An audit of COVID-19 death reporting in counties Cork and Kerry, Ireland, winter 2021-2022

BACKGROUND

In Ireland, a 'COVID-19 death' is defined as any death in which the decedent was COVID-19 positive and had no clear alternative cause of death unrelated to COVID-19, a definition based on World Health Organization guidance.

AIMS

The objectives of this audit were to determine the proportion of COVID-19 deaths notified in the Cork/Kerry region of Ireland during winter 2021-2022 which adhered to this national definition, and to determine whether COVID-19 was deemed to be the primary cause of death, or a contributory or incidental factor.

METHODS

A review of all deaths in individuals who were COVID-19 positive at the time of death notified to the Department of Public Health for Cork and Kerry between 22 November 2021 and 31 January 2022 was conducted to determine whether each death adhered to the national COVID-19 death definition. The clinical opinion on cause of death was obtained by contacting decedents' clinicians.

RESULTS

Sixty deaths in individuals who were COVID-19 positive at the time of death were notified to the Department in the study period. Of deaths notified as being due to COVID-19, COVID-19 was deemed the primary cause of death, a contributory factor or an incidental factor in 72.7%, 21.8%, and 5.5% of cases, respectively. Most (93.3%) notified deaths adhered to the national COVID-19 death definition.

CONCLUSIONS

The COVID-19 death definition in Ireland may require revision so it can distinguish between deaths caused by COVID-19 and those in which COVID-19 played a less direct role. The current COVID-19 mortality reporting system may also need updating to capture more clinical nuance.

A large outbreak of the Kappa mutation of COVID-19 in Cork, Ireland, April-May 2021

BACKGROUND

In May 2021, the B.1.617 variant of SARS-CoV-2 emerged in Ireland, and both Delta and Kappa sub-lineages were initially deemed variants of concern (VOCs) on a precautionary basis. We describe a large outbreak of SARS-CoV-2 B.1.617.1 (Kappa mutation) linked to a private gathering among third level students in Cork, Ireland.

METHODS

Surveillance data were available from the Health Service Executive COVID Care Tracker. The epidemiological sequence of infection for each new case in this outbreak was tracked and whole genome sequencing was requested on all linked cases. Enhanced public health control measures were implemented by the Department of Public Health HSE-South to contain onward spread of VOCs, including retrospective contact tracing, lengthy isolation and quarantine periods for cases and close contacts. Extensive surveillance efforts were used to describe and control onward transmission.

RESULTS

There were 146 confirmed SARS-CoV-2 cases linked to the outbreak. All sequenced cases (53/146; 36%) confirmed Kappa mutation. The median age was 21 years (range 17-65). The majority (88%) had symptoms of SARS-CoV-2 infection. There were 407 close contacts; the median was 3 per case (range 0-14). There were no known hospitalisations, ICU admissions or deaths. Vaccination data was unavailable, but the outbreak pre-dated routine availability of COVID-19 vaccines among younger adults in Ireland.

CONCLUSION

Enhanced public health control measures for new and emerging variants of SARS-CoV-2 may be burdensome for cases and close contacts. The overall public health benefit of enhanced controls may only become apparent when evidence on disease transmissibility and severity becomes more complete.

Amniotic band syndrome and limb body wall complex in Europe 1980-2019

Amniotic band syndrome (ABS) and limb body wall complex (LBWC) have an overlapping phenotype of multiple congenital anomalies and their etiology is unknown. We aimed to determine the prevalence of ABS and LBWC in Europe from 1980 to 2019 and to describe the spectrum of congenital anomalies. In addition, we investigated maternal age and multiple birth as possible risk factors for the occurrence of ABS and LBWC. We used data from the European surveillance of congenital anomalies (EUROCAT) network including data from 30 registries over 1980-2019. We included all pregnancy outcomes, including live births, stillbirths, and terminations of pregnancy for fetal anomalies. ABS and LBWC cases were extracted from the central EUROCAT database using coding information responses from the registries. In total, 866 ABS cases and 451 LBWC cases were included in this study. The mean prevalence was 0.53/10,000 births for ABS and 0.34/10,000 births for LBWC during the 40 years. Prevalence of both ABS and LBWC was lower in the 1980s and higher in the United Kingdom. Limb anomalies and neural tube defects were commonly seen in ABS, whereas in LBWC abdominal and thoracic wall defects and limb anomalies were most prevalent. Twinning was confirmed as a risk factor for both ABS and LBWC. This study includes the largest cohort of ABS and LBWC cases ever reported over a large time period using standardized EUROCAT data. Prevalence, clinical characteristics, and the phenotypic spectrum are described, and twinning is confirmed as a risk factor.

