The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong.

INTRODUCTION: Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM. METHODS: The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling. RESULTS: In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years. CONCLUSION: The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Intracranial haemorrhage among Chinese children with immune thrombocytopenia in a Hong Kong regional hospital.

OBJECTIVE: To evaluate potential risk factors, presenting symptoms, management, and outcomes of intracranial haemorrhage in Chinese children with immune thrombocytopenia managed in a regional hospital. DESIGN: Retrospective case series. SETTING: A regional hospital in Hong Kong. PATIENTS: All paediatric patients with immune thrombocytopenia complicated by intracranial haemorrhage in the period January 1996 to December 2009. RESULTS: Nine episodes of intracranial haemorrhage were reported in eight patients (aged 0.9 to 19 years) with immune thrombocytopenia; three of the patients had acute immune thrombocytopenia and the other five had chronic immune thrombocytopenia. Intracranial haemorrhage occurred as early as the initial presentation with immune thrombocytopenia (n=2) and as late as up to 5 years after the diagnosis. The median platelet count at the time of intracranial haemorrhage was 12 x 10(9) /L (<10 x 10(9) /L [n=4]; 10-20 x 10(9) /L [n=2]; >20 x 10(9) /L [n=3]). The bleeding was considered spontaneous in six episodes, while head trauma (n=2) and vascular malformation (n=1) were identified in three patients with mild-to-moderate thrombocytopenia (42-82 x 10(9) /L) at the time of the bleed. Headache and mucosal bleeding were the commonest presenting symptoms (n=5). All patients received multimodal treatment after diagnosis of intracranial haemorrhage, and included platelet transfusion (n=8), intravenous immunoglobulin (n=6), methylprednisolone (n=4), and splenectomy (n=4); three individuals underwent neurosurgical interventions. One (11%) patient died of posterior fossa bleeding and one (11%) had neurological sequelae. All survivors achieved remission of their immune thrombocytopenia with a median follow-up of 5.3 years. CONCLUSION: Intracranial haemorrhage can occur anytime during the course of immune thrombocytopenia. A high index of suspicion for intracranial haemorrhage should be maintained during follow-up, as favourable outcomes can be achieved after early and vigorous interventions.

Uses and abuses of paediatric electroencephalography.

OBJECTIVE: To investigate whether requests for standard paediatric electroencephalograms accord with guideline recommendations, subsequent changes in clinical management according to reported results, and extent to which the service meets waiting time targets. DESIGN: Case series. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients aged less than 18 years who underwent electroencephalography between December 2009 and February 2010. MAIN OUTCOME MEASURES: Appropriateness of the electroencephalogram request and the impact of its findings on clinical management. RESULTS: A total of 109 patients were recruited, but requests for standard electroencephalograms were considered 'inappropriate' with respect to guidelines in 44% of the patients, of which 50% were made to diagnose 'funny turns'. The standard electroencephalogram contributed to the diagnosis or management in only 28% of patients. In all of the latter, the request for an electroencephalogram had been appropriate. Nonspecialists made referrals for 86% of the patients. Inadequate information was provided in 66% of the requests. Standard electroencephalograms were performed within guideline targets, the wait being less than 4 weeks in 95% of requests. CONCLUSION: An effective electroencephalogram service was being provided, though abuses were common. These were mainly because of misconceptions regarding the role and limitations of standard electroencephalograms. Through an educative, non-confrontational approach, and with time to explain guideline recommendations to clinicians, sustainable change in practice could be achieved so as to benefit patients, clinicians, and service provision.

Frequency of developmental dysplasia of the hip in breech-presented Chinese neonates in Hong Kong.

OBJECTIVES. To clarify the use of ultrasonography by determining the frequency of developmental dysplasia of the hip among breech-presented Chinese neonates in Hong Kong. DESIGN. Prospective case series. SETTING. Regional hospital, Hong Kong. PATIENTS. All breech-presented Chinese neonates born during January 2008 to June 2009 were included (except premature neonates). They were examined clinically from birth till the age of 1 year. Ultrasound of the hips was performed at the age of 2 weeks, and X-ray of the pelvis at the age of 1 year. RESULTS. A total of 209 breech-presented neonates were born during the study period; 110 neonates completed all necessary investigations and follow-up. Among the latter, there were three neonates with developmental dysplasia of the hip warranting treatment, which amounted to a frequency of 2.7%. CONCLUSION. Developmental dysplasia of the hip among breech-presented Chinese babies is only slightly less common than in corresponding populations in other regions in the world. Since early diagnosis is important, ultrasonography screening in high-risk cases such as those with breech presentation may be useful.

