34. Epidemiology and prevention of zoonotic protozoon and viral infections

From greek.doctor
  • Viral zoonoses
    • Rabies
    • Hantavirus
    • Influenza
    • Crimean-Congo haemorrhagic fever
    • Ebola
    • Rift valley fever
  • Protozoan zoonoses
    • Toxoplasma

Rabies

  • Rabies virus is a type of lyssavirus
  • Epidemiology
    • Very few cases in Europe
    • Present in all parts of the world
    • 95% of death occur in Asia and Africa
  • Reservoir
    • Dogs, bats, wolves, foxes
  • Transmission:
    • Bite or direct contact with saliva of infected animal
    • Retrograde transport from nerves at bite site to the CNS
  • Incubation period
    • 1-3 months
    • Depends on how far from the CNS the infection occurred
  • Two types
    • Encephalitic rabies (most common)
      • CNS symptoms
      • Agitation
      • Confusion
      • Hypersalivation
    • Paralytic rabies
      • Flaccid paralysis spreading from the bite wound
    • Both
      • Hydrophobia
  • Prevention
    • Human vaccine
      • For travellers spending much time outdoors
      • For high-risk occupations, like veterinarians
    • Oral immunization of animals
      • Releasing baits containing oral vaccine into high-risk areas
      • Vaccination of dogs
    • Teaching children to avoid animal bites
    • Post-exposure prophylaxis
      • Washing wound for 15 minutes
      • Giving rabies vaccine soon after bite
      • Administration of rabies antibodies if needed

Hantavirus

  • Hantavirus is a bunyavirus
  • Reservoir
    • Rodents
  • Transmission
    • Inhalation of infected rodent urine or droppings
    • Bites
  • Risk groups
    • Forest workers
    • Farmers
  • Clinical features
    • Haemorrhagic fever with renal syndrome
    • Hantavirus cardiopulmonary syndrome
  • Prevention
    • Avoidance of dust
    • Minimizing contact with rodents

Toxoplasmosis

  • Toxoplasma gondii (a helminth)
  • Reservoir
    • Cats
  • Transmission
    • Ingestion of cysts
    • Direct through cat faeces
    • Indirect through food or water contaminated with cat faeces
    • Pigs, cows can ingest cyst, making their meat infected
  • Clinical features
    • A part of TORCH
    • Perinatal death
    • Congenital infection
      • Neurocognitive deficit
  • Prevention
    • Avoid contact with cat litter
    • Hand hygiene
    • Avoid undercooked meat