Class 11- Natural Disasters

Question 1

Factors in emergence of pathogens

Answer 1

• Population growth – the most important factor
  
  • Expansion of Human Populations into previously uninhabited forested areas
• Speed and ease of travel
• Changes in the food industry
• Antibiotic use and abuse
• Dam Building
• Relocation of animals
• Contact with Exotic Animals
• Climate change

Question 2

Emerging Pathogens

Answer 2

• Nipah virus
• Monkey pox
• SARS
• MERS CoV
• Anthrax

Question 3

Nipah Virus

Answer 3

• Emerging zoonotic virus that can produce encephalitis or respiratory disease
  
  • Natural host: Fruit bat
  • No treatment or vaccine
  • NV outbreak in Malaysia (1999)
• How does it reach humans?
  
  • Pigs come into contact with bat droppings, when bats roost in farms, pigs become infected, pigs sneeze, droplets infect humans.
  • Pig farmers in Malaysia began growing mangos to supplement their income. Mangos attracted bats.

Question 4

Nipah virus Disease Profile

Answer 4

• Reservoir – Fruit bats (Pteropus species) with incidental hosts being swine
• Route – Primarily through contact with infected swine
  
  • In Bangladesh and India – transmission can occur through contaminated date sap/juice.
  • Pigs spread through airborne
  • Bats contaminate food which is then ingested
• Incubation – 4 to 18 days
• Symptoms- from mild respiratory distress to coma, respiratory failure, and death. Includes disorientation, drowsiness and influenza like symptoms.
• Period of communicability – unknown

Question 5

Monkey Pox

Answer 5

• Similar to smallpox but less typically much less serious
• Introduced through Exotic pets.
• First identified in 1970 in the DRC. Cross protection from small pox vaccination
  
  • Likely why we are seeing a reemergence of Monkey Pox in African Populations
• Disease is indigenousness in Central and West Africa

Question 6

Monkey Pox Disease Profile

Answer 6

• Reservoir- variety of wild animals and rodents
  
  • Gets into human population through contact with exotic animals
  • Spreads through human to human transmission
• Route – index case results from direct contact with blood or bodily fluids from infected animals
  
  • Secondary transmission is human to human resulting from close contact with infected skin lesions or recently contaminated objects
• Incubation- 6-16 days
• Symptoms – Case fatality rate is less than 10% , There is no treatment available
  
  • invasion period – ever intense headache, back pain, myalgia (0-5 days)
  • Skin eruption period – eruption appear on the face palms a of hands, soles of feet and on the body nearly simultaneously. Rash changes to fluid filled blisters and pustules, which then crust over in ~10 days. Three weeks until crusts go away.
• Communicability- as long as symptoms persist.

Question 7

Cornonaviruses

Answer 7

• SARS: Severe Acute Respiratory Syndrome
  
  • Newly emergent zoonotic disease
  • First documented human case 2002
• Major outbreaks in China and Toronto
• MERS – CoV: Middle Eastern Respiratory Syndrom, Coronoa Virus
  
  • 3-4 out of every 10 reported MERS infections have died

Question 8

Amoy Gardens Epidemic

Answer 8

• A patient recovering from SARS visited his brother in the Amoy Gardens building comples for two days in march
  
  • Amoy Gardens - Densely populated complex
  • Total of 330 persons in the complex and 128 who lived nearby became ill. (21% of all SARS cases in Hong Kong)
    
    • Determined that exhaust from the toilets spread the virus by aerosol transmission

Question 9

MERS Disease Profile

Answer 9

• Reservoir- Unknown, maybe camels
  
  • All that is known is it comes from the Arabian Peninsula
• Route – Spread from ill people to others through close contact… maybe?
  
  • Chronic conditions or Co-morbidities make you more susceptible to infection.
• Incubation – 2 -14 days
• Symptoms – Fever, cough, shortness of breath, GI symptoms, and vomiting.
• Communicability – no clue

Question 10

Risk of Infection at Hajj and Umrah

Answer 10

• 3.1 million Hajj pilgrims in 2012 (6 day period)
  
  • 1.7 million are foreigners
    
    • More than twice the population of Mecca which is already considered over populated
• Considered the largest mass gathering event in World History
• Umrah is off season pilgrimage to Mecca.
• Huge public health risk because of of the risk of a contagious airborne virus, paired with international travel.
  
  • Virus is already transmissible person to person, with each additional infection you increase risk of antigenic shift and drift.

Question 11

Bioterrorism Categorization

Answer 11

Question 12

Anthrax – Bacillus anthracius Disease Profile

Answer 12

• Historically was known as Woolsorter’s disease (early form of occupational exposure)
• Reservoir – Livestock and wildlife- ruminants – shed the anthrax through terminal hemorrhaging at death. Spores then stay in soil.
• Route- dermal, inhalation, and ingestion
  
  • Severity of symptoms depend on route of exposure
• Incubation – 1 to 7 days
• Symptoms –
  
  • Inhalation Anthrax – 90% Mortality rate
    
    • Flu-like symptoms, such as sore throat, mild fever, fatigue and muscle aches, which may last a few hours or days
    • Mild chest discomfort, shortness of breath, nausea, coughing up blood, painful swallowing
    • As the disease progresses, you may experience: High fever, trouble breathing, shock, meningitis
  • Ingested Anthrax – 25-75% mortality rate
    
    • Nausea, vomiting, abdominal pain, headache, loss of appetite, fever,
    • Severe, bloody diarrhea in the later stages of the disease,
    • Sore throat and difficulty swallowing, swollen neck
  • Cutaneous Anthrax- 20% mortality rate
    
    • A raised, itchy bump resembling an insect bite that quickly develops into a painless sore with a black center
    • Swelling in the sore and nearby lymph glands
• Communicability – rarely person to person