The epidemiology of respiratory infections may vary depending on factors such as climate changes, geographical features, and urbanization. Pandemics also change the epidemiological characteristics of not only the relevant infectious agent itself but also other infectious agents. This study aims to assess the impact of the COVID-19 pandemic on the epidemiology of viral respiratory infections in children. We retrospectively reviewed the medical records of children aged ≤18 years with laboratory-confirmed viral respiratory infections other than COVID-19 from January 2018 to March 2023. Data on demographic characteristics, month and year of admission, and microbiological results were collected. During the study period, 1,829 respiratory samples were sent for polymerase chain reaction testing. Rhinovirus was identified in 24% of the patients, mixed infections in 21%, influenza virus in 20%, and respiratory syncytial virus in 12.5%. A 38.6% decrease in viral respiratory infections was observed in 2020, followed by a 188% increase in 2021. The respiratory syncytial virus was significantly more common in the post-pandemic period (13.8%) compared to the pre-pandemic period (8.1%), but no seasonal shift in respiratory syncytial virus infection was observed. There was also a yearly increase in influenza infections in the post-pandemic period compared to the pre-pandemic period. After the COVID-19 pandemic, the frequency of parainfluenza virus infections increased during the summer months, and this finding provides a new contribution to the existing literature.

In the past 10–15 years, the government of China has made various efforts in tackling excessive antibiotics use. Yet, little is known about their effects at rural primary care settings. This study aimed to determine the impact of government policies and the COVID-19 pandemic on antibiotic prescribing practices at such settings utilizing data from separate studies carried out pre- and during the pandemic, in 2016 and 2021 in Anhui province, China, using identical sampling and survey approaches. Data on antibiotics prescribed, diagnosis, socio-demographic, etc., were obtained through non-participative observation and a structured exit survey. Data analysis comprised mainly descriptive comparisons of 1153 and 762 patients with respiratory infections recruited in 2016 and 2021, respectively. The overall antibiotics prescription rate decreased from 89.6% in 2016 to 69.1% in 2021, and the proportion of prescriptions for two or more classes of antibiotics was estimated as 35.9% in 2016 and 11.0% in 2021. There was a statistically significant decrease in the number of days from symptom onset to clinic visits between the year groups. In conclusion, measures to constrain excessive prescription of antibiotics have led to some improvements at the rural primary care level, and the COVID-19 pandemic has had varying effects on antibiotic use.

Predicting the magnitude of the annual seasonal peak in influenza-like illness (ILI)-related emergency department (ED) visit volumes can inform the decision to open influenza care clinics (ICCs), which can mitigate pressure at the ED. Using ILI-related ED visit data from the Alberta Real Time Syndromic Surveillance Net for Edmonton, Alberta, Canada, we developed (training data, 1 August 2004–31 July 2008) and tested (testing data, 1 August 2008–19 February 2014) spatio-temporal statistical prediction models of daily ILI-related ED visits to estimate high visit volumes 3 days in advance. Our Main Model, based on a generalised linear mixed model with random intercept, incorporated prediction residuals over 14 days and captured increases in observed volume ahead of peaks. During seasonal influenza periods, our Main Model predicted volumes within ±30% of observed volumes for 67%–82% of high-volume days and within 0.3%–21% of observed seasonal peak volumes. Model predictions were not as successful during the 2009 H1N1 pandemic. Our model can provide early warning of increases in ILI-related ED visit volumes during seasonal influenza periods of differing intensities. These predictions may be used to support public health decisions, such as if and when to open ICCs, during seasonal influenza epidemics.

