Biennial Pattern Research Articles

Assessing the accuracy and robustness of a process-based model for coffee agroforestry systems in Central America

Coffee is often grown in production systems associated with shade trees that provide different ecosystem services. Management, weather and soil conditions are spatially variable production factors. CAF2007 is a dynamic model for coffee agroforestry systems that takes these factors as inputs and simulates the processes underlying berry production at the field scale. There remain, however, uncertainties about process rates that need to be reduced through calibration. Bayesian statistics using Markov chain Monte Carlo algorithms is increasingly used for calibration of parameter-rich models. However, very few studies have employed multi-site calibration, which aims to reduce parameter uncertainties using data from multiple sites simultaneously. The main objectives of this study were to calibrate the coffee agroforestry model using data gathered in long-term experiments in Costa Rica and Nicaragua, and to test the calibrated model against independent data from commercial coffee-growing farms. Two sub-models were improved: calculation of flowering date and the modelling of biennial production patterns. The modified model, referred to as CAF2014, can be downloaded at https://doi.org/10.5281/zenodo.3608877 . Calibration improved model performance (higher R2, lower RMSE) for Turrialba (Costa Rica) and Masatepe (Nicaragua), including when all experiments were pooled together. Multi-site and single-site Bayesian calibration led to similar RMSE. Validation on new data from coffee-growing farms revealed that both calibration methods improved simulation of yield and its bienniality. The thus improved model was used to test the effect of N fertilizer and shade in different locations on coffee yield.

Prevalence, risk factors, and clinical characteristics of rotavirus and adenovirus among Lebanese hospitalized children with acute gastroenteritis

BackgroundAcute gastroenteritis is a very common infectious disease facing all age groups worldwide, especially the pediatric population. Viruses, bacteria, and parasites are all possible causes of infectious gastroenteritis; however, viruses have become more frequently identified with the advances in the ability to diagnose viral infections, particularly rotavirus and adenovirus. We aimed in our study to compare between the prevalence, risk factors, and clinical characteristics of rotavirus and adenovirus among children with viral gastroenteritis in Lebanon. Materials and methodsA 12-months retrospective study was performed between January 1st and December 31st, 2018 including 308 children aged 1 month to 12 years, who were admitted to three tertiary healthcare centers in South Lebanon. Medical data were retrieved from patients’ files, including clinical and laboratory information. ResultsRotavirus was found in stool of 204 patients (66.23 %), followed by adenovirus in 78 cases (25.32 %), and mixed group (rotavirus and adenovirus) in 26 cases (8.44%). The highest prevalence of rotavirus in our present study was seen among children between 12 and 23 months old, whereas patients infected with adenovirus were mainly aged between 24-35 months or 4–11 months. Majority of patients in the adenovirus and mixed groups had high-grade fever compared to the rotavirus group. Laboratory findings presented significantly higher average of white blood cells (WBCs), absolute neutrophil count (ANC), and C-reactive protein (CRP) in the mixed group compared to the two other groups. Monthly distribution of rotavirus and adenovirus infection revealed a biennial pattern of rotavirus incidence during January and July–August while frequency of adenovirus infection was highest during July–August. ConclusionDue to the high prevalence of viral diarrhea among the pediatric age group in our region, particularly rotavirus and adenovirus, along with the associated non-specific signs and symptoms, we highly recommend that medical laboratories be equipped for virus detection. Also, vaccination against rotavirus should be considered as a prevention strategy.

Continued Evidence of the Impact of Rotavirus Vaccine in Children Less Than 3 Years of Age From the United States New Vaccine Surveillance Network: A Multisite Active Surveillance Program, 2006-2016.

Since 2006, the New Vaccine Surveillance Network has conducted active, population-based surveillance for acute gastroenteritis (AGE) hospitalizations and emergency department (ED) visits in 3 United States counties. Trends in the epidemiology and disease burden of rotavirus hospitalizations and ED visits were examined from 2006 to 2016. Children < 3 years of age hospitalized or visiting the ED with AGE were enrolled from January 2006 through June 2016. Bulk stool specimens were collected and tested for rotavirus. Rotavirus-associated hospitalization and ED visit rates were calculated annually with 2006-2007 defined as the prevaccine period and 2008-2016 as the postvaccine period. Rotavirus genotype trends were compared over time. Over 11 seasons, 6954 children with AGE were enrolled and submitted a stool specimen (2187 hospitalized and 4767 in the ED). Comparing pre- and postvaccine periods, the proportion of children with rotavirus dramatically declined for hospitalization (49% vs 10%) and ED visits (49% vs 8%). In the postvaccine era, a biennial pattern of rotavirus rates was observed, with a trend toward an older median age. G1P[8] (63%) was the predominant genotype in the prevaccine period with a significantly lower proportion (7%) in the postvaccine period (P < .001). G2P[4] remained stable (8% to 14%) in both periods, whereas G3P[8] and G12P[8] increased in proportion from pre- to postvaccine periods (1% to 25% and 17% to 40%), respectively. The epidemiology and disease burden of rotavirus has been altered by rotavirus vaccination with a biennial disease pattern, sustained low rates of rotavirus in children < 3 years of age, and a shift in the residual genotypes from G1P[8] to other genotypes.

