Survey Analysis of Influenza Vaccination Status Among Children Aged 0-6 Years

Objective:This study aims to investigate the influenza vaccination status of children aged 0-6 years in Changzhi City and to analyze its influencing factors.Methods:A questionnaire was distributed to 228 randomly selected parents of children aged 0-6 in Changzhi City to investigate the children’s influenza vaccination status.Results:(1)A total of 217 valid questionnaires were collected in this survey,with a response rate of 95.2%.(2)The results showed that the main reasons affecting children’s influenza vaccination were,in order,worrying about the safety of the influenza vaccine,believing that influenza vaccination was not necessary,and not knowing the time of the vaccination.(3)Multivariate logistic regression analysis showed that compared with children aged 0-2 years old,those aged 2-4 years old(OR=0.121,95%CI=0.032-0.301)and 4-6 years old(OR=0.385,95%CI=0.228-0.530)had lower cumulative influenza vaccination rates.Compared to the group with parental awareness of flu vaccines,the moderate awareness group(OR=2.319,95%CI=1.527-3.015)and the high awareness group(OR=2.932,95%CI=1.598-4.966)exhibited higher cumulative influenza vaccination rates among children.Parents acquire knowledge about influenza and its vaccines through vaccination centers(OR=1.396,95%CI=1.049-2.050)and doctors(OR=1.763,95%CI=1.291-2.774),which serves as a facilitating factor for influenza vaccination among 0-6-year-old children in Changzhi urban area.Conclusion:The age of the child,parental knowledge of the influenza vaccine,and parental communication with the vaccination center and the physician at the visit were the main influencing factors for influenza vaccination.

The Epidemiology of Influenza in Children Hospitalized at the Hospital of Sikasso, Mali 2015-2019

Introduction: Influenza is an acute respiratory infectious disease, highly contagious due to influenza viruses. The objective of this work was to identify, understand the epidemiology of circulating strains and estimate disease transmission. Patients and Methods: The study was carried out in the pediatric department of the Sikasso Hospital. This was a prospective, longitudinal descriptive study over a five-year period (January 1, 2015 to December 31, 2019). She was interested in severe acute respiratory infections (SARI) for hospitalized patients in the pediatric department. Results: During the study period the prevalence of severe acute respiratory infections among hospitalized children was 21.85‰. The majority of cases were observed in 2019 with 58 cases, the sex ratio was 1.8. The age group from 0 to 1 was the most represented with 100 cases (48.30%) followed by 2 to 4 years 73 cases (35.24%) and 5 to 15 years 34 cases (16.46%). More than half of the patients lived in rural areas 129 (62.31%). Fever and cough were present in the majority of patients. No children had received influenza vaccination. In study 36 (17.39%) cases were positive for influenza A and B.

Parents＇ Perception and their Decision on their Children＇s Vaccination Against Seasonal Influenza in Guangzhou

Background： Seasonal influenza epidemic occurs every year in Guangzhou, which can affect all age groups. Young children are the most susceptible targets. Parents can decide whether to vaccinate their children or not based on their own consideration in China. The aim of this study was to identify factors that are important for parental decisions on vaccinating their children against seasonal influenza based on a modified health belief model （HBM）. Methods： A cross-sectional study was conducted in Guangzhou, China. A total of 335 parents who had at least on child aged between 6 months and 3 years were recruited from women and children＇s hospital in Guangzhou, China. Each eligible subject was invited for a face-to-face interview based on a standardized questionnaire. Results： Uptake of seasonal influenza within the preceding 12 months among the target children who aged between 6 months and 36 months was 47.7%. Around 62.4% parents indicated as being ＂likely/very likely＂ to take their children for seasonal influenza vaccination in the next 12 months. The hierarchical logistic regression model showed that children＇s age （odds ratio [OR] =2.59, 95% confidence interval [C/I： 1.44-4.68）, social norm （OR = 2.08, 95% CI： 1.06-4.06） and perceived control （OR - 2.96, 95% CI： 1.60-5.50） were significantly and positively associated with children＇s vaccination uptake within the preceding 12 months; children with a history of taking seasonal influenza vaccine （OR = 2.50, 95% CI： 1.31-4.76）, perceived children＇s health status （OR = 3.36, 95% C1： 1.68-6.74）, worry/anxious about their children influenza infection （OR = 2.31, 95% CI： 1.19-4.48） and perceived control （OR = 3.21, 95% CI： 1.65-6.22） were positively association with parental intention to vaccinate their children in the future 12 months. However, anticipated more regret about taking children for the vaccination was associated with less likely to vaccinate children within the preceding 12 months （OR = 0.21, 95% CI： 0.08-0.52）. Conclusions： The modified HBM provided a good theoretical basic for understanding factors associated with parents＇ decisions on their children＇s vaccination against seasonal influenza.