Reversible posterior leukoencephalopathy syndrome in Chinese children induced by chemotherapy: a review of five cases.

This is a retrospective review of the clinico-radiological features and neurological outcomes of reversible posterior leukoencephalopathy syndrome episodes in Chinese cancer children receiving chemotherapy in a regional hospital in Hong Kong from 1998 to 2008. Five children (3 males and 2 females) with a mean age of 7 years were identified, four of whom had acute lymphoblastic leukaemia and one had a central nervous system germ cell tumour. Presenting symptoms included seizures (100%), altered mental function (100%), headache (40%), and visual disturbance (60%). The mean systolic blood pressure at presentation was 158 mm Hg. Approximately 80% had typical radiological features of reversible posterior leukoencephalopathy syndrome. All showed complete recovery after the acute stage, but one subsequently developed epilepsy. Two patients ultimately died of refractory malignant disease. Two others were followed up for a mean of 6 years, and remained neurologically normal. This report was the first case review documenting reversible posterior leukoencephalopathy syndrome in Chinese cancer children. The clinico-radiological features and neurological outcomes were similar to those reported in western series. Early recognition of the syndrome is important to facilitate appropriate treatment. The central nervous system damage may not be reversible and thus long-term follow-up is warranted.

Complete recovery from acute encephalopathy of late-onset ornithine transcarbamylase deficiency in a 3-year-old boy.

Ornithine transcarbamylase deficiency is the commonest urea cycle disorder which is transmitted in X-linked inheritance. It is mainly characterized in males by acute encephalopathy and hyperammonaemia with fatal outcomes in both classical neonatal and late-onset types. We report a 3-year-old healthy Hong Kong Chinese boy who presented with acute encephalopathy and coma after three days of gastroenteritis. He had no focal neurological deficit and brain CT imaging was normal. His plasma ammonia (54 micromol/L) and glutamine (747 micromol/L) concentrations were normal. The only biochemical abnormalities detected were marked orotic aciduria (700 micromol/mmol creatinine) and elevated urinary uracil. He regained consciousness spontaneously after three days under intensive care with parenteral fluid therapy. He recovered completely without any neurological deficits. Five months after discharge, urinary uracil concentration remained elevated despite normalized orotic acid concentration. Finally, ornithine transcarbamylase deficiency was diagnosed by DNA analysis. A missense mutation of arginine-to-glutamine substitution on amino acid 277 (p.R277Q) was revealed to be a late-onset mutant. Our case strengthens the argument that in any child with coma or acute encephalopathy of undetermined cause, genetic analysis of the OTC gene and the measurement of urinary uracil concentration remain the most reliable indicators of late-onset OTCD during acute and even quiescent phases. Existing neonatal screening programmes for inheritable metabolic disorders fail to detect late-onset variants. Therefore, a high clinical suspicion is a key to correct and timely diagnosis, especially in those patients with atypical presentations.

Incidence of neonatal chlamydial conjunctivitis and its association with nasopharyngeal colonisation in a Hong Kong hospital, assessed by polymerase chain reaction.

