Hospital-based Surveillance System Research Articles

Incidence of Hospitalization due to Influenza-Associated Severe Acute Respiratory Infection During 2010-2019 in Bangladesh.

Global influenza-associated acute respiratory infections contribute to 3-5 million severe illnesses requiring hospitalization annually, with 90% of hospitalizations occurring among children < 5 years in developing countries. In Bangladesh, the inadequate availability of nationally representative, robust estimates of influenza-associated hospitalizations limits allocation of resources for prevention and control measures. This study used data from the hospital-based influenza surveillance (HBIS) system in Bangladesh from 2010 to 2019 and healthcare utilization surveys to determine hospital utilization patterns in the catchment area. We estimated annual influenza-associated hospitalization numbers and rates for all age groups in Bangladesh using WHO methods, adjusted for a 6-day-a-week enrollment schedule, selective testing of specimens from children under five, and healthcare-seeking behavior, based on the proportion of symptomatic community participants seeking healthcare within the past week. We then estimated national hospitalization rates by multiplying age-specific hospitalization rates with the corresponding annual national census population. Annual influenza-associated hospitalization rates per 100,000 population for all ages ranged from 31 (95% CI: 27-36) in 2011 to 139 (95% CI: 130-149) in 2019. Children < 5 years old had the highest rates of influenza-associated hospitalization, ranging from 114 (95% CI: 90-138) in 2011 to 529 (95% CI: 481-578) in 2019, followed by adults aged ≥ 65 years with rates ranging from 46 (95% CI: 34-57) in 2012 to 252 (95% CI: 213-292) in 2019. The national hospitalization estimates for all ages during 2010-2019 ranged from 47,891 to 236,380 per year. The impact of influenza-associated hospitalizations in Bangladesh may be considerable, particularly for young children and older adults. Targeted interventions, such as influenza vaccination for these age groups, should be prioritized and evaluated.

Common Seasonal Pathogens and Epidemiology of Henoch-Schönlein Purpura Among Children

Henoch-Schönlein purpura (HSP) is the most common type of vasculitis in children. The factors that trigger the disease are poorly understood. Although several viruses and seasonal bacterial infections have been associated with HSP, differentiating the specific associations of these pathogens with the onset of HSP remains a challenge due to their overlapping seasonal patterns. To analyze the role of seasonal pathogens in the epidemiology of HSP. This cohort study comprised an interrupted time-series analysis of patient records from a comprehensive national hospital-based surveillance system. Children younger than 18 years hospitalized for HSP in France between January 1, 2015, and March 31, 2023, were included. Implementation and relaxation of nonpharmaceutical interventions (NPIs) for the COVID-19 pandemic, such as social distancing and mask wearing. The main outcomes were the monthly incidence of HSP per 100 000 children, analyzed via a quasi-Poisson regression model, and the estimated percentage of HSP incidence potentially associated with 14 selected common seasonal pathogens over the same period. The study included 9790 children with HSP (median age, 5 years [IQR, 4-8 years]; 5538 boys [56.4%]) and 757 110 children with the infectious diseases included in the study (median age, 0.7 years [IQR, 0.2-2 years]; 393 697 boys [52.0%]). The incidence of HSP decreased significantly after implementation of NPIs in March 2020 (-53.6%; 95% CI, -66.6% to -40.6%; P < .001) and increased significantly after the relaxation of NPIs in April 2021 (37.2%; 95% CI, 28.0%-46.3%; P < .001). The percentage of HSP incidence potentially associated with Streptococcus pneumoniae was 37.3% (95% CI, 22.3%-52.3%; P < .001), the percentage of cases associated with Streptococcus pyogenes was 25.6% (95% CI, 16.7%-34.4%; P < .001), and the percentage of cases associated with human rhino enterovirus was 17.1% (95% CI, 3.8%-30.4%; P = .01). Three sensitivity analyses found similar results. This study found that significant changes in the incidence of HSP simultaneously with major shifts in circulating pathogens after NPIs for the COVID-19 pandemic indicated that approximately 60% of HSP incidence was potentially associated with pneumococcus and group A streptococcus. This finding suggests that preventive measures against these pathogens could reduce the incidence of pediatric HSP.

Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies

IntroductionOverlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood.MethodsRetrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa’s criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM).ResultsSixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4–17) with median follow up of 7.9 years (2.1–19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1–7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure.ConclusionThis is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

Epidemiology of birth defects in a national hospital-based birth defect surveillance spot in Southern Jiangsu, China, 2014-2018.