Brain Complications with Influenza Infection in Children

Objectives: To summarize the characteristics and research progress of influenza-associated brain complications in children and provide references for early diagnosis and brain protection treatment. Methods: Studied published articles of influenza-associated neurocomplications in children from PubMed and summarizes them from epidemiology, clinical manifestations, diagnosis and treatment, and basic research progress. Results: Common brain complications in flu-children include febrile seizures, influenza-associated encephalopathy (IAE), acute or post-influenza encephalitis, and the most severe condition is acute necrotizing encephalopathy (ANE). However, the mechanism and relevant factors of influenza-associated brain damage have not been elucidated. Conclusion: Influenza could be accompanied by various brain lesion complications in dif ferent stages of the disease, some of which are life-threatening or leave severe neurological sequelae, such as ANE. Due to different brain injury mechanisms, specific early diagnosis and brain protection treatment for different complications are unclear or unanimous. Therefore, further classification and basic research are needed.

Pandemic influenza 2009: Impact of vaccination coverage on critical illness in children, a Canada and France observational study

AIM To study the impact of vaccination critical illness due to H1N1pdm09, we compared the incidence and severity of H1N1pdm09 infection in Canada and France.METHODS We studied two national cohorts that included children with documented H1N1pdm09 infection, admitted to a pediatric intensive care unit(PICU) in Canada and in France between October 1, 2009 and January 31, 2010.RESULTS Vaccination coverage prior to admission to PICUs was higher in Canada than in France(21% vs 2% of children respectively, P < 0.001), and in both countries, vaccination coverage prior to admission of these critically ill patients was substantially lower than in the general pediatric population(P < 0.001). In Canada, 160 children(incidence = 2.6/100000 children) were hospitalized in PICU compared to 125 children(incidence = 1.1/100000) in France(P < 0.001). Mortality rates were similar in Canada and France(4.4% vs 6.5%, P = 0.45, respectively), median invasive mechanical ventilation duration and mean PICU length of stay were shorter in Canada(4 d vs 6 d, P = 0.02 and 5.7 d vs 8.2 d, P = 0.03, respectively). H1N1pdm09 vaccination prior to PICU admission was associated with a decreased risk of requiring invasive mechanical ventilation(OR = 0.30, 95%CI: 0.11-0.83, P = 0.02).CONCLUSION The critical illness due to H1N1pdm09 had a higher incidence in Canada than in France. Critically ill children were less likely to have received vaccination prior to hospitalization in comparison to general population and children vaccinated had lower risk of ventilation.

A SEASONAL INFLUENZA THEORY AND MATHEMATICAL MODEL INCORPORATING METEOROLOGICAL AND SOCIO-BEHAVIORAL FACTORS

On the basis of a comprehensive literature review and data analysis of global influenza surveillance, a transmission theory based numerical model is developed to understand the causative factors of influenza seasonality and the biodynamical mechanisms of seasonal flu. The model is applied to simulate the seasonality and weekly activity of influenza in different areas across all continents and climate zones around the world. Model solution and the good matches between model output and actual influenza indexes affirm that influenza activity is highly auto-correlative and relies on determinants of a broad spectrum. Internal dynamic resonance; variations of meteorological elements (solar radiation, precipitation and dewpoint); socio-behavioral influences and herd immunity to circulating strains prove to be the critical explanatory factors of the seasonality and weekly activity of influenza. In all climate regions, influenza activity is proportional to the exponential of the number of days with precipitation and to the negative exponential of quarter power of sunny hours. Influenza activity is a negative exponential function of dewpoint in temperate and arctic regions and an exponential function of the absolute deviation of dewpoint from its annual mean in the tropics. Epidemics of seasonal influenza could be deemed as the consequence of the dynamic resonance and interactions of determinants. Early interventions (such as opportune vaccination, prompt social distancing, and maintaining incidence well below a baseline) are key to the control and prevention of seasonal influenza. Moderate amount of sunlight exposure or Vitamin D supplementation during rainy and short-day photoperiod seasons, more outdoor activities, and appropriate indoor dewpoint deserve great attention in influenza prevention. To a considerable degree, the study reveals the mechanism of influenza seasonality, demonstrating a potential for influenza activity projection. The concept and algorithm can be explored for further applications.