Disease burden and seasonal impact of improving rotavirus vaccine coverage in the United States: A modeling study

Prior to vaccine introduction in 2006, rotavirus was the leading cause of severe diarrhea in children under five years of age in the U.S. Vaccination of infants has led to major reductions in disease burden, a shift in the seasonal peak and the emergence of a biennial pattern of disease. However, rotavirus vaccine coverage has remained relatively low (70-75%) compared to other infant immunizations in the U.S. Part of the reason for this lower coverage is that children whose care is provided by family practitioners (FP) have considerably lower probability of being vaccinated compared to those seen be pediatricians (PE). We used a dynamic transmission model to assess the impact of improving rotavirus vaccine coverage by FP and/or PE on rotavirus gastroenteritis (RVGE) incidence and seasonal patterns. A deterministic age-structured dynamic model with susceptible, infectious, and recovered compartments (SIRS model) was used to simulate rotavirus transmission and vaccination. We estimated the reduction of RVGE cases by 2 doses of rotavirus vaccine with three vaccination scenarios: (Status Quo: 85% coverage by pediatricians and 45% coverage by family practitioners; Improved FP: 85% coverage by pediatricians and family practitioners; Improved FP+PE: 95% coverage by pediatricians and family practitioners). In addition, we tested the sensitivity of the model to the assumption of random mixing patterns between children visiting pediatricians and children visiting family practitioners. In this model, higher vaccine coverage provided by family practitioners and pediatricians leads to lower incidence of severe RVGE cases (23% averted in Improved FP and 57% averted in Improved FP+PE compared to Status Quo) including indirect effects. One critical impact of higher total vaccine coverage is the effect on rotavirus epidemic patterns in the U.S.; the biennial rotavirus epidemic patterns shifted to reduced annual epidemic patterns. Additionally, assortative mixing patterns in children visiting pediatricians and family practitioners amplify the impact of increasing vaccine coverage. Other high-income countries that introduced vaccine have not experienced biennial patterns, like the U.S. Our results suggest that increasing overall vaccine coverage to 85% among infants would lead to an overall reduction in incidence with annual epidemic patterns.

93. Trends in the Laboratory Detection of Rotavirus Before and After Implementation of Routine Rotavirus Vaccination: the United States, 2000–2018

BackgroundBefore the introduction of rotavirus vaccine in the United States in 2006, rotavirus infection was the leading cause of severe gastroenteritis among US children.MethodsTo evaluate the long-term impact of rotavirus vaccination on disease burden in the United States, CDC analyzed national laboratory testing data for rotavirus from laboratories participating in CDC’s National Respiratory and Enteric Viruses Surveillance System (NREVSS) during the pre- (2000–2006) and post-vaccine (2007–2018) periods.ResultsNationally, the median annual percentage of positive rotavirus tests declined from 25.6% (range: 25.2–29.4%) in the pre-vaccine era to 6.1% (range: 2.6–11.1%) in the post-vaccine period. When comparing the pre- and post-vaccine era, the annual peak in rotavirus positivity declined from a median of 43.1% (range: 43.8–56.3%) to a median 14.0% (range: 4.8–27.3%) while the season duration was reduced from a median of 26 weeks (range: 23–27 weeks) to 9 weeks (range: 0–18 weeks). In the post-vaccine period, a biennial pattern emerged with alternating years of low and high rotavirus activity.ConclusionThe implementation of rotavirus vaccine has dramatically reduced the disease burden and altered seasonal patterns of rotavirus in the United States; these changes have been sustained over 11 post-vaccine introduction seasons.Disclosures All Authors: No reported Disclosures.

