• Typhoid fever
• 1st week of illness: Rising, “stepwise” fever, bacteraemia and diarrhoea (78% of children) or constipation (more frequent in adults).
• 2nd week of illness: Abdominal pain and rash (rose spots)
• 3rd week of illness: Hepatosplenomegaly, intestinal bleeding and perforation

• Complications (rare if diagnosed and treated early)
• Intestinal haemorrhage or perforation
• Toxic myocarditis
• Confusion, convulsions, encephalitis
• Haemolytic anaemia (especially in G6PD deficiency)
• Renal failure
• Abscesses in liver, spleen, bone etc.

• Paratyphoid fever
• Maybe clinically mild or asymptomatic
• Nausea, vomiting, fever, diarrhoea, and cramping—usually occur within 8 to 72 hours of ingesting contaminated food or water
• Less than 5% of non-typhoidal salmonella gastroenteritis develop bacteraemia and may result in extra-intestinal manifestations including endocarditis, mycotic aneurysm and osteomyelitis.

• Blood test frequently show anaemia, elevated hepatic transaminases and either leucopoenia or leucocytosis.
• Isolation of organism is the gold standard for diagnosis.
• Blood culture usually positive for 1st two weeks only.
• Stool and urine culture positive from 2nd to 4th weeks.
• The yield from bone marrow culture is high and is usually positive even after antibiotics have been initiated.
• The Widal test is unreliable in itself, but may provide additional support for the diagnosis when the clinical picture is suggestive.

A legally notifiable disease in Singapore. Notify Ministry of Health (Form MD 131 or electronically via CD-LENS) not later than 24 hours from the time of diagnosis.

Typhoid

• Patients should be hospitalised during antibiotic treatment.
• Rehydration and other supportive care.
• Current drugs of choice:
• PO Ciprofloxacin 500 mg bd x 7-10 days (if sensitive to ciprofloxacin andnalidixic acid)
• IV Ceftriaxone 2-3g once daily x 10-14 days
• Alternative: PO Azithromycin 1g once then 500mg once daily x 5-7 days
• N.B. 70-90 % of isolates in some parts of Nepal, India and Vietnam are nalidixic acid resistant strains.
• Dexamethasone 3mg/kg then 1mg/kg 6 hourly x 8 doses for severe typhoid fever (as suggested by delirium, shock and altered mental status) decreases mortality.
• Relapse rate 1-6% with newer antibiotics (10-25% with chloramphenicol)
• One to four percent of adults become chronic carriers despite antibiotics.
• Follow-up stool evaluation to document stool clearance after treatment:
• Three consecutive stool samples taken at weekly intervals no sooner than two weeks after completion of antibiotic treatment.
• Chronic carriers (positive stool samples after 6 months): give prolonged course of ciprofloxacin (750 bd orally for 1 month) and perform abdominal ultrasound; cholecystectomy may be necessary if gallstones are present and prolonged antibiotic treatment fails.

• Public health measures: education on good personal and food hygiene.
• Vaccination for travellers: (see section on travel vaccination in Appendix 3).
• Follow up stool examinations recommended for all cases and mandatory for food handlers.
• Food handlers require further stool examination (three consecutive daily stool samples) at three and six months post treatment.
• Carriers (convalescent, temporary and chronic) must not work as food handlers.