13 Epidemiology - BIOLOGY 101L Lab 13 Epidemiology...

BIOLOGY 101L
Lab 13: Epidemiology
Objectives
(1) Introduction to Epidemiology
(2) Develop an understanding of how an infectious agent can be
spread through a population
(3) Disease profiling
I. Introduction
Epidemiology is the study of how a disease spreads through a
population. An increase in the prevalence of a disease over a given
time, within an area or population is considered an epidemic. Data is
collected on the causative agent, number of known cases, the
location and history of the disease, the individuals involved,
contributing factors and other types of important information. A
thorough investigation is then conducted where the data is used to
determine the best mode of control. Depending on the morbidity and
mortality of the disease, strict measures may have to be taken to
control the spread of the disease. One of measure is to notify the
public health department of the US.
Microbes, more commonly known as germs, are known to cause
infectious diseases. These microbes, which can be bacteria, fungi,
protozoa, or viruses, are transmitted by direct or indirect contact.
Direct contact transmission occurs when there is actual physical
contact between the host (the infected patient) and the susceptible
person. Indirect transmission often occurs by means of contaminated,
inanimate objects such as bed sheets, clothing, towels, etc. Food
handlers at restaurants can also transmit disease by contaminating
food served to patrons. This means of spreading disease is the basis
for strict regulation of eating establishments by local health
departments.
Indirect contact may also occur through the action of vectors, which
are secondary organisms that do not themselves infect a host but
transfer a disease-causing microorganism from one host to another.
Vectors include mice, mosquitoes, ticks, and cockroaches. A well-
known example of a vector-transmitted disease is malaria, which is
propagated in tropical climates by mosquitoes. Indirect contact can
also occur through airborne infectious particles that travel from one

person to another. A very familiar example of this is rhinovirus, or the