Responding to the Pandemic: Challenges With Public Health Surveillance Systems and Development of a COVID-19 National Surveillance Case Definition to Support Case-Based Morbidity Surveillance During the Early Response.

Responding to introductions of diseases and conditions of unknown etiology is a critical public health function. In late December 2019, investigation of a cluster of pneumonia cases of unknown origin in Wuhan, China, resulted in the identification of a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Multiple public health surveillance actions were rapidly implemented to detect introduction of the virus into the United States and track its spread including establishment of a national surveillance case definition and addition of the disease, coronavirus disease 2019, to the list of nationally notifiable conditions. Challenges in conducting effective case-based surveillance and the public health data supply chain and infrastructure are discussed.

Electronic Case Reporting Development, Implementation, and Expansion in the United States.

INTRODUCTION: The COVID-19 pandemic highlighted the need for a nationwide health information technology solution that could improve upon manual case reporting and decrease the clinical and administrative burden on the US health care system. We describe the development, implementation, and nationwide expansion of electronic case reporting (eCR), including its effect on public health surveillance and pandemic readiness. METHODS: Multidisciplinary teams developed and implemented a standards-based, shared, scalable, and interoperable eCR infrastructure during 2014-2020. From January 27, 2020, to January 7, 2023, the team conducted a nationwide scale-up effort and determined the number of eCR-capable electronic health record (EHR) products, the number of reportable conditions available within the infrastructure, and technical connections of health care organizations (HCOs) and jurisdictional public health agencies (PHAs) to the eCR infrastructure. The team also conducted data quality studies to determine whether HCOs were discontinuing manual case reporting and early results of eCR timeliness. RESULTS: During the study period, the number of eCR-capable EHR products developed or in development increased 11-fold (from 3 to 33), the number of reportable conditions available increased 28-fold (from 6 to 173), the number of HCOs connected to the eCR infrastructure increased 143-fold (from 153 to 22 000), and the number of jurisdictional PHAs connected to the eCR infrastructure increased 2.75-fold (from 24 to 66). Data quality reviews with PHAs resulted in select HCOs discontinuing manual case reporting and using eCR-exclusive case reporting in 13 PHA jurisdictions. The timeliness of eCR was <1 minute. PRACTICE IMPLICATIONS: The growth of eCR can revolutionize public health case surveillance by producing data that are more timely and complete than manual case reporting while reducing reporting burden.

Epidemiology of 2009 pandemic influenza A (H1N1) deaths in the United States, April-July 2009.

During the spring of 2009, pandemic influenza A (H1N1) virus (pH1N1) was recognized and rapidly spread worldwide. To describe the geographic distribution and patient characteristics of pH1N1-associated deaths in the United States, the Centers for Disease Control and Prevention requested information from health departments on all laboratory-confirmed pH1N1 deaths reported from 17 April through 23 July 2009. Data were collected using medical charts, medical examiner reports, and death certificates. A total of 377 pH1N1-associated deaths were identified, for a mortality rate of .12 deaths per 100,000 population. Activity was geographically localized, with the highest mortality rates in Hawaii, New York, and Utah. Seventy-six percent of deaths occurred in persons aged 18-65 years, and 9% occurred in persons aged ≥ 65 years. Underlying medical conditions were reported for 78% of deaths: chronic lung disease among adults (39%) and neurologic disease among children (54%). Overall mortality associated with pH1N1 was low; however, the majority of deaths occurred in persons aged <65 years with underlying medical conditions.

Pertussis in Florida, 2000-2006: trends in a historically low-incidence state.

OBJECTIVE: Florida, the fourth most populous state in the nation, has had historically low incidence rates of pertussis, the only vaccine-preventable disease with increasing numbers of reported cases. We compared the epidemiology and incidence rates of pertussis in Florida with other states and the United States. METHODS: We used Florida and federal surveillance data from 2000 through 2006. RESULTS: Reported incidence of pertussis in Florida, numbers of cases, and proportions of adolescents and adults all increased during the seven-year study period. Florida incidence rates increased from 0.44 to 1.28, but the state's incidence was always ranked 45th or lower among the states. Reported pertussis cases and those among adolescents and adults in Florida increased during the study period. Ten counties, containing 60% of Florida's population, reported two-thirds of the state's cases. CONCLUSIONS: Pertussis reported from Florida mirrored national trends with increasing incidence, numbers of cases, and proportions of adolescent and adult cases. Despite the increases, Florida maintained its historic pattern of pertussis incidence rates that are consistently lower than national figures. Limited laboratory diagnostics and a focus on the pediatric population likely contributed to the lower rates of pertussis in Florida. More emphasis on surveillance of adolescent and adult cases is needed.

