The influence of age and gender on the population-based incidence of community-acquired pneumonia caused by different microbial pathogens
Introduction
Community-acquired pneumonia (CAP) remains a major cause of morbidity and mortality in developed countries and it is a large contributor to excessive healthcare resource consumption and cost.1, 2, 3 While numerous studies on CAP have been published, most epidemiological data have been obtained from patients requiring hospitalization and some epidemiological aspects are not well defined. The frequency of CAP has varied greatly between studies. According to the few population-based studies published, the annual incidence rate of CAP in adults varies between 16 and 130 per 10,000 inhabitants.4, 5, 6, 7, 8 The differences in the incidence figures probably depend on several factors, including study population, diagnostic methods and criteria used for diagnosis, and the occurrence of epidemic outbreaks during some studies. Most information on the frequency of pneumonia due to specific pathogens by age and gender refers to pneumococcal pneumonia, and comes from two population studies carried out in 1982 in Finland8 and in 1991 in Ohio (USA).9 Data on the population-based incidence of CAP with evidence of specific infection are limited, especially in the case of CAP caused by other organisms, such as Mycoplasma pneumoniae, Legionella pneumophila, influenza virus or Chlamydophila spp.
CAP has long been an active field of investigation. During the past decade, significant progress was made in understanding many epidemiological and microbial aspects of CAP, and the benefits of immunization with pneumococcal polysaccharide in specific patient groups led to recommendations for the use of this vaccine in patients at risk for CAP.10 In the last few years there have been further advances in the medical management of CAP with the development of novel immunochromatographic assays to detect Streptococcus pneumoniae and Legionella pneumophila antigens in urine. The availability of these rapid and sensitive techniques has facilitated the microbial diagnosis of pneumonia and provided new tools that may improve our epidemiological understanding of CAP.
Updated data about the incidence of pneumonia may be important to recognize changes in disease patterns, to assess the new etiological profile according to the new diagnostic technologies, to evaluate preventive interventions and to allocate health care and research resources. Our objectives were to: (1) determine the overall incidence of CAP at the dawn of the twenty-first century in a defined geographic area of the Mediterranean coast of Spain; (2) determine the incidence of CAP caused by different microbial pathogens, especially the incidence of CAP caused by M. pneumoniae, L. pneumophila, influenza virus and Chlamydophila spp. and (3) assess the relative importance of age and gender on the overall incidence of CAP, and on the incidence of CAP caused by specific pathogens in this geographic region. In three previous reports we evaluated the Binax immunochromatographic assay for detection of S. pneumoniae urinary antigen in this cohort,11 and we described the microbial epidemiology and outcome of the patients12 and the characteristics of mixed infections.13
Section snippets
Design
A two-year population-based prospective cohort study.
Setting
A 430-bed university-affiliated teaching center covering a population of 239,335 people living in three municipalities of the “Health Authority of Bajo Vinalopó” on the Mediterranean coast of Spain. Mean temperatures for summer and winter seasons through the study period were 28.5 °C (83.3 °F) and 12.5 °C (54.5 °F), respectively. An active surveillance program on CAP was established before the study period and primary care physicians were asked
Incidence of community-acquired pneumonia
There were 200,430 inhabitants ≥15 years living in the three municipalities in 2001. The population-based incidence of CAP according to age groups and gender is shown in Table 1. During the study period, 516 patients presented with signs and symptoms compatible with pneumonia, 23 of whom were subsequently found not to have CAP, leaving 493 patients (males 308, females 185). Three hundred sixty-one (73.2%) patients were admitted to hospital, 6 (1.2%) of whom required admission to the intensive
Discussion
This prospective study provides data of a large cohort of patients with CAP from a defined geographic area at the Mediterranean coast of Spain. The design of the study allowed estimation of the overall incidence of CAP and of pneumonia with evidence of specific infection, including age- and sex-specific incidences. The study results show that age and gender have a strong influence on the incidence of pneumonia caused by the main microbial pathogens, including not only S. pneumoniae, but also
References (26)
- et al.
Prospective study of aetiology and outcome of community in the community
Lancet
(1987) - et al.
Epidemiology of community-acquired pneumonia at the dawn of the twenty-first century: a prospective study on the Mediterranean coast of Spain
Clin Microbiol Infect
(2005) Community-acquired pneumonia
Br J Dis Chest
(1987)- et al.
Ambulatory patients with community-acquired pneumonia: the frequency of atypical agents and clinical course
Am J Med
(1996) - et al.
Community acquired pneumonia in patients older than 60 years. Incidence of atypical agents and clinical-radiological progression
Med Clin (Barc)
(2001) - et al.
Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults
Clin Infect Dis
(2003) - et al.
American Thoracic Society. Guidelines for the management of adults with community-acquired pneumonia. Diagnosis, assessment of severity, antimicrobial therapy, and prevention
Am J Respir Crit Care Med
(2001) - et al.
The cost of treating community-acquired pneumonia
Clin Ther
(1998) - et al.
Incidence of community-acquired pneumonia and Chlamydia pneumoniae infection. A prospective multicentre study
Eur Respir J
(1993) - et al.
Epidemiology of community-acquired pneumonia in adults: a population-based study
Eur Respir J
(2000)
Incidence of community-acquired pneumonia in the population of four municipalities in Eastern Finland
Am J Epidemiol
Microbial etiology of community-acquired pneumonia in the adult population of 4 municipalities in eastern Finland
Clin Infect Dis
Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group
Arch Intern Med
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