Emerging Infections

Question 1

Name 4 emerging diseases

Answer 1

TB
Zika
SARS
Anthrax

Question 2

Why do emerging and re-emerging diseases occur

Answer 2

Antibacterial/antibiotic resistance

Question 3

Explain emergence of crowd disease

Answer 3

Closer contact with animals and microorganisms - during early settlements

Question 4

Factors favouring eradication of infectious disease

Answer 4

Complete industrialisation
Few serotypes
Good vaccines

Question 5

Factors responsible for emerging diseases

Answer 5

• global travel
• centralised processing of food
• globalisation of food supplies
• deforestation and reforestation
• increases use of antimicrobial agents and pesticides
• global warming

Question 6

Characteristics of SARS virus (Sever Acute Respiritory Syndrome)

Answer 6

Coronavirus (SARS-CoV)
Envelopes
Positive sense ssRNA

Question 7

Describe the transmission pattern of SARS

Answer 7

Respiratory droplets

SARS virus may live on hands, tissues for up to 6 hours in droplets, 3 hours after droplets dry

Question 8

Describe symptoms of SARS

Answer 8

Ever, headache, discomfort, body aches, mild respiratory symptoms

Question 9

Characteristics Zika virus

Answer 9

Flaviviridae
Envelopes icosahedral
Non segmented, positive sense ssRNA

Question 10

Explain the transmission pattern of Zika virus

Answer 10

• Transmitted to people through infected mosquitos

- during pregnancy can cause birth defects lie microcephaly

Question 11

How do you treat Zika infection

Answer 11

No fully developed vaccine

Treat symptoms via rest, drinking fluid, medicate to relieve pain

Question 12

Factors responsible for RE-emerging disease

Answer 12

Natural genetic variation (antigenic shift/drift)

Recombination and adaptation allow new strains to appear

Question 13

Characteristics of Mycobacterium tuberculosis

Answer 13

Bacillus, infects upper lives of lungs

Question 14

Symptoms of tuberculosis

Answer 14

90% asymptomatic

• mild cough
• chronic cough, pain in chest, weakness, fatigue, weight loss, coughing up blood

Question 15

Describe the transmission pattern of tuberculosis

Answer 15

Airborne
Implant in lung
Spreads to other parts of the lungs
A single sneeze can release 40,000

Question 16

Describe the prevention and treatment of tuberculosis

Answer 16

BCG Vaccine
Standard 6 month course of antimicrobial drugs which most patients fail to adhere to.
Second line drugs: aminoglycosides

Question 17

How is tuberculosis diagnosed

Answer 17

• Tuberculin rest - mantoux tuberculin skintest
• chest x-ray
• culturing m. Tuberculosis from sputum
• blood test

Question 18

Characteristics of deliberately (re)emerging diseases

Answer 18

Developed by man for nefarious use

• anthrax
• bioengineered microorganism by insertion of genetic virulence factors to enhance infectivity or pathogenicity

Question 19

Characteristics of bacillus anthracis

Answer 19

Non motile, gram positive

• facultative anaerobes
• endospore forming

Question 20

Describe the pathogenicity of bacillus anthracis

Answer 20

• Infection imitated by endospores
• 2 endotoxins
• capsule

Question 21

Characteristics of cutaneous anthrax

Answer 21

• contract with material containing anthrax endospores through minor skin lesions
• most common form is least dangerous, on head, neck, forearm and hands
• low fever, malaise

Question 22

Characteristics of gastrointestinal anthrax

Answer 22

Passed through food

• bloody diarrhoea
• nausea
• abdominal pain

Question 23

Characteristics of inhalational anthrax

Answer 23

Endospores inhales - most dangerous

- high chance of bacteraemia

Question 24

Symptoms of inhalational anthrax

Answer 24

Mild fever
Coughing
Chest pain
- bacteraemia —> RBC prolif, septic shock usually kills in 24-36 hours

Question 25

Treatment and diagnostics of anthrax

Answer 25

Antibiotics: ciprofoxacin or doxycycline
Traditional culture
Blood tests
Automated electronic sensors - anthrax spores