Predictors of severity and prolonged hospital stay of viral acute respiratory infections (ARI) among children under five years in Burkina Faso, 2016-2019.

BACKGROUND: Viruses are the leading etiology of acute respiratory infections (ARI) in children. However, there is limited knowledge on drivers of severe acute respiratory infection (SARI) cases involving viruses. We aimed to identify factors associated with severity and prolonged hospitalization of viral SARI among children < 5 years in Burkina Faso. METHODS: Data were collected from four SARI sentinel surveillance sites during October 2016 through April 2019. A SARI case was a child < 5 years with an acute respiratory infection with history of fever or measured fever ≥ 38 °C and cough with onset within the last ten days, requiring hospitalization. Very severe ARI cases required intensive care or had at least one danger sign. Oropharyngeal/nasopharyngeal specimens were collected and analyzed by multiplex real-time reverse-transcription polymerase chain reaction (rRT-PCR) using FTD-33 Kit. For this analysis, we included only SARI cases with rRT-PCR positive test results for at least one respiratory virus. We used simple and multilevel logistic regression models to assess factors associated with very severe viral ARI and viral SARI with prolonged hospitalization. RESULTS: Overall, 1159 viral SARI cases were included in the analysis after excluding exclusively bacterial SARI cases (n = 273)very severe viral ARI cases were common among children living in urban areas (AdjOR = 1.3; 95% CI: 1.1-1.6), those < 3 months old (AdjOR = 1.5; 95% CI: 1.1-2.3), and those coinfected with Klebsiella pneumoniae (AdjOR = 1.9; 95% CI: 1.2-2.2). Malnutrition (AdjOR = 2.2; 95% CI: 1.1-4.2), hospitalization during the rainy season (AdjOR = 1.71; 95% CI: 1.2-2.5), and infection with human CoronavirusOC43 (AdjOR = 3; 95% CI: 1.2-8) were significantly associated with prolonged length of hospital stay (> 7 days). CONCLUSION: Younger age, malnutrition, codetection of Klebsiella pneumoniae, and illness during the rainy season were associated with very severe cases and prolonged hospitalization of SARI involving viruses in children under five years. These findings emphasize the need for preventive actions targeting these factors in young children.

Acute Gastroenteritis Outbreak Among Colorado River Rafters and Backpackers in the Grand Canyon, 2022.

INTRODUCTION: From April 1 to May 31, 2022, Grand Canyon National Park received increased acute gastroenteritis reports. Pooled portable toilet specimens identified norovirus genogroups I and II. We sought to determine outbreak transmission contributors and individual risk factors while rafting or backpacking in the park. METHODS: Grand Canyon rafters and backpackers were surveyed online from June 13-July 8, 2022, and a Cox proportional hazards model was used to identify predictors associated with illness and adjusted for potential confounding factors. RESULTS: Among 762 surveys, 119 cases and 505 well persons submitted complete survey data. Illness among rafters was associated with interaction with ill persons during the trip (adjusted hazard ratio [adjHR] = 3.4 [95%CI 2.3-5.0]) and lack of any hand hygiene (1.2 [0.7-1.9]) or use of only sanitizer or water (1.6 [1.04-2.6]) before snacks. Younger rafters had higher illness rates compared to those ≥60 y (1.5 [1.2-1.8] for ages 40-59 and 2.2 [1.4-3.5] for ages <40 y). CONCLUSIONS: Person-to-person transmission likely accounted for the widespread outbreak. Future outbreak mitigation efforts on river trips could focus on symptom screening before the trip starts, prompt separation of ill and well passengers, strict adherence to hand hygiene with soap and water, minimizing social interactions among rafting groups, and widespread outbreak notices and education to all park users.

Epidemiology and Risk Factors of Norovirus Infections Among Diarrhea Patients Admitted to Tertiary Care Hospitals in Bangladesh.