As the only hospital-based national surveillance spot of birth defects (BDs) in Changzhou city located in the economically developed eastern part of China, Changzhou Maternal and Child Health Care Hospital has encountered serious challenges in BD prevention. This study aimed to describe the epidemiology of total BDs born in the hospital from 2014 to 2018. The data were collected from the national hospital-based birth defect surveillance system. BD prevalence was calculated by Poisson distribution. Trends of prevalence and the associations regarding information with BDs were analyzed by Poisson regression. The reported prevalence of total BDs was 313.92 (95% confidence interval [CI]: 299.59-328.76) per 10,000 perinatal infants (PIs), while the perinatal prevalence of BD was 160.19 (95% CI: 150.00-170.89) per 10,000 PIs. A remarkable uptrend in the prevalence of BDs was noticed with a prevalence rate ratio (PRR) of 1.09 (95% CI: 1.04-1.14) and 1.13 (95% CI: 1.09-1.16), respectively. Congenital heart disease (CHD), cleft lip with or without cleft palate (CL/P), congenital malformation of the kidney (CMK), polydactyly, Down syndrome (DS), cystic hygroma, neural tube defect (NTD), and congenital talipes equinovarus (CTE) were common types of total BDs. Mothers living in the urban area (PRR = 1.67, 95% CI:1.50-1.87), male fetuses (PRR = 1.16, 95% CI: 1.05-1.28), and maternal age younger than 20 (PRR = 2.28, 95% CI: 1.60-3.25) and 25 years (PRR = 1.41, 95% CI: 1.22-1.63) or older than 35 years (PRR = 1.18, 95% CI: 1.00-1.40) were risk factors for BD occurrence. The reported prevalence of total BDs was nearly two times higher than the perinatal prevalence of BDs in PIs, and the ranks of total BDs and BDs in PIs were different. Mothers living in the urban area, male fetuses, and maternal ages younger than 25 or older than 35 years were risk factors for BD incidence. Thus, improving prenatal examination technology, expanding the surveillance time quantum of BDs, and keeping maternal health may be warranted.

Unique Changes in the Incidence of Acute Chest Syndrome in Children With Sickle Cell Disease Unravel the Role of Respiratory Pathogens: A Time Series Analysis

Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD). Although respiratory pathogens are frequently detected in children with ACS, their respective role in triggering the disease is still unclear. We hypothesized that the incidence of ACS followed the unprecedented population-level changes in respiratory pathogen dynamics after COVID-19-related nonpharmaceutical interventions (NPIs). What is the respective role of respiratory pathogens in ACS epidemiology? This study was an interrupted time series analysis of patient records from a national hospital-based surveillance system. All childrenaged < 18 years with SCD hospitalized for ACS in France between January 2015 and May 2022 were included. The monthly incidence of ACS per 1,000 children with SCD over time was analyzed by using a quasi-Poisson regression model. The circulation of 12 respiratory pathogens in the general pediatric population over the same period was included in the model to assess the fraction of ACS potentially attributable to each respiratory pathogen. Among the 55,941 hospitalizations of children with SCD, 2,306 episodes of ACS were included (median [interquartile range] age, 9 [5-13] years). A significant decrease was observed in ACS incidence after NPI implementation in March 2020 (-29.5%; 95%CI, -46.8 to -12.2; P= .001) and a significant increase after lifting of the NPIs in April 2021 (24.4%; 95%CI, 7.2 to 41.6; P= .007). Using population-level incidence of several respiratory pathogens, Streptococcus pneumoniae accounted for 30.9%(95%CI, 4.9 to 56.9; P= .02) of ACS incidence over the study period and influenza 6.8%(95%CI, 2.3 to 11.3; P= .004); other respiratory pathogens had only a minor role. NPIs were associated with significant changes in ACS incidence concomitantly with major changes in the circulation of several respiratory pathogens in the general population. This unique epidemiologic situation allowed determination of the contribution of these respiratory pathogens, in particular S pneumoniae and influenza, to the burden of childhood ACS, highlighting the potential benefit of vaccine prevention in this vulnerable population.

Implementation of a Surveillance System for Severe Acute Respiratory Infections at a Tertiary Care Hospital in Austria: Protocol for a Retrospective Longitudinal Feasibility Study.

