Superiority of acridine orange‐stained buffy coat smears for diagnosis of partially treated neonatal septicemia

Abstract

Early diagnosis of neonatal septicemia is a vexing problem because of its non-specific clinical picture. Many of the neonates with septicemia reaching a referral centre have already been exposed to antibiotics and their blood cultures are often sterile. Scarcity of studies evaluating acridine orange-stained buffy coat smears in detecting neonatal septicemia after administration of antibiotics prompted us to undertake this study. The population studied consisted of 34 cases of neonatal septicemia with positive blood cultures and/or positive buffy coat smears (of these 25 had a positive blood culture) and 25 neonates with a clinical course not suggestive of any infection. Venous blood was drawn for culture, preparation of buffy coat smears, blood counts and micro ESR. The culture and smears were repeated after administration of antibiotics for 48-72 h. Acridine orange stain was the most sensitive test and was significantly more sensitive than Gram's stain (p < 0.005). After the administration of antibiotics, acridine orange was significantly more sensitive than Gram's stain and blood culture (p < 0.05).

Clinical utility of acridine orange stained buffy coat smears

“…Clinical utility of acridine orange stained buffy coat smears Sir, In their recently published article, Mathur et al (1) highlighted the advantages of acridine orange (AO) stained buffy coat smears for the diagnosis of neonatal septicemia. The investigators evaluated A 0 staining of buffy coat smear in comparison with other tests for neonatal sepsis, before and 48-72 h after antibiotic treatment.…”

Use of Acridine Orange Leukocyte Cytospin Test in Diagnosis of Neonatal Sepsis

“…The early diagnosis of sepsis during the newborn period is an important problem because the early signs and symptoms of septicemia in term or preterm infants are usually non‐specific 1,2 . Examination of buffy coat smears stained with Gram, methylene blue or acridine orange (AO) stains or an acridine orange leukocyte cytospin (AOLC) test have been used as a rapid test for bacteremia 2,3 .…”

“…Examination of buffy coat smears stained with Gram, methylene blue or acridine orange (AO) stains or an acridine orange leukocyte cytospin (AOLC) test have been used as a rapid test for bacteremia 2,3 . However, studies evaluating AO‐stained smears in detecting neonatal sepsis are scarce 1–4 . In this present study, blood culture was accepted as gold standard, and the results of concentrated blood smears stained with AO and Gram stain were compared.…”

“…Of the 24 infants, nine (37.5%) were boys, 15 (62.5%) were girls and the age ranged from 12 h to 30 days (mean 10.89 ± 8.45 days). In 12 (50%) patients, various microorganisms were cultured from blood; enterococci, 3 Klebsiella pneumonia , 2 Escherichia coli , 2 coagulase‐negative Staphylococci, 1 Staphylococcus epidermidis , 1 Group A beta hemolytic streptococci, 1 enterocbacter 1 and non‐fermentative bacterium 1 . While bacteria were observed in 11 (91%) of 12 samples, which were prepared concentrated and stained with AO staining in the patients who were blood culture positive, bacteria were observed in two of the patients who were blood culture negative.…”

“…The AO‐stained buffy coat smear examination is a sensitive and specific test for detection of neonatal septicemia, even after exposure to antibiotics, when culture was sterile 1,3 . Kite et al 2 noted that the AOLC test gave the highest specificity and positive predictive accuracy, but was less sensitive than the neutrophil count, CRP assay or nitroblue tetrazolium (NBT) test.…”