The Link between Seasonal Influenza and NCDs: Strategies for Improving Vaccination Coverage

Seasonal influenza is a major public health problem globally, causing significant morbidity and mortality, especially in high-risk groups. Children and adults with underlying chronic non-communicable diseases (NCDs) are especially vulnerable to complications, hospitalizations and even death from the infection. However, the link between NCDs and influenza is frequently underestimated. Vaccination against influenza is the single most effective way to reduce this vulnerability in people living with NCDs. Irrespective vaccination rates in this group fall short of the WHO recommended target of 75%. This paper explores the relationship between seasonal influenza and NCDs and proposes strategies for increasing vaccination coverage among the target groups.

Immunological Responses against Different Lineages of Influenza B Antigen in School Children during Two Consecutive Seasons

While Influenza B viruses currently circulating worldwide are of two distinct evolutionary hemagglutinin lineages, current trivalent inactivated influenza virus vaccines (TIV) contain only a single component. Single doses of TIV containing B antigen of B/Florida/4/2006 (Yamagata-like) or B/Brisbane/60/2008 (Victoria-like) were administered during 2008/2009 and 2009/2010 influenza seasons, respectively. The objective of this study was to evaluate the immunological response against different lineages of B antigens in school-aged children. A non-randomized sero-epidemiological study was conducted and the immunogenicity responses based on sero-protection rate and geometric mean titre ratio (GMTR) of hemagglutination inhibition (HI) antibodies were measured before and after immunization as well as post-influenza season. Our results suggested that school-aged children under the age of 9 years receiving TIV vaccination induced and retained higher level of sero-protection rate (66.7% and 69% for the 2008-09 and 2009-10 season, respectively) to the homologous lineage than the heterologous lineage post-vaccination (19.4% and 27.6% for the 2008-09 and 2009-10 season, respectively). The need for the quadrivalent TIV by including both lineages of influenza B viruses is recommended in this study, particularly for children under the age of 9 years.

Characteristics and Mortality Risk Factors of Influenza-Associated Encephalopathy/Encephalitis in Children in a Tertiary Pediatric Hospital in China, 2016-2019

Background: Seasonal influenza associated neurological complications had high mortality and morbidity rates in children. In this study, we aimed to investigate the clinical characteristics and mortality risk factors in children with influenza-associated encephalopathy. Methods: Retrospectively analyze the clinical data, laboratory tests, and imaging examinations of 68 children diagnosed with influenza-associated encephalopathy from January 2016 to December 2019 at Guangzhou Women and Children’s Medical Center, and the cases were divided into survival and non-survival groups by disease outcome and analyzed between two groups. Chi-square test or Mann-Whitney rank sum test was used for comparison between groups, and multivariate Logistic regression analysis was used for the analysis of risk factors for death. Results: Among the 68 children with influenza-associated encephalopathy, 40 were male, and 28 were female, aged from 3 months to 13 years, of which 66.18% (45/68) were under 5 years old. Pathogenetic tests showed that influenza virus type A accounted for 63.24% (43/68), and influenza virus type B accounted for 36.76% (25/68). Typical brain MRI changes in childhood influenza-associated encephalopathy were bilateral symmetrical lesions of the thalamus, basal ganglia, brainstem, and cerebellum. 68 patients had a mortality rate of 20.59% (14/68), with a significantly higher proportion of fever peak > 39°C, Acute Disturbance of Consciousness (ADOC), and cardiac arrest in the non-survival group than in the survival group (P < 0.05). Laboratory tests showed significantly higher in Alanine Aminotransferase (ALT), Aspartate Transaminase (AST), Creatinine Kinase (CK), Lactate Dehydrogenase (LDH), lactate, and C-Reactive Protein (CRP). And CSF protein levels in the non-survival group compared with the survivor (P < 0.05), among them, elevated ALT, AST, LDH, and CSF protein were independent high-risk factors for death from influenza-associated encephalopathy. Conclusions: Children under 5 years of age with influenza are prone to combine neurological complications and have a higher mortality rate. Significant elevations in ALT, AST, LDH, and CSF proteins predict death from influenza-associated encephalopathy in children.