Epidemiology of aplasia cutis congenita: A population-based study in Europe

BACKGROUND

Aplasia cutis congenita (ACC) is a rare congenital anomaly characterized by localized or widespread absence of skin at birth, mainly affecting the scalp. Most information about ACC exists as individual case reports and medium-sized studies.

OBJECTIVES

This study aimed to investigate the epidemiology of ACC, using data from a large European network of population-based registries for congenital anomalies (EUROCAT).

METHODS

Twenty-eight EUROCAT population-based registries in 16 European countries were involved. Poisson regression models were exploited to estimate the overall and live birth prevalence, to test time trends in prevalence between four 5-year periods and to evaluate the impact of the change of coding for ACC from the unspecific ICD9-BPA code to the specific ICD10 code. Proportions of ACC cases associated with other anomalies were reported.

RESULTS

Five hundred cases were identified in the period 1998-2017 (prevalence: 5.10 per 100,000 births). Prevalence across 5-year periods did not differ significantly and no significant differences were evident due to the change from ICD9 to ICD10 in ACC coding. Heterogeneity in prevalence was observed across registries. The scalp was the most common site for ACC (96.4%) and associated congenital anomalies were present in 33.8% of cases. Patau and Adams-Oliver syndromes were the most frequent among the associated chromosomal anomalies (88.3%) and the associated genetic syndromes (57.7%), respectively. 16% of cases were associated with limb anomalies and 15.4% with congenital heart defects. A family history of ACC was found in 2% of cases.

CONCLUSION

To our knowledge, this is the only population-based study on ACC. The EUROCAT methodologies provide reliable prevalence estimates and proportions of associated anomalies.

Prevalence of vascular disruption anomalies and association with young maternal age: A EUROCAT study to compare the United Kingdom with other European countries

BACKGROUND

Younger mothers are at a greater risk of having a pregnancy with gastroschisis and the risk is higher in the United Kingdom than other European countries. Gastroschisis is thought to be a vascular disruption anomaly and the aim of this study was to analyze the prevalence of other possible vascular disruption anomalies to determine whether both the younger maternal age and the UK associations also occur with these anomalies.

METHODS

All pregnancies with anomalies considered potentially due to vascular disruption from January 1, 2005 to December 31, 2017 from 26 European population-based congenital anomaly registries who were members of EUROCAT were analyzed. Multilevel models were used to allow for differences between registries when analyzing associations with maternal age, year of birth and whether the registry was in the United Kingdom.

RESULTS

There were 5,220 cases with potential vascular disruption anomalies, excluding chromosomal and genetic conditions, with a prevalence of 8.85 per 10,000 births in the United Kingdom and 5.44 in the other European countries. The prevalence per 10,000 births of gastroschisis (4.45 vs. 1.56) and congenital constriction bands (0.83 vs. 0.42) was significantly higher in the United Kingdom, even after adjusting for maternal age. However, transverse limb reduction defects had a similar prevalence (2.16 vs. 2.14 per 10,000). The expected increased prevalence in younger mothers was observed for vascular disruption anomalies overall and for the individual anomalies: gastroschisis and congenital constriction bands.

CONCLUSION

Vascular disruption anomalies that had an increased risk for younger mothers (such as gastroschisis) had a higher maternal age standardized prevalence in the United Kingdom, while vascular disruption anomalies with weaker associations with younger mothers (such as transverse limb reduction defects) did not have an increased prevalence in the United Kingdom, which may indicate a different etiology for these anomalies.

