(N/A) $Salmonella \ typhi$ is a pathogenic bacterium which causes $Typhoid$ fever in humans. These pathogens generally enter the small intestine through contaminated food and water and migrate to other organs through the blood.
Common symptoms of this disease include sustained high fever ($39^o C$ to $40^o C$),weakness,stomach pain,constipation,headache,and loss of appetite. In severe cases,intestinal perforation and death may occur. The diagnosis of this disease is confirmed by the $Widal \ Test$.
$A$ classic case in medicine is that of $Mary \ Mallon$,nicknamed $Typhoid \ Mary$. She was a cook by profession and remained a carrier of this disease for several years through the food she prepared.