Estimate the incidence and pattern of reactive thrombocytosis among febrile young infants with serious bacterial infection

Rohit Chib, Mohsin Rashid, Surinder Kumar


Background: Thrombocytosis or elevation in the peripheral blood platelet count to values >400,000/μL is common in infancy and childhood, occurring in 3 to 13% of children. The objective of study was to estimate the incidence and pattern of reactive thrombocytosis among febrile young infants with serious bacterial infections (SBIs).

Methods: The study was conducted in the Postgraduate Department of Pediatrics, G.B. Pant hospital, an associated hospital of Govt. Medical College Srinagar, which is a referral tertiary care hospital for the children of Kashmir valley. The study was a prospective non-randomized study conducted from April 2011 to March 2012. All infants of age 30-89 days admitted in hospital with rectal temperature >38C/100.4F without an apparent focus of infection on history and clinical examination were included in the study.

Results: The incidence of reactive thrombocytosis >4 lakh/mm3 in our study was 33 out of 39 (84.6%) in SBI versus 60 out of 110 (54.5%) in Non-SBI, which was statistically significant in SBI, p value < 0.05. Mean platelet count in urinary tract infections was 5.3 lakh/mm3, bacterial meningitis 5.2 lakh/mm3, occult bacteremia 4.9 lakh/mm3, pneumonia 4.7 lakh/mm3 and 3.9 lakh/mm3 across Non-SBI.

Conclusions: The incidence of reactive thrombocytosis >4 lakh/mm3 in our study was significantly higher in SBI (84.6%) than in Non-SBI (54.5%), p value < 0.05. Mean platelet count was highest in urinary tract infections followed by bacterial meningitis, occult bacteremia and pneumonia. So platelet count >4 lakh/mm3, reactive thrombocytosis, being simple and easy test to perform can be used for early prediction of SBI.


SBI, Platelets, Fever, Infant, Diagnosis

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