The risk of a large number of severe acute respiratory infection (SARI) cases emerging is a global concern. SARI can overwhelm the health care capacity and cause several deaths. Therefore, the Austrian Agency for Health and Food Safety will explore the feasibility of implementing an automatic electronically based SARI surveillance system at a tertiary care hospital in Austria as part of the hospital network, initiated by the European Centre for Disease Prevention and Control. We aim to investigate the availability of routinely collected health record data pertaining to respiratory infections and the optimal approach to use such available data for systematic surveillance of SARI in a real-world setting, describe the characteristics of patients with SARI before and after the beginning of the COVID-19 pandemic, and investigate the feasibility of identifying the risk factors for a severe outcome (intensive care unit admission or death) in patients with SARI. We will test the feasibility of a surveillance system, as part of a large European network, at a tertiary care hospital in the province of Lower Austria (called Regional Hospital Wiener Neustadt). It will be a cross-sectional study for the inventory of the electronic data records and implementation of automatic data retrieval for the period of January 2019 through the end of December 2022. The analysis will include an exploration of the database structure, descriptive analysis of the general characteristics of the patients with SARI, estimation of the SARI incidence rate, and assessment of the risk factors and different levels of severity of patients with SARI using logistic regression analysis. This will be the first study to assess the feasibility of SARI surveillance at a large 800-bed tertiary care hospital in Austria. It will provide a general overview of the potential for establishing a hospital-based surveillance system for SARI. In addition, if successful, the electronic surveillance will be able to improve the response to early warning signs of new SARI, which will better inform policy makers in strengthening the surveillance system. The findings will support the expansion of the SARI hospital-based surveillance system to other hospitals in Austria. This network will be of use to Austria in preparing for future pandemics. PRR1-10.2196/47547.

Piloting a hospital-based road traffic injury surveillance system in Nairobi County, Kenya, 2018–2019

BackgroundKenya's estimated road traffic injury (RTI) death rate is 27.8/100,000 population, which is 1.5 times the global rate. Some RTI data are collected in Kenya; however, a systematic and integrated surveillance system does not exist. Therefore, we adopted and modified the World Health Organization's injury surveillance guidelines to pilot a hospital-based RTI surveillance system in Nairobi County, Kenya. MethodsWe prospectively documented all RTI cases presenting at two public trauma hospitals in Nairobi County from October 2018–April 2019. RTI cases were defined as injuries involving ≥1 moving vehicles on public roads. Demographics, injury circumstances, and outcome information were collected using standardized case report forms. The Kampala Trauma Score (KTS) was used to assess injury severity. RTI cases were characterized with descriptive statistics. ResultsOf the 1,840 RTI cases reported during the seven-month period, 73.2% were male. The median age was 29.8 years (range 1–89 years). Forty percent (n = 740) were taken to the hospital by bystanders. Median time for hospital arrival was 77 min. Pedestrians constituted 54.1% (n = 995) of cases. Of 400 motorcyclists, 48.0% lacked helmets. Similarly, 65.7% of bicyclists (23/35) lacked helmets. Among 386 motor vehicle occupants, 59.6% were not using seat belts (19.9% unknown). Seven percent of cases (n = 129) reported alcohol use (49.0% unknown), and 8.8% (n = 161) reported mobile phone use (59.7% unknown). Eleven percent of cases (n = 199) were severely injured (KTS <11), and 220 died. ConclusionWe demonstrated feasibility of a hospital-based RTI surveillance system in Nairobi County. Integrating information from crash scenes and hospitals can guide prevention.

Trends in the Prevalence of Births with Chromosomal Abnormalities - Haidian District, Beijing Municipality, China, 2013-2022.

The primary causes of early miscarriage and stillbirth are chromosomal abnormalities (CAs) whose prevalence has been observed to increase in recent years. According to data received from a hospital-based birth-defect surveillance system in the Haidian District, Beijing, there was a significant increase in the prevalence of CAs along with most subtypes from 2013 to 2022. This noted increase in the reported prevalence is potentially attributable to factors such as a rise in maternal age, alongside the enhanced detection efficacy resulting from the utilization of noninvasive prenatal testing. The escalating prevalence of sex CAs and other previously rare CAs pose novel challenges for genetic counseling and healthcare practitioners. These professionals are tasked with the accurate evaluation and interpretation of detection data, which must then be conveyed appropriately to patients. Furthermore, it is imperative to intensify health education efforts to assist women in making informed treatment decisions, considering the diverse prognoses associated with different CAs.

Characteristics of hospitalised COVID-19 patients during the first two pandemic waves, Gauteng.