Practicalities and Yield from Mass Swabbing for COVID-19 in Residential Care Facilities in the South of Ireland

Over 19,000 residents and health-care workers in 315 RCFs were swabbed in a once - off mass swabbing of residents and staff in residential care facilities (RCFs) in the Cork/Kerry region in Ireland in April and May 2020. This exercise was in response to epidemiological evidence demonstrating increasing community transmission of COVID-19 and emerging evidence of the vulnerability of older persons, particularly those with underlying medical conditions. The effectiveness of such strategies is uncertain and may depend on both the positive case yield and efficiency of testing turn-around to ensure that timely control measures are put in place. The overall positivity rate was 0.88% (n = 172). Mass swabbing allowed early identification of some new cases and outbreaks in RCFs. This facilitated early public health interventions to protect the most vulnerable members of society.

Epidemiology of Pierre-Robin sequence in Europe: A population-based EUROCAT study

BACKGROUND

Pierre Robin sequence (PRS) is a rare congenital anomaly. Respiratory disorders and feeding difficulties represent the main burden.

OBJECTIVE

The aim of this study was to investigate the epidemiology of PRS using a cohort of cases from EUROCAT, the European network of population-based registries of congenital anomalies.

METHODS

We analysed cases of PRS born in the period 1998-2017 collected by 29 population-based congenital anomaly registries in 17 different countries. We calculated prevalence estimates, prenatal detection rate, survival up to 1 week, and proportions of associated anomalies. The effect of maternal age was tested using a Poisson regression model.

RESULTS

Out of 11 669 155 surveyed births, a total of 1294 cases of PRS were identified. The estimate of the overall prevalence was 12.0 per 100 000 births (95% CI 9.9, 14.5). There was a total of 882 (68.2%) isolated cases, and the prevalence was 7.8 per 100 000 births (95% CI 6.7, 9.2). A total of 250 cases (19.3%) were associated with other structural congenital anomalies, 77 cases (6.0%) were associated with chromosomal anomalies and 77 (6.0%) with genetic syndromes. The prenatal detection rate in isolated cases was 12.0% (95% CI 9.8, 14.5) and increased to 16.0% (95% CI 12.7, 19.7) in the sub-period 2008-2017. The prevalence rate ratio of non-chromosomal cases with maternal age ≥35 was higher than in cases with maternal age <25 for total (PRR 1.26, 95% CI 1.05, 1.51) and isolated cases (PRR 1.33, 95% CI 1.00, 1.64). Survival of chromosomal cases (94.2%) and multiple anomaly cases (95.3%) were lower than survival of isolated cases (99.4%).

CONCLUSIONS

This epidemiological study using a large series of cases of PRS provides insights into the epidemiological profile of PRS in Europe. We observed an association with higher maternal age, but further investigations are needed to test potential risk factors for PRS.

Prevention of Neural Tube Defects in Europe: A Public Health Failure

Objective: Thirty years ago it was demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). Despite Public Health Initiatives across Europe recommending that women take 0.4 mg folic acid before becoming pregnant and during the first trimester, the prevalence of NTD pregnancies has not materially decreased in the EU since 1998, in contrast to the dramatic fall observed in the USA. This study aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in Europe from 1998 as it had been in the USA. Design and Setting: The number of NTD pregnancies from 1998 to 2017 that would have been prevented if folic acid fortification had been implemented in the 28 countries who were members of the European Union in 2019 was predicted was predicted using data on NTD prevalence from 35 EUROCAT congenital anomaly registries and literature searches for population serum folate levels and folic acid supplementation. Results: From 1998 to 2017 an estimated 95,213 NTD pregnancies occurred amongst 104 million births in the 28 countries in the EU, a prevalence of 0.92 per 1,000 births. The median serum folate level in Europe over this time period was estimated to be 14.1 μg/L. There is a lack of information about women taking folic acid supplements before becoming pregnant and during the first trimester of pregnancy, with one meta-analysis indicating that around 25% of women did so. An estimated 14,600 NTD pregnancies may have been prevented if the European countries had implemented fortification at the level adopted by the USA in 1998 and 25% of women took folic acid supplements. An estimated 19,500 NTD pregnancies would have been prevented if no women took folic acid supplements. Conclusions: This study suggests that failure to implement mandatory folic acid fortification in the 28 European countries has caused, and continues to cause, neural tube defects to occur in almost 1,000 pregnancies every year.

Maternal risk factors for the VACTERL association: A EUROCAT case-control study

BACKGROUND

The VACTERL association (VACTERL) is the nonrandom occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Despite suggestions for involvement of several genes and nongenetic risk factors from small studies, the etiology of VACTERL remains largely unknown.

