Sarah-Blythe Ballard
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Sarah-Blythe Ballard has a total of 17 co-authors. Here are the top co-authors by number of shared publications:
Leland P. Beaty
2 shared publicationsSusan P. Baker
2 shared publicationsCapt Drake H. Tilley
Naval Medical Research Unit No. 6, Callao, Peru
1 shared publicationCarmen Taquiri
Infectious Disease Research Laboratory, Department of Cellular and Molcular Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru
1 shared publicationCaryn Bern
Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California
1 shared publicationCdr Mark P. Simons
Naval Medical Research Unit No. 6, Callao, Peru
1 shared publication
Latest Publications
- Open Access
- 23 December 2021
- Published by American Academy of Pediatrics (AAP) in Pediatrics
- Vol. 149 (1)
Enteropathogen Changes After Rotavirus Vaccine Scale-up
To inform next steps in pediatric diarrhea burden reduction by understanding the shifting enteropathogen landscape after rotavirus vaccine implementation. We conducted a case-control study of 1788 medically attended children younger than 5 years, with and without gastroenteritis, after universal rotavirus vaccine implementation in Peru. We tested case and control stools for 5 viruses, 19 bacteria, and parasites; calculated coinfection-adjusted attributable fractions (AFs) to determine pathogen-specific burdens; and evaluated pathogen-specific gastroenteritis severity using Clark and Vesikari scales. Six pathogens were independently positively associated with gastroenteritis: norovirus genogroup II (GII) (AF 29.1, 95% confidence interval [CI]: 28.0–32.3), rotavirus (AF 8.9, 95% CI: 6.8–9.7), sapovirus (AF 6.3, 95% CI: 4.3–7.4), astrovirus (AF 2.8, 95% CI: 0.0–4.0); enterotoxigenic Escherichia coli heat stable and/or heat labile and heat stable (AF 2.4, 95% CI: 0.6–3.1), and Shigella spp. (AF 2.0, 95% CI: 0.4–2.2). Among typeable rotavirus cases, we most frequently identified partially heterotypic strain G12P[8] (54 of 81, 67%). Mean severity was significantly higher for norovirus GII–positive cases relative to norovirus GII–negative cases (Vesikari [12.7 vs 11.8; P < .001] and Clark [11.7 vs 11.4; P = .016]), and cases in the 6- to 12-month age range relative to cases in other age groups (Vesikari [12.7 vs 12.0; P = .0002] and Clark [12.0 vs 11.4; P = .0016]). Norovirus is well recognized as the leading cause of pediatric gastroenteritis in settings with universal rotavirus vaccination. However, sapovirus is often overlooked. Both norovirus and sapovirus contribute significantly to the severe pediatric disease burden in this setting. Decision-makers should consider multivalent vaccine acquisition strategies to target multiple caliciviruses in similar countries after successful rotavirus vaccine implementation.
- 23 December 2021
- Published by American Academy of Pediatrics (AAP) in Pediatrics
- Vol. 149 (1)
Open AccessEnteropathogen Changes After Rotavirus Vaccine Scale-up
To inform next steps in pediatric diarrhea burden reduction by understanding the shifting enteropathogen landscape after rotavirus vaccine implementation. We conducted a case-control study of 1788 medically attended children younger than 5 years, with and without gastroenteritis, after universal rotavirus vaccine implementation in Peru. We tested case and control stools for 5 viruses, 19 bacteria, and parasites; calculated coinfection-adjusted attributable fractions (AFs) to determine pathogen-specific burdens; and evaluated pathogen-specific gastroenteritis severity using Clark and Vesikari scales. Six pathogens were independently positively associated with gastroenteritis: norovirus genogroup II (GII) (AF 29.1, 95% confidence interval [CI]: 28.0–32.3), rotavirus (AF 8.9, 95% CI: 6.8–9.7), sapovirus (AF 6.3, 95% CI: 4.3–7.4), astrovirus (AF 2.8, 95% CI: 0.0–4.0); enterotoxigenic Escherichia coli heat stable and/or heat labile and heat stable (AF 2.4, 95% CI: 0.6–3.1), and Shigella spp. (AF 2.0, 95% CI: 0.4–2.2). Among typeable rotavirus cases, we most frequently identified partially heterotypic strain G12P[8] (54 of 81, 67%). Mean severity was significantly higher for norovirus GII–positive cases relative to norovirus GII–negative cases (Vesikari [12.7 vs 11.8; P < .001] and Clark [11.7 vs 11.4; P = .016]), and cases in the 6- to 12-month age range relative to cases in other age groups (Vesikari [12.7 vs 12.0; P = .0002] and Clark [12.0 vs 11.4; P = .0016]). Norovirus is well recognized as the leading cause of pediatric gastroenteritis in settings with universal rotavirus vaccination. However, sapovirus is often overlooked. Both norovirus and sapovirus contribute significantly to the severe pediatric disease burden in this setting. Decision-makers should consider multivalent vaccine acquisition strategies to target multiple caliciviruses in similar countries after successful rotavirus vaccine implementation.
