[Clinical value and multiple risk factors analysis of sputum culture for fungus in neonates].

OBJECTIVE

In recent years, the incidence of fungal infection in neonates has been risen year by year, but there are no widely accepted criteria to identify the clinical significance of the culture results of secretion from lower respiratory tract at present. The aim of the present study was to understand the clinical value and risk factors of fungal infections as suggested by sputum culture in neonates, which may help clinicians to diagnose and treat the neonates with fungal infection of respiratory tract.

METHODS

One hundred and forty nine neonates with positive sputum culture results and suffered from pneumonia hospitalized from October, 2002 to May, 2005 in Children's Hospital of Chongqing Medical University were analyzed. The cases were divided into three groups according to the results of sputum culture. Forty cases who were only fungus positive were enrolled into the fungal group, 30 cases who were positive for both fungus and bacteria were classified into the mixed group, and the remaining 79 cases who were positive for bacteria only were recruited into bacterial group. Several clinical characteristics of neonates from the three groups were compared retrospectively. t test, chi-square test and Logistic regression analysis were used for statistical analyses.

RESULTS

Seventy of the 149 patients (47.0%) had fungal infections. Candida was the main genus cultured from sputum. Rate of resistance to fluconazole was 25.7% (9/35). Candida albicans was the most common strain, which was found in 56.9% of cases whose sputum culture was positive for fungi. In fungal group (n = 40), mixed group (n = 30) and bacterial group (n = 79), white blood cell count were (10.3 +/- 3.5) x 10(9)/L (11.7 +/- 5.2) x 10(9)/L and (14.4 +/- 10.5) x 10(9)/L, respectively, F = 3.78, P = 0.03, with neutrophil count (5.1 +/- 3.3) x 10(9)/L, (7.4 +/- 4.7) x 10(9)/L and (9.0 +/- 7.4) x 10(9)/L, respectively, F = 5.50, P = 0.01. Ratios of risk factors were as follows:for preterm infant, 32.5% (13/40), 20% (6/30) and 12.7% (10/79), chi(2) = 6.68, P = 0.04; for antepartum glucocorticoid used, 10.0% (4/40), 6.7% (2/30) and 0% (0/79), P = 0.01; for trilogy of antibiotics used, 10.0% (4/40), 16.7% (5/30) and 2.5% (2/79), P = 0.02; for therapy with carbapenems (Carbenin or Tienam), 32.5% (13/40), 63.3% (19/30) and 17.7% (14/79), chi(2) = 21.26, P = 0.00. There was significant difference among the three groups in the above factors respectively. Using the sputum culture results with or without fungus as the dependent variable, multivariate logistic regression showed that preterm infant (X(1)) and the therapy with carbapenems (X(2)) suited the best regression equation: Logistic (SCF) = beta(0) (0.12) + 1.63X(1) + 1.20X(2) (chi(2) = 43.04, P < 0.05).

CONCLUSION

Fungal growth in sputum culture in the neonates with pneumonia was common, Candida was the main genus, and Candida albicans was the most common one. Prematurity and the therapy with carbapenems were the most important independent risk factors associated with fungal growth in culture of sputum specimen from neonates.