ENT/BIO 561
Insects Affecting Human and
Animal Health
Dr. Grayson Brown
Public Health Entomology Lab
107 Dimmock Bldg
Syllabus
• Dr. Grayson C. Brown,
gcbrown147@gmail.com; 257 – 3148
• Office & Hours: Rm. 107 Dimmock Bldg
(Animal Pathology Bldg); MW 9:00 – 10:00
AM, Anytime by appointment
Course Description
Insects Affecting Human and Animal Health is a 3-credit class that
presents current information on pests that have and continue to
plague humans. This course will explore the arthropods of importance
in human and public health and will include those arthropods of
veterinary significance to the extent that they impact human health
risk. The course will include information on the biology, ecology,
human impact (both real and potential), and management of the
medically-important arthropods around the world.
The medical topics covered will mostly involve disease and
transmission by arthropods to humans although we will also study
other subjects such as direct attack, psychological impacts, forensic
entomology, and nuisance species.
The factors involved with the epidemiology of vector-borne
diseases, host, parasite, vector and reservoir will be stressed as this is
a recurrent theme in medical entomology. However, we will also
investigate the public health aspects of these issues including legal
issues, municipal vector management programs, and wide-area
management efforts. Students will be encouraged to share their own
experiences throughout the course.
Learning Outcomes
Upon completion of the course, the student will be able to:
•
Recognize medically important arthropod pests and disease vectors and
arthropod borne pathogens.
•
Understand the morphology, physiology, behavior, and ecology of medicallyimportant arthropods, and how these biological elements contribute to
disease transmission.
•
Understand important factors that promote pest problems and disease
transmission and will be aware of prevention and treatment practices.
•
Understand the principles of organization behind public health vector control
programs along with the limits and capabilities of these programs.
•
Assess the likelihood of new approaches in solving future vector-borne
pathogen challenges.
Textbook Required
Mullen, G. and L. Durden,
(eds), 2009. Medical and
Veterinary Entomology, 2nd
Ed. Academic Press, London.
637 pp. ISBN 978-0-12372500-4.
Note: ONLY THE 2ND EDITION
IS ACCEPTABLE FOR THIS
CLASS!!!!
Order from your favorite retailer
(Not available in the UK
bookstore).
Grading
Events
Point Value Each
Total Points
1-hr Lecture Exams (2)
100
200
Final Exam
100
100
Announced Quizzes (4)
10
40
Written Exercise (2)
20
40
Oral Presentation
20
20
Total Points Possible ............................................................... 400
Class Policies
• Attendance – Expected. You cannot do
well in this class if you do not attend
all/nearly all lectures.
• Make-up exams – Only in extreme
circumstances. Written note needed.
• Cheating – Automatically flunk the course.
Insects Affecting Human and
Animal Health
Opening Lecture and Introduction
Insects have long been known to
precede disease
• … and when Aaron stretched out his hand with the staff
and struck the dust of the ground, gnats came upon men
and animals. All the dust throughout the land of Egypt
became gnats. … And the gnats were on men and
animals. Ex 8-16
• Dense swarms of flies poured into Pharaoh's palace and
into the houses of his officials, and throughout Egypt the
land was ruined by the flies. Ex 8-24
• … a terrible plague on … livestock in the field—on your
horses and donkeys and camels and on … cattle and
sheep and goats. Ex 9-4
• … and festering boils broke out on men and animals. Ex
9-11
Historical Overview
– 2700 BC - Nei Ching
– 600 BC - Malaria invaded Europe
– 1674 - Anton van Leeuwenhoek
– 1877 - Louis Pasteur “germ theory”
A few other examples from early
history
• 600 BC Malaria invades Europe
• 430 BC During the Pelopponesian Wars, typhus
ravaged the Athenian navy; Athens loses war
• 541-2 CE – First documented plague pandemic.