- Open Access
- 1 February 2014
- Published by Aerospace Medical Association in Aviation, Space, and Environmental Medicine
- Vol. 85 (2) , 160-6
The U.S. commercial air tour industry: a review of aviation safety concerns.
Ballard SB. The U.S. commercial air tour industry: a review of aviation safety concerns. Aviat Space Environ Med 2014; 85:160–6. The U.S. Title 14 Code of Federal Regulations defines commercial air tours as “flight[s] conducted for compensation or hire in an airplane or helicopter where a purpose of the flight is sightseeing.” The incidence of air tour crashes in the United States is disproportionately high relative to similar commercial aviation operations, and air tours operating under Part 91 governance crash significantly more than those governed by Part 135. This paper reviews the government and industry response to four specific areas of air tour safety concern: surveillance of flight operations, pilot factors, regulatory standardization, and maintenance quality assurance. It concludes that the government and industry have successfully addressed many of these tenet issues, most notably by: advancing the operations surveillance infrastructure through implementation of en route, ground-based, and technological surveillance methods; developing Aeronautical Decision Making and cue-based training programs for air tour pilots; consolidating federal air tour regulations under Part 136; and developing public-private partnerships for raising maintenance operating standards and improving quality assurance programs. However, opportunities remain to improve air tour safety by: increasing the number and efficiency of flight surveillance programs; addressing pilot fatigue with more restrictive flight hour limitations for air tour pilots; ensuring widespread uptake of maintenance quality assurance programs, especially among high-risk operators not currently affiliated with private air tour safety programs; and eliminating the 25-mile exception allowing Part 91 operators to conduct commercial air tours without the safety oversight required of Part 135 operators.
- 1 February 2014
- Published by Aerospace Medical Association in Aviation, Space, and Environmental Medicine
- Vol. 85 (2) , 160-6
Open AccessThe U.S. commercial air tour industry: a review of aviation safety concerns.
Ballard SB. The U.S. commercial air tour industry: a review of aviation safety concerns. Aviat Space Environ Med 2014; 85:160–6. The U.S. Title 14 Code of Federal Regulations defines commercial air tours as “flight[s] conducted for compensation or hire in an airplane or helicopter where a purpose of the flight is sightseeing.” The incidence of air tour crashes in the United States is disproportionately high relative to similar commercial aviation operations, and air tours operating under Part 91 governance crash significantly more than those governed by Part 135. This paper reviews the government and industry response to four specific areas of air tour safety concern: surveillance of flight operations, pilot factors, regulatory standardization, and maintenance quality assurance. It concludes that the government and industry have successfully addressed many of these tenet issues, most notably by: advancing the operations surveillance infrastructure through implementation of en route, ground-based, and technological surveillance methods; developing Aeronautical Decision Making and cue-based training programs for air tour pilots; consolidating federal air tour regulations under Part 136; and developing public-private partnerships for raising maintenance operating standards and improving quality assurance programs. However, opportunities remain to improve air tour safety by: increasing the number and efficiency of flight surveillance programs; addressing pilot fatigue with more restrictive flight hour limitations for air tour pilots; ensuring widespread uptake of maintenance quality assurance programs, especially among high-risk operators not currently affiliated with private air tour safety programs; and eliminating the 25-mile exception allowing Part 91 operators to conduct commercial air tours without the safety oversight required of Part 135 operators.
