Exam 1 Flashcards
endemic
a disease regularly found among particular people or in a certain area, always present (malaria)
epidemic
specific to a city, region, country, unexpected rapid widespread occurrence, affects many communities in a specific region ex ebola
pandemic
an epidemic that is geographically widespread
Typhus
“camp fever”: louse borne bacteria
Rickettsia prowazekii
smallpox
Variola virus that causes a highly infectious disease, 300-500 million deaths
90-95% indigenous people
Dr. edward jenner invented the process of vaccination in the late 18th century to combat
only infectious disease to be eradicated through vaccination
origin of concept: immunity and vaccination
black death
bubonic plague
Yersinia pestis bacteria transmitted by rodents and flea bites
>17million deaths
2/3 european population
syphilis
Treponema pallidum
sexually transmitted
1400s european battles lost due to soldiers fleeing from ‘the disease that caused flesh to fall from faces’
global pandemic, decreased due to penicillin
re-emergence, >10million cases annually
spanish flu
influenza A virus, H1N1, 50-100 million deaths
killed more ppl than WW1
influenza
influenza A virus, H1N1 >1million deaths
HIV/AIDS
the virus that causes AIDS, spread through bodily fluids rather than casual contact or airborne
>70 million infected, >35 million deaths
tuberculosis
Mycobacterium tuberculosis, evidence in mummies
infectious nature prompted building of sanatoria for treatment
remains pandemic, 1.8 billion infected >1.3 million deaths/year
origin of concepts: antibiotics, pasteurization, quarantine
COVID-19
296,500,000 cases world wide
>5.5 million deaths
10 examples of infectious diseases
COVID-19, syphillis, tuberculosis, bubonic plague, small pox, typhus, spanish flu, influenza, HIV/AIDS
unintentional introduction
hispanic community was severely affected by measles, influenza and smallpox, within 50 years of columbus arriving 3 million Tanio people died (85% of population)
Fiji was severely affected by measles, loss of 25% of Fijioans and nearly all Chiefs
intentional introduction (germ warfare)
12th century italy, diseased corpses were placed in water supply, Tartar forces catapult bodies of plague victims over the city walls of Caffa, Crimean Peninsula
British distribute blankets from smallpox patients to North American indigenous population
global deaths per year
based on type of disease
1. respiratory infections
2. HIV AIDS
3. Diarrhoel diseases
4. TB
5. vaccine-preventable childhood diseases
comunicable disease
a disease that can be passed from person to another person
Global deaths per year based on pathogen taxonomy
largely bacterial and viral
Sir Alexander Fleming
Discovered penicillin in 1928
one of most important advances in history of medical science
Nobel prize
He indicated warning of resistance
deaths associated with antimicrobial resistance
low estimate now = 700,000
estimate by 2050 = 10 million
multi-drug resistant bacteria
resistant to at least 3 classes of antibiotivs
extensively drug resistant bacteria
resistant to all but 2 classes of antibiotics
Pandrug resistant (PDR)
resistant to all available antibiotics
Salmonella typhi (2016)
pakistan 858 cases, resistant to 5 antibiotics
Mycobacterium tuberculosis
13% cases multidrug-resistant
6% extensively
123 countries
Neisseria gonorrhoea
78 million cases annually, 1/3 drug-resistant
new super gon. strain resistant to all but one anti.
Psuedomonas aeruginosa
29 cases of pandrug-resistant infection in england in the last 5 years
Klebsiella pneumoniae
8000 cases in US death rate 50%
2016 patient died of pandrug-resistant strain
by understanding microbial pathogenesis we can develop…
new drugs, vaccines, alternative ways of preventing infection
emerging diseases
recognized in the human host for the first time
20th, 20st centuries
SARS, HIV/AIDS, BSE (mad cow), H1N1, ebola, lyme disease (borrelia burgdoferi)
re-emerging disease
existed previously but are rapidly increasing in incidence, geographic range
reappear after apparent control or elimination
dengue virus, west nile virus, cholera, tuberculosis, malaria
factors contributing to disease emergence and re-emergence
population - overcrowding, poor sanitation
food - mass production, international distribution
poverty
war and famine
international trade and travel
climate and weather
economic development and land use (human exposure to disease, vectors and reservoirs)
Human susceptibility to infection
microbial adaptation and change
2 main pathogenic strategies
- frontal assault strategy
- stealth assault strategy
frontal assault strategy
Cholera
symptoms start 2h-5d after ingestion
produce 10-20 L of diarrhea a day
fatality rate 50% without treatment
death or disease resolution in a few days or as little as 12h
V. cholerae pathogenesis
ecological niche: saline coastal waters, zooplankton and shellfish
water and food contaminated with human feces = ingested
GM1: monosialic ganglioside receptor
- cholera toxin (CT) attaches
stealth assault strategy
slower infection
set up chronic or persistent infection
manipulate innate and adaptive immune responses
ex: TB
33% global population infected
90-95% of infections asymptomatic
generally active infection present within 2 years or remain latently infected
persist in granulomas during the latency phase of infection
fatality rates 50% without treatment in individuals who develop active disease