BackgroundGauteng province (GP) was one of the most affected provinces in the country during the first two pandemic waves in South Africa. We aimed to describe the characteristics of coronavirus disease 2019 (COVID-19) patients admitted in one of the largest quaternary hospitals in GP during the first two waves.ObjectivesStudy objectives were to determine factors associated with hospital admission during the second wave and to describe factors associated with in-hospital COVID-19 mortality.MethodData from a national hospital-based surveillance system of COVID-19 hospitalisations were used. Multivariable logistic regression models were conducted to compare patients hospitalised during wave 1 and wave 2, and to determine factors associated with in-hospital mortality.ResultsThe case fatality ratio was the highest (39.95%) during wave 2. Factors associated with hospitalisation included age groups 40–59 years (adjusted odds ratio [aOR]: 2.14, 95% confidence interval [CI]: 1.08–4.27), 60–79 years (aOR: 2.49, 95% CI: 1.23–5.02) and ≥ 80 years (aOR: 3.39, 95% CI: 1.35–8.49). Factors associated with in–hospital mortality included age groups 60–79 years (aOR: 2.55, 95% CI: 1.11–5.84) and ≥ 80 years (aOR: 5.66, 95% CI: 2.12–15.08); male sex (aOR: 1.56, 95% CI: 1.22–1.99); presence of an underlying comorbidity (aOR: 1.76, 95% CI: 1.37–2.26), as well as being admitted during post–wave 2 (aOR: 2.42, 95% CI: 1.33–4.42).ConclusionCompared to the recent omicron-driven pandemic waves characterised by lower admission rates and less disease severity among younger patients, COVID-19 in-hospital mortality during the earlier waves was associated with older age, being male and having an underlying comorbidity.ContributionThis study showed how an active surveillance system can contribute towards identifying changes in disease trends.

Effectiveness of pertussis vaccination in pregnancy to prevent hospitalisation in infants aged

BackgroundPERTINENT is an active hospital-based surveillance system for pertussis in infants. In 2019, four of the six participating European countries recommended pertussis vaccination in pregnancy. Among infants aged <2 months, we measured the vaccine effectiveness (VE) in pregnancy; among infants aged 2–11 months, VE of vaccination in pregnancy and of primary vaccination (PV). MethodsFrom December 2015 to 2019, we included all infants aged <1 year presenting with pertussis-like symptoms. Using a test-negative-design, cases were infants testing positive for Bordetella pertussis by PCR or culture. Controls were those testing negative for all Bordetella species. Vaccinated mothers were those who received vaccine in pregnancy. Vaccinated infants were those who received ≥1 dose of PV > 14 days before symptom onset. We excluded infants with unknown maternal or PV status or with mothers vaccinated ≤14 days before delivery. We calculated pooled VE as 100 * (1-odds ratio of vaccination) adjusted for study site, onset date in quarters and infants’ age group. ResultsOf 829 infants presenting with pertussis-like symptoms, 336 (41%) were too young for PV. For the VE in pregnancy analysis, we included 75 cases and 201 controls. Vaccination in pregnancy was recorded for 9 cases (12%) and 92 controls (46%), adjusted VE was between 75% [95%CI: 35–91%] and 88% [95%CI: 57–96%].Of 493 infants eligible for PV, we included 123 cases and 253 controls. Thirty-one cases and 98 controls recorded both PV with ≥ 1 dose and vaccination in pregnancy, adjusted VE was between 74% [95%CI: 33–90] and 95% [95%CI: 69–99]; 27 cases and 53 controls recorded PV only, adjusted VE was between 68% [95%CI: 27–86] and 94% [95%CI: 59–99]. ConclusionOur findings suggest that vaccination in pregnancy reduces pertussis incidence in infants too young for PV. In infants aged 2–11 months, PV only and both PV and vaccination in pregnancy provide significant protection against severe pertussis.

Incidence of Acute Chest Syndrome in Children With Sickle Cell Disease Following Implementation of the 13-Valent Pneumococcal Conjugate Vaccine in France