OBJECTIVE

To identify maternal risk factors for VACTERL in offspring in a large European study.

METHODS

A case-control study was performed using data from 28 EUROCAT registries over the period 1997-2015 with case and control ascertainment through hospital records, birth and death certificates, questionnaires, and/or postmortem examinations. Cases were diagnosed with VACTERL, while controls had a genetic syndrome and/or chromosomal abnormality. Data collected included type of birth defect and maternal characteristics, such as age, use of assisted reproductive techniques (ART), and chronic illnesses. Multivariable logistic regression analyses were performed to estimate confounder adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

RESULTS

The study population consisted of 329 VACTERL cases and 49,724 controls with recognized syndromes or chromosomal abnormality. For couples who conceived through ART, we found an increased risk of VACTERL (aOR 2.3 [95% CI 1.3, 3.9]) in offspring. Pregestational diabetes (aOR 3.1 [95% CI 1.1, 8.6]) and chronic lower obstructive pulmonary diseases (aOR 3.9 [95% CI 2.2, 6.7]) also increased the risk of having a child with VACTERL. Twin pregnancies were not associated with VACTERL (aOR 0.6 [95% CI 0.3, 1.4]).

CONCLUSION

We identified several maternal risk factors for VACTERL in offspring befitting a multifactorial etiology.

Multilevel analyses of related public health indicators: The European Surveillance of Congenital Anomalies (EUROCAT) Public Health Indicators

BACKGROUND

Public health organisations use public health indicators to guide health policy. Joint analysis of multiple public health indicators can provide a more comprehensive understanding of what they are intended to evaluate.

OBJECTIVE

To analyse variaitons in the prevalence of congenital anomaly-related perinatal mortality attributable to termination of pregnancy for foetal anomaly (TOPFA) and prenatal diagnosis of congenital anomaly prevalence.

METHODS

We included 55 363 cases of congenital anomalies notified to 18 EUROCAT registers in 10 countries during 2008-12. Incidence rate ratios (IRR) representing the risk of congenital anomaly-related perinatal mortality according to TOPFA and prenatal diagnosis prevalence were estimated using multilevel Poisson regression with country as a random effect. Between-country variation in congenital anomaly-related perinatal mortality was measured using random effects and compared between the null and adjusted models to estimate the percentage of variation in congenital anomaly-related perinatal mortality accounted for by TOPFA and prenatal diagnosis.

RESULTS

The risk of congenital anomaly-related perinatal mortality decreased as TOPFA and prenatal diagnosis prevalence increased (IRR 0.79, 95% confidence interval [CI] 0.72, 0.86; and IRR 0.88, 95% CI 0.79, 0.97). Modelling TOPFA and prenatal diagnosis together, the association between congenital anomaly-related perinatal mortality and TOPFA prevalence became stronger (RR 0.70, 95% CI 0.61, 0.81). The prevalence of TOPFA and prenatal diagnosis accounted for 75.5% and 37.7% of the between-country variation in perinatal mortality, respectively.

CONCLUSION

We demonstrated an approach for analysing inter-linked public health indicators. In this example, as TOPFA and prenatal diagnosis of congenital anomaly prevalence decreased, the risk of congenital anomaly-related perinatal mortality increased. Much of the between-country variation in congenital anomaly-related perinatal mortality was accounted for by TOPFA, with a smaller proportion accounted for by prenatal diagnosis.

Epidemiology of congenital cerebral anomalies in Europe: a multicentre, population-based EUROCAT study

OBJECTIVES

To describe the epidemiology and geographical differences in prevalence of congenital cerebral anomalies in Europe.

DESIGN AND SETTING

Congenital cerebral anomalies (International Classification of Diseases, 10th Revision code Q04) recorded in 29 population-based EUROCAT registries conducting surveillance of 1.7 million births per annum (29% of all European births).

PARTICIPANTS

All birth outcomes (live births, fetal deaths from 20 weeks gestation and terminations of pregnancy after prenatal diagnosis of a fetal anomaly (TOPFA)) from 2005 to 2014.

MAIN OUTCOME MEASURES

Prevalence, proportion of associated non-cerebral anomalies, prenatal detection rate.

