Typhoid fever is caused by salmonella Typhi(Ingrid koo 2008)
Species name; salmonella typhi is the most common species that causes typhoid fever, other species including salmonella enteritis or salmonella typhurium; can cause gastroenteritis(diarrhea) or typhoid like disease.
The Organism can survive in water for seven days, in sewage for fourteen days and in ice cream for thirty days.
The primary sources of infection are faeces and urine of cases of carvers, the organism then make their way into a new patient by way of contaminated food or water. The secondary sources are contaminated water, food, fingers and flies.
The highest incidence of this disease occur in five to nineteen years of age group.