BACKGROUND: Norovirus is a major cause of endemic acute gastroenteritis (AGE) worldwide. We described the epidemiology, risk factors, and genotypic distribution of noroviruses among hospitalized patients of all ages in Bangladesh. METHODS: From March 2018 to October 2021, 1250 AGE case patients and controls (age, sex, season, and site matched) were enrolled at 10 hospitals. Demographic and clinical information was collected; real-time reverse-transcriptase polymerase chain reaction (RT-PCR) used to test stool specimens, and positive samples were genotyped. RESULTS: Norovirus was detected in 9% of cases (111 of 1250) and 15% (182 of 1250) of controls. Eighty-two percent of norovirus-positive cases were in children <5 years old. Norovirus-positive AGE hospitalizations occurred year-round, with peaks in April and October. Risk factors for norovirus included age <5 years (adjusted odds ratio, 3.1 [95% confidence interval, 1.9-5.2]) and exposure to a patient with AGE in the 10 days before enrollment (3.8 [1.9-7.2]). GII.3[P16] and GII.4 Sydney[P16] were the predominant genotypes. CONCLUSIONS: We highlight the burden of norovirus in hospital settings. Young age and recent exposure to a patient with AGE were risk factors for norovirus. A high prevalence of norovirus among controls might represent asymptomatic reinfections or prolonged shedding from a previous infection; carefully designed longitudinal studies are needed to improve our understanding of norovirus infections in Bangladesh.

Spatiotemporal Trends in Norovirus Outbreaks in the United States, 2009-2019.

BACKGROUND: Globally, noroviruses cause infections year-round but have recognized winter seasonality in the Northern Hemisphere and yearly variations in incidence. With candidate norovirus vaccines in development, understanding temporal and geographic trends in norovirus disease is important to inform potential vaccination strategies and evaluate vaccine impact. METHODS: We analyzed data from the National Outbreak Reporting System (NORS) and CaliciNet on single-state norovirus outbreaks that occurred during August 2009-July 2019 in the contiguous United States. We defined norovirus season onset and offset as the weeks by which 10% and 90% of norovirus outbreaks in a surveillance year occurred, respectively, and duration as the difference in weeks between onset and offset. We compared norovirus seasons across surveillance years and geographic regions. RESULTS: During August 2009-July 2019, 24 995 single-state norovirus outbreaks were reported to NORS and/or CaliciNet. Nationally, the median norovirus season duration was 24 weeks, with onset occurring between October and December and offset occurring between April and May. Across all years combined, we observed a west-to-east trend in seasonality, with the earliest onset (October) and latest offset (May) occurring in western regions and the latest onset (December) and earliest offset (April) occurring in northeastern regions. CONCLUSIONS: Timing and duration of the US norovirus season varied annually but generally occurred during October-May. Norovirus wintertime seasonality was less distinct in western regions and was progressively more pronounced moving east. Further understanding the drivers of spatiotemporal dynamics of norovirus could provide insights into factors that promote virus transmission and help guide future interventions.

Predicting norovirus and rotavirus resurgence in the United States following the COVID-19 pandemic: a mathematical modelling study.

BACKGROUND: To reduce the burden from the COVID-19 pandemic in the United States, federal and state local governments implemented restrictions such as limitations on gatherings, restaurant dining, and travel, and recommended non-pharmaceutical interventions including physical distancing, mask-wearing, surface disinfection, and increased hand hygiene. Resulting behavioral changes impacted other infectious diseases including enteropathogens such as norovirus and rotavirus, which had fairly regular seasonal patterns prior to the COVID-19 pandemic. The study objective was to project future incidence of norovirus and rotavirus gastroenteritis as contacts resumed and other NPIs are relaxed. METHODS: We fitted compartmental mathematical models to pre-pandemic U.S. surveillance data (2012-2019) for norovirus and rotavirus using maximum likelihood estimation. Then, we projected incidence for 2022-2030 under scenarios where the number of contacts a person has per day varies from70%, 80%, 90%, and full resumption (100%) of pre-pandemic levels. RESULTS: We found that the population susceptibility to both viruses increased between March 2020 and November 2021. The 70-90% contact resumption scenarios led to lower incidence than observed pre-pandemic for both viruses. However, we found a greater than two-fold increase in community incidence relative to the pre-pandemic period under the 100% contact scenarios for both viruses. With rotavirus, for which population immunity is driven partially by vaccination, patterns settled into a new steady state quickly in 2022 under the 70-90% scenarios. For norovirus, for which immunity is relatively short-lasting and only acquired through infection, surged under the 100% contact scenario projection. CONCLUSIONS: These results, which quantify the consequences of population susceptibility build-up, can help public health agencies prepare for potential resurgence of enteric viruses.

