routes of infection - block b Flashcards
modes of transmission
person to person - blood/sexual transmission/vertical transmission
orally - contaminated food or water
vector-borne - insects and spores
person to person
blood - arthropods, blood transfusion, needles
bodily fluids - sti
saliva and mucus - sneezing and coughing
vertical transmission
parent to offspring
prenatal
placental route
rubella, hepatitis B, toxoplasmosis, syphilis, cytomegalovirus
postnatal
milk
direct contact with blood at delivery
hepatitis B, HIV, HTLV-1, cytomegaovirus
germline
viral dna sequences in genome
ancient retroviruses
orally
faecal shed into drinking water - heavily controlled in resource rich countries, eg. cholera
contamination of food products directly
contamination of food products in the preparation process
vector borne
insects, ticks, and mites - the blood suckers are most important for spreading infection
zoonoses - any infection that is transmitted from animals to humans
domestic pets or pests
routes of entry
external surface - physical contact, tricchphyton = athletes foot
wounds and abrasions - minor abrasions, puncture wounds, bacillus anthracis = anthrax , tetanus, f. tularanesis = tularemia,
anthrax and tetanus are gram positive, tularemia is gram negative
routes of infection
mouth and respiratory tract - inhalation or ingestion of infective material (droplets) - spores - flu, measles, varicella-zoster, epstein barr, pyogenes, meningitis
pyogenes
tonsillitis
gram positive
pneumonia, meningitis
haemophilus influenzae
gram negative
meningococcal meningitis
neisseria meningitidis
gram negative
spores
bacillus anthracis
inhalation anthrax
gram positive
contaminated food/water
rotavirus - diarrhea
hepatitis a - jaundice - picomavirus
salmonella enteritidis, typhimurium - food poisoning - gram negative
cholerae - cholera - gram negative
salmonella typhi - typhoid fever - gram negative
trichuris trichuria - trichuriasis - helminth