RESULTS

4927 cases with congenital cerebral anomalies were identified; a prevalence (adjusted for under-reporting) of 9.8 (95% CI: 8.5 to 11.2) per 10 000 births. There was a sixfold difference in prevalence across the registries. Registries with higher proportions of prenatal diagnoses had higher prevalence. Overall, 55% of all cases were liveborn, 3% were fetal deaths and 41% resulted in TOPFA. Forty-eight per cent of all cases were an isolated cerebral anomaly, 25% had associated non-cerebral anomalies and 27% were chromosomal or part of a syndrome (genetic or teratogenic). The prevalence excluding genetic or chromosomal conditions increased by 2.4% per annum (95% CI: 1.3% to 3.5%), with the increases occurring only for congenital malformations of the corpus callosum (3.0% per annum) and 'other reduction deformities of the brain' (2.8% per annum).

CONCLUSIONS

Only half of the cases were isolated cerebral anomalies. Improved prenatal and postnatal diagnosis may account for the increase in prevalence of congenital cerebral anomalies from 2005 to 2014. However, major differences in prevalence remain between regions.

Epidemiology of achondroplasia: A population-based study in Europe

Achondroplasia is a rare genetic disorder resulting in short-limb skeletal dysplasia. We present the largest European population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991-2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14-4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011-2015 vs. 36% in 1991-1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia.

Prevalence of valproate syndrome in Europe from 2005 to 2014: A registry based multi-centre study

Women with epilepsy need to continue to take anticonvulsants during their pregnancies to prevent seizures from occurring. Since the 1980's, it has been known that the use of valproate (an anticonvulsant) in the first trimester of pregnancy is associated with an increased risk of spina bifida. Recent studies have also demonstrated increased risks of other congenital anomalies as well as a risk of cognitive impairment. Doctors in the EU are now advised not to prescribe valproate in pregnant women, in women who can become pregnant or in girls unless other treatments are ineffective or not tolerated. This study aimed to determine if there has been a reduction in the numbers of babies born with valproate syndrome in Europe from 2005 to 2014. Data from 15 European congenital anomaly registries, who are members of EUROCAT (A European network of population-based registries for the epidemiologic surveillance of congenital anomalies), identified 28 cases of valproate syndrome in 2.74 million births from 2005 to 2014. The prevalence of valproate syndrome in Europe significantly decreased from 0.22 per 10,000 births in 2005/6 to 0.03 per 10,000 births in 2013/14. One registry, Ile de la Reunion, had the majority of cases (17). After excluding these cases there still remained a decreasing trend even though it no longer reached statistical significance due to the small number of cases. This study emphasises the continued need for European collaboration in analysing rare exposures and rare anomalies.

Epidemiology of septo-optic dysplasia with focus on prevalence and maternal age - A EUROCAT study

Septo-optic nerve dysplasia is a rare congenital anomaly with optic nerve hypoplasia, pituitary hormone deficiencies and midline developmental defects of the brain. The clinical findings are visual impairment, hypopituitarism and developmental delays. The aim of this study was to report prevalence, associated anomalies, maternal age and other epidemiological factors from a large European population based network of congenital anomaly registries (EUROCAT). Data from 29 full member registries for the years 2005-2014 were included, covering 6.4 million births. There were 99 cases with a diagnosis of septo-optic dysplasia. The prevalence of septo-optic dysplasia in Europe was calculated to lie between 1.9 and 2.5 per 100,000 births after adjusting for potential under-reporting in some registries. The prevalence was highest in babies of mothers aged 20-24 years of age and was significantly higher in UK registries compared with other EUROCAT registries (P = 0.021 in the multilevel model) and the additional risk for younger mothers was significantly greater in the UK compared to the rest of Europe (P = 0.027). The majority of septo-optic dysplasia cases were classified as an isolated cerebral anomaly (N = 76, 77%). Forty percent of diagnoses occurred in fetuses with a prenatal diagnosis. The anomaly may not be visible at birth, which is reflected in that 57% of the postnatal diagnoses occurred over 1 month after birth. This is the first population based study to describe the prevalence of septo-optic dysplasia in Europe. Septo-optic dysplasia shares epidemiological patterns with gastroschisis and this strengthens the hypothesis of vascular disruption being an aetiological factor for septo-optic dysplasia.