Norovirus Outbreaks in Long-term Care Facilities in the United States, 2009-2018: A Decade of Surveillance.

BACKGROUND: In the United States, norovirus is the leading cause of healthcare-associated gastroenteritis outbreaks. To inform prevention efforts, we describe the epidemiology of norovirus outbreaks in long-term care facilities (LTCFs). METHODS: The Centers for Disease Control and Prevention (CDC) collect epidemiologic and laboratory data on norovirus outbreaks from US health departments through the National Outbreak Reporting System (NORS) and CaliciNet. Reports from both systems were merged, and norovirus outbreaks in nursing homes, assisted living, and other LTCFs occurring in 2009-2018 were analyzed. Data from the Centers for Medicare and Medicaid Services and the National Center for Health Statistics were used to estimate state LTCF counts. RESULTS: During 2009-2018, 50 states, Washington D.C., and Puerto Rico reported 13 092 norovirus outbreaks and 416 284 outbreak-associated cases in LTCFs. Participation in NORS and CaliciNet increased from 2009 to 2014 and median reporting of LTCF norovirus outbreaks stabilized at 4.1 outbreaks per 100 LTCFs (interquartile range [IQR]: 1.0-7.1) annually since 2014. Most outbreaks were spread via person-to-person transmission (90.4%), and 75% occurred during December-March. Genogroup was reported for 7292 outbreaks with 862 (11.8%) positive for GI and 6370 (87.3%) for GII. Among 4425 GII outbreaks with typing data, 3618 (81.8%) were GII.4. LTCF residents had higher attack rates than staff (median 29.0% vs 10.9%; P < .001). For every 1000 cases, there were 21.6 hospitalizations and 2.3 deaths. CONCLUSIONS: LTCFs have a high burden of norovirus outbreaks. Most LTCF norovirus outbreaks occurred during winter months and were spread person-to-person. Outbreak surveillance can inform development of interventions for this vulnerable population, such as vaccines targeting GII.4 norovirus strains.

Outbreak of Acute Gastroenteritis Among Rafters and Backpackers in the Backcountry of Grand Canyon National Park, April-June 2022.

On May 11, 2022, the National Park Service (NPS) Office of Public Health (OPH) and Coconino County Health and Human Services (CCHHS) in Flagstaff, Arizona contacted CDC about a rising number of acute gastroenteritis cases among backcountry visitors to Grand Canyon National Park (Grand Canyon). The agencies reviewed illness report forms, assessed infection prevention and control (IPC) practices, and distributed a detailed survey to river rafters and hikers with backcountry permits (backpackers) who visited the Grand Canyon backcountry. During April 1-June 17, a total of 191 rafters and 31 backpackers reported symptoms consistent with acute gastroenteritis. Specimens from portable toilets used by nine river rafting trip groups were tested using real-time reverse transcription-polymerase chain reaction and test results were positive for norovirus. Norovirus-associated acute gastroenteritis is highly transmissible in settings with close person-to-person contact and decreased access to hand hygiene, such as backpacking or rafting. IPC assessments led to recommendations for regular disinfection of potable water spigots throughout the backcountry, promotion of proper handwashing with soap and water when possible, and separation of ill persons from those who are not ill. Prevention and control of acute gastroenteritis outbreaks in the backcountry requires rapid reporting of illnesses, implementing IPC guidelines for commercial outfitters and river rafting launch points, and minimizing interactions among rafting groups.

Impact of Nonpharmaceutical Interventions for Severe Acute Respiratory Syndrome Coronavirus 2 on Norovirus Outbreaks: An Analysis of Outbreaks Reported By 9 US States.

In April 2020, the incidence of norovirus outbreaks reported to the National Outbreak Reporting System dramatically declined. We used regression models to determine if this decline was best explained by underreporting, seasonal trends, or reduced exposure due to nonpharmaceutical interventions (NPIs) implemented for severe acute respiratory syndrome coronavirus 2 using data from 9 states from July 2012 to July 2020. The decline in norovirus outbreaks was significant for all 9 states, and underreporting and/or seasonality are unlikely to be the primary explanation for these findings. These patterns were similar across a variety of settings. NPIs appear to have reduced incidence of norovirus, a nonrespiratory pathogen.