Level of Implementation of Seasonal Malaria Chemoprevention in Children Aged between 3 to 59 Months in Koza, Far North Region of Cameroon

Background: Seasonal Malaria Chemoprevention (SMC) is a strategy put in place by World Health Organisation (WHO) to fight against malaria in zones of high seasonal malaria transmission since the year 2012. This strategy has been implemented in the Far North and North regions of Cameroon since the year 2016. Despite the implementation of this program the number of cases and deaths from seasonal malaria among the under 5 seems to be rising in Koza health area. Objective: To determine the level of implementation of the SMC Program and its impact on the mortality of children aged 03 to 59 months during the season of high transmission. Methods: This was a community-based cross-sectional and 7-years retrospective study. Data was surveyed for 3 months in 3 health areas of Koza health area. Data were collected and typed in Kobo collect, cleaned in MS Excel and analyzed in SPSS version 25 to come out with descriptive statistics. Results: Among the 172 households, female children were mostly represented 99 (57%) The age group mostly represented was 2 years. The population knowledge on SMC’s overall score was above average. The overall coverage rate (4 cycles) was 84% from interviewed parents and 67.5% from SMC cards. More than 23% of children experienced at least one side effect with the most common being vomiting (72%). The population’s overall impression of the program was good at 85%. The trends SMC coverage showed a sinusoidal fluctuation from 2015 to 2021, 2016 to 2019 and 2020 to 2021. Conclusion: The coverage rate of SMC was high thus the program is well implemented.

Influenza B infections in children:A review

Influenza B(IFB)virus belongs to the Orthomyxoviridae family and has two antigenically and genetically distinct lineages;B/Victoria/2/87-like(Victoria lineage)and B/Yamagata/16/88-like(Yamagata lineage).The illness caused by IFB differs from that caused by influenza A.Outbreaks of IFB occur worldwide and young children exposed to IFB are likely to have a higher disease severity compared with adults.IFB mostly causes mild to moderate respiratory illness in healthy children.However,the involvement of other systems,a severe disease especially in children with chronic medical conditions and immunosuppression,and rarely mortality,has been reported.Treatment with oseltamivir or zanamivir decreases the severity of illness and hospitalization.Due to the enormous health and economic impact of IFB,these strains are included in vaccines.IFB illness is less studied in children although its impact is substantial.In this review,the epidemiology,clinical manifestations,treatment,prognosis,and prevention of IFB illness in children are discussed.

Risk Factors of Influenza-Associated Necrotizing Encephalopathy in Children

Objective: A case-control study of Influenza-Associated Necrotizing Encephalopathy (IANE) in children was conducted to explore the risk factors for the diagnosis of IANE, and to provide a predictive reference for the diagnosis of IANE. Methods: The children with IANE who received treatment in our hospital from January 2016 to December 2020 were selected as the study group, and the children with Influenza-Associated Encephalopathy (IAE) group who received treatment in the same period were selected as the control group. The blood biochemical, coagulation function and cerebrospinal fluid test results of the two groups were analyzed by univariate analysis. Receiver Operating Characteristic curve (ROC) analysis was used to determine the optimal threshold point of each index for the indicators with statistically significant differences in univariate analysis results, and multivariate Logistic stepwise regression analysis was performed according to the optimal threshold points. Results: In the IANE group, there were 32 children, including 20 males and 12 females, aged 60 (35, 84) months. There were 40 children in IAE group, including 26 males and 14 females, aged 58 (23, 97) months. Univariate results showed that serum Lactate Dehydrogenase (LDH), Cerebrospinal Fluid Lactate Dehydrogenase (CSF LDH) and Cerebrospinal Fluid Protein (CSF PRO) in the IANE group were significantly higher than those in the IAE group, and the difference between the two groups was statistically significant (P < 0.001). The optimal threshold points of blood LDH, CSF LDH and CSF PRO by ROC curve analysis were 535 U/L, 67 U/L and 0.49 g/L, respectively. Further Multivariate Logistic stepwise regression analysis showed that LDH > 535 U/L (OR = 31.264, 95% CI: 5.892 - 165.878, P < 0.001) and CSF PRO > 0.49 g/L (OR = 7.695, 95% CI: 1.052 - 56.305, P = 0.044) were independent risk factors for IANE. Conclusion: For children with influenza whose neurological symptoms appear rapidly and persist in the early stages of the disease, blood LDH > 535 U/L and CSF PRO > 0.49 g/L are independent risk factors for IANE.

