Symptoms

• Pyelonephritis is infection of the kidney. Fever nearly always accompanies this infection. Other symptoms are pain in the side of the lower back, nausea, vomiting, burning or pain when urinating, urgency and frequency of urination, and pain above the pubic area.
  
  

Causes

• Although E. Coli bacteria are responsible for pyelonephritis about 90 percent of the time, group B streptococcus is the culprit in a small number of cases.
  
  Group B strep often colonizes in the vaginas of healthy women, and in the gastrointestinal tracts of both men and women, without causing infection. Between 15 and 45 percent of women carry the bacteria. Because infants can become infected during pregnancy or delivery, and infection can be fatal for newborns, group B strep is a concern for pregnant women.
  
  Underlying disease, abnormality of the urinary system and pregnancy are some things that can trigger infection to develop among adults. When a bladder or urinary tract infection occurs, the bacteria can travel up the ureter and invade the kidney, causing pyelonephritis.
  
  Among young and middle-aged adults, women are more likely to get infections from group B strep. Among elderly people, the infection is often linked to congestive heart failure and being bedridden, with urinary tract infection being a common manifestation.
  
  

Severity

• Pyelonephritis can be fatal if secondary conditions develop. Secondary conditions include emphysematous pyelonephritis (a severe form of infection that causes gas formation within the kidney), abscess or sepsis.
  
  

Treatment

• Penicillin and ampicillin are the antibiotics of choice for group B strep infections. Cefazolin, erythromycin, and clindamycin are also used to treat it.
  
  The majority of patients are admitted to a hospital for treatment for pyelonephritis. In severe cases, surgery on the kidney might be necessary.