The Ratio of Emergency Department Visits for ILI to Seroprevalence of 2009 Pandemic Influenza A (H1N1) Virus Infection, Florida, 2009.

BACKGROUND: A seroprevalence survey carried out in four counties in the Tampa Bay area of Florida provided an estimate of cumulative incidence of infection due to the 2009 influenza A (H1N1) as of the end of that year's pandemic in the four counties from which seroprevalence data were obtained Methods. Excess emergency department (ED) visits for influenza-like illness (ILI) during the pandemic period (compared to four non-pandemic years) were estimated using the ESSENCE-FL syndromic surveillance system for the four-county area. RESULTS: There were an estimated 44 infections for every ILI ED visit. Age-specific ratios rose from 19.7 to 1 for children aged <5 years to 143.8 to 1 for persons aged >64 years. CONCLUSIONS: These ratios provide a way to estimate cumulative incidence. These estimated ratios can be used in real time for planning and forecasting, when carrying out timely seroprevalence surveys is not practical. Syndromic surveillance data allow age and geographic breakdowns, including for children.

Maternal and neonatal outcomes among pregnant women with 2009 pandemic influenza A(H1N1) illness in Florida, 2009-2010: a population-based cohort study.

INTRODUCTION: Pregnant women have been identified as a high risk group for severe illness with 2009 pandemic influenza A(H1N1) virus infection (pH1N1). Obesity has also been identified as a risk factor for severe illness, though this has not been thoroughly assessed among pregnant women. The objectives of this study were to provide risk estimates for adverse maternal and neonatal outcomes associated with pH1N1 illness during pregnancy and to assess the role of obesity in these outcomes. METHODS: We established a retrospective population-based cohort of all live births occurring in Florida during the first 15 months of the pandemic. Illness with pH1N1 during pregnancy was ascertained through record linkage with the Florida state notifiable disease surveillance database. Data from the birth record, including pre-pregnancy body mass index, were analyzed to assess risk of adverse outcomes associated with pH1N1 illness. RESULTS: A total of 194 women were identified through surveillance with pH1N1 illness during pregnancy. Children born to women with pH1N1 illness during pregnancy were at increased risk for low birth weight [OR (95%CI): 1.78 (1.11-2.860)], premature birth [2.21 (1.47-3.330)], and infant death [4.46 (1.80-11.00)], after adjusting for other factors. Women with pH1N1 illness during pregnancy were at increased risk for severe outcomes including admission to an intensive care unit. Obesity was an observed risk factor, both for the more severe pH1N1 illness detected through surveillance, and for severe maternal outcomes. CONCLUSIONS: Case-patients in this analysis likely represent the most severely ill subset of all women infected with pH1N1 during pregnancy, limiting the generalizability of these findings to more severely ill patients rather than influenza infection in general. Nevertheless, these results suggest that more severe pH1N1 illness during pregnancy is associated with adverse neonatal outcomes and that pregnant women should continue to be targeted for appropriate prophylaxis and early treatment.

Prevalence of 2009 pandemic influenza A (H1N1) virus antibodies, Tampa Bay Florida--November-December, 2009.

BACKGROUND: In 2009, a novel influenza virus (2009 pandemic influenza A (H1N1) virus (pH1N1)) caused significant disease in the United States. Most states, including Florida, experienced a large fall wave of disease from September through November, after which disease activity decreased substantially. We determined the prevalence of antibodies due to the pH1N1 virus in Florida after influenza activity had peaked and estimated the proportion of the population infected with pH1N1 virus during the pandemic. METHODS: During November-December 2009, we collected leftover serum from a blood bank, a pediatric children's hospital and a pediatric outpatient clinic in Tampa Bay Florida. Serum was tested for pH1N1 virus antibodies using the hemagglutination-inhibition (HI) assay. HI titers ≥40 were considered seropositive. We adjusted seroprevalence results to account for previously established HI assay specificity and sensitivity and employed a simple statistical model to estimate the proportion of seropositivity due to pH1N1 virus infection and vaccination. RESULTS: During the study time period, the overall seroprevalence in Tampa Bay, Florida was 25%, increasing to 30% after adjusting for HI assay sensitivity and specificity. We estimated that 5.9% of the population had vaccine-induced seropositivity while 25% had seropositivity secondary to pH1N1 virus infection. The highest cumulative incidence of pH1N1 virus infection was among children aged 5-17 years (53%) and young adults aged 18-24 years (47%), while adults aged ≥50 years had the lowest cumulative incidence (11-13%) of pH1N1 virus infection. CONCLUSIONS: After the peak of the fall wave of the pandemic, an estimated one quarter of the Tampa Bay population had been infected with the pH1N1 virus. Consistent with epidemiologic trends observed during the pandemic, the highest burdens of disease were among school-aged children and young adults.