Virus

101 Incredible Microbes from Coronavirus to Zika

Marilyn Roossinck

• Publisher: Ivy Press
• Year: 2020
• ISBN:
  9780711260917
• Topic: Ciencias biológicas
• Subtopic: Microbiología y biología molecular

Viruses are the last frontier of undiscovered life on our planet. The most abundant type of organism on Earth, they infect all types of cellular life, and, as micro-organisms that cause disease in their hosts, they are highly opportunistic and relentlessly efficient. They exist at the vanguard of DNA variance, exhibiting more structural diversity than plants, animals, archaea, or even bacteria. This 21st-century guide offers an engaging introductory section explaining exactly what viruses are and how they operate, followed by individual profiles of 101 of the world's most notable examples, each with its own dazzling mugshot

HUMAN VIRUSES

Introduction

The viruses in this section are called human viruses because they have been studied from the human-infection perspective. However, viruses that infect humans often infect other animals, and sometimes the insects that vector them as well. Some viruses may have animals or insects as their primary hosts, and cause only a “dead-end” infection in their human hosts. This means that they cannot be transmitted from human to human. Here we still classify these as human viruses, because that is where they are most well known.

This section covers a variety of human viruses, chosen because they are well known by most people, because of their importance to the fields of virology, immunology, and molecular biology, or because they have unique features that make them particularly interesting.

The ecology of human viruses is intimately tied to the ecology of other hosts and of vectors. In some cases this is an interesting part of the virus story. There are only a few viruses that have humans as their only host—the most notable are Variola virus, the cause of smallpox, and Poliovirus. Because these viruses have no animal hosts that could harbor the virus, it should be possible to eradicate them. In fact, vaccination has eradicated smallpox, but, so far, not polio. One reason is that the vaccination for smallpox was a different virus, whereas polio vaccination often still uses an attenuated version of the virus. This means that there is still live virus coming from the vaccination. Wild poliovirus is extremely rare now, but may still occur in some remote parts of the world.

Included among the viruses in this section is one virus, Torque teno, that doesn’t cause disease. It is certainly not the only human virus that is not a pathogen, but it is the most well known. Since most viruses have been studied from the perspective of disease, little is known about these nonpathogenic viruses. In other sections of this book there ar...