Marisa Bargsten

Enhancing disease surveillance with novel data streams: challenges and opportunities

Novel data streams (NDS), such as web search data or social media updates, hold promise for enhancing the capabilities of public health surveillance. In this paper, we outline a conceptual framework for integrating NDS into current public health surveillance. Our approach focuses on two key questions: What are the opportunities for using NDS and what are the minimal tests of validity and utility that must be applied when using NDS? Identifying these opportunities will necessitate the involvement of public health authorities and an appreciation of the diversity of objectives and scales across agencies at different levels (local, state, national, international). We present the case that clearly articulating surveillance objectives and systematically evaluating NDS and comparing the performance of NDS to existing surveillance data and alternative NDS data is critical and has not sufficiently been addressed in many applications of NDS currently in the literature.

Increased Antiviral Treatment Among Hospitalized Children and Adults With Laboratory-Confirmed Influenza, 2010-2015

(See the Editorial Commentary by Martin on pages 368–9.)Using population-based surveillance data, we analyzed antiviral treatment among hospitalized patients with laboratory-confirmed influenza. Treatment increased after the influenza A(H1N1) 2009 pandemic from 72% in 2010–2011 to 89% in 2014–2015 (P < .001). Overall, treatment was higher in adults (86%) than in children (72%); only 56% of cases received antivirals on the day of admission.

Influenza Vaccination Modifies Disease Severity Among Community-dwelling Adults Hospitalized With Influenza

Background We investigated the effect of influenza vaccination on disease severity in adults hospitalized with laboratory-confirmed influenza during 2013-14, a season in which vaccine viruses were antigenically similar to those circulating. Methods We analyzed data from the 2013-14 influenza season and used propensity score matching to account for the probability of vaccination within age strata (18-49, 50-64, and ≥65 years). Death, intensive care unit (ICU) admission, and hospital and ICU lengths of stay (LOS) were outcome measures for severity. Multivariable logistic regression and competing risk models were used to compare disease severity between vaccinated and unvaccinated patients, adjusting for timing of antiviral treatment and time from illness onset to hospitalization. Results Influenza vaccination was associated with a reduction in the odds of in-hospital death among patients aged 18-49 years (adjusted odds ratios [aOR] = 0.21; 95% confidence interval [CI], 0.05 to 0.97), 50-64 years (aOR = 0.48; 95% CI, 0.24 to 0.97), and ≥65 years (aOR = 0.39; 95% CI, 0.17 to 0.66). Vaccination also reduced ICU admission among patients aged 18-49 years (aOR = 0.63; 95% CI, 0.42 to 0.93) and ≥65 years (aOR = 0.63; 95% CI, 0.48 to 0.81), and shortened ICU LOS among those 50-64 years (adjusted relative hazards [aRH] = 1.36; 95% CI, 1.06 to 1.74) and ≥65 years (aRH = 1.34; 95% CI, 1.06 to 1.73), and hospital LOS among 50-64 years (aRH = 1.13; 95% CI, 1.02 to 1.26) and ≥65 years (aRH = 1.24; 95% CI, 1.13 to 1.37). Conclusions Influenza vaccination during 2013-14 influenza season attenuated adverse outcome among adults that were hospitalized with laboratory-confirmed influenza.

Reduced Severity of Pertussis in Persons With Age-Appropriate Pertussis Vaccination—United States, 2010–2012

Background In 2012, >48000 pertussis cases were reported in the United States. Many cases occurred in vaccinated persons, showing that pertussis vaccination does not prevent all pertussis cases. However, pertussis vaccination may have an impact on disease severity. Methods We analyzed data on probable and confirmed pertussis cases reported through Enhanced Pertussis Surveillance (Emerging Infections Program Network) between 2010 and 2012. Surveillance data were collected through physician and patient interview and vaccine registries. We assessed whether having received an age-appropriate number of pertussis vaccines (AAV) (for persons aged ≥3 months) was associated with reduced odds of posttussive vomiting, a marker of more clinically significant illness, or of severe pertussis (seizure, encephalopathy, pneumonia, and/or hospitalization). Adjusted odds ratios were calculated using multivariable logistic regression. Results Among 9801 pertussis patients aged ≥3 months, 77.6% were AAV. AAV status was associated with a 60% reduction in odds of severe disease in children aged 7 months-6 years in multivariable logistic regression and a 30% reduction in odds of posttussive vomiting in persons aged 19 months-64 years. Conclusions Serious pertussis symptoms and complications are less common among AAV pertussis patients, demonstrating that the positive impact of pertussis vaccination extends beyond decreasing risk of disease.

Benefit of Early Initiation of Influenza Antiviral Treatment to Pregnant Women Hospitalized With Laboratory-Confirmed Influenza

BACKGROUND We describe the impact of early initiation of influenza antiviral treatment among pregnant women hospitalized with laboratory-confirmed influenza during the 2010-2014 influenza seasons. METHODS Severe influenza was defined as illness with ≥1 of the following: intensive care unit admission, need for mechanical ventilation, respiratory failure, pulmonary embolism, sepsis, or death. Within severity stratum, we used parametric survival analysis to compare length of stay by timing of antiviral treatment, adjusting for underlying conditions, influenza vaccination, and pregnancy trimester. RESULTS Among 865 pregnant women, the median age was 27 years (interquartile range [IQR], 23-31 years). Most (68%) were healthy, and 85% received antiviral treatment. Sixty-three women (7%) had severe influenza, and 4 died. Severity was associated with preterm delivery and fetal loss. Women with severe influenza were less likely to be vaccinated than those without severe influenza (14% vs 26%; P = .03). Among women treated with antivirals ≤2 days versus those treated >2 days from illness onset, the median length of stay was 2.2 days (interquartile range [IQR], 0.9-5.8 days; n = 8) versus 7.8 days (IQR, 3.0-20.6 days; n = 7), respectively, for severe influenza (P = .03) and 2.4 days (IQR, 2.3-2.5 days; n = 153) versus 3.1 days (IQR, 2.8-3.5 days; n = 62), respectively, for nonsevere influenza (P < .01). CONCLUSIONS Early initiation of influenza antiviral treatment to pregnant women hospitalized with influenza may reduce the length of stay, especially among those with severe influenza. Influenza during pregnancy is associated with maternal and infant morbidity, and annual influenza vaccination is warranted.

Impact of pregnancy on observed sex disparities among adults hospitalized with laboratory-confirmed influenza, FluSurv-NET, 2010-2012

Previous FluSurv‐NET studies found that adult females had a higher incidence of influenza‐associated hospitalizations than males. To identify groups of women at higher risk than men, we analyzed data from 14 FluSurv‐NET sites that conducted population‐based surveillance for laboratory‐confirmed influenza‐associated hospitalizations among residents of 78 US counties.