Acute chest syndrome (ACS) is one of the leading acute severe complications of sickle-cell disease (SCD). Although Streptococcus pneumoniae (S pneumoniae) is highly prevalent in children with SCD, its precise role in ACS is unclear. The efficacy of 13-valent pneumococcal conjugate vaccine (PCV13) implementation on ACS is still unknown. To assess the association of PCV13 implementation in the general pediatric population with the incidence of ACS in children with SCD. This cohort study used an interrupted time-series analysis of patient records from a national hospital-based French surveillance system. All children younger than 18 years with SCD (based on the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision definition) hospitalized in France between January 2007 and December 2019 were included. PCV13 implementation. Monthly incidence of ACS per 1000 children with SCD over time as analyzed by segmented linear regression with autoregressive error; monthly incidence of hospitalization for vaso-occlusive crisis, asthma crisis, and acute pyelonephritis per 1000 children with SCD over the same period as the control outcomes. Among the 107 694 hospitalizations of children with SCD, 4007 episodes of ACS were included (median [IQR] age, 8 [4-12] years; 2228 [55.6%] boys). PCV13 implementation in 2010 was followed by a significant decrease in the incidence of ACS (-0.9% per month; 95% CI, -1.4% to -0.4%; P < .001), with an estimated cumulative change of -41.8% (95% CI, -70.8% to -12.7%) by 2019. Sensitivity analyses yielded the same results, including the incidence of ACS adjusted for that of vaso-occlusive crisis over time. The results were similar among different age groups. By contrast, no change was found for the 3 control outcomes over the study period. PCV13 implementation was associated with an important reduction in the incidence of ACS in children with SCD. This vaccine benefit provides new evidence of the key role of S pneumoniae in ACS and should be considered when estimating outcomes associated with current PCVs and the potential benefit of next-generation PCVs in children.

Association of Nonpharmaceutical Interventions During the COVID-19 Pandemic With Invasive Pneumococcal Disease, Pneumococcal Carriage, and Respiratory Viral Infections Among Children in France

An association between pneumococcal nasopharyngeal carriage and invasive pneumococcal disease (IPD) has been previously established. However, it is unclear whether the decrease in IPD incidence observed after implementation of nonpharmaceutical interventions (NPIs) during the COVID-19 pandemic was associated with concomitant changes in pneumococcal carriage and respiratory viral infections. To assess changes in IPD incidence after the implementation of NPIs during the COVID-19 pandemic and examine their temporal association with changes in pneumococcal carriage rate and respiratory viral infections (specifically respiratory syncytial virus [RSV] and influenza cases) among children in France. This cohort study used interrupted time series analysis of data from ambulatory and hospital-based national continuous surveillance systems of pneumococcal carriage, RSV and influenza-related diseases, and IPD between January 1, 2007, and March 31, 2021. Participants included 11 944 children younger than 15 years in France. Implementation of NPIs during the COVID-19 pandemic. The estimated fraction of IPD change after implementation of NPIs and the association of this change with concomitant changes in pneumococcal carriage rate and RSV and influenza cases among children younger than 15 years. The estimated fraction of change was analyzed using a quasi-Poisson regression model. During the study period, 5113 children (median [IQR] age, 1.0 [0.6-4.0] years; 2959 boys [57.9%]) had IPD, and 6831 healthy children (median [IQR] age, 1.5 [0.9-3.9] years; 3534 boys [51.7%]) received a swab test. Data on race and ethnicity were not collected. After NPI implementation, IPD incidence decreased by 63% (95% CI, -82% to -43%; P < .001) and was similar for non-13-valent pneumococcal conjugate vaccine serotypes with both high disease potential (-63%; 95% CI, -77% to -48%; P < .001) and low disease potential (-53%; 95% CI, -70% to -35%; P < .001). The overall pneumococcal carriage rate did not significantly change after NPI implementation (-12%; 95% CI, -37% to 12%; P = .32), nor did the carriage rate for non-PCV13 serotypes with high disease potential (-26%; 95% CI, -100% to 52%; P = .50) or low disease potential (-7%; 95% CI, -34% to 20%; P = .61). After NPI implementation, the estimated number of influenza cases decreased by 91% (95% CI, -74% to -97%; P < .001), and the estimated number of RSV cases decreased by 74% (95% CI, -55% to -85%; P < .001). Overall, the decrease in influenza and RSV cases accounted for 53% (95% CI, -28% to -78%; P < .001) and 40% (95% CI, -15% to -65%; P = .002) of the decrease in IPD incidence during the NPI period, respectively. The decrease in IPD incidence was not associated with pneumococcal carriage, with carriage accounting for only 4% (95% CI, -7% to 15%; P = .49) of the decrease. In this cohort study of data from multiple national continuous surveillance systems, a decrease in pediatric IPD incidence occurred after the implementation of NPIs in France; this decrease was associated with a decrease in viral infection cases rather than pneumococcal carriage rate. The association between pneumococcal carriage and IPD was potentially modified by changes in the number of RSV and influenza cases, suggesting that interventions targeting respiratory viruses, such as immunoprophylaxis or vaccines for RSV and influenza, may be able to prevent a large proportion of pediatric IPD cases.

