Typhoid Fever

Typhoid fever is caused by Salmonella typhi, a Gram-negative bacterium. A very similar but often less severe disease is caused by the Salmonella serotype paratyphi A.

Humans are the only natural host and reservoir. The infection is transmitted by ingestion of faecally contaminated food or water.

Case Definition

Any person with gradual onset of steadily increasing and then persistently high fever, chills, malaise, headache, sore throat, cough, and sometimes abdominal pain and constipation or diarrhoea.

Clinical features

The clinical presentation of typhoid fever varies from a mild illness with low grade fever, malaise and dry cough to a severe clinical picture with abdominal discomfort, altered mental status and multiple complications.

Clinical diagnosis is difficult to make as it is confused with many similar conditions. In the absence of laboratory confirmation, any case of fever of at least 38 °C for 3 or more days is considered suspect if the epidemiological context is suggestive.

Depending on the clinical setting and quality of available medical care, some 5-10% of typhoid patients may develop serious complications, the most frequent being intestinal haemorrhage or peritonitis due to intestinal perforation.

Laboratory Testing

In Zimbabwe, blood culture samples, stool/rectal swab and bone marrow aspirate have been used to culture for isolation of S typhi.

Blood culture is the usual diagnostic test with a sensitivity of 90% (60% to 80%) in the first week of onset of fever. Stool and rectal swabs yield positive results in up to 40% of the cases.

Case Management

More than 90% of patients can be managed at home with oral antimicrobials, minimal nursing care, and close medical follow-up for complications or failure to respond to therapy.

Antimicrobial Therapy For Treatment Of Typhoid Fever

Uncomplicated Typhoid Disease

Susceptibility: Fully Sensitive

	Medicine	Adult dose	Frequency	Duration
	ciprofloxacin po	500mg	twice a day	5-7days
or	ofloxacin po	400mg	once a day	5-7days

Susceptibility: Multidrug Resistant TB

	Medicine	Adult dose	Frequency	Duration
	azithromycin po	250-500mg	once a day	7 days
or	cefixime po	500-750mg	once daily	7-14 days

Complicated Typhoid Disease

Susceptibility: Fully Sensitive

	Medicine	Adult dose	Frequency	Duration
	ciprofloxacin po	500mg	twice daily	10-14 days
or	ofloxacin po	400mg	once a day	10-14 days

Susceptibility: Multidrug Resistant TB

	Medicine	Adult dose	Frequency	Duration
	azithromycin po	250-500mg	once a day	10-14 days
or	cefixime po	500-750mg	once daily	10-14days

Alternative Medicines

Medicine	Adult Dose	Frequency	Duration
Ceftriaxone iv	1g	once daily	10 – 14 days

Dehydration is uncommon in Typhoid fever; however, electrolyte imbalance, hypoglycaemia and hypokalaemia and hyponatremia frequently occur and need to be corrected using appropriate electrolyte solution. In cases where intestinal perforation is suspected surgery and parenteral nutrition may be required. In cases of moderate to severe dehydration, follow the guideline for treatment of dehydration.

Treatment of Carriers

An individual is considered to be a chronic carrier if he or she is asymptomatic and continues to have positive stool or rectal swab cultures for S. typhi a year following recovery from acute illness:

Medicine	Adult Dose	Frequency	Duration
ciprofloxacin po	750mg	twice daily	4 weeks

Ciprofloxacin can be used in children if the benefits outweigh the potential harms.

And/or:

Cholecystectomy if lithiasis is present
Treat schistosomiasis if present
Vi (virulence) antibody test useful to screen carriers