Mixture Mixed Models: Biennial Growth as a Latent Variable in Coffee Bean Progenies

ABSTRACTStatistical analysis ofCoffea arabicaL. progeny production has been a great challenge. In this species, genotypes may present differential biennial behaviors due to different physiological responses to the environmental conditions, indicating a mixture of two subpopulations in the tested progenies. Previously proposed statistical methods are unable to handle data overdispersion and/or bimodality because they assume the same stochastic process generating different phenotypes. This study proposes a finite mixture mixed model for modeling the biennial patterns. Production data for 21 S0:1progenies, evaluated through eight harvests, were used. Individual (per harvest) and repeated measures analyses were performed using conventional mixed models and Gaussian mixture mixed models. The proposed methodology is also illustrated in a simulation study. On a real dataset, the approximated prediction error variance, CV, and residual variance were drastically reduced using mixture mixed models, resulting in a higher estimated heritability and expected gain from selection. Residual dependence across years was lower for the mixture model, but no differences were observed in genetic correlations. The posterior probability matrix captured the biennial pattern, which indicates the probability of a progeny's physiological stage. The Spearman correlation coefficient (0.87) indicates that selection based on grouped means may not be efficient. In general, the proposed model was more efficient for higher subpopulations means differences. The results suggest that for analysis ofC. arabicaprogenies exhibiting different biennial patterns, mixture mixed models are superior to traditional mixed models and to models that structure biennial effects using covariance matrices.

Trends in the Laboratory Detection of Rotavirus Before and After Implementation of Routine Rotavirus Vaccination - United States, 2000-2018.

Before the introduction of rotavirus vaccine in the United States in 2006, rotavirus infection was the leading cause of severe gastroenteritis among U.S. children (1). To evaluate the long-term impact of rotavirus vaccination on disease prevalence and seasonality in the United States, CDC analyzed national laboratory testing data for rotavirus from laboratories participating in CDC's National Respiratory and Enteric Viruses Surveillance System (NREVSS) during the prevaccine (2000-2006) and postvaccine (2007-2018) periods. Nationally, the median annual percentage of tests positive for rotavirus declined from 25.6% (range=25.2-29.4) in the prevaccine period to 6.1% (range=2.6-11.1) in the postvaccine period. When compared with the prevaccine period, the postvaccine period saw declines in the annual peak in rotavirus positivity from a median of 43.1% (range=43.8-56.3) to a median of 14.0% (range=4.8-27.3) and in the season duration from a median of 26 weeks (range=23-27) to a median of 9 weeks (range=0-18). In the postvaccine period, a biennial pattern emerged, with alternating years of low and high rotavirus activity. Implementation of the rotavirus vaccination program has substantially reduced prevalence of the disease and altered seasonal patterns of rotavirus in the United States; these changes have been sustained over 11 seasons after vaccine introduction. Ongoing efforts to improve coverage and on-time vaccination (2) can help maximize the public health impact of rotavirus vaccination.

Unprecedented biennial pattern of birth and mortality in an endangered apex predator, the southern resident killer whale, in the eastern North Pacific Ocean

Unprecedented biennial pattern of birth and mortality in an endangered apex predator, the southern resident killer whale, in the eastern North Pacific Ocean

Seasonal patterns and etiologies of croup in children during the period 2010–2015: A multicenter retrospective study

Purpose: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of para influenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to ex amine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. Methods: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medi cal records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical informa tion were cross-sectionally reviewed and analyzed. Results: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11-31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hos pitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). Conclusion: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most com mon cause of childhood croup; however, croup epidemics could be attributed to other viruses. (Allergy Asthma Respir Dis 2019;7:78-85)

Orange Cane Blotch of Commercial Blackberry in the Southeastern United States

Orange cane blotch affects commercial blackberry production in the southeastern United States, mainly in the Coastal Plain region. The causal agent is a slow-growing parasitic alga, Cephaleuros virescens, which has a wide host range. Disease development is linked to the biennial growth pattern of blackberry, whereby symptoms appear in the early fall and algal lesions expand throughout the winter, spring, and early summer of the following year. Preliminary phylogenetic analysis of 18S rDNA sequences suggests that blackberry isolates from different geographical locations cluster together and are genetically similar to each other and yet differ from isolates of C. virescens obtained from commercial blueberry.

