Chapter 25.1, Problem 1TQ

Summary Introduction

To review:

Virulence of a microbe with LD50 (lethal dose 50%) with 5 Ă— 104 and another microbe of LD50 with 5 Ă— 107.

Introduction:

Virulence is a parameter by which the severity or degree of a disease is measured. The fatality rates of different microbes define the virulence of the pathogen. For example, Ebola and Marburg virus have fatality rates of 70% and hence, are highly virulent. Lethal dose 50% is used to measure the virulence of a microbe such as a virus or bacteria. It is the number of microbes needed for killing 50% of the experimental group of animal hosts.