Countries with delayed COVID-19 introduction - characteristics, drivers, gaps, and opportunities.

BACKGROUND: Three months after the first reported cases, COVID-19 had spread to nearly 90% of World Health Organization (WHO) member states and only 24 countries had not reported cases as of 30 March 2020. This analysis aimed to 1) assess characteristics, capability to detect and monitor COVID-19, and disease control measures in these 24 countries, 2) understand potential factors for the reported delayed COVID-19 introduction, and 3) identify gaps and opportunities for outbreak preparedness, particularly in low and middle-income countries (LMICs). We collected and analyzed publicly available information on country characteristics, COVID-19 testing, influenza surveillance, border measures, and preparedness activities in these countries. We also assessed the association between the temporal spread of COVID-19 in all countries with reported cases with globalization indicator and geographic location. RESULTS: Temporal spreading of COVID-19 was strongly associated with countries' globalization indicator and geographic location. Most of the 24 countries with delayed COVID-19 introduction were LMICs; 88% were small island or landlocked developing countries. As of 30 March 2020, only 38% of these countries reported in-country COVID-19 testing capability, and 71% reported conducting influenza surveillance during the past year. All had implemented two or more border measures, (e.g., travel restrictions and border closures) and multiple preparedness activities (e.g., national preparedness plans and school closing). CONCLUSIONS: Limited testing capacity suggests that most of the 24 delayed countries may have lacked the capability to detect and identify cases early through sentinel and case-based surveillance. Low global connectedness, geographic isolation, and border measures were common among these countries and may have contributed to the delayed introduction of COVID-19 into these countries. This paper contributes to identifying opportunities for pandemic preparedness, such as increasing disease detection, surveillance, and international collaborations. As the global situation continues to evolve, it is essential for countries to improve and prioritize their capacities to rapidly prevent, detect, and respond, not only for COVID-19, but also for future outbreaks.

The Effect of Influenza Vaccination on Birth Outcomes in a Cohort of Pregnant Women in Lao PDR, 2014-2015.

BACKGROUND: Some studies suggest that maternal influenza vaccination can improve birth outcomes. However, there are limited data from tropical settings, particularly Southeast Asia. We conducted an observational study in Laos to assess the effect of influenza vaccination in pregnant women on birth outcomes. METHODS: We consented and enrolled a cohort of pregnant woman who delivered babies at 3 hospitals during April 2014-February 2015. We collected demographic and clinical information on mother and child. Influenza vaccination status was ascertained by vaccine card. Primary outcomes were the proportion of live births born small for gestational age (SGA) or preterm and mean birth weight. Multivariate models controlled for differences between vaccinated and unvaccinated women and influenza virus circulation. RESULTS: We enrolled 5103 women (2172 [43%] were vaccinated). Among the 4854 who had a live birth, vaccinated women were statistically significantly less likely than unvaccinated women to have an infant born preterm during the period of high influenza virus circulation (risk ratio [RR] = 0.56, 95% confidence interval [CI], .45-.70), and the effect remained after adjusting for covariates (adjusted RR, 0.69; 95% CI, .55-.87). There was no effect of vaccine on mean birth weight. Vaccinated mothers had a statistically significant elevated risk of having an infant born SGA (adjusted RR, 1.25; 95% CI, 1.11­1.41). CONCLUSIONS: In this observational study, we found indirect evidence of influenza vaccine safety during pregnancy, and women who received vaccine had a reduced risk of delivering a preterm infant during times of high influenza virus circulation. Vaccination may prevent 1 in 5 preterm births that occur during periods of high influenza circulation.

Human Rotaviruses of Multiple Genotypes Acquire Conserved VP4 Mutations during Serial Passage.

