microbes in the news

Question 1

bioterrorism

Answer 1

• 2001 US anthrax attacks
• 22 infected, 5 fatalities
• cross contamination in US postal system
• economic and political impacts

Question 2

Influenza

Answer 2

• haemagglutinin (H) spike or Neuraminidase (N) spike on surface determines type of flu
• capsid coat to protect against UV degradation
• viral RNA
• lipid envelope from host cell membrane (weakens and causes death of host cells when exiting)

Question 3

avian influenza

Answer 3

• H5 spikes on surface
• transmitted into cattle
• indirect and direct impact on humans

Question 4

new strains of influenza virus

Answer 4

• vaccines based on predictions of strains
• double infection (2 strains at once infecting same cell in animal, often a pig) creates a new strain through genetic recombination
• new antigens (antigen shift) means reduced immunity
• e.g. 1918 ‘Spanish flu’ epidemic was a strain from human and swine flu, 20-40m deaths

Question 5

measles

Answer 5

• viral
• rash, flu-like symptoms
• complications include encephalitis, subacute sclerosing panencephalitis (progressive CNS destruction, fatal), pneumonia
• out of 100 susceptible people, 90 people catch it and 7 have complications (high R number)

Question 6

Mpox

Answer 6

• zoonotic, transmitted from animals to humans
• related to smallpox (eradicated)
• discovered in Europe in 1958 in lab primates
• endemic to central and west Africa
• flu-like symptoms, distinctive skin lesions
• skin-to-skin transmission

Question 7

bacteria and antibiotic resistance

Answer 7

• ~5m people die each year
• growing problem, estimated 40m deaths from now to 2050
  e.g. mRSA

Question 8

staphylococcus aureas

Answer 8

• gram positive bacteria
• coccus
• ~1 micrometer diameter
• clumps of cells
• found on human skin and nasal membranes
• usually non-harmful and block harmful pathogens from growing by occupying space but can be an opportunistic pathogen e.g. in a cut
• can be treated with antibiotics

Question 9

mRSA

Answer 9

• methicillin resistant staphylococcus aureus
• also resistant to other antibiotics
• backup drug usually vancomyocin but VRSA also observed

Question 10

mRSA infections

Answer 10

• usually boils and abscesses on skin surface or styes on eye
• furunculosis = localised reocurring infection
• can become more serious, causing pneumonia, ostomyelitis in bones, phlebitis in veins, endocarditis on outer layer of heart

Question 11

mRSA transmission

Answer 11

• common in ill/immunocompromised patients in hospital as there is more mRSA and less resistance
• nosocomial infection = develop in hospital
• post-operative wound infections
• indwelling medical devices
• community-associated infections can be from skin-to-skin contact, damp environments or crowded conditions