Mean age of the 18 patients included in the study was 23.72 d and only 33% were female. The anthropometrical and clinical characteristics were comparable between newborns in the case and the control groups (table I).
Table I Newborns’ charateristics
Parameters
|
Cases
|
Controls
|
p-value
|
Age (days)
|
23.11 ± 09.09
|
24.33 ± 01.32
|
0.33
|
Term of birth
|
38.22 ± 02.44
|
38.11 ± 01.90
|
0.69
|
Weight (g)
|
2706.67 ± 360
|
2811.11 ± 357
|
0.48
|
Length (cm)
|
46.78 ± 01.86
|
48.72 ± 02.14
|
0.08
|
Skull circonference (cm)
|
32.83 ± 01.12
|
34.11 ± 01.02
|
0.04
|
Calcemia (mg/l)
|
09.14 ± 0.54
|
09.34 ± 0.52
|
0.33
|
Phosphoremia (mg/l)
|
06.14 ± 0.49
|
06.39 ± 0.72
|
0.49
|
25-OH Vitamin D level (ng/ml)
|
05.40 ± 01.94
|
17.67 ± 05.54
|
<0.01
|
The duration of prodromal symptoms was between 1–4 days before admission. In addition to symptoms of upper respiratory infection, cough, wheezing, tachypnea, decreased suctioning, fever, apnea (two cases), hypotonia (two cases) were present. As a source of transmission, there were signs of upper respiratory tract infection in the parents/siblings. The duration of gestational period ranged from 33 to 41 weeks. Two babies were born with low birth weight and two others were born prematurely. All cases were fed with breast milk, and two infants were given supplementation with formula in addition to breast milk. Only 5 babies had passive smoking exposure among the newborns with LRTI. All newborns with LRTI presented vitamin D deficiency and 11.1% of controls had normal vitamin D status (Fig. 1). Median serum 25-OH vitamin D level was significantly lower in newborns with severe LRTI than in controls (6.4 ng/ml and 18.3 ng/ml respectively in cases and controls, p < 0.01). Table II presents the mothers’ characteristics. Median vitamin D level was 7.6 ng/ml (3.8–14.6) in mothers of cases and 21.5 ng/ml (9.9–30.1) for the controls’ mothers. There was a significant correlation between newborn’s serum vitamin D level and the mother’s one among case and control gs (cases: r = 0.88, p = < 0.01, controls: r = 0.77 p = 0.02). All newborns had normal calcium, phosphorus, and alkaline phosphatase levels. However, any mother did not receive adequate vitamin D supplementation during pregnancy. However, babies with vitamin D deficiency and their mothers were given vitamin D at the treatment dose. Two patients had Staphylococcus epidermidis in blood culture and one patient had Enterobacter cloaca in tracheal aspirate culture. Interstitial infiltration was detected on chest radiographs of patients with LRTI due to RSV. Echocardiography revealed secundum atrial septal defect (ASD) in two patients and patent foramen ovale (PFO) in one patient. All RSV antigen-positive infants were hospitalized in an isolated room. For the management of patients with LRTI, mechanical ventilation support, oxygen, TPN, iv fluid, antibiotic and β2-agonists were used. Two patients required advanced mechanical ventilation with High-Frequency Ventilation (HFO). Four patients required intubated mechanical ventilation during 3 to 11 days. This duration was inversely correlated to vitamin D level (r=-0.65 ; p = 0.02). Nine patients required nasal CPAP and total parenteral nutrition support was given to seven babies.
Table II Mothers’ characteristics
Parameters
|
Mothers of cases
|
Mothers of controls
|
p-value
|
Age (years)
|
30.89 ± 06.77
|
27.56 ± 05.43
|
0.33
|
Education level
primary school
middle school
high school
uneducated
|
33.33 %
22.22 %
22.22 %
22.22 %
|
33.33 %
22.22 %
22.22 %
22.22 %
|
1.00
|
Number of pregnancy
|
02.22 ± 0.97
|
02,33 ± 1,00
|
0.78
|
Number of attended prenatal visits
|
02.22 ± 0,97
|
02,33 ± 1,00
|
0.78
|
Level of exposition to smoking
|
55.55 %
|
33.33 %
|
0.56
|
Calcemia (mg/l)
|
09.30 ± 0.41
|
09.67 ± 0.48
|
0.08
|
Phosphatemia (mg/l)
|
06.36 ± 0.49
|
06.28 ± 0.44
|
0.93
|
25-OH Vitamin D level (ng/ml)
|
07.61 ± 3.68
|
20.31 ± 7.32
|
<0.01
|