Mode of Transmission
Typhoid is transmitted mainly by faeco-oral route. The bacilli are excreted
for varying periods in Faeces and urine of cases and carriers. There is no
evidence that the bacilli are excreted in sputum of milk. Typhoid infection
can spread through
Contaminated drinking water or food. Large epidemics usually related to
faecal contamination of water supplies.
Contaminated food/drink due to poor personal hygiene and food handlers
Vehicle transmission: The major vehicles of infection are water and food, contaminated
by faeces or urine of infected patients or carriers. Paratyphoid fever
is seldom conveyed by water unless the infecting dose is large; it is generally
by contaminated foods,
e.g. ice, ice-cream, frozen foods, confectionary.
Direct contact: A small proportion of typhoid cases may occur due to direct
transmission of infection through contaminated hands. The hands may
be contaminated while handling patients, their excreta or infected linen.
Transmission by flies
is also a possibility in endemic areas.