Parasitic sea louse infestations on wild sea trout: separating the roles of fish farms and temperature

BackgroundThe causal relation between parasitic sea lice on fish farms and sea lice on wild fish is a controversial subject. A specific scientific debate has been whether the statistical association between infestation pressure (IP) from fish farms and the number of parasites observed on wild sea trout emerges purely because of a confounding and direct effect of temperature (T).MethodsWe studied the associations between louse infestation on wild sea trout, fish farm activity and temperature in an area that practices coordinated fallowing in Nordhordland, Norway. The data were sampled between 2009 and 2016. We used negative binomial models and mediation analysis to determine to what degree the effect of T is mediated through the IP from fish farms.ResultsThe number of attached lice on sea trout increased with the T when the IP from fish farms was high but not when the IP was low. In addition, nearly all of the effect of rising T was indirect and mediated through the IP. Attached lice remained low when neighbouring farms were in the first year of the production cycle but rose substantially during the second year. In contrast to attached lice, mobile lice were generally seen in higher numbers at lower water temperatures. Temperature had an indirect positive effect on mobile louse counts by increasing the IP which, in turn, raised the sea trout louse counts. Mobile louse counts rose steadily during the year when neighbouring farms were in the first year of the production cycle and stayed high throughout the second year.ConclusionsThe estimates of the IP effect on louse counts along with the clear biennial pattern emerging due to the production cycle of fish farms clearly indicate that fish farms play an important role in the epidemiology of sea lice on wild sea trout. Furthermore, the mediation analysis demonstrates that a large proportion of the effect of T on louse counts is mediated through IP.

Molecular diversity and biennial circulation of enterovirus D68: a systematic screening study in Lyon, France, 2010 to 2016.

BackgroundUnderstanding enterovirus D68 (EV-D68) circulation patterns as well as risk factors for severe respiratory and neurological illness is important for developing preventive strategies. Methods: Between 2010 and 2016, 11,132 respiratory specimens from hospitalised patients in Lyon, France, were screened for EV-D68 by PCR. Phylogenetic relationships of the viral-protein-1 sequences were reconstructed using maximum-likelihood and Bayesian-Markov-Chain-Monte-Carlo approaches. Results: Overall, 171 infections with a biennial pattern were detected, including seven, one, 55, none, 42, one and 65 cases annually during 2010–16. Children (< 16 years-old; n = 150) were mostly affected and 71% (n = 121) of the total patients were under 5 years-old. In 146 patients with medical reviews, 73% (n = 107) presented with acute respiratory distress. Among paediatric patients with medical reviews (n = 133), 55% (n=73) had an asthma/wheezing history, while among adults (n = 13), 11 had underlying diseases. In total, 45 patients had severe infections and 28 patients needed intensive care unit stays. No acute flaccid myelitis (AFM) was detected. We found genotypes A, B1, B2 B3 and D circulating, and no associations between these and clinical presentations. During the study, new genotypes continuously emerged, being replaced over time. We estimated that ancestors of currently circulating genotypes emerged in the late-1990s to 2010. Rises of the EV-D68 effective population size in Lyon coincided with infection upsurges. Phylogenetic analyses showed ongoing diversification of EV-D68 worldwide, coinciding with more infections in recent years and increases of reported AFM paediatric cases. Conclusions: Reinforcement of diagnostic capacities and clinical-based surveillance of EV-D68 infections is needed in Europe to assess the EV-D68 burden.

Biennial Pattern of Rotavirus Gastroenteritis in The Netherlands and a Shifting Age Distribution After a Low Rotavirus Season, 2010-2016.

A hyperendemic rotavirus season was expected after a low-endemic 2014 season in the Netherlands. Rotavirus detections were however similar in 2015 and lower in 2016 compared with 2010-2013. Gastroenteritis consultation rates were also similar in 2015, but the age distribution shifted to older children because of an accumulation of noninfected children. Results indicate a possible shift to a biennial rotavirus pattern.

Longer-term Direct and Indirect Effects of Infant Rotavirus Vaccination Across All Ages in the United States in 2000-2013: Analysis of a Large Hospital Discharge Data Set.

Rotavirus disease rates dramatically declined among children <5 years of age since the rotavirus vaccine was introduced in 2006; population-level impacts remain to be fully elucidated. Data from the Healthcare Cost and Utilization Project State Inpatient Databases were used to conduct a time-series analysis of monthly hospital discharges across age groups for acute gastroenteritis and rotavirus from 2000 to 2013. Rate ratios were calculated comparing prevaccine and postvaccine eras. Following vaccine introduction, a decrease in rotavirus hospitalizations occurred with a shift toward biennial patterns across all ages. The 0-4-year age group experienced the largest decrease in rotavirus hospitalizations (rate ratio, 0.14; 95% confidence interval, .09-.23). The 5-19-year and 20-59-year age groups experienced significant declines in rotavirus hospitalization rates overall; the even postvaccine calendar years were characterized by progressively lower rates, and the odd postvaccine years were associated with reductions in rates that diminished over time. Those aged ≥60 years experienced the smallest change in rotavirus hospitalization rates overall, with significant reductions in even postvaccine years compared with prevaccine years (rate ratio, 0.51; 95% confidence interval, .39-.66). Indirect impacts of infant rotavirus vaccination are apparent in the emergence of biennial patterns in rotavirus hospitalizations that extend to all age groups ineligible for vaccination. These observations are consistent with the notion that young children are of primary importance in disease transmission and that the initial postvaccine period of dramatic population-wide impacts will be followed by more complex incidence patterns across the age range in the long term.

