EESA10H3 Lecture 7: Biological Hazards & Human Health
23 Jun 2018
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EESA10 lecture 7: Biological Hazards & Human Health
Infectious Disease – host-centered concept; human body=habitat/host to many organisms
- Associations that harm/bother us are infectious diseases; agents = pathogens
- Zoonosis – infectious disease transmissible to humans from other animals
- PATHOGENS:
o Worms – multicellular; parasitic
o Protozoa – unicellular; parasitic
Malaria – spread by several species of mosquitoes; 4 species of the protozoa
Plasmodium which lives as parasite in gut of female mosquito. Kills b/w 1-3 mill.
annually
Plasmodium transferred thru mosquito to human – then reproduces in
human’s liver and bloodstream developing malaria
Infected person bitten by another mosquito can pass the mature
Plasmodium on = transmission cycle
o Bacteria – unicellular; most not parasitic (aerobic vs anaerobic/tolerate either, some
form spores)
Tuberculosis (TB)
1/3 world’s pop.infected w/TB; leading killer of people who are HIV
infected
2011 – nearly 9 mill. Sick w.TV, 1.4 mill deaths worldwide
HEALTH EFFECTS: most commonly attacks lungs
o Chest pain, coughing up blood, productive prolonged cough for
>3wks
o Fever, chills, night sweats, appetite loss, weight loss, paleness,
fatigue
o Transmitted through cough, sneeze, speak, kiss, or spit
Anthrax – Bacillus anthracis (large, spore forming bacteria), produce toxin,
bioterrorism, can’t be transmitted from person-person
Cutaneous Anthrax – naturally occurring type (>95%)
o Skin contact w/contaminated meat, wool/leather from infected
animals (incubation period ranges from 1-12 days)
o Begins small raising bump, progresses into vesicle _ then
painless ulcer
o Fever, headache, + lymph glands swell; 20% of untreated cases
results in death
Inhalation Anthrax – most lethal form; inhalation of spores of anthrax
o Incubation period 1-60 days; starts as viral respiratory illness;
sore throat, mild fever, muscle aches may progress to
respiratory failure + shock w/developing meningitis
o 75% of cases result in death even w/all possible supportive care
Gastrointestinal Anthrax – consumption of raw/undercooked
contaminated meat
o Incubation period 1-7 days; 25-60% cases result in death
o Nausea, loss of appetite, vomiting, fever followed by abdominal
pain, vomiting blood + bloody diarrhea
o Effect of early treatment = not defined
Bioterrorism Related Anthrax – mixed w/powder to transport the
bacteria, suspicious mails environmental testing, diagnosis, cure
(antibiotics + vaccine)
Plague – caused by bacteria Yersinia pestis; can be used as a bioweapon,
antibiotics (no vaccine)
Bubonic Plague
o Most common form; bites from flea/infected rodent
(transmission thru break in person’s skin)
o Swollen, tender lymph glands (buboes), fever, headache, chills +
weakness doesn’t spread from person to person
Document Summary
Eesa10 lecture 7: biological hazards & human health. Infectious disease host-centered concept; human body=habitat/host to many organisms. Associations that harm/bother us are infectious diseases; agents = pathogens. Zoonosis infectious disease transmissible to humans from other animals. Pathogens: worms multicellular; parasitic, protozoa unicellular; parasitic. Malaria spread by several species of mosquitoes; 4 species of the protozoa. Plasmodium which lives as parasite in gut of female mosquito. Plasmodium transferred thru mosquito to human then reproduces in human(cid:859)s liver and bloodstream developing malaria. Infected person bitten by another mosquito can pass the mature. Plasmodium on = transmission cycle: bacteria unicellular; most not parasitic (aerobic vs anaerobic/tolerate either, some form spores) 1/3 world(cid:859)s pop. infected w/tb; leading killer of people who are hiv infected. Health effects: most commonly attacks lungs: chest pain, coughing up blood, productive prolonged cough for. >3wks: fever, chills, night sweats, appetite loss, weight loss, paleness, fatigue, transmitted through cough, sneeze, speak, kiss, or spit.
