Clinical overview of phototherapy for neonatal hyperbilirubinaemia.

The most efficient emission spectrum of light for phototherapy is blue-green light emission diode light with peak emission at 478 nm. In the irradiance interval of phototherapy, the relationship between efficacy and irradiance is almost linear, and it is negatively related to the haemoglobin. The action sites of phototherapy are the extravascular compartment and cutaneous blood. The most immature neonates treated aggressively had not only a lower frequency of neurodevelopmental impairment than conservatively treated, but also greater mortality. Intermittent and continuous phototherapy are assumed to be equally efficient. Home-based fibreoptic phototherapy is effective and safe. Important progress is still occurring in phototherapy.

ABO haemolytic disease of the newborn: Improved prediction by novel integration of causative and protective factors in newborn and mother.

BACKGROUND AND OBJECTIVES: Prediction of haemolytic disease of the foetus and newborn (HDFN) caused by maternal anti-A/-B enables timely therapy, thereby preventing the development of kernicterus spectrum disorder. However, previous efforts to establish accurate prediction methods have been only modestly successful. MATERIALS AND METHODS: In a case-control study, we examined 76 samples from mothers and 76 samples from their newborns; 38 with and 38 without haemolysis. The IgG subclass profile of maternal anti-A and anti-B was determined by flow cytometry. Samples from newborns were genetically analysed for the A2 subgroup, secretor and FcγRIIa receptor alleles. RESULTS: Surprisingly, we found a correlation between the newborn secretor allele and haemolysis (p = 0.034). No correlation was found for FcγRIIa alleles. The A2 subgroup was found only in newborns without haemolysis. Unexpectedly, different reaction patterns were found for maternal anti-A and anti-B; consequently, the results were treated separately. For the prediction of haemolysis in A-newborns, the maternal IgG1 subclass determination resulted in an accuracy of 83% at birth. For B-newborns, an accuracy of 91% was achieved by the maternal IgG2 subclass determination. CONCLUSION: We improved the prediction of ABO-HDFN by characterizing maternal anti-A and anti-B by flow cytometry and we presented genetic traits in newborns with correlation to haemolysis. We propose a new understanding of A- and B-substances as immunogens that enhance the maternal immune response and protect the newborn, and we suggest that the development of ABO-HDFN is different when caused by maternal anti-A compared to maternal anti-B.

Prolonged rectal shedding of SARS-CoV-2 in a 22-day-old-neonate: a case report.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the novel coronavirus disease 2019 (COVID-19), which is characterized by a diverse clinical picture. Children are often asymptomatic or experience mild symptoms and have a milder disease course compared to adults. Rectal shedding of SARS-CoV-2 has been observed in both adults and children, suggesting the fecal-oral route as a potential route of transmission. However, only a few studies have investigated this in neonates. We present a neonate with a mild disease course and prolonged rectal SARS-CoV-2 shedding. CASE PRESENTATION: A 22-day old neonate was admitted to the hospital with tachycardia and a family history of COVID-19. The boy later tested positive for COVID-19. His heart rate normalized overnight without intervention , but a grade 1/6 heart murmur on the left side of the sternum was found. After excluding signs of heart failure, the boy was discharged in a habitual state after three days of admission. During his admission, he was enrolled in a clinical study examining the rectal shedding of SARS-CoV-2. He was positive for SARS-CoV-2 in his pharyngeal swabs for 11 days after initial diagnosis and remained positive in his rectal swabs for 45 days. Thereby, the boy remained positive in his rectal swabs for 29 days after his first negative pharyngeal swab. CONCLUSIONS: The presented case shows that neonates with a mild disease course can shed SARS-CoV-2 in the intestines for 45 days. In the current case, it was not possible to determine if fecal-oral transfer to the family occurred, and more research is needed to establish the potential risk of the fecal-oral transmission route.

The Prevalence and Clinical Implications of Rectal SARS-CoV-2 Shedding in Danish COVID-19 Patients and the General Population.

