Enteric fever (typhoid/paratyphoid)

The Salmonella group contains many members, most of which cause diarrhoeal diseases. They are aerobic, Gram-negative rods which are not normally present as commensals in the gut.

Typhoid and paratyphoid are caused by Salmonella typhi and Salmonella paratyphi (types A, B & C) respectively. They are often termed enteric fevers, producing systemic symptoms such as headache, fever, arthralgia.

Pathophysiology

• typhoid is transmitted via the faecal-oral route (also in contaminated food and water)

Features

• initially systemic upset as above
• relative bradycardia
• abdominal pain, distension
• constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid
• rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid

Possible complications include

• osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens)
• GI bleed/perforation
• meningitis
• cholecystitis
• chronic carriage (1%, more likely if adult females)