Interpretation
The present study emphasises the importance of vital signs and the early recognition of infection for preventing a rapid infectious sequala. The regression analysis of the characteristics and clinical course of the 13 women whose pregnancy had been complicated with STSS and who were admitted to the ICU revealed that tachycardia as the first presenting sign and delay in providing antibiotic treatment were independent risk factors for severe infection that led to STSS and hospitalisation in the ICU. It is noteworthy that a high level of suspicion of STSS is always warranted because no single risk factor, specific clinical sign, or laboratory point to this serious complication. Since vital signs have been demonstrated as being of the utmost clinical importance with regard to infection prediction in cases of delay, the implementation of simple wearable technologies with the capacity for continuous monitoring of vitals should be considered.
Although GAS is a highly virulent pathogen, it has almost no resistance toward chemo-prophylactic agents commonly administered in labour. It was interesting to trace the natural history of patients diagnosed with GAS who received antimicrobial prophylaxis regardless of whether the source of infection was or was not known. The impact of antimicrobial prophylaxis has been described extensively by many authors as prolonging the disease-free state/latency period {Mercer, 1997, Antibiotic therapy for reduction of infant morbidity after preterm premature rupture of the membranes. A randomized controlled trial. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network}. The eventual reduction in disease morbidity would be logical in this case, but it has yet to be proven. A large number of these individuals in the current work had received antimicrobial prophylaxis prior to undergoing a caesarean delivery, which could be a potential confounder. However, as stated in the results, the rates of caesarean delivery-related GAS infection were similar to its relative proportion in vaginal deliveries over the entire study period at the authors’ institution. Assuming that antimicrobial prophylaxis at labor may indeed reduce the risk of severe infection, and specifically STSS, the calculated number needed to treat one case of STSS by antimicrobial prophylaxis is 14,375 women. The seasonality of the incidence of GAS has been reported before (15) in a large epidemiologic survey from 1975–2012. Those authors reported a significant seasonal variation in the incidence of GAS infections. They noticed a mid- to late-winter increase from January to April in both incidence and severity of infection (the diagnoses of sepsis, STSS, and death) among children and adults (38% vs 16%, respectively, P< 0.01). Puerperal sepsis was diagnosed in only eight of their study women, precluding the drawing of any specific inferences for that subgroup. The current study had similar results, with most of the identified cases of GAS infection having occurred between October and April, although there was no significant correlation between specific emm-type and infection severity or seasonality.