Mobile tablets for real-time data collection for hospital-based birth defects surveillance in Kampala, Uganda: Lessons learned.

Sustainable birth defects surveillance systems provide countries with estimates of the prevalence of birth defects to guide prevention, care activities, and evaluate interventions. We used free and open-source software (Open Data Kit) to implement an electronic system to collect data for a hospital-based birth defects surveillance system at four major hospitals in Kampala, Uganda. We describe the establishment, successes, challenges, and lessons learned from using mobile tablets to capture data and photographs. After intensive training, surveillance midwives collected data using Android tablets with inbuilt logic checks; another surveillance midwife checked the quality of the data in real-time before data were securely uploaded onto a local server. Paper forms were used when needed as a backup for the electronic system. We experienced several challenges implementing the surveillance system, including forgotten passwords, unstable network, reduced tablet speed and freezing, loss of touch-screen sensitivity, decreased battery strength, and repetitive extensive retraining. We addressed these challenges by backing up and removing all photos from the tablet, uninstalling irrelevant applications to the study to increase storage space and speed, and monitoring and updating the system based mainly on feedback from the midwives. From August 2015 to December 2018, surveillance midwives documented information on 110,752 births at the participating hospitals. Of these, 110,573 (99.8%) were directly entered into the electronic data system and 179 (0.2%) were captured on paper forms. The use of mobile tablets for real-time data collection was successful in a hospital-based birth defects surveillance system in a resource-limited setting. Extensive training and follow-up can overcome challenges and are key to preparing staff for a successful data collection system.

A more accurate approach to define abortion cohorts using linked administrative data: an application to Ontario, Canada.

The shifting landscape of abortion care from a hospital-only to a distributed service including primary care has implications for how to identify abortion cohorts for research and surveillance. The objectives of this study were to 1) create an improved approach to define abortion cohorts using linked administrative data sets and 2) evaluate the performance of this approach for abortion surveillance compared with standard approaches. We applied four principles to identify induced abortion cohorts when some services are delivered beyond hospital settings; 1) exclude early pregnancy losses and postpartum procedures; 2) use multiple data sources; 3) define episodes of care; 4) apply a hierarchical algorithm to determine abortion date to a population-based cohort of all abortion events in Ontario (Canada) from January 1, 2018-March 15, 2020. We calculated risk differences (RD, with 95% confidence intervals) comparing the proportion of medication vs. surgical, first vs. second trimester, and complication incidence applying these principles vs. standard approaches. Hospital-only data (versus multiple data sources) underestimated the frequency of medication abortion (16.1% vs. 31.4%; RD -15.3% [-14.3, -16.3]) and first-trimester abortion (82.1% vs. 94.5%; RD -12.8 [-11.4, 13.4]) and overestimated incidence of abortion complication (2.9% vs. 0.69%; RD 2.2% [1.8, 2.7]). An unlinked (versus linked) approach underestimated the frequency of abortion complications (0.19% vs 0.69%, -RD 0.50% [-0.44--0.56]). Including (versus excluding) abortions following early pregnancy loss or delivery events increased the estimated incidence of abortion complications (1.29% vs. 0.69%, RD 0.60% [0.51-0.69]. New methods are required to accurately identify abortion cohorts for surveillance or research. When legal or regulatory approaches to medication abortion evolve to enable abortion in primary care or office-based settings, hospital-based surveillance systems will become incomplete and biased; to continue valid and complete abortion surveillance, methods must be adjusted to ensure complete capture of procedures across all settings.

Risk factors and disease severity in Australian infants aged under 6 months hospitalised with influenza 2011–2019

