Puerperal Fever - Causal Organisms

Causal Organisms

The most common causative agents in inflammation of the inner lining of the uterus (this lining is known as the endometrium) are Staphylococcus aureus and Streptococcus spp.

Group A Streptococcus (abbreviated to GAS, or more specifically the Streptococcus pyogenes) is a form of Streptococcus bacteria responsible for most cases of severe hemolytic streptococcal illness. Other types (B, C, D, and G) may also cause infection. Group B Streptococcus (abbreviated to GBS, or more specifically Streptococcus agalactiae) usually causes less severe maternal disease.

Other causal organisms, in order of prevalence, include staphylococci, coliform bacteria, anaerobic bacteria, Chlamydia, Mycoplasma and very rarely, Clostridium welchii.

There are several strains of GAS. Some strains usually cause skin infections, they are more common in warm climates, and they usually cause local rather than systemic effects. Other strains, in particular Streptococcus pyogenes, attack the throat and cause severe infections. The human nasopharynx is the main reservoir of S. pyogenes, and infection is more common during winter, and it is rarely found in the normal vaginal flora. It is likely that most puerperal hemolytic infections arise from this reservoir in the patient or attendants.

Group B Streptococcus (Streptococcus agalactiae) causes pneumonia and meningitis in neonates and the elderly, with occasional systemic bacteremia. They can also colonize the intestines and the female reproductive tract, increasing the risk for transmission to the infant. The American College of Obstetricians and Gynecologists, American Academy of Pediatrics and the Centers for Disease Control recommend all pregnant women between 35 and 37 weeks gestation should be tested for GBS.