Use of serum procalcitonin as a marker of bacterial infection in infants presenting with acute diarrhea

ABSTRACT

Bacterial infection may be a causative factor in some cases of infantile diarrhea, and can cause sepsis with acute organ dysfunction, which is considered a major threat to life. There is a need for an effective and accurate biochemical marker to support or exclude the diagnosis of bacterial infection as routine laboratory tests lack both sensitivity and specificity in correctly identifying which patients should receive antibiotics, and most confirmatory microbiological test results are not available for 24 hours. The present study aimed to determine plasma PCT level in infants with acute diarrhea to evaluate its tote as a marker of bacterial infection and hence to detect cases that may benefit from early institution of antimicrobial drugs. This study was carried out in the gastroenterology unit, and the intensive care wilt of Pediatric department, Tanta faculty of medicine, and started at January 2002, and ended by July 2002. It was conducted on 53 infants [35 ware males and 18 females], and their ages ranged from 6-24 months. The following investigations were made immediately alter admission 1- Complete blood count, 2- Blood urine, and stool bacterial aerobic and anaerobic cultures [culture of ear discharge was done in cases with otitis media], 3-Cerebrospinal fluid [CSF] examination and culture were done in cases with positive blood cultures, 4- Serum C- reactive protein [CRP] and plasma concentration of procalcitonin [PCT], and 5- Chest X-ray. The patients warn classified into 2 groups, those who have negative microbiological cultures, 31 cases [group I], and others with positive cultures, 22 cases [group II]. It was found that in infants proved to have bacterial infection with positive cultures had significantly elevated serum PCT and CRP mole than the infants who had negative bacterial cultures [1.41 +/- 0.64, and 48.18 +/- 17.8 versus 0.53 +/- 0.23 and 5.6 7 +/- 2.47 respectively, p < 0.001]. Group II had significantly higher total leukocytic count [TLC] and lower platelet count than group I [13.5 +/- 3.58, and 161.41 +/- 79.56 versus 5.41 +/- 1.082 and 247.35 +/- 79.033 respectively]. We found that no significant difference between cases with and without bacteremia as regard to TCL, CRP, and PCT, but platelet count was significantly lower in cases of bacteremia than in others with no bacteremia [t=3.72 and p =0.001]. Serum PCT levels were found to be correlated significantly with the duration of diarrhea in infants proved to have bacterial growth on different cultures, but not with TLC, platelet count, or CRP. We concluded and recommended that1] PCT is a useful indicator of bacterial infection among cases presenting with acute infantile diarrhea in which bacteria may be the causative underlying factor or complicating such cases, so it can help in selecting cases that need lipid administration of antibacterial agents. 2] PCT should be added to the required laboratory investigations as CRP, TLC, and platelet count in all cases of acute infantile diarrhea suspected to have bacterial etiology or in those who are critically ill, because most microbiological tests need time and couldn't help in emergency situations