Infants aged <6months are vulnerable to severe influenza disease and no vaccine is approved for use in this age group. We aimed to describe the epidemiology, risk factors associated with severe outcomes and management of influenza in Australian infants aged <6months. Incident cases aged <6months of laboratory-confirmed influenza were captured through two national active prospective sentinel hospital-based surveillance systems in Australia from 2011 to 2019, inclusive. Demographic and clinical features, disease risk factors and outcomes (intensive care unit (ICU) admission and length of stay) and oseltamivir use were analysed. The proportion of infant influenza hospitalisations and nosocomial cases among all hospitalisations were also reported. Of 680 hospitalised infants aged <6months, 57.9% were male and 14.5% were Indigenous Australian. Median age was 2.6months, 19.2% were born premature and 19.0% had a comorbidity, excluding prematurity. Overall, 77.9% had influenza A. Nosocomial cases accounted for 7.8%. ICU admission occurred in 14.7% and oseltamivir was prescribed for 18.8%. Factors associated with ICU admission included age <1month (adjusted odds ratio (aOR) 3.95, 95% confidence interval (CI): 1.47-10.60), comorbidity (aOR 7.69, 95% CI: 4.04-14.64) and prematurity (aOR 2.60, 95% CI: 1.40-4.81). The proportion of infants with influenza among all infant hospitalisations ranged 1.0-2.6% in the 2019 influenza season. Infants aged <6months, and particularly neonates, experience serious disease from influenza. This data underpins the need for preventative strategies such as maternal immunisation and continued investigation into the possibility of safe and efficacious vaccination prior to 6months of age.

The Spectrum, Severity and Outcomes of Rheumatic Mitral Valve Disease in Pregnant Women in Australia and New Zealand

Rheumatic heart disease (RHD) poses significant perinatal risks. We aimed to describe the spectrum, severity and outcomes of rheumatic mitral valve disease in pregnancy in Australia and New Zealand. A prospective, population-based cohort study of pregnant women with RHD recruited 2013-14 through the hospital-based Australasian Maternity Outcomes Surveillance System. Outcome measures included maternal and perinatal morbidity and mortality. Univariable and multivariable logistic regression analyses were undertaken to test for predictors of adverse maternal and perinatal outcomes. Of 274 pregnant women identified with RHD, 124 (45.3%) had mitral stenosis (MS) and 150 (54.7%) had isolated mitral regurgitation (MR). One woman with mild MS/moderate MR died. There were six (2.2%) stillbirths and two (0.7%) neonatal deaths. Babies born to women with MS were twice as likely to be small-for-gestational-age (22.7% vs 11.4%, p=0.013). In women with MS, use of cardiac medication (AOR 7.42) and having severe stenosis (AOR 16.35) were independently associated with adverse cardiac outcomes, while New York Heart Association (NYHA) class >1 (AOR 3.94) was an independent predictor of adverse perinatal events. In women with isolated MR, use of cardiac medications (AOR 7.03) and use of anticoagulants (AOR 6.05) were independently associated with adverse cardiac outcomes. Careful monitoring and specialist care for women with RHD in pregnancy is required, particularly for women with severe MS, those on cardiac medication, and those on anticoagulation, as these are associated with increased risk of adverse maternal cardiac outcomes. In the context of pregnancy, contraception and preconception planning are important for young women diagnosed with RHD.

Sensitivity of Guillain-Barre Syndrome Surveillance in the Brazilian Federal District, using the Capture-Recapture Method.

Guillain-Barre Syndrome (GBS) is an acute immune-mediated polyneuropathy that compromises the peripheral and cranial nerves. It is characterized by rapid-onset paresthesia accompanied by progressive weakness in the lower extremities followed by symmetric ascending paralysis. assessment of sensitivity to detect GBS between March 2017 and May 2019 in a public referral hospital, using the capture-recapture method based on the Chapman estimator and comparing three GBS data sources: the hospital-based sentinel surveillance system (VSBH), Human Immunoglobulin Dispensing Records System (RDIH), and Hospital Information System (SIH). A total of 259 possible cases were identified (captured). Of these, 58 were confirmed and most resided in the Federal District. The VSBH showed the greatest sensitivity in case identification. The temporal distribution of cases showed periods with no cases identified, and more were registered during the rainy season from October to May, when high temperatures also occur. Increased circulation of arboviruses and gastrointestinal infections during the rainy season may explain the greater concentration of GBS cases. It is important to note that one-third of the cases identified in the different data sources do not converge, demonstrating that no single surveillance system is 100% effective. The severity and possible increase in cases related to GBS demonstrates the need for an improved surveillance system capable of monitoring and following-up cases involving neurological syndromes, regardless of the event preceding infection.

Evaluation of a hospital-based surveillance system for birth defects in Chennai, India.

