Kidney infections (Table 64.6)

Aetiology

Renal infections arise in the following ways.

  Haematogenous infection from a primary site in the tonsils or carious teeth, or from cutaneous infections, particularly boils or a carbuncle. Renal tuberculosis occurs by blood-borne spread from lymph nodes in the neck, chest or abdomen.

  Ascending infection in the urinary tract is the most common route, and it is most likely to occur when there is vesicouretenic reflux. Urinary stasis and the presence of calculi are common contributory factors.

     Bacteriology. Escherichia coli and other Gram-negative organ­isms are commonly responsible. When Streptococcus faecalis is present it is usually accompanied by other organisms. In E. coli and streptococcal infections the urine is acid. Proteus sp. and staphylococci split urea, forming ammonia which makes the urine alkaline and promotes the formation of calculi.