Incidence and Risk of Pneumococcal Pneumonia in Adults with Distinct Underlying Medical Conditions: A Population-Based Study

PURPOSE

This study investigated the incidence of pneumococcal pneumonia requiring hospitalisation among middle-aged and older adults with and without specific underlying medical conditions, evaluating the influence of these conditions in the risk of developing pneumonia.

METHODS

Population-based prospective cohort study included 2,025,730 individuals ≥ 50 years around Catalonia, Spain. The Catalonian information system for the development of research in primary care (SIDIAP) was used to establish baseline characteristics of the cohort (comorbidities and underlying medical conditions). Hospitalisations from pneumococcal pneumonia occurred among cohort members between 01/01/2015 and 31/12/2015 were collected from hospital discharge codes of 68 reference Catalonian hospitals. Cox regression was used to estimate the association between baseline conditions and the risk of developing pneumonia.

RESULTS

Global incidence rate (IR) of hospitalised pneumococcal pneumonia was 82.8 cases per 100,000 persons-year. Maximum IRs (per 100,000 persons-year) emerged among persons with haematological neoplasia (837.4), immunodeficiency (709.2), HIV infection (474.7), severe renal disease (407.5) and chronic pulmonary disease (305.7). In the multivariable analyses, apart from increasing age, HIV infection (hazard ratio [HR] 6.78), haematological neoplasia (HR 6.30), prior all-cause pneumonia (HR 5.27), immunodeficiency (HR 4.57) and chronic pulmonary disease (HR 2.89) were the conditions most strongly associated with an increasing risk. Pneumococcal vaccination did not emerge associated with a reduced risk in our study population (nor PPsV23 neither PCV13).

CONCLUSION

Old age, immunocompromising conditions and chronic pulmonary/respiratory disease are major risk factors for pneumococcal pneumonia in adults. Our data underline the need for better prevention strategies in these persons.

A severe case of persistent diarrhoea associated with Arcobacter cryaerophilus but attributed to Campylobacter sp. and a review of the clinical incidence of Arcobacter spp

Although rarely, Arcobacter spp. have been associated with diarrhoea and bacteraemia. We report a persistent case in a healthy 26-year-old Spanish male of bloody diarrhoea, which was attributed to Campylobacter but in fact was caused by Arcobacter cryaerophilus, as determined by sequencing of the rpoB gene. The isolate was re-identified by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) and genotyped for five putative virulence genes and for seven genes included in the Arcobacter multilocus sequence typing database. The low score obtained by MALDI-TOF indicates the need to complement the database with more isolates. Only the ciaB gene, which encodes for an invasin, was detected. Despite the isolate belonging to a new sequence type, three of the alleles (glnA, pgm and tkt) had been found previously in isolates from faeces of patients with diarrhoea. This study, together with the reviewed literature, indicates that Arcobacter can produce bacteraemia and that the isolation from patients with diarrhoea range from 0.11% to 1.25%. This study also demonstrates that Arcobacter species are confused with Campylobacter spp., as previously suggested. This is one of the factors that leads to underestimation of their incidence together with the use of inappropriate detection and identification methods.