Invasive <i>Haemophilus influenzae</i>Type b (Hib) Infections in Children in the Pediatric Department of the University Hospital Gabriel Touré(UH-GT)

Introduction: According to Mali’s National Immunization Center, the Haemophilus influenzae b (Hib) vaccine coverage rate was 90% in 2015. Our work aimed to study invasive bacterial infections due to Haemophilus influenzae type b in children aged 0 - 15 years hospitalized in the pediatrics department of the UH-GT. Method: We carried out a retrospective descriptive study from January 2017 to December 2018 (i.e. 2 years) among children aged 0 - 15 years and hospitalized for Haemophilus influenzae type b infection confirmed by culture (blood culture, Cerebro-spinal Fluid, and pleural and skin fluid). Results: Thirty-three cases of Hib infections were collected giving a frequency of 0.2% and the age group 3 months to 3 years was the most affected (72.73%). Children who received no vaccine accounted for 21.21%. The Cerebro-spinal Fluid culture and other samples (pleural and skin) identified the bacterium in 100% of cases, against 72.72% in the blood culture Meningitis was the most frequent pathology (78.79%) and the lethality was high (21.21%). Conclusion: Despite the introduction of the Hib vaccine in the routine immunization program in Mali, Hib infections remain with a high lethality linked to meningitis.

Cost-effectiveness of seasonal influenza vaccination of children in China:a modeling analysis

Background China has a high burden of influenza-associated illness among children.We aimed to evaluate the cost-effectiveness of introducing government-funded influenza vaccination to children in China(fully-funded policy)compared with the status quo(self-paid policy).Methods A decision tree model was developed to calculate the economic and health outcomes,from a societal perspective,using national-and provincial-level data.The incremental cost-effectiveness ratio(ICER)[incremental costs per quality-adjusted life year(QALY)gained]was used to compare the fully-funded policy with the self-paid policy under the willingness-to-pay threshold equivalent to national and provincial GDP per capita.Sensitivity analyses were performed and various scenarios were explored based on real-world conditions,including incorporating indirect effect into the analysis.Results Compared to the self-paid policy,implementation of a fully-funded policy could prevent 1,444,768[95%uncertainty range(UR):1,203,446-1,719,761]symptomatic cases,92,110(95%UR:66,953-122,226)influenza-related hospitalizations,and 6494(95%UR:4590-8962)influenza-related death per season.The fully-funded policy was cost-effective nationally(7964 USD per QALY gained)and provincially for 13 of 31 provincial-level administrative divisions(PLADs).The probability of a funded vaccination policy being cost-effective was 56.5%nationally,and the probability in 9 of 31 PLADs was above 75%.The result was most sensitive to the symptomatic influenza rate among children under 5 years[ICER ranging from−25,612(cost-saving)to 14,532 USD per QALY gained].The ICER of the fully-funded policy was substantially lower(becoming cost-saving)if the indirect effects of vaccination were considered.Conclusions Introducing a government-funded influenza policy for children is cost-effective in China nationally and in many PLADs.PLADs with high symptomatic influenza rate and influenza-associated mortality would benefit the most from a government-funded influenza vaccination program.

Three Cases of Rhabdomyolysis Induced by Viral Infections in Children and Literature Review

The clinical data of 3 patients with rhabdomyolysis(RM)caused by different viral infections were retrospectively reviewed.The diagnoses were established according to the clinical symptoms,physical signs,myocardial enzymes,and muscle biopsy.Case 1 was a 11-year-old boy with influenza A virus infection,whose major symptoms were fever,cough and myalgia.After the treatment of active anti-virus,hydration,and alkalinization,the patient completely recovered.Case 2 was a 10-year-old girl with Epstein-Barr(EB)virus infection who had significant musculoskeletal pain and muscle weakness symptoms with significantly elevated serum creatine kinase.After active hydration and anti-infective treatment,the patient s condition returned to normal.Case 3 was a 15-year・old boy with human cytomegalovirus infection,whose symptoms were mainly repeated fever,accompanied by myalgia and facial edema.Antibacterial therapy was ineffective,and the disease progressed with respiratory muscle weakness and multiple organ injuries.After antiviral treatment,respiratory support and hemofiltration,the symptoms relieved and patient recovered without sequela.With literature review,we believe that although influenza virus,Epstein-Barr virus and cytomegalovirus rarely cause RM in children,it should be attached attention to.With early diagnosis and treatment,the prognosis is favorable.

