Seroprevalence of Chlamydia pneumoniae in Chile

Evaluation of the level of antibodies against Chlamydophila (Chlamydia) pneumoniae in post-surgery heart ischaemia patients and their clinical conditions - a six-year study

