Increasing hospital admissions for pneumonia have been reported recently but it is not known whether pneumonia incidence rates have increased in the community. To determine whether incidence rates of pneumonia increased in primary care in the United Kingdom from 2002 to 2017, an open cohort study was conducted using electronic health records from the UK Clinical Practice Research Datalink. Clinically diagnosed pneumonia, influenza pneumonia, pleural infection and clinically suspected pneumonia, defined as chest infection treated with antibiotics, were evaluated. Age-standardised and age-specific rates were estimated. Joinpoint regression models were fitted and annual percentage changes (APC) were estimated. There were 70.7 million person-years of follow-up with 120 662 episodes of clinically diagnosed pneumonia, 1 831 005 of clinically suspected pneumonia, 23 814 episodes of influenza pneumonia and 2644 pleural infections over 16 years. The incidence of clinically diagnosed pneumonia increased from 1.50 per 1000 person-years in 2002 to 2.22 per 1000 in 2017. From 2010 to 2017, the APC in age-standardised incidence was 5.1% (95% confidence interval 3.4–6.9) compared with 0.3% (−0.6 to 1.2%) before 2010. Clinically suspected pneumonia incidence rates increased from 2002 to 2008 with an APC 3.8% (0.8–6.9) but decreased with an APC −4.9% (−6.7 to −3.1) from 2009 to 2017. Influenza pneumonia increased in the epidemic year of 2009. There was no overall trend in pleural infection. The results show that clinically diagnosed pneumonia has increased in primary care but there was a contemporaneous decline in recording of clinically suspected pneumonia or ‘chest infection’. Changes in disease labelling practice might partly account for these trends.

We conducted a longitudinal assessment in 466 underweight and 446 normal-weight children aged 6–24 months living in the urban slum of Dhaka, Bangladesh to determine the association between vitamin D and other micronutrient status with upper respiratory tract infection (URI) and acute lower respiratory infection (ALRI). Incidence rate ratios of URI and ALRI were estimated using multivariable generalized estimating equations. Our results indicate that underweight children with insufficient and deficient vitamin D status were associated with 20% and 23–25% reduced risk of URI, respectively, compared to children with sufficient status. Underweight children, those with serum retinol deficiency were at 1·8 [95% confidence interval (CI) 1·4–2·4] times higher risk of ALRI than those with retinol sufficiency. In normal-weight children there were no significant differences between different vitamin D status and the incidence of URI and ALRI. However, normal-weight children with zinc insufficiency and those that were serum retinol deficient had 1·2 (95% CI 1·0–1·5) times higher risk of URI and 1·9 (95% CI 1·4–2·6) times higher risk of ALRI, respectively. Thus, our results should encourage efforts to increase the intake of retinol-enriched food or supplementation in this population. However, the mechanisms through which vitamin D exerts beneficial effects on the incidence of childhood respiratory tract infection still needs further research.

The burden of respiratory infections is mainly seen in primary healthcare. To evaluate the potential impact of new preventive strategies against respiratory infections, such as the implementation of pneumococcal conjugate vaccines for infants in 2006 in The Netherlands, we conducted a baseline retrospective cohort study of electronic primary-care patient records to assess consultation rates, comorbidities and antibiotic prescription rates for respiratory infections in primary care. We found that between 1995 and 2005, overall registered consultation rates for lower respiratory tract infections had increased by 42·4%, upper respiratory infections declined by 4·9%, and otitis media remained unchanged. Concomitantly, there was a steady rise in overall comorbidity (75·7%) and antibiotic prescription rates (67·7%). Since Dutch primary-care rates for respiratory infections changed considerably between 1995 and 2005, these changes must be taken into account to properly evaluate the effect of population-based preventive strategies on primary-care utilization.