Pattern of Acute Asthma Seen in Children Emergency Department of the River State University Teaching Hospital Portharcourt Nigeria

Acute exacerbations of asthma are one of the leading causes of emergency room visits and hospitalizations in children. Asthma exacerbations also demonstrate a seasonal pattern in which high rates can be seen at a particular season and knowledge of the seasonal pattern of asthma exacerbation in any locality can improve asthma management. Objective: To determine the prevalence, management outcome and seasonal pattern of emergency department visits for acute exacerbation of asthma. Methods: This was a retrospective review of the emergency department register of all asthma admissions in the Rivers State University Teaching Hospital, Portharcourt, Nigeria over a five year period from January 2014 to December 2018. Results: A total of 205 (2.9%) asthma-related visits were recorded out of 7046 emergency room visits. The mean age of the patients was 6.1 (±4.2) yrs, with an M:F ratio of 1.97:1. The median length of hospital stay was 24 hrs. Children older than 11 yrs were more likely to be admitted for >48 hrs (OR 4.18, 95% CI;1.67, 10.39, P;0.003). Emergency department visits for asthma were more in the rainy season April-September 129 (63.9%) with a peak in May. There is a significant variation in the seasonal pattern of emergency room asthma admission with age (P = 0.018). Children >3 yrs have their highest admission rates in May while younger children experience two peaks in February and November. Conclusion: Asthma exacerbation is more in rainy season among children in Portharcourt although there is a variation in seasonal pattern of asthma exacerbation with age.

Clinical Demographic Patterns of Type 1 Diabetes in Saudi Children in Tabuk City, 2000-2010

We aimed to identify the variation in the clinical background of children diagnosed with type 1 diabetes mellitus (T1DM) at King Salman Military Hospital (KSMH), Tabuk City, Kingdom of Saudi Arabia, from 2000 to 2010. Methods: This retrospective observational study was based on the clinical records of pediatric diabetes outpatients at KSMH. All children aged Results: Of 313 patients recruited, female patients were predominant (p = 0.002). The mean age of onset was 6.46 years (standard deviation, 3.02). One-third of the newly diagnosed patients were overweight (35.5%). Diabetic ketoacidosis (DKA) was the presenting feature in 38.0% of patients, wherein female patients and those aged 0 - 3 years exhibited the highest likelihood of developing DKA (odds ratio, 1.7 and 2.9, respectively). Moreover, underweight children had a greater DKA incidence than healthy, overweight, or obese children (p = 0.02). Conclusion: This study provides additional data on T1DM in the population of the Kingdom of Saudi Arabia. In particular, we found a female predominance at presentation as well as 2 peaks for age at onset. Moreover, the BMI was lower in younger age groups overall, but was greater in older boys. Furthermore, the DKA rates were high in younger children. Thus, our data confirm the presence of variable clinical patterns in the Kingdom of Saudi Arabia, which requires further epidemiological analysis using national registry data.

Epidemiological features of seasonal influenza transmission among 11 climate zones in Chinese mainland