OBJECTIVES: Using polymerase chain reactions, this study aimed to evaluate the incidence of neonatal chlamydial conjunctivitis in our region of Hong Kong and explore any association between such conjunctivitis and nasopharyngeal colonisation with Chlamydia trachomatis. DESIGN: Prospective epidemiological study. SETTING: Regional hospital, Hong Kong. PATIENTS: Consecutive patients with neonatal conjunctivitis presenting to our hospital were recruited from May 2004 to April 2005 inclusive. Both eyes were investigated separately for Chlamydia trachomatis by polymerase chain reaction, direct immunofluorescent assay, and cell culture by two assigned ophthalmologists. Neonates diagnosed to have ocular Chlamydia trachomatis infection were subjected to additional nasopharyngeal investigations. Complete sets of ocular and nasopharyngeal investigations were also undertaken 1 week after oral erythromycin treatment to confirm complete eradication of Chlamydia trachomatis. RESULTS: Of 192 patients with neonatal conjunctivitis, 24 were diagnosed to have chlamydial conjunctivitis. Fifteen of them had nasopharyngeal colonisation with Chlamydia trachomatis. Among the 20 neonatal chlamydial conjunctivitis patients that completed the follow-up study, one suffered treatment failure. None had clinically diagnosed systemic Chlamydia trachomatis infection 3 months after oral erythromycin. CONCLUSIONS: The incidence of neonatal chlamydial conjunctivitis in our region of Hong Kong was 4 in 1000 live births, of whom 63% had nasopharyngeal presence of Chlamydia trachomatis. Owing to the high rate of nasopharyngeal isolation and possibility of treatment failure, post-treatment ocular and nasopharyngeal polymerase chain reaction testing for Chlamydia trachomatis may be considered to confirm complete eradication.

Neonatal haemorrhagic conjunctivitis: a specific sign of chlamydial infection.

OBJECTIVE: To review the bacteriological causes and clinical features of acute neonatal conjunctivitis in a local paediatric centre. DESIGN: Retrospective review. SETTING: Paediatric unit of a regional hospital, Hong Kong. PATIENTS: All neonates who presented to Tuen Mun Hospital from 1 January 1996 to 31 December 2002 with persistent eye discharge and a positive eye swab culture. MAIN OUTCOME MEASURES: Clinical features of neonates with chlamydial and non-chlamydial conjunctivitis. RESULTS: Of 90 neonates with positive eye swab or conjunctival scraping cultures, Chlamydia trachomatis was the second most common (n=19, 21%) cause of acute neonatal conjunctivitis after Staphylococcus aureus (n=32, 36%). All of the neonates with chlamydial conjunctivitis were delivered vaginally: two of them had concomitant chlamydial pneumonia. Neisseria gonorrhoeae conjunctivitis was rare (n=1, 1%). None of the mothers of neonates with Chlamydia had any history of sexually transmitted disease. The timing of presentation, gestational age, birth weight, and sex of the neonates did not suggest a risk of chlamydial infection. Nonetheless haemorrhagic eye discharge had a specificity of 100% and positive predictive value of 100% for chlamydial infection. There were no adverse ophthalmological consequences or complications of pyloric stenosis in any neonate following treatment with oral erythromycin. CONCLUSIONS: Haemorrhagic eye discharge is a highly specific sign of neonatal chlamydial conjunctivitis. Early and prompt treatment with oral erythromycin is safe and effective.

Neonaticide, newborn abandonment, and denial of pregnancy--newborn victimisation associated with unwanted motherhood.

We report two cases of newborn death and two cases of near-miss newborn death. One neonate was strangled to death after delivery in the hospital and one died from lethal congenital malformations. The third was found on the verge of death after being abandoned in a dumpster. The fourth was rescued from the toilet bowl by the mother's boyfriend while the mother was in a state of panic. In the three cases where the infants' maternal identities were known, the women were all primiparous and aged 22, 13, and 17 years. The paternity was extramarital, incestuous, and concealed, respectively. Denial or concealment of pregnancy was present in all cases, but none of the women had any overt psychiatric manifestations at the time of delivery. Neonaticide and newborn abandonment are closely associated with denial of pregnancy, and are serious forms of childhood victimisation. Their occurrence in Hong Kong is poorly understood and no representative figures are available. A concerted effort among the health care, social work, and judicial professionals is needed to define the scope of the problem and devise preventive measures.

Fiber-optic sensor using a tandem combination of a multimode fiber and a self-pumped phase conjugator.

An interferometric sensing scheme using a multimode fiber and a self-pumped phase conjugator is proposed. The self-pumped phase conjugator corrects the distortion due to mode scrambling in the fiber and responds to any uniform optical phase change caused by environmental factors. A temperature sensor based on the proposed scheme is used to demonstrate the feasibility of the scheme.