Serological Study of Responses to Selected Pathogens Causing Respiratory Tract Infection in the Institutionalized Elderly

Abstract

In a prospective 2-year study, serological responses to selected pathogens were analyzed in 224 episodes of fever attributable to respiratory tract infection (51.8%) or of unknown source (48.2%) in 131 residents of two long-term-care facilities. A serological response was identified in 45 episodes (20.1%): Chlamydia pneumoniae (14 episodes), Haemophilus influenzae type b (1), influenza virus type A (14), respiratory syncytial virus (RSV;2), parainfluenza virus type 3 (7), C. pneumoniae and H. influenzae (3), C. pneumoniae and influenza virus type A (2), C. pneumoniae and RSV (1), and C. pneumoniae and parainfluenza virus type 3 (1). No serological responses to Chlamydia psittaci, Chlamydia trachomatis, parainfluenza virus types 1 and 2, influenza virus type B, or Mycoplasma pneumoniae were seen. Vaccination did not affect the duration of fever in those residents with serologically confirmed influenza A. Serologically confirmed C. pneumoniae infection was detected in 9.4% of all febrile episodes. Serological responses to a second agent were detected in 33% of the patients with C. pneumoniae infections, and these dual infections were associated with an underlying malignancy (P = .02). C. pneumoniae should be recognized as a potential pathogen when choosing empirical antimicrobial therapy for respiratory tract infection in residents of long-term-care facilities.

Comparison of Two Commercial Microimmunofluorescence Kits and an Enzyme Immunoassay Kit for Detection of Serum Immunoglobulin G Antibodies to Chlamydia pneumoniae

“…The half-life of specific IgG antibodies is reported to be as long as 3 years in some individuals (7). A significant percentage of donors with high specific antibody titers might indicate a population characterized not by chronic infection needing treatment but a population characterized by frequent past exposure (12), and high IgG titers can be present in sera from elderly individuals in the absence of clinically apparent disease (5). Even when the patient exhibits appropriate clinical symptoms, diagnosis of C. pneumoniae infection based on the results for a single serum specimen should be interpreted with caution.…”

A Prediction Model for Community-Acquired Chlamydia pneumoniae Pneumonia in Hospitalized Patients

“…In multivariate analysis, living in a nursing home was found to be a statistically significant predictor of C. pneumoniae pneumonia. Currently, the issue of C. pneumoniae in institutionalized individuals is being addressed by several studies [23].…”

Audit and Feedback-Focused approach to Evidence-based Care in Treating patients with pneumonia in hospital (AFFECT Study)

“…[2][3][4][21][22][23][24] It is also not well defined whether HCAP treatment should align with CAP or HAP therapy. [38][39][40][41][42][43][44][45][46] The classification of HCAP was introduced in the 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines, 3 which suggested that patients who develop pneumonia in the community and have specific risk factors should be treated similarly to those with HAP, including coverage for MDR pathogens ( Table 2). The frequency of MDR pathogens and whether all MDR risk factors are relevant in all practice settings is unclear and complicate determination of antibiotic recommendations using local data.…”

“…The frequency of MDR pathogens and whether all MDR risk factors are relevant in all practice settings is unclear and complicate determination of antibiotic recommendations using local data. [38][39][40][41][42][43][44][45][46] Given limited identification of MDR pathogens in the authors' health region and to prevent the unnecessary use of broad-spectrum antibiotics, the algorithms did not incorporate all MDR risk factors identified by the ATS/IDSA guidelines ( Table 2). The most common MDR pathogens identified in the health region were Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) ( Table 3).…”