Self-harm among the homeless population in Ireland: A national registry-based study of incidence and associated factors

BACKGROUND

Self-harm is a strong predictor of future suicide, but little is known about self-harm among the homeless population. The study aim was to estimate the incidence of self-harm among the homeless population and to assess factors associated with self-harm.

METHODS

Data on self-harm presentations to 34 hospital emergency departments in Ireland were collected by the National Self-Harm Registry Ireland (NSHRI). Index presentations between 2010 and 2014 were included for the homeless and fixed residence populations. Incidence rates of self-harm were calculated using NSHRI data and census estimates. Factors associated with self-harm and repeated self-harm were analysed by multivariable-adjusted logistic regression.

RESULTS

The age-standardised incidence rate of self-harm was 30 times higher among the homeless (5572 presentations per 100,000) compared with those with a fixed residence (187 presentations per 100,000). Homeless people had significantly higher odds of being male (OR 1.86, 95%CI 1.56-2.23), presenting with self-cutting (vs. overdose, OR 2.15, 95%CI 1.74-2.66) and having psychiatric admission (vs. general admission, OR 2.43, 95%CI 1.66-3.57). Homeless people had higher odds of self-harm repetition within 12 months (vs. fixed residence, OR 1.46, 95%CI 1.21-1.77). The odds of repetition were significantly increased among homeless who engaged in self-cutting (vs. overdose, OR 1.76, 95%CI 1.17-2.65) and did not receive psychiatric review at index presentation (vs. reviewed, OR 1.54, 95%CI 1.05-2.26).

LIMITATIONS

The study only reflects self-harm presenting to hospital, and assumes no change in homelessness status after index presentation. Residual confounding may affect the results.

CONCLUSION

There is a disproportionate burden of self-harm among the homeless. Targeted preventive actions are warranted.

An Audit of Neural Tube Defects in the Republic Of Ireland for 2012-2015

Neural tube defects (NTD) are potentially preventable in two-thirds of cases by periconceptional maternal Folic Acid (FA) supplementation. A national audit for the years 2009-11 showed no decline in NTD rates over twenty years. The aim of this national audit was to determine trends/rates and inform revision of national FA supplementation and food fortification strategies. Of 274,732 live and stillbirths there were 121(42.0%) cases of anencephaly, 136(47.2%) cases of spina bifida and 31(10.8%) cases of encephalocoele giving a total of 288 and overall rate of 1.05/1000 compared with 1.04/1000 in 2009-11(NS). In the 184 women where the information was available, only 29.9%(n=55) reported starting FA before pregnancy. The number of cases diagnosed antenatally was 91%(n=262) and 53%(n=154) were live-born. This audit confirms that over a generation, healthcare interventions have not succeeded in decreasing the number of pregnancies in Ireland complicated by NTD, and that revised strategies need to be developed and implemented.

Prevalence of microcephaly in Europe: population based study

OBJECTIVES

 To provide contemporary estimates of the prevalence of microcephaly in Europe, determine if the diagnosis of microcephaly is consistent across Europe, and evaluate whether changes in prevalence would be detected using the current European surveillance performed by EUROCAT (the European Surveillance of Congenital Anomalies).

DESIGN

 Questionnaire and population based observational study.

SETTING

 24 EUROCAT registries covering 570 000 births annually in 15 countries.

PARTICIPANTS

 Cases of microcephaly not associated with a genetic condition among live births, fetal deaths from 20 weeks' gestation, and terminations of pregnancy for fetal anomaly at any gestation.

MAIN OUTCOME MEASURES

 Prevalence of microcephaly (1 Jan 2003-31 Dec 2012) analysed with random effects Poisson regression models to account for heterogeneity across registries.

RESULTS

 16 registries responded to the questionnaire, of which 44% (7/16) used the EUROCAT definition of microcephaly (a reduction in the size of the brain with a skull circumference more than 3 SD below the mean for sex, age, and ethnic origin), 19% (3/16) used a 2 SD cut off, 31% (5/16) were reliant on the criteria used by individual clinicians, and one changed criteria between 2003 and 2012. Prevalence of microcephaly in Europe was 1.53 (95% confidence interval 1.16 to 1.96) per 10 000 births, with registries varying from 0.4 (0.2 to 0.7) to 4.3 (3.6 to 5.0) per 10 000 (χ(2)=338, df=23, I(2)=93%). Registries with a 3 SD cut off reported a prevalence of 1.74 per 10 000 (0.86 to 2.93) compared with those with the less stringent 2 SD cut off of 1.21 per 10 000 (0.21 to 2.93). The prevalence of microcephaly would need to increase in one year by over 35% in Europe or by over 300% in a single registry to reach statistical significance (P<0.01).

