When was computer virus first discovered

Morris was the first person to be tried and convicted under the Computer Fraud and Abuse Act of He was given three years probation and is now a professor at MIT. The growth of viruses and worms was fairly slow after this until the mids, when the proliferation of desktop PCs and e-mail usage opened the way for large-scale infections. Viruses that previously relied on floppy disks and the "sneakernet" to spread, could now infect millions of machines with a little clever social engineering designed to trick users into opening infected attachments.

The Melissa virus set the tone for fast-moving viruses in , reaching about , computers. Its payload was mostly innocuous, however. Whenever the time of day matched the date -- say, on May 20 -- a quote from The Simpsons popped up on the screen. The Love Bug struck a year later, leaving Melissa in the dust. The result is shown in figure 4. The most striking feature of the plot is that there are no examples of human viruses with broad host ranges that do not use highly conserved cell receptors i.

Statistical analyses requires correction for phylogenetic correlation: viruses in the same family are both more likely to use the same cell receptor and more likely to have a narrow or broad host range. This can be crudely but conservatively allowed for by testing for an association between host range and receptor homology at the family, not species, level. Number of virus species with broad blue bars or narrow red bars host range as a function of the percent homology of the cell receptor used see main text.

We conclude that the use of a conserved receptor is a necessary but not sufficient condition for a virus to have a broad host range encompassing different mammalian orders. It follows that a useful piece of knowledge about a novel mammalian virus, helping to predict whether or not it poses a risk to humans, would be to identify the cell receptor it uses.

However, this may not always be practicable: at present, we do not know the cell receptor used by over half the viruses that infect humans, and this fraction is considerably smaller for those that infect other mammals.

The lines of evidence described earlier combine to suggest the following tentative model of the emergence process for novel human viruses. First, humans are constantly exposed to a huge diversity of viruses, though those of others mammals and perhaps birds are of greatest importance. Moreover, these viruses are very genetically diverse and new genotypes, strains and species evolve rapidly over periods of years or decades.

A fraction of these viruses both existing and newly evolved are capable of infecting humans. The distinction is potentially important as it implies different determinants of the rate of emergence of viruses with epidemic or pandemic potential: for off-the-shelf pathogens this rate is largely driven by the rate of human contact with a diversity of virus genotypes possibly rare genotypes within the non-human reservoir i.

Whichever of these two models is correct perhaps both , there is a clear implication that the emergence of new human viruses is a long-standing and ongoing biological process.

Whether this process will eventually slow down or stop if the bulk of new virus species constitute extant diversity or whether it will continue indefinitely if a significant proportion of newly discovered virus species are newly evolved remains unclear, although this makes little difference to immediate expectations.

If anthropogenic drivers of this process are important then it is possible that we are in the midst of a period of particularly rapid virus emergence and, in any case, with the advent of new virus detection technologies, we are very likely to be entering a period of accelerated virus discovery.

By no means all of these will pose a serious risk to public health but, if the recent past is a reliable guide to the immediate future, it is very likely that some will.

The first line of defence against emerging viruses is effective surveillance. This topic has been widely discussed in recent years [ 10 , 41 ], but we will re-iterate a few key points here. Firstly, emerging viruses are everyone's problem: the ease with which viruses can disperse, potentially worldwide within days, coupled with the very wide geographical distribution of emergence events [ 9 ], means that a coordinated, global surveillance network is essential if we are to ensure rapid detection of novel viruses.

This immediately highlights the enormous national and regional differences in detection capacity, with the vast majority of suitable facilities located in Europe or North America. Secondly, reporting of unusual disease events is patchy, even once detected, reflecting both governance issues and lack of incentives [ 10 ].

Thirdly, we need to consider extending the surveillance effort to other mammal populations as well as humans, because these are the most likely source of new human viruses. Improving the situation will require both political will and considerable investment in infrastructure, human capacity and new tools [ 10 , 41 ]. However, the benefits are potentially enormous. It is possible to forestall an emerging disease event, as experience with SARS has shown.

However, our ability to achieve this is closely linked to our ability to detect such an event, and deliver effective interventions, as rapidly as possible. A better understanding of the emergence of new human viruses as a biological and ecological process will allow us to refine our currently very crude notions of the kinds of pathogens, or the kinds of circumstances, we should be most concerned about, and so direct our efforts at detection and prevention more efficiently.

We are grateful to colleagues in Edinburgh's Epidemiology Research Group and elsewhere for stimulating discussions and to two anonymous referees for thoughtful comments on the manuscript.

National Center for Biotechnology Information , U. Author information Copyright and License information Disclaimer. This is an open-access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

This article has been cited by other articles in PMC. Abstract There are virus species that are known to be able to infect humans. Keywords: discovery curves, emerging infectious diseases, public health, risk factors, surveillance. Virus diversity and discovery a Survey of human viruses As a starting point for our survey, we used a previously published database see [ 5 ] obtained by systematically searching the primary scientific literature up to and including for reports of human infection with recognized virus species, using species as defined by the International Committee on Taxonomy of Viruses ICTV [ 6 ].

Open in a separate window. Figure 1. Table 1. Figure 2. Table 2. Emergence as a biological process a Non-human reservoirs More than two-thirds of human virus species are zoonotic, i. Figure 3. Figure 4. Conclusions The lines of evidence described earlier combine to suggest the following tentative model of the emergence process for novel human viruses.

References 1. Levine A. History of virology. In Fields virology eds Fields B. Woolhouse M. Ecological origins of novel human pathogens. Population biology of emerging and re-emerging pathogens: preface. B , — Parrish C. Molecular epidemiology of parvoviruses. Temporal trends in the discovery of human viruses. International Committee on Taxonomy of Viruses.

Bebber D. Predicting unknown species numbers using discovery curves. Even with a full Internet security software suite, there are still more precautions that can be taken. Users should still be wary about any unfamiliar attachments or links via email, as well as social media. Always run system updates, which usually repair security flaws and can protect the computer against a variety of online threats. Not only should you run the updates for your operating system, you should also update programs such as Java and Flash, as lots of hackers tend to prey on computers with outdated versions of these programs.

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Written by a NortonLifeLock employee. Safety for every device. Learn More. Brain Prior to , most viruses were mere annoyances and virtually harmless. Keep Yourself Protected Contrary to popular belief, traditional antivirus software alone will not fully protect you from threats. Join today. Scans of her lungs taken two years after her original trip to the ER showed that they had recovered and were healthy.

McIntosh suspects that coronaviruses will continue to perplex researchers. First, because coronaviruses are large and complex, and second because they can change relatively easily on a genetic level.

He notes that these viruses can also recombine fairly easily within the same cell, and that such mutations are likely what led to both the coronavirus that causes SARS and the novel coronavirus that has caused the current pandemic. McIntosh says. This is a BETA experience. You may opt-out by clicking here. Edit Story. I write about the future of science, technology, and culture. Follow me on Twitter or LinkedIn.