FENOLOGIA DE &lt;i&gt;Astronium graveolens&lt;/i&gt; Jacq. EM FLORESTA ESTACIONAL DECIDUAL EM VITÓRIA DA CONQUISTA, BAHIA

O presente trabalho teve como objetivo estudar a fenologia da espécie arbórea Astronium graveolens Jacq. e correlacioná-la com a precipitação, umidade relativa e temperatura da região de estudo. Os estudos foram conduzidos em um fragmento de Floresta Estacional Decidual, no campus da Universidade Estadual do Sudoeste da Bahia em Vitória da Conquista, Bahia, Brasil. Os indivíduos foram visitados quinzenalmente de setembro de 2010 a dezembro de 2014, quando foram registradas as características fenológicas referentes a desfolhamento, brotamento, floração e frutificação. A análise dos dados fenológicos foi feita através de testes de normalidade, utilização de estatística circular para testar a sazonalidade das fenofases e teste de correlação de postos de Spearman, para verificar com qual intensidade e sentido os eventos climáticos se relacionavam com as fenofases. A espécie apresentou uma queda foliar com padrão decíduo de alta sincronia com concentração no período de seca, seguido pelo brotamento altamente sincrônico que se iniciou no começo da estação úmida. A floração e frutificação apresentaram um padrão bianual, sendo um evento que se manifestou como sendo de baixa sincronia a assincrônico.

Pink Salmon induce a trophic cascade in plankton populations in the southern Bering Sea and around the Aleutian Islands

AbstractWe examined the hypothesis of top‐down (predator) control of plankton populations around the Aleutian Islands and in the southern Bering Sea using a 15 year time series (2000–2014) of plankton populations sampled during summer by Continuous Plankton Recorders. Our analyses reveal opposing biennial patterns in abundances of large phytoplankton and copepods. This pattern is likely caused by the predation pressure on copepods from biennially abundant eastern Kamchatka Pink Salmon that results in a trophic cascade. In odd years, Pink Salmon are exceptionally abundant, large copepod abundance is low, and abundance of large diatoms grazed by copepods is high. Furthermore, large copepod abundance was inversely correlated, and diatom abundance was positively correlated, with Pink Salmon abundance. In addition to influencing the abundance of diatoms and large copepods we also report an effect on phytoplankton taxonomic composition. We find regional differences in the expression of these effects with alternating odd/even year patterns being strongest in the central Southern Bering Sea and eastern Aleutians and reduced, or absent, in the western Aleutians. When the abundance of 2013 Pink Salmon was unexpectedly low, there were consequent changes in the plankton populations, with highest recorded numbers in the time series of large copepods and microzooplankton (hard‐shelled ciliates). These findings emphasise the importance of variability in predator abundance and its effect across the ecosystem, which in this case was greater than physical oceanographic variability.

Three Rotavirus Outbreaks in the Postvaccine Era - California, 2017.

Before the introduction of rotavirus vaccine in 2006, rotavirus was the most common cause of severe diarrhea among U.S. children (1). Currently, two rotavirus vaccines are licensed for use in the United States, both of which have demonstrated good field effectiveness (78%-89%) against moderate to severe rotavirus illness (2), and the use of these vaccines has substantially reduced the prevalence of rotavirus in the United States (3). However, the most recent national vaccine coverage estimates indicate lower full rotavirus vaccine-series completion (73%) compared with receipt of at least 3 doses of vaccines containing diphtheria, tetanus, and pertussis antigens (95%), given on a similar schedule to rotavirus vaccines (4). In the postvaccine era in the United States, rotavirus activity persists in a biennial pattern (3). This report describes three rotavirus outbreaks that occurred in California in 2017. One death was reported; however, the majority of cases were associated with mild to moderate illness, and illness occurred across the age spectrum as well as among vaccinated children. Rotavirus vaccines are designed to mimic the protective effects of natural infection and are most effective against severe rotavirus illness (2). Even in populations with high vaccination coverage, some rotavirus infections and mild to moderate illnesses will occur. Rotavirus vaccination should continue to be emphasized as the best means of reducing disease prevalence in the United States.

