Microbial Diseases Flashcards Preview

MB 351 - Exam 4 > Microbial Diseases > Flashcards

Flashcards in Microbial Diseases Deck (21):
1

Why has infectious disease decreased since the 1900's in the U.S.?

-Decrease in host susceptibility: Better housing and nutrition, antibiotics
-Decrease in disease transmission: Improved hygiene and sanitation, safer food and water, and immunizations

2

Differences in cause of death between Africa and US

-Africa: Infectious Disease (Malaria, Pneumonia, TB)
-US: Chronic Illnesses (Heart Disease, Cancer)

3

Airborne Transmission of Disease (2)

-Transmit through aerosols
-Mainly impact respiratory system

4

ARI

Acute Respiratory Infection: Leading cause of death among infectious diseases

5

Strep Throat is caused by...

Streptococcus pyogenes in the upper respiratory tract

6

Pneumonia is caused by...

Streptococcus pneumoniae in the lower respiratory tract

7

Direct Contact Diseases (3)

-Spread by direct contact with person, blood, or excreta
-Many respiratory diseases can spread directly
-E.g. Staph infections, leprosy, Ebola

8

STDs (4)

-Caused by wide variety of bacteria, viruses, protists, fungi
-Pathogens live in fluids from genitourinary tract, sensitive to drying
-Complications: infertility, cancer, birth defects, immune impairment, neural degeneration
-E.g. Neisseria gonorrhoeae, HIV, Herpes virus

9

Animal Transmitted Diseases (3)

-Host is a nonhuman vertebrate
-Can be spread by direct contact, aerosols, or bites
-E.g. Rabies, Hantavirus, Avian influenza

10

Arthropod Borne Diseases (3)

-Pathogens can be spread from bite of an infected arthropod vector
-Humans can be accident host (Rickettsial diseases) or required host (Malaria)
-E.g. Plague from fleas, West Nile, Yellow Fever from mosquitoes

11

Black Plague (3)

-Caused by Yersinia pestis
-Rodents are reservoirs with their fleas as vectors
-Virulence factors:
1) Capsules, V&W antigens prevent phagocytosis
2) Produces exotoxin and endotoxin
3) Proteins that inhibit immune system

12

Plague transmits via...(4)

-Sylvatic cycle: Rodent -> Flea -> Human
-Can transmit from wild rodents to domestic rodents via fleas
-Can be transmitted by direct contact with rodent
-Can be transmitted by people, if progresses to secondary plague pneumonia

13

Soil Borne Diseases

-Live in soil, making an unlimited reservoir of the pathogen
-Accidental agents of infection, no host dependency
-E.g. Tetanus, Botulism, Anthrax

14

Anthrax Forms

-Endospores transmit disease
-Cutaneous-spores contracted by damaged skin
-GI from consumption of spore contaminated food
-Pulmonary from inhaled spores (pulmonary infection, hemorrhage of brain and lungs, death)

15

Biological Weapon Characteristics

-High Fatality Rate
-Create Fear and Panic
-Affects Only Enemy
-Rapid Spread
-Difficult to Detect
-Cheap
-Airborne
-Latent Period

16

Pathogenic Escherichia coli

-Five classes cause diarrheal diseases (EHEC, EIEC, ETEC, EAEC, EPEC)
-Intestinal pathogens and several make enterotoxins

17

EHEC (4)

-Enterohemorrhagic E. coli strain O157:H7 grows in small intestine
-Makes verotoxin, causing bloody diarrhea and kidney failure
-Found in feces
-Comes from contaminated meat

18

Waterborne Diseases

-Problematic in developing countries: Inadequate water and sewage treatment, limited access to safe, potable water
-Water-based reservior

19

Cholera

-Vibrio cholera
-Shellfish are natural reservoir, transmitted by contaminated water
-A:B exotoxin promotes rapid and extensive fluid loss

20

Factors of Emergence of Infectious Diseases (8)

-Widespread use of antibiotics and pesticides
-Changes in/evolution of existing organisms
-Global warming changes reservoirs and vectors
-Genetic recombination
-Ecological changes
-Speed and spread of transportation
-Animal control measures (control of animal reservoirs)
-Failures in public health measures

21

Ability of pathogen to transmit between species

Zoonosis