Background Previous studies provided some evidence of meteorological factors influence seasonal influenza transmission patterns varying across regions and latitudes. However, research on seasonal influenza activities based on climate zones are still in lack. This study aims to utilize the ecological-based Koppen Geiger climate zones classification system to compare the spatial and temporal epidemiological characteristics of seasonal influenza in Chinese mainland and assess the feasibility of developing an early warning system.Methods Weekly influenza cases number from 2014 to 2019 at the county and city level were sourced from China National Notifiable Infectious Disease Report Information System. Epidemic temporal indices, time series seasonality decomposition, spatial modelling theories including Moran’s/ and local indicators of spatial association were applied to identify the spatial and temporal patterns of influenza transmission.Results All climate zones had peaks in Winter-Spring season. Arid, desert, cold (BWk) showed up the first peak. Only Tropical, savannah (Aw) and Temperate, dry winter with hot summer (Cwa) zones had unique summer peak. Temperate, no dry season and hot summer (Cfa) zone had highest average incidence rate (IR) at 1.047/100,000. The Global Moran’s/ showed that average IR had significant clustered trend (z = 53.69,P < 0.001), with local Moran’s/ identified high-high cluster in Cfa and Cwa. IR differed among three age groups between climate zones (0-14 years old:F = 26.80,P < 0.001;15-64 years old:F = 25.04,P < 0.001;Above 65 years old:F = 5.27,P < 0.001). Age group 0-14 years had highest average IR in Cwa and Cfa (IR= 6.23 and 6.21) with unique dual peaks in winter and spring season showed by seasonality decomposition.Conclusions Seasonal influenza exhibited distinct spatial and temporal patterns in different climate zones. Seasonal influenza primarily emerged in BWk, subsequently in Cfa and Cwa. Cfa, Cwa and BSk pose high risk for seasonal influenza epidemics. The research finds will provide scientific evidence for developing seasonal influenza early warning system based on climate zones.

Molecular Epidemiology and Vaccine Compatibility Analysis of Seasonal Influenza Viruses in Wuhan, 2016–2019

Influenza viruses(FLUV)cause high morbidity and mortality annually in the world and pose a serious threat to the public health.Wuhan,as an important transportation hub in China,has a dense population and suitable climate,which also lays a major hidden danger for the outbreak of influenza.To survey and characterize the seasonal FLUV in Wuhan during 2016–2019,we collected 44,738 throat swabs,among which 15.5%were influenza A(FLUAV)positive,6.1%influenza B(FLUBV)and 0.3%co-infection.By monitoring FLUV in each month from June 2016 to May 2019,different with the previously seasonality pattern,only a single influenza peak was appeared in winter of 2017–2018 and 2018–2019,respectively.These data indicated that the complex circulation pattern of seasonal influenza in Wuhan.In addition,we found the age group was skewed towards 5–14 years group whose activity were mostly school based,which suggested school may be an important place for influenza outbreaks.Meanwhile,phylogenic analysis revealed that two subtypes(subclade 3C.2 a2 and 3C.2 a1b)of A(H3N2)were circulating in Wuhan and there was an obvious transition in 2018 because the two subclades were detected simultaneously.Furthermore,by estimating the vaccine effectiveness,we found that the vaccine strain of FLUAV didn’t seem to match very well the current epidemic strain,especially A(H3N2).Hence,more accurate prediction of seasonal outbreak is essential for vaccine design.Taken together,our results provided the current information about seasonal FLUV in Wuhan which form the basis for vaccine updating.

Global dynamic spatiotemporal pattern of seasonal influenza since 2009 influenza pandemic

Background:Understanding the global spatiotemporal pattern of seasonal influenza is essential for influenza control and prevention.Available data on the updated global spatiotemporal pattern of seasonal influenza are scarce.This study aimed to assess the spatiotemporal pattern of seasonal influenza after the 2009 influenza pandemic.Methods:Weekly influenza surveillance data in 86 countries from 2010 to 2017 were obtained from FluNet.First,the proportion of influenza A in total influenza viruses(PA)was calculated.Second,weekly numbers of influenza positive virus(A and B)were divided by the total number of samples processed to get weekly positive rates of influenza A(RWA)and influenza B(RWB).Third,the average positive rates of influenza A(RA)and influenza B(RB)for each country were calculated by averaging RWA,and RWB of 52 weeks.A Kruskal-Wallis test was conducted to examine if the year-to-year change in PA in all countries were significant,and a universal kriging method with linear semivariogram model was used to extrapolate RA and RB in all countries.Results:PA ranged from 0.43 in Zambia to 0.98 in Belarus,and PA in countries with higher income was greater than those countries with lower income.The spatial patterns of high RB were the highest in sub-Saharan Africa,Asia-Pacific region and South America.RWA peaked in early weeks in temperate countries,and the peak of RWB occurred a bit later.There were some temperate countries with non-distinct influenza seasonality(e.g.,Mauritius and Maldives)and some tropical/subtropical countries with distinct influenza seasonality(e.g.,Chile and South Africa).Conclusions:Influenza seasonality is not predictable in some temperate countries,and it is distinct in Chile,Argentina and South Africa,implying that the optimal timing for influenza vaccination needs to be chosen with caution in these unpredictable countries.