5 – 10k/day die in Constantinople
• 1346-50 CE -- Mongol tartars, besiege Feodosia
by catapulting plague-infested cadavers over the
walls of the city. Escaping residents of the city
introduce plague into Italy, initiating the
European pandemic (the Black Death) that killed
>20% of the populace
Examples from Early Americas
Stone
representation of a
flea from Mexico,
1200 – 1500 AD
Peru, 400 – 900
AD, pottery
celebrating the
removal of
chigoe fleas
from foot
New Mexico, 1200 AD,
pottery showing
mosquitoes swarming.
Military Examples
War
Number Serving in
Army
Battle Injuries (BI)
Disease Non
Battle Injuries
(DNBI)
Arthropod Borne
Diseases
Civil War (Union)
2,128,948
138,154
221,374
Yellow fever,
typhoid, malaria
Spanish American
War
280,564
369
2,061
Typhoid, malaria
World War I
4,057,101
50,510
55,868
Trench fever,
malaria, louse
borne typhus
World War II
11,260,000
234,874
83,400
Malaria, scrub
typhus
Vietnam
4,368,000
30,922
7,273
Malaria
Desert Shield
246,682
98
105
Leishmaniasis
Will revisit the history of “big”
diseases in more detail later
• Main ideas:
– Connection between insects & disease known
for centuries
– Transmission cycle concepts known for a
century or less
– Management options available for 60 years
– Stewardship options for management tools for
30 years.
Definitions
• Medical Entomology - study of insects (arthropods)
that parasitize or otherwise affect humans
• Veterinary Entomology - study of insects (arthropods)
that parasitize or otherwise affect animals (not
human)
• Livestock Entomology - study of insects and related
arthropods that parasitize or otherwise affect
domestic animals
More Definitions
• host - Any living animal or plant affording subsistence and/or
lodging to a parasite
• parasite - An organism which lives at the expense of a host
• parasitoid – An organism which lives at the expense of the host
and the host necessarily dies
• predator - An animal which consumes a number of prey in its
lifetime; fast kill and consumption
• disease - Illness or sickness often characterized by typical
patient problems (symptoms) and physical findings (signs).
• pathogen – A microorganism that is a parasite and which
causes disease
Example – Horse Bot
Parasite
Host
Disease
•obstruct passage of
material from the
stomach
•colic.
•rupture of the stomach
wall, death.
Insect Pest
• Any insect that causes “damage”
• “Damage” any outcome that is undesirable
from man’s perspective
• In Medical/Veterinary entomology – two
kinds of damage:
– Economic (Veterinary)
– Medical/Psychological (Human)
From the man-insect-pathogen
perspective, two general types of
damage
Direct – Immediate effects of an
insect bite or sting.
Indirect – Subsequent effects, not
a direct product of a bite or sting.
Direct Damage Effects
• Biting
– exsanguination
• Invasion
– myiasis
• Toxins
• Disturbance / Irritation
Examples -- Myiasis
Palate
Rhino-orbital
Many Forms of Cutaneous Myiasis
Bite/Sting Effects
Mosquito Bites
Wasp Sting
Spider bite
Toxin Examples
Brown Recluse Bites
Indirect Damage
• Disease / pathogen transmission
• Secondary Reactions
– Allergies,
– weakening
• Psychoses
– entomophobia
– dilussory parasitosis
Disease – Bubonic Plague
Allergies
Systemic Response
Local Response
Disturbance/Irritation
Peripheral Damage
• Quarantine and Restrictions
• Medical treatment problems (incorrect, treatment avoidance, etc.)
• Contamination
– Blood Donations
– Food Contamination
• Societal Costs
– Associated with damage
– Associate with damage prevention measures
In many cases, man has
worsened problem
• Transportation of arthropods
• Transportation of pathogens
• Transportation of pathogens in humans
• Transportation of pathogens in livestock, insects, other
animals
• Justinian created the first plague: “Without the
empire, the bread dole, the huge shipments of
grain and cloth from Africa, it is difficult to
imagine how the First Pandemic could ever have
erupted.” Orent, 2004
In many cases, man has
worsened problem
• Increased population densities
• Expansion into new areas
• Environmental Modification
• Artificial Selection