Seasonal influenza virus epidemics have a major impact on healthcare systems. Data on population susceptibility to emerging influenza virus strains during the interepidemic period can guide planning for resource allocation of an upcoming influenza season. This study sought to assess the population susceptibility to representative emerging influenza virus strains collected during the interepidemic period. The microneutralisation antibody titers (MN titers) of a human serum panel against representative emerging influenza strains collected during the interepidemic period before the 2018/2019 winter influenza season (H1N1-inter and H3N2-inter) were compared with those against influenza strains representative of previous epidemics (H1N1-pre and H3N2-pre). A multifaceted approach, incorporating both genetic and antigenic data, was used in selecting these representative influenza virus strains for the MN assay. A significantly higher proportion of individuals had a ⩾four-fold reduction in MN titers between H1N1-inter and H1N1-pre than that between H3N2-inter and H3N2-pre (28.5% (127/445) vs. 4.9% (22/445), P < 0.001). The geometric mean titer (GMT) of H1N1-inter was significantly lower than that of H1N1-pre (381 (95% CI 339–428) vs. 713 (95% CI 641–792), P < 0.001), while there was no significant difference in the GMT between H3N2-inter and H3N2-pre. Since A(H1N1) predominated the 2018–2019 winter influenza epidemic, our results corroborated the epidemic subtype.

The ability to predict upper respiratory infections (URI), lower respiratory infections (LRI), and gastrointestinal tract infections (GI) in independently living older persons would greatly benefit population and individual health. Social network parameters have so far not been included in prediction models. Data were obtained from The Maastricht Study, a population-based cohort study (N = 3074, mean age (±s.d.) 59.8 ± 8.3, 48.8% women). We used multivariable logistic regression analysis to develop prediction models for self-reported symptomatic URI, LRI, and GI (past 2 months). We determined performance of the models by quantifying measures of discriminative ability and calibration. Overall, 953 individuals (31.0%) reported URI, 349 (11.4%) LRI, and 380 (12.4%) GI. The area under the curve was 64.7% (95% confidence interval (CI) 62.6–66.8%) for URI, 71.1% (95% CI 68.4–73.8) for LRI, and 64.2% (95% CI 61.3–67.1%) for GI. All models had good calibration (based on visual inspection of calibration plot, and Hosmer–Lemeshow goodness-of-fit test). Social network parameters were strong predictors for URI, LRI, and GI. Using social network parameters in prediction models for URI, LRI, and GI seems highly promising. Such parameters may be used as potential determinants that can be addressed in a practical intervention in older persons, or in a predictive tool to compute an individual's probability of infections.

Analyses in nutritional epidemiology usually assume a uniform effect of a nutrient. Previously, four subgroups of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study of Finnish male smokers aged 50–69 years were identified in which vitamin E supplementation either significantly increased or decreased the risk of pneumonia. The purpose of this present study was to quantify the level of true heterogeneity in the effect of vitamin E on pneumonia incidence using the I2 statistic. The I2 value estimates the percentage of total variation across studies that is explained by true differences in the treatment effect rather than by chance, with a range from 0 to 100 %. The I2 statistic for the effect of vitamin E supplementation on pneumonia risk for five subgroups of the ATBC population was 89 % (95 % CI 78, 95 %), indicating that essentially all heterogeneity was true variation in vitamin E effect instead of chance variation. The I2 statistic for heterogeneity in vitamin E effects on pneumonia risk was 92 % (95 % CI 80, 97 %) for three other ATBC subgroups defined by smoking level and leisure-time exercise level. Vitamin E decreased pneumonia risk by 69 % among participants who had the least exposure to smoking and exercised during leisure time (7·6 % of the ATBC participants), and vitamin E increased pneumonia risk by 68 % among those who had the highest exposure to smoking and did not exercise (22 % of the ATBC participants). These findings refute there being a uniform effect of vitamin E supplementation on the risk of pneumonia.

College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34 % with probiotics v. placebo (P< 0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P= 0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P= 0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost–benefit of prophylactic supplementation.

