Emerging Infections Flashcards
Name 4 emerging diseases
TB
Zika
SARS
Anthrax
Why do emerging and re-emerging diseases occur
Antibacterial/antibiotic resistance
Explain emergence of crowd disease
Closer contact with animals and microorganisms - during early settlements
Factors favouring eradication of infectious disease
Complete industrialisation
Few serotypes
Good vaccines
Factors responsible for emerging diseases
- global travel
- centralised processing of food
- globalisation of food supplies
- deforestation and reforestation
- increases use of antimicrobial agents and pesticides
- global warming
Characteristics of SARS virus (Sever Acute Respiritory Syndrome)
Coronavirus (SARS-CoV)
Envelopes
Positive sense ssRNA
Describe the transmission pattern of SARS
Respiratory droplets
SARS virus may live on hands, tissues for up to 6 hours in droplets, 3 hours after droplets dry
Describe symptoms of SARS
Ever, headache, discomfort, body aches, mild respiratory symptoms
Characteristics Zika virus
Flaviviridae
Envelopes icosahedral
Non segmented, positive sense ssRNA
Explain the transmission pattern of Zika virus
- Transmitted to people through infected mosquitos
- during pregnancy can cause birth defects lie microcephaly
How do you treat Zika infection
No fully developed vaccine
Treat symptoms via rest, drinking fluid, medicate to relieve pain
Factors responsible for RE-emerging disease
Natural genetic variation (antigenic shift/drift)
Recombination and adaptation allow new strains to appear
Characteristics of Mycobacterium tuberculosis
Bacillus, infects upper lives of lungs
Symptoms of tuberculosis
90% asymptomatic
- mild cough
- chronic cough, pain in chest, weakness, fatigue, weight loss, coughing up blood
Describe the transmission pattern of tuberculosis
Airborne
Implant in lung
Spreads to other parts of the lungs
A single sneeze can release 40,000
Describe the prevention and treatment of tuberculosis
BCG Vaccine
Standard 6 month course of antimicrobial drugs which most patients fail to adhere to.
Second line drugs: aminoglycosides
How is tuberculosis diagnosed
- Tuberculin rest - mantoux tuberculin skintest
- chest x-ray
- culturing m. Tuberculosis from sputum
- blood test
Characteristics of deliberately (re)emerging diseases
Developed by man for nefarious use
- anthrax
- bioengineered microorganism by insertion of genetic virulence factors to enhance infectivity or pathogenicity
Characteristics of bacillus anthracis
Non motile, gram positive
- facultative anaerobes
- endospore forming
Describe the pathogenicity of bacillus anthracis
- Infection imitated by endospores
- 2 endotoxins
- capsule
Characteristics of cutaneous anthrax
- 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
Characteristics of gastrointestinal anthrax
Passed through food
- bloody diarrhoea
- nausea
- abdominal pain
Characteristics of inhalational anthrax
Endospores inhales - most dangerous
- high chance of bacteraemia
Symptoms of inhalational anthrax
Mild fever
Coughing
Chest pain
- bacteraemia —> RBC prolif, septic shock usually kills in 24-36 hours
