies and influenza were thought to be attributable to viruses.…”

Zoonoses: Proceedings of the third Liverpool Tropical School Bayer Symposium on Microbial Diseases held on 3 February 1996

“…For example, it is estimated that rats destroy 33 million tons of food worldwide each year [l]. Futhermore, over the period [1976][1977][1978][1979]5.2% of UK premises inspected by environmental health inspectors were found to be infested by brown rats, but by 1993 the figure had risen to 7.7% [2]. The brown rat has been shown to carry and excrete various microorganisms pathogenic for man including Leptospira spp., Pseudomonas mallei, Coxiella burnetti and hantavirus [ 11. The concept that animals might be a source of infection for man is not new.…”

“…The Eshunni code of Mesopotamia (before 2300 BC) stated that the owner of a vicious dog that had bitten a man causing his death should be fined [4]. This, however, might not necessarily have been rabies but merely a badly behaved dog [5]. In 100 AD, Celsus recommended that 'Especially if the dog was rabid the virus must be drawn out with a cupping glass' [6].…”

Fighting viruses with antibiotics: an overlooked path

“…This likely relates partly to the fact that studies of microbes and viruses have been partitioned for a long time. Thus, from the very onset of the history of virology in the 1890s, viruses were understood as differing from microbes owing to their ultrafilterability and their invisibility under a light microscope [12,13]. Then, the concept of virus was eventually defined during the 1950s with criteria that definitively separated viruses from microbes [12,14].…”