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.