Human rotaviruses exhibit limited tropism and replicate poorly in most cell lines. Attachment protein VP4 is a key rotavirus tropism determinant. Previous studies in which human rotaviruses were adapted to cultured cells identified mutations in VP4. However, most such studies were conducted using only a single human rotavirus genotype. In the current study, we serially passaged 50 human rotavirus clinical specimens representing five of the genotypes most frequently associated with severe human disease, each in triplicate, three to five times in primary monkey kidney cells then ten times in the MA104 monkey kidney cell line. From 13 of the 50 specimens, we obtained 25 rotavirus antigen-positive lineages representing all five genotypes, which tended to replicate more efficiently in MA104 cells at late versus early passage. We used Illumina next-generation sequencing and analysis to identify variants that arose during passage. In VP4, variants encoded 28 mutations that were conserved for all P[8] rotaviruses and 12 mutations that were conserved for all five genotypes. These findings suggest there may be a conserved mechanism of human rotavirus adaptation to MA104 cells. In the future, such a conserved adaptation mechanism could be exploited to study human rotavirus biology or efficiently manufacture vaccines.

Attitudes toward a future norovirus vaccine among members of an integrated healthcare delivery system in Portland, Oregon, 2016-2017.

With recent advances in U.S. clinical trials for norovirus vaccines, it is an opportune time to examine what is known about the public receptivity to this novel vaccine. From October 2016-September 2017, we surveyed Kaiser Permanente Northwest members in Portland, Oregon, to ask their level of agreement on a 5-point scale with statements about the need for and willingness to get a potential norovirus vaccine for themselves or their child and analyzed their responses according to age, occupational status, prior vaccine uptake, and history of prior norovirus diagnoses. The survey response rate was 13.5% (n = 3,894); 807 (21%) responded as legal guardians, on behalf of a child <18 y of age and 3,087 (79%) were adults aged 18+ y. The majority of respondents were in agreement about getting the norovirus vaccine, if available (60% of legal guardians, 52% of adults aged 18-64 y, and 55% of adults aged 65+ y). Prior vaccination for influenza and rotavirus (among children) was the only correlate significantly associated with more positive attitudes toward receiving norovirus vaccine. Pre-pandemic attitudes in our all-ages study population reveal generally positive attitudes toward willingness to get a norovirus vaccine, particularly among those who previously received influenza or rotavirus vaccines.

Health Care Utilization and Clinical Management of All-Cause and Norovirus-Associated Acute Gastroenteritis Within a US Integrated Health Care System.

Background: Norovirus-associated acute gastroenteritis (AGE) exacts a substantial disease burden, yet the health care utilization for and clinical management of norovirus-associated AGE are not well characterized. Methods: We describe the health care encounters and therapeutics used for patients with all-cause and norovirus-associated AGE in the Kaiser Permanente Northwest health system from 1 April 2014 through 30 September 2016. Medical encounters for patients with AGE were extracted from electronic health records, and encounters within 30 days of one another were grouped into single episodes. An age-stratified random sample of patients completed surveys and provided stool samples for norovirus testing. Results: In total, 40 348 individuals had 52 509 AGE episodes; 460 (14%) of 3310 participants in the substudy tested positive for norovirus. An overall 35% of all-cause AGE episodes and 29% of norovirus-associated AGE episodes had ≥2 encounters. While 80% of norovirus-associated AGE episodes had at least 1 encounter in the outpatient setting, all levels of the health care system were affected: 10%, 22%, 10%, and 2% of norovirus-associated AGE episodes had at least 1 encounter in virtual, urgent care, emergency department, and inpatient settings, respectively. Corresponding proportions of therapeutic use between norovirus-positive and norovirus-negative episodes were 13% and 10% for intravenous hydration (P = .07), 65% and 50% for oral rehydration (P < .001), 7% and 14% for empiric antibiotic therapy (P < .001), and 33% and 18% for antiemetics (P < .001). Conclusions: Increased health care utilization and therapeutics are likely needed for norovirus-associated AGE episodes during peak norovirus winter seasons, and these data illustrate that effective norovirus vaccines will likely result in less health care utilization.

Household economic costs of norovirus gastroenteritis in two community cohorts in Peru, 2012-2019.