Background: SARS-CoV-2 has resulted in a global pandemic since its outbreak in Wuhan, 2019. Virus transmission primarily occurs through close contact, respiratory droplets, and aerosol particles. However, since SARS-CoV-2 has been detected in fecal and rectal samples from infected individuals, the fecal-oral route has been suggested as another potential route of transmission. This study aimed to investigate the prevalence and clinical implications of rectal SARS-CoV-2 shedding in Danish COVID-19 patients. Methods: Hospitalized and non-hospitalized adults and children who were recently tested with a pharyngeal COVID-19 test, were included in the study. A rectal swab was collected from all participants. Hospitalized adults and COVID-19 positive children were followed with both pharyngeal and rectal swabs until two consecutive negative results were obtained. RT-qPCR targeting the envelope gene was used to detect SARS-CoV-2 in the samples. Demographic, medical, and biochemical information was obtained through questionnaires and medical records. Results: Twenty-eight of 52 (53.8%) COVID-19 positive adults and children were positive for SARS-CoV-2 in rectal swabs. Seven of the rectal positive participants were followed for more than 6 days. Two of these (28.6%) continued to test positive in their rectal swabs for up to 29 days after the pharyngeal swabs had turned negative. Hospitalized rectal positive and rectal negative adults were comparable regarding demographic, medical, and biochemical information. Furthermore, no difference was observed in the severity of the disease among the two groups. Conclusions: We provided evidence of rectal SARS-CoV-2 shedding in Danish COVID-19 patients. The clinical importance of rectal SARS-CoV-2 shedding appears to be minimal.

[An update on unconjugated neonatal hyperbilirubinaemia in Denmark].

Approximately 60% of term newborn infants are jaundiced during the first week of life, which is caused by unconjugated bilirubin. Bilirubin encephalopathy is seen with severe hyperbilirubinaemia, when unbound bilirubin crosses the blood-brain barrier. The chronic form is called kernicterus spectrum disorder. To avoid this devastating condition, the treatment of choice for neonatal hyperbilirubinaemia is phototherapy, which is most efficient with LED light of 478-nm wavelength. In this review, we argue, that a systematic approach to hyperbilirubinaemic infants as well as surveillance of extreme neonatal hyperbilirubinaemia is highly important.

Extreme neonatal hyperbilirubinemia and kernicterus spectrum disorder in Denmark during the years 2000-2015.

OBJECTIVE: To determine the incidence and etiology of extreme neonatal hyperbilirubinemia, defined as total serum bilirubin (TSB) ≥450 µmol/L, and kernicterus spectrum disorder (KSD) in Denmark between 2000 and 2015. STUDY DESIGN: We identified all infants born between 01.01.2000 and 31.12.2015 with TSB ≥450 µmol/L, ratio of conjugated to TSB <0.30, gestational age ≥35 weeks, and postnatal age ≤4 weeks, using Danish hospitals' laboratory databases. RESULT: We included 408 infants. The incidence of extreme neonatal hyperbilirubinemia among infants with gestational age ≥35 weeks was 42/100,000 during the study period with a seemingly decreasing incidence between 2005 and 2015. Twelve of the 408 infants developed KSD, (incidence 1.2/100,000) Blood type ABO isohemolytic disease was the most common explanatory etiology. CONCLUSIONS: Our study stresses the importance of a systematic approach to neonatal jaundice and ongoing surveillance of extreme neonatal hyperbilirubinemia and KSD.

Extreme neonatal hyperbilirubinemia, acute bilirubin encephalopathy, and kernicterus spectrum disorder in children with galactosemia.

BACKGROUND: Galactosemia has not been recognized as a cause of extreme neonatal hyperbilirubinemia, although growing evidence supports this association. METHODS: In a retrospective cohort study, we identified children with galactosemia due to GALT deficiency using the Danish Metabolic Laboratory Database. Among these, we identified children with extreme neonatal hyperbilirubinemia or symptoms of ABE. Extreme neonatal hyperbilirubinemia was defined as maximum total serum bilirubin (TSBmax)) level ≥450 µmol/L and a ratio of conjugated serum bilirubin/TSB <0.30. RESULTS: We identified 21 children with galactosemia (incidence:1:48,000). Seven children developed extreme neonatal hyperbilirubinemia (median [range] TSBmax level: 491 [456-756] µmol/L), accounting for 1.7% of all extreme neonatal hyperbilirubinemia cases. During the first 10 days of life, hyperbilirubinemia was predominantly of unconjugated type. Four children developed symptoms of intermediate/advanced ABE. One additional child had symptoms of intermediate/advanced ABE without having extreme neonatal hyperbilirubinemia. On follow-up, one child had KSD. CONCLUSIONS: Galactosemia is a potential cause of extreme neonatal hyperbilirubinemia, ABE, and KSD. It is crucial that putative galactosemic children are treated aggressively with phototherapy to prevent ABE and KSD. Thus it is important that galactosemia is part of the work up for unconjugated hyperbilirubinemia.