1 Background

Neonatal sepsis is a syndrome characterized by systemic signs of infection [1,2,3].

The organisms are most associated with early onset neonatal sepsis range from gram positive and negative bacteria [4, 5].

Red cell distribution width (RDW) has been classically used as a screening index for iron deficiency anemia. Neonatal sepsis (NS) remains a significant contributor to morbidity and mortality [5].

The need for accurate biomarkers to aid in the timely and accurate diagnosis of NS, thus remains as important as issue. RDW is associated with inflammatory markers such as C-reactive protein (CRP) [6, 7].

The need for accurate biomarkers to aid in the timely and accurate diagnosis of Neonatal sepsis (NS) thus remains as important as ever. The study aimed to determine RDW with positive blood culture of neonatal sepsis.

2 Methods

2.1 Study settings and population

This was a descriptive laboratory-based study, conducted during the period from January to September 2023, performed in Obstetrics and gynecology Hospitals in Sudan including Gaafar Ibnauf Children’s, AL- Baraa, Fedeal Hospitals, from December 2022 to April 2023. The study population was term neonates aged from 1 to 28 days with culture positive proven neonatal sepsis admitted to NICU. Inclusion criteria included neonate age from one day to 28 days, diagnosed as early onset neonatal sepsis, while exclusion criteria included neonates, from 1 to 28 days not diagnosed as neonatal sepsis.

Study group was selected according to diagnosis as early onset neonatal sepsis, sample size included 244 study populations collected during the study period.

2.2 Study procedure

Blood conventional culture included sample of 2 ml of blood collected by senior nurse in 2 containers. The first one contained brain heart infusion media with sodium polysulfide as anticoagulant for aerobic organism and the second one contained thiosulfate growth media for an aerobic organism. The incubation period was 24 h initial culture, 3 days mid culture and 7-day last culture [8, 9].

For isolation of candida, we used Sabouraud dextrose agar (SDA) as selective culture media for only selected patients.

Gram’s staining technique was used [10]. Biochemical tests performed for primary and secondary tests for Gram positive cocci included Catalase test [11], Coagulase test [12], DNase test [13], Mannitol Salt Agar [14].

For Primary and secondary tests for Gram Negative bacilli biochemical tests included Oxidase Test [15], Kliglar iron agar (KIA) [16], Urease Utilization Test [17], Indole Test [18], Citrate utilization test [19], Motility Test [20, 21]. Also, complete blood count (CBC) was done using automated analyzer. Normal range: WBCs (6000 to 20,000/mm3), PLT (150 × 103 to 450 × 103 /mcL), RDW (15.5 ± 2.5%) [22].

3 The RDW was categorized in 3 group, Group (1): minimum 17%, Group (2): average 18–19%, and Group (3): maximum than 20%

3.1 Statistical analysis

Structured questionnaire has been used to gather data. Information included age of mother, antenatal care, antibiotic use during pregnancy, baby gender, symptoms and signs of participant, medical history, and laboratory culture isolation result. Data was analyzed by using SPSS, ver. 23. Frequency tables were constructed and test of significant was applied. The values considered as statistically significant when the p value < 0.05 at confidence level of 95%. Data was presented in form of cross tabulation, tables which were presented in the form of graphs for each variable in the objectives of the study.

4 Results

This study was conducted to determine red cell distribution width (RDW) with positive blood culture of neonatal sepsis, 244 blood proven in EDTA continuer for CBC tests and blood culture samples diagnosed as neonatal sepsis at different Khartoum hospitals participated in this study between January and April 2023.

The study population had their gender 126 (51.6%) were males and 118 (48.4%) subjects were females, as demonstrated in Table 1.

Table 1 Frequency of sociodemographic factors (Baby gender, age of mother, antibiotic use during pregnancy)
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The study showed the cultured organism was isolated as following: according to the percentage of organism from highest to lowest, first 95 (38.93%) was Staphylococcus aureus, next 70 (28,6%) were Candida Spp, After that 28 (11.48%) then Pseudomonas ssp, then 27 (11.07%) were Klebsiella ssp, 16 (6.56%) were Escherichia coli, after that 6 (2.46%) were Enterococcus feacalis and finally 2 (0.82%) were Listeria monocytogenes, Table 2.

Table 2 Result of isolated cultured organism
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The result of RDW was categorized in 3 group, Group (1): minimum 17%: represents 107 (43.8%). Group (2): average 18–19% represents 96 (39.34%), and Group (3): maximum than 20% represent 41 (16.8%), demonstrated in Table 2.

The study showed there was insignificant correlation between isolation result and gender group of neonates, p value (0.076), Out of 126 male and 118 female the most organism is Staphylococcus aureus demonstrated in Table 3.

Table 3 Statistical significance between the gender and result of isolation
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The results of isolated organisms showed there was significant correlation between RDW% and result of isolation p value (0.000) demonstrated in Table 4.

Table 4 Statistical significance between RDW% and result of isolation
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The study showed there was insignificant correlation between RDW% and gender p value (0.202) demonstrated in Table 5.

Table 5 Statistical significance between RDW% and gender
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5 Discussion

A total of (244) patient babies with blood culture positive diagnosed as early onset neonatal sepsis who full filled the eligible criteria were enrolled in the study.

Gender distribution among the studied group revealed that (51.6%) were males and (48.4%) were females and this distribution of result agree with previous studies showed (60%) was male and (39%) was females [23].

In this study the most cultured organism was isolated as first was Staphylococcus aureus 95 (38.9%) followed by Candida ssp 70 (11%), and finally 2 (0.8%) were Listeria monocytogenes. A previous report agreed with the current findings, which is in consistent with the present study [24,25,26].

Other similar studies revealed that mean RDW was significantly higher among neonates with septic shock which are in consistent with the present study (18.53 ± 2.63%) [27,28,29].

Red cell distribution width to platelet ratio (RPR) has been reported as a useful inflammatory marker and prognostic indicator of adult inflammatory diseases. RPR may be used in diagnosis of early onset neonatal sepsis and may be a good alternative to other tools as a readily available biomarker [30].

Red blood cell distribution width to platelet ratio calculation is practical, inexpensive, and based on CBC-derived data. Calculation of RPR along with CBC can aid in the diagnosis of sepsis and estimation of outcome [31, 32].

RDW is independent predictors of prognosis and help in predicting the prognosis of preterm with neonatal sepsis in the early stage [33].

5.1 Study limitation

There data available in the study is very little. The sample size is small.

6 Conclusion

The study concluded that RDW are quickly and easily available parameters in all hospitals and especially in those in developing countries and they can be used by clinicians as cost-effective markers to predict the outcome in neonatal sepsis syndrome. The study recommend that more studies should be performed to evaluate the relationship between other hematological parameters or biomarkers with neonatal sepsis.