While costs of norovirus acute gastroenteritis (AGE) to healthcare systems have been estimated, out-of-pocket and indirect costs incurred by households are not well documented in community settings, particularly in developing countries. We conducted active surveillance for AGE in two communities in Peru: Puerto Maldonado (October 2012-August 2015) and San Jeronimo (April 2015-April 2019). Norovirus AGE events with PCR-positive stool specimens were included. Data collected in follow-up interviews included event-related medical resource utilization, associated out-of-pocket costs, and indirect costs. There were 330 norovirus-associated AGE events among 3,438 participants from 685 households. Approximately 49% of norovirus events occurred among children <5 years of age and total cost to the household per episode was highest in this age group. Norovirus events cost a median of US $2.95 (IQR $1.04-7.85) in out-of-pocket costs and $12.58 (IQR $6.39-25.16) in indirect costs. Medication expenses accounted for 53% of out-of-pocket costs, and productivity losses accounted for 59% of the total financial burden on households. The frequency and associated costs of norovirus events to households in Peruvian communities support the need for prevention strategies including vaccines. Norovirus interventions targeting children <5 years of age and their households may have the greatest economic benefit.

Evaluation of a Modified Vesikari Severity Score as a Research Tool for Assessing Pediatric Acute Gastroenteritis.

A modified Vesikari severity score (MVSS) is a useful research tool for assessing severity of acute gastroenteritis. We present a MVSS for studies in which a follow-up assessment of symptoms cannot be obtained. The MVSS significantly correlated with other markers of severity, including illness duration and work and school absenteeism.

Tobacco use in 3 billion individuals from 16 countries: an analysis of nationally representative cross-sectional household surveys.

BACKGROUND: Despite the high global burden of diseases caused by tobacco, valid and comparable prevalence data for patterns of adult tobacco use and factors influencing use are absent for many low-income and middle-income countries. We assess these patterns through analysis of data from the Global Adult Tobacco Survey (GATS). METHODS: Between Oct 1, 2008, and March 15, 2010, GATS used nationally representative household surveys with comparable methods to obtain relevant information from individuals aged 15 years or older in 14 low-income and middle-income countries (Bangladesh, Brazil, China, Egypt, India, Mexico, Philippines, Poland, Russia, Thailand, Turkey, Ukraine, Uruguay, and Vietnam). We compared weighted point estimates and 95% CIs of tobacco use between these 14 countries and with data from the 2008 UK General Lifestyle Survey and the 2006-07 US Tobacco Use Supplement to the Current Population Survey. All these surveys had cross-sectional study designs. FINDINGS: In countries participating in GATS, 48·6% (95% CI 47·6-49·6) of men and 11·3% (10·7-12·0) of women were tobacco users. 40·7% of men (ranging from 21·6% in Brazil to 60·2% in Russia) and 5·0% of women (0·5% in Egypt to 24·4% in Poland) in GATS countries smoked a tobacco product. Manufactured cigarettes were favoured by most smokers (82%) overall, but smokeless tobacco and bidis were commonly used in India and Bangladesh. For individuals who had ever smoked daily, women aged 55-64 years at the time of the survey began smoking at an older age than did equivalently aged men in most GATS countries. However, those individuals who had ever smoked daily and were aged 25-34-years when surveyed started to do so at much the same age in both sexes. Quit ratios were very low (<20% overall) in China, India, Russia, Egypt, and Bangladesh. INTERPRETATION: The first wave of GATS showed high rates of smoking in men, early initiation of smoking in women, and low quit ratios, reinforcing the view that efforts to prevent initiation and promote cessation of tobacco use are needed to reduce associated morbidity and mortality. FUNDING: Bloomberg Philanthropies' Initiative to Reduce Tobacco Use, Bill and Melinda Gates Foundation, Brazilian and Indian Governments.

A cross-country comparison of secondhand smoke exposure among adults: findings from the Global Adult Tobacco Survey (GATS).

OBJECTIVE: Exposure to secondhand smoke (SHS) from burning tobacco products causes disease and premature death among non-smoking adults and children. The objective of this study was to determine the nature, extent and demographic correlates of SHS exposure among adults in low- and middle-income countries with a high burden of tobacco use. METHODS: Data were obtained from the Global Adult Tobacco Survey (GATS), a nationally representative household survey of individuals 15 years of age or older. Interviews were conducted during 2008-2010 in Bangladesh, Brazil, China, Egypt, India, Mexico, the Philippines, Poland, Russia, Thailand, Turkey, Ukraine, Uruguay and Vietnam. Descriptive statistics were used to determine the prevalence and correlates of SHS exposure in homes, workplaces, government buildings, restaurants, public transportation and healthcare facilities. RESULTS: Exposure to SHS in the home ranged from 17.3% (Mexico) to 73.1% (Vietnam). Among those who work in an indoor area outside the home, SHS exposure in the workplace ranged from 16.5% (Uruguay) to 63.3% (China). Exposure to SHS ranged from 6.9% (Uruguay) to 72.7% (Egypt) in government buildings, 4.4% (Uruguay) to 88.5% (China) in restaurants, 5.4% (Uruguay) to 79.6% (Egypt) on public transportation, and 3.8% (Uruguay) to 49.2% (Egypt) in healthcare facilities. CONCLUSIONS: A large proportion of adults living in low- and middle-income countries are exposed to SHS in their homes, workplaces, and other public places. Countries can enact and enforce legislation requiring 100% smoke-free public places and workplaces, and can also conduct educational initiatives to reduce SHS exposure in homes.