The Birth Defects Registry of India-Chennai (BDRI-C) was created in 2001 to monitor birth defects and provide timely referrals. Using established guidelines to evaluate surveillance systems, we examined the following attributes of BDRI-C to help strengthen the registry: simplicity, flexibility, data quality, representativeness, acceptability, timeliness, and stability. We reviewed BDRI-C documents, including reporting forms; interviewed key informants; and calculated data completeness, coverage, and reporting time. BDRI-C captured 14% of the births in Chennai April 2013 - March 2014. About 7% of institutions in Chennai registered in BDRI-C, and of those registered, 37% provided data in 2013. Median reporting time was 44 days after birth in 2013. BDRI-C is a useful, simple, flexible, and timely passive birth defects surveillance system; however, improvements can be made to ensure BDRI-C is representative of Chennai, data processing and quality checks are on-going, and the system is acceptable for member institutions and stable.

Paediatric Active Enhanced Disease Surveillance (PAEDS) 2019: Prospective hospital-based surveillance for serious paediatric conditions.

The Paediatric Active Enhanced Disease Surveillance (PAEDS) network is an Australian hospital-based active surveillance system employing prospective case ascertainment for selected serious childhood conditions, particularly vaccine preventable diseases and potential adverse events following immunisation (AEFI). This report presents surveillance data for 2019. Specialist nurses screened hospital admissions, emergency department records, laboratory and other data on a daily basis in seven paediatric tertiary referral hospitals across Australia, to identify children with the conditions under surveillance. Standardised protocols and case definitions were used across all sites. In 2019, the conditions under surveillance comprised: acute flaccid paralysis (AFP; a syndrome associated with poliovirus infection), acute childhood encephalitis (ACE), influenza, intussusception (IS; a potential AEFI with rotavirus vaccines), pertussis, varicella-zoster virus infection (varicella and herpes zoster), invasive meningococcal and invasive Group A streptococcus diseases and two new conditions, Kawasaki disease and gram-negative bloodstream infections. An additional social research component continued to evaluate parental attitudes to influenza vaccination. PAEDS captured 2,701 cases for 2019 across all conditions under surveillance. Key outcomes of PAEDS included: contribution to national AFP surveillance to reach the World Health Organization reporting targets for detection of poliomyelitis cases; demonstration of high influenza activity in 2019 and influenza-associated deaths in ACE cases; identification of key barriers to influenza vaccination of children hospitalised for acute respiratory illness; reporting of all IS cases associated with vaccine receipt to relevant state health department; and showing a further reduction nationally in varicella cases. Enhanced pertussis surveillance continued to capture controls to support vaccine efficacy estimation. Invasive meningococcal disease surveillance showed predominance of serotype B and a reduction in cases nationally. Surveillance for invasive group A streptococcus captured severe cases in children. Monitoring of Kawasaki disease incidence and gram-negative bloodstream infections commenced. PAEDS continues to provide unique policy-relevant data on serious paediatric conditions using sentinel hospital-based enhanced surveillance. Keywords: paediatric, surveillance, child, hospital, vaccine preventable diseases, adverse event following immunisation, acute flaccid paralysis, encephalitis, influenza, intussusception, pertussis, varicella zoster virus, meningococcal, group A streptococcus, Kawasaki, bloodstream infections.

Accuracy of hospital-based surveillance systems for surgical site infection after adult spine surgery: a Bayesian latent class analysis

Surgical site infections (SSIs) of the spine are morbid and costly complications. An accurate surveillance system is required to properly describe the disease burden and the impact of interventions that mitigate SSI risk. Unfortunately, uniform approaches to conducting SSI surveillance are lacking because of varying SSI case definitions, the lack of a perfect reference case definition and heterogeneous data sources. To assess the accuracy of four independent data sources that capture SSIs after spine surgery, with estimation of a measurement-error-adjusted SSI incidence. A Bayesian latent class model assessed the sensitivity/specificity of each data source to identify SSI and to estimate a measurement-error-adjusted incidence. The four data sources used were: the discharge abstract database (DAD), the National Surgical Quality Improvement Program (NSQIP) database, the Infection Prevention and Control Canada (IPAC) database, and the Spine Adverse Events Severity database. A total of 904 patients underwent spine surgery in 2017. The most sensitive data source was DAD (0.799; 95% credible interval (CrI): 0.597-0.943); the least sensitive was NSQIP (0.497; 95% CrI: 0.308-0.694). The most specific data source was IPAC (0.997; 95% CrI: 0.993-1.000) and the least specific was DAD (0.969; 95% CrI: 0.956-0.981). The measurement-error-adjusted SSI incidence was 0.030 (95% CrI: 0.019-0.045). The crude incidence using the DAD overestimated the incidence, and the three other data sources underestimated it. SSI surveillance in the spine surgery population is feasible using several data sources, provided that measurement error is considered.