Age Specific Prevalence of Antibodies against Chlamydia pneumoniae in Iceland

Abstract

Chlamydia pneumoniae is a newly recognized common cause of respiratory tract infections. The aim of this study was to examine its prevalence in Iceland. The study was based on 1020 serum samples from individuals 0-99 years old. The samples were divided into 10-year age groups. IgG and IgM antibodies were determined with microimmunofluorescence assay. An IgG titer > or = 32 and IgM titer > or = 16 were considered positive. The prevalence of positive IgG titer in the study population was 53 +/- 16% (mean +/- SD, age group range 14-66%). Neither seasonal nor gender-based difference in IgG antibody prevalence was demonstrated. It was lowest in the youngest group, 0-9 years old (p < 0.001), but rose linearly to age 70 (p < 0.005). 34 samples were IgM positive on initial testing; most from the older age groups. 12 were rheumatoid factor positive as well. After treatment with caprine antihuman IgG antibodies all became negative. The prevalence of C. pneumoniae infections is high in Iceland according to these results and similar to that in neighbouring countries. The presence of IgM rheumatoid factor may cause false positive tests for pathogen-specific IgM by immune complex binding with pathogen-specific IgG, thereby requiring its removal before testing.

<i>Chlamydia pneumoniae</i> in Elderly Patients with Stroke (C-PEPS): A Case-Control Study on the Seroprevalence of <i>Chlamydia pneumoniae</i> in Elderly Patients with Acute Cerebrovascular Disease

“…This is in keeping with reports from other countries that C. pneumoniae seropositivity increases with age [14, 15, 16], with a 50–70% prevalence of seropositivity in middle-aged adults [23]. In contrast, a few studies report declining C. pneumoniae IgG titres with age [24, 25]. Most adults are infected two to three times during their lifetime [23], and increasing seropositivity with age is suggestive of chronic infection or reinfection throughout life.…”

Chlamydia pneumoniaeand Cardiovascular Disease: An Evolutionary Perspective on Infectious Causation and Antibiotic Treatment

“…Age-related seropositivity suggests that systemic C. pneumoniae may be relatively or wholly nontransmissible. Seropositivity is very low among children who have not yet attended school, rises steeply during the next three decades of life, and then levels off in older age groups, who remain predominantly seropositive [38][39][40][41][42]. About one-third of the adults who are in the typical age range of parents of such children (e.g., 25-35 years old) have some atherosclerotic damage [43].…”

Chlamydia pneumoniae is not detectable in subretinal neovascular membranes in the exudative stage of age‐related macular degeneration

“…C. pneumoniae has been detected in numerous studies by various techniques in atheromatous plaques. Successful recovery of viable organisms from atherosclerotic lesions has also been reported (Einarsson et al 1994; Ramirez 1996).…”

“…C. pneumoniae is an obligate intracellular bacterial pathogen and a significant cause of respiratory tract infections in humans. Approx‐imately 10% of cases of community‐acquired pneumonia are associated with C. pneumoniae (Steinhoff et al 1996) and its prevalence rises with age (Einarsson et al 1994). In addition, seroepidemiological studies have shown an association between the antibody response to the organism and atherosclerosis (Saikku et al 1988).…”