- 1 November 2013
- Published by Aerospace Medical Association in Aviation, Space, and Environmental Medicine
- Vol. 84 (11) , 1172-1177
Hot-Air Balloon Tours: Crash Epidemiology in the United States, 2000-2011
Ballard SB, Beaty LP, Baker SP. Hot-air balloon tours: crash epidemiology in the United States, 2000-2011. Aviat Space Environ Med 2013; 84:1172–7. Introduction: Hot-air balloon tours are FAR Part 91-governed balloon rides conducted for compensation or hire. Part 91, General Aviation, in general involves the least strict federal regulations and accounts for the majority of aviation crashes and fatalities. Methods: National Transportation Safety Board reports of hot-air balloon tour crashes in the United States from 2000 through 2011 were read and analyzed. Results: During the 12-yr period, 78 hot-air balloon tours crashed, involving 518 occupants. There were 91 serious injuries and 5 fatalities; 83% of crashes resulted in one or more serious or fatal outcomes. Of the serious injuries characterized, 56% were lower extremity fractures. Most crashes (81%) occurred during landing; 65% involved hard landings. Fixed object collisions contributed to 50% of serious injuries and all 5 fatalities. During landing sequences, gondola dragging, tipping, bouncing, and occupant ejection were associated with poor outcomes. Of the crashes resulting in serious or fatal outcomes, 20% of balloons were significantly damaged or destroyed. Discussion: The incidence of morbidity and mortality is high among hot-air balloon tour crashes, and the proportion of balloon crashes attributed to paid rides appears to have increased over time. In addition to examining the role of restraint systems, personal protective equipment, and power line emergency procedures in ballooning, injury prevention efforts should target factors such hard landings, object strikes, gondola instability, and occupant ejections, which are associated with balloon injuries and deaths. Crash outcomes may also improve with vehicle engineering that enables balloons themselves to absorb impact forces.
- 1 November 2013
- Published by Aerospace Medical Association in Aviation, Space, and Environmental Medicine
- Vol. 84 (11) , 1172-1177
Hot-Air Balloon Tours: Crash Epidemiology in the United States, 2000-2011
Ballard SB, Beaty LP, Baker SP. Hot-air balloon tours: crash epidemiology in the United States, 2000-2011. Aviat Space Environ Med 2013; 84:1172–7. Introduction: Hot-air balloon tours are FAR Part 91-governed balloon rides conducted for compensation or hire. Part 91, General Aviation, in general involves the least strict federal regulations and accounts for the majority of aviation crashes and fatalities. Methods: National Transportation Safety Board reports of hot-air balloon tour crashes in the United States from 2000 through 2011 were read and analyzed. Results: During the 12-yr period, 78 hot-air balloon tours crashed, involving 518 occupants. There were 91 serious injuries and 5 fatalities; 83% of crashes resulted in one or more serious or fatal outcomes. Of the serious injuries characterized, 56% were lower extremity fractures. Most crashes (81%) occurred during landing; 65% involved hard landings. Fixed object collisions contributed to 50% of serious injuries and all 5 fatalities. During landing sequences, gondola dragging, tipping, bouncing, and occupant ejection were associated with poor outcomes. Of the crashes resulting in serious or fatal outcomes, 20% of balloons were significantly damaged or destroyed. Discussion: The incidence of morbidity and mortality is high among hot-air balloon tour crashes, and the proportion of balloon crashes attributed to paid rides appears to have increased over time. In addition to examining the role of restraint systems, personal protective equipment, and power line emergency procedures in ballooning, injury prevention efforts should target factors such hard landings, object strikes, gondola instability, and occupant ejections, which are associated with balloon injuries and deaths. Crash outcomes may also improve with vehicle engineering that enables balloons themselves to absorb impact forces.
- 1 August 2013
- Published by Elsevier in Accident Analysis & Prevention
- Vol. 57, 49-54
US commercial air tour crashes, 2000–2011: Burden, fatal risk factors, and FIA Score validation
- 1 August 2013
- Published by Elsevier in Accident Analysis & Prevention
- Vol. 57, 49-54
US commercial air tour crashes, 2000–2011: Burden, fatal risk factors, and FIA Score validation