CONCLUSIONS

 EUROCAT could detect increases in the prevalence of microcephaly from the Zika virus of a similar magnitude to those observed in Brazil. Because of the rarity of microcephaly and discrepant diagnostic criteria, however, the smaller increases expected in Europe would probably not be detected. Clear diagnostic criteria for microcephaly must be adopted across Europe.

Long term trends in prevalence of neural tube defects in Europe: population based study

STUDY QUESTION

What are the long term trends in the total (live births, fetal deaths, and terminations of pregnancy for fetal anomaly) and live birth prevalence of neural tube defects (NTD) in Europe, where many countries have issued recommendations for folic acid supplementation but a policy for mandatory folic acid fortification of food does not exist?

METHODS

This was a population based, observational study using data on 11,353 cases of NTD not associated with chromosomal anomalies, including 4162 cases of anencephaly and 5776 cases of spina bifida from 28 EUROCAT (European Surveillance of Congenital Anomalies) registries covering approximately 12.5 million births in 19 countries between 1991 and 2011. The main outcome measures were total and live birth prevalence of NTD, as well as anencephaly and spina bifida, with time trends analysed using random effects Poisson regression models to account for heterogeneities across registries and splines to model non-linear time trends.

SUMMARY ANSWER AND LIMITATIONS

Overall, the pooled total prevalence of NTD during the study period was 9.1 per 10,000 births. Prevalence of NTD fluctuated slightly but without an obvious downward trend, with the final estimate of the pooled total prevalence of NTD in 2011 similar to that in 1991. Estimates from Poisson models that took registry heterogeneities into account showed an annual increase of 4% (prevalence ratio 1.04, 95% confidence interval 1.01 to 1.07) in 1995-99 and a decrease of 3% per year in 1999-2003 (0.97, 0.95 to 0.99), with stable rates thereafter. The trend patterns for anencephaly and spina bifida were similar, but neither anomaly decreased substantially over time. The live birth prevalence of NTD generally decreased, especially for anencephaly. Registration problems or other data artefacts cannot be excluded as a partial explanation of the observed trends (or lack thereof) in the prevalence of NTD.

WHAT THIS STUDY ADDS

In the absence of mandatory fortification, the prevalence of NTD has not decreased in Europe despite longstanding recommendations aimed at promoting peri-conceptional folic acid supplementation and existence of voluntary folic acid fortification.

FUNDING, COMPETING INTERESTS, DATA SHARING

The study was funded by the European Public Health Commission, EUROCAT Joint Action 2011-2013. HD and ML received support from the European Commission DG Sanco during the conduct of this study. No additional data available.

Emergency planning and the Control of Major Accident Hazards (COMAH/Seveso II) Directive: an approach to determine the public safety zone for toxic cloud releases

The EU Control of Major Accidents Hazards Directive (Seveso II) requires an external emergency plan for each top tier site. This paper sets out a method to build the protection of public health into emergency planning for Seveso sites in the EU. The method involves the review of Seveso site details prescribed under the directive. The site safety report sets out the potential accident scenarios. The safety report's worst-case scenario, and chemical involved, is used as the basis for the external emergency plan. A decision was needed on the appropriate threshold value to use as the level of concern to protect public health. The definitions of the regulatory standards (air quality standards and occupational standards) in use were studied, how they are derived and for what purpose. The 10 min acute exposure guideline level (AEGL) for a chemical is recommended as the threshold value to inform decisions taken to protect public health from toxic cloud releases. The area delimited by AEGL 1 defines the population who may be concerned about being exposed. They need information based on comprehensive risk assessment. The area delimited by AEGL 2 defines the population for long-term surveillance when indicated and may include first responders. The area delimited by AEGL 3 defines the population who may present acutely to the medical services. It ensures that the emergency responders site themselves safely. A standard methodology facilitates discussions with plant operators and concerned public. Examples show how the methodology can be adapted to suit explosive risk and response to fire.