Timing of Birth as an Emergent Risk Factor for Rotavirus Hospitalization and Vaccine Performance in the Postvaccination Era in the United States.

Rotavirus vaccines were introduced in the United States in 2006, and in the years since they have fundamentally altered the seasonality of rotavirus infection and have shifted disease outbreaks from annual epidemics to biennial epidemics. We investigated whether season and year of birth have emerged as risk factors for rotavirus or have affected vaccine performance. We constructed a retrospective birth cohort of US children under age 5 years using the 2001-2014 MarketScan database (Truven Health Analytics, Chicago, Illinois). We evaluated the associations of season of birth, even/odd year of birth, and interactions with vaccination. We fitted Cox proportional hazards models to estimate the hazard of rotavirus hospitalization according to calendar year of birth and season of birth assessed for interaction with vaccination. After the introduction of rotavirus vaccine, we observed monotonically decreasing rates of rotavirus hospitalization for each subsequent birth cohort but a biennial incidence pattern by calendar year. In the postvaccine period, children born in odd calendar years had a higher hazard of rotavirus hospitalization than those born in even years. Children born in winter had the highest hazard of hospitalization but also had greater vaccine effectiveness than children born in spring, summer, or fall. With the emergence of a strong biennial pattern of disease following vaccine introduction, the timing of a child's birth has become a risk factor for rotavirus infection.

Annual changes in rotavirus hospitalization rates before and after rotavirus vaccine implementation in the United States

BackgroundHospitalizations for rotavirus and acute gastroenteritis (AGE) have declined in the US with rotavirus vaccination, though biennial peaks in incidence in children aged less than 5 years occur. This pattern may be explained by lower rotavirus vaccination coverage in US children (59% to 73% from 2010–2015), resulting in accumulation of susceptible children over two successive birth cohorts.MethodsRetrospective cohort analysis of claims data of commercially insured US children aged <5 years. Age-stratified hospitalization rates for rotavirus and for AGE from the 2002–2015 rotavirus seasons were examined. Median age and rotavirus vaccination coverage for biennial rotavirus seasons during pre-vaccine (2002–2005), early post-vaccine (2008–2011) and late post-vaccine (2012–2015) years.ResultsAge-stratified hospitalization rates decreased from pre-vaccine to early post-vaccine and then to late post-vaccine years. The clearest biennial pattern in hospitalization rates is the early post-vaccine period, with higher rates in 2009 and 2011 than in 2008 and 2010. The pattern diminishes in the late post-vaccine period. For rotavirus hospitalizations, the median age and the difference in age between biennial seasons was highest during the early post-vaccine period; these differences were not observed for AGE hospitalizations. There was no significant difference in vaccination coverage between biennial seasons.ConclusionsThese observations provide conflicting evidence that incomplete vaccine coverage drove the biennial pattern in rotavirus hospitalizations that has emerged with rotavirus vaccination in the US. As this pattern is diminishing with higher vaccine coverage in recent years, further increases in vaccine coverage may reach a threshold that eliminates peak seasons in hospitalizations.

Trends in rotavirus from 2001 to 2015 in two paediatric hospitals in Atlanta, Georgia.

We compared rotavirus detection patterns before (2001-2006) and after (2008-2015) rotavirus vaccine introduction. We also compared rotavirus detection patterns in odd (2009, 2011, 2013, 2015) and even (2008, 2010, 2012, 2014) years post-vaccine separately. Results of stool rotavirus antigen testing from inpatient, outpatient and emergency department encounters from July 2000 to July 2015 at two paediatric hospital laboratories in Atlanta, Georgia were reviewed. Post-vaccine, rotavirus detection declined (30.2% vs. 13.7% (overall 54.6% decline, P <0.001)), occurred more frequently outside the rotavirus season (19.8% vs. 3.5%; P < 0.001), and was more common among older children (26 vs. 13 median months of age; P < 0.001). During odd years post-vaccine, rotavirus detection was significantly higher than even years (20.2% vs. 6.4%; P < 0.001). Rotavirus detection declined substantially and developed a biennial pattern in the post-vaccine era. The intensity and temporality of rotavirus detection in odd years post-vaccine resembled that observed pre-vaccine, although considerably reduced in magnitude.