Risk of Hospitalization and Mortality Following Medically Attended Norovirus Infection-Veterans Health Administration, 2010-2018.

Background: While prior studies have suggested a role for norovirus gastroenteritis in contributing to severe morbidity and mortality, the importance of norovirus as a causal pathogen for hospitalization and mortality remains poorly understood. We estimated the effect of laboratory-confirmed norovirus infection on hospitalization and mortality among a national cohort of veterans who sought care within the Veterans Affairs health care system. Methods: We analyzed electronic health record data from a cohort study of adults who were tested for norovirus within the Veterans Affairs system between 1 January 2010 and 31 December 2018. Adjusted risk ratios (aRRs) for hospitalization and mortality were estimated using log-binomial regression models, adjusting for age, Clostridioides difficile, underlying medical conditions, and nursing home residence. Results: In total, 23 196 veterans had 25 668 stool samples tested for norovirus; 2156 samples (8.4%) tested positive. Testing positive for norovirus infection, compared with testing negative, was associated with a slight increased risk of hospitalization (aRR, 1.13 [95% confidence interval, 1.06-1.21]) and a significant increased risk of mortality within 3 days after the norovirus test (2.14 [1.10-4.14]). The mortality aRR within 1 week and 1 month were reduced to 1.40 (95% confidence interval, .84-2.34) and 0.97 (.70-1.35), respectively. Conclusions: Older veterans with multiple comorbid conditions were at a slight increased risk of hospitalization and significant increased risk of mortality in the 3 days after a norovirus-positive test, compared with those testing negative. Clinicians should be aware of these risks and can use these data to inform clinical management for veterans with norovirus.

Household Transmission of Viral Acute Gastroenteritis Among Participants Within an Integrated Health Care Delivery System, 2014-2016.

Background: While enteric viruses are highly transmissible, household factors associated with transmission are less well documented. We identified individual- and household-level factors associated with viral acute gastroenteritis (AGE) transmission in a large health care network in the United States. Methods: Patients presenting with AGE were enrolled from April 2014 to September 2016. Patients and symptomatic household members were interviewed, and stool specimens were collected and tested for viral pathogens. Within a household, primary cases were those with the earliest symptom onset and a positive viral test result; secondary cases were household contacts (HHCs) with symptom onset 1-7 days from the primary case onset. Transmission households had at least 1 secondary case. Results: Our analysis included 570 primary cases with 1479 HHCs. The overall secondary attack rate was 23%. HHCs were likely to become secondary cases (n = 338) if they were <5 years old (adjusted odds ratio [aOR], 1.8; 95% CI, 1.2-2.6). Secondary transmission was likely to occur if the primary case was aged <5 years (aOR, 2.2; 95% CI, 1.4-3.6) or 5 to 17 years (aOR, 3.3; 95% CI, 1.9-5.7), was norovirus positive (aOR, 2.7; 95% CI, 1.9-3.7), had a diapered contact (aOR: 2.2, 95% CI: 1.6-3.2), or reported symptoms for >4 days (aOR, 1.5; 95% CI, 1.1-2.1). Households with ≥3 members (aOR, 2.1; 95% CI, 1.1-4.5) were more likely to experience transmission. Discussion: Risk of AGE transmission within households increased if the primary case was younger, was norovirus positive, had a longer symptom duration, or had a diapered contact. Targeted prevention messaging around appropriate cleaning, disinfection, and isolation of persons with AGE should be encouraged.