We sought to systematically review the published literature describing the epidemiological aspects of the first wave of pandemic A(H1N1) 2009 influenza in the Southern Hemisphere. Fifteen studies were included in this review, originating from South America, Australia or New Zealand, and Africa. Across the different studies, 16·8–45·3% of the laboratory-confirmed cases were admitted to hospital, and 7·5–26·0% of these cases were admitted to intensive care units (ICUs). The fatality rate was 0·5–1·5% for laboratory-confirmed cases in 6/8 studies reporting specific relevant data, and 14·3–22·2% for cases admitted to ICUs in 5/7 studies, respectively. In 4/5 studies the majority of laboratory-confirmed cases were observed in young and middle-aged adults, the percentage of older adults increased the higher the level of healthcare the cases received (e.g. laboratory confirmation, hospitalization or ICU admission) or for fatal cases. Many of the cases had no prior comorbidity, including conditions identified as risk factors for seasonal influenza. Pregnant women represented 7·4–9·1% and 7·1–9·1% of unselected laboratory-confirmed cases and of those admitted to ICUs, respectively. Obesity and morbid obesity were more commonly reported as the level of healthcare increased.

Previous clinical vitamin A trials have found no consistent effect on diarrhoeal disease and respiratory tract infection. These inconsistent results may be due to the distinct effects vitamin A supplementation has among children stratified by factors related to socio-economic status, nutritional status and season. We evaluated the effect of supplementation on the overall incidence of diarrhoeal disease and respiratory tract infections and on the incidence among children stratified by these factors. A total of 188 children, aged 6–15 months, from periurban, marginalized communities of Mexico City were assigned to receive vitamin A ( < 12 months of age, 20 000 IU retinol; ≥ 12 months, 45 000 IU retinol) or a placebo every 2 months, and were followed for up to 15 months. Project personnel visited households twice a week to determine the onset and duration of diarrhoeal disease and respiratory tract infections. Vitamin A supplementation had no significant effect on risk of overall diarrhoeal disease but reduced mild watery diarrhoea (incidence rate ratio (RR) 0·69; 95 % CI 0·50, 0·93) and cough with fever (RR 0·69; 95 % CI 0·48, 0·98). Vitamin A supplementation decreased diarrhoeal disease during the summer (RR 0·74; 95 % CI 0·57, 0·94), among non-stunted children (RR 0·69; 95 % CI 0·52, 0·93) and among children from households with better socio-economic measures. Heterogeneity in the response to vitamin A supplementation may reflect heterogeneity in the aetiology and epidemiology of diarrhoeal disease and respiratory tract infections and the impact that supplementation has on the immune response.

The bacterium Pseudomonas aeruginosa (PA) produces two carbohydrate binding lectins, designated PA lectin-I and lectin-II (PA-IL, PA-IIL). Both lectins are used by the bacterium to adhere to the glycocalyx of mammalian cells. In addition, the lectins immobilize ciliary beat. The kinetics of ciliary beat inhibition by each individual lectin have been analysed; however, their joint action on cilia has not been reported. Here we demonstrate that PA-IL and PA-IIL inhibit ciliary beat in a similar time-dependent manner. If applied simultaneously, ciliary beat inhibition after five hours of incubation was weaker than if each lectin was applied separately. Thus it can be hypothesized that the lectins compete for the same binding site(s) of the glycocalyx. Sugar inhibition experiments demonstrate that D-galactose and L-fucose inhibit both lectins, although clear preferences of D-galactose for PA-IL and of L-fucose for PA-IIL exist. These interactions have to be kept in mind when designing sugar-based therapies.

A growing body of evidence suggests that a variety of upper respiratory symptoms (URS) are associated with gastro-oesophageal reflux (GORD). The aim of this study was to determine the prevalence of endoscopic erosive, and non-erosive, oesophagitis among patients complaining of persistent URS, in the absence of typical GORD symptoms, and to compare them with a comparison group of similar age. A group of 110 patients aged 18–75, presenting with persistent URS with no suspicion of GORD symptoms, underwent upper flexible endoscopy, with biopsy sampling for histology, and was compared with a group of 117 patients of similar age undergoing endoscopy for reasons other than GORD. Patients affected with upper airway disorders, such as posterior laryngitis, chronic sinusitis and vocal fold nodules, had a significantly higher prevalence of oesophagitis of varying degrees (31 per cent) compared to the comparison population(15.4 per cent) (p < 0.01). These data suggest that in many patients with chronic URS occult gastro-oesophageal diseases are present.