[Serum procalcitonin: a reliable tool for the diagnosis and follow-up of neonatal bacterial infections in Sub-Saharan Africa]

Abstract

Background and aim: Neonatal infection (NNI) is a public health problem in developing countries where pediatricians and specifically neonatologists encounter many diagnostic difficulties. Having a precise and easily measurable biological marker, with a high sensitivity and a high negative predictive value, that can rapidly detect NNI, remains a great challenge. The aim of this study was to determine the place of serum procalcitonin (PCT) in the diagnosis and follow-up of bacterial NNI in resource-limited contexts.

Methods: We carried out a cross-sectional study from October 2009 to February 2010 at the Mother and Child Centre of the Chantal Biya Foundation, Cameroon. We included all neonates born at term, suspected of NNI, and hospitalized in the Neonatal Care Unit of the aforementioned centre during the study period. We measured PCT levels at entry and 48h later, and determined its sensitivity, specificity, and positive and negative predictive values.

Results: Twenty-five out of the 98 neonates enrolled presented with a confirmed diagnosis of NNI. PCT was positive in 92.4% of cases. Contrariwise, serum C-reactive protein was positive in 84.6% of patients with a cut-off point at 6mg/L, and remained positive in only 38.4% of cases when the cut-off point was raised to 20mg/L. The sensitivity, specificity, and positive and negative predictive values of PCT were 96.0%, 77.7%, 85.3%, and 93.3%, respectively. Six deaths were recorded, five of which exhibited very high PCT levels (≥10ng/mL). All neonates with negative PCT levels had a good clinical outcome as none of them died. If PCT were to be considered as a diagnostic tool of NNI, only 43 (43.9%) neonates would have benefited from a justified antibiotic therapy exceeding 48h, with a significant reduction in duration of hospitalization (9.1±3.3 vs 5.1±4.6 days; P<0.05).

Conclusion: PCT may be an early and reliable indicator of bacterial NNI. Its course throughout hospitalization may reflect the therapeutic response, and elevated levels of PCT may be highly suggestive of a poor clinical prognosis. PCT could therefore serve as a useful tool for the screening, diagnosis, and follow-up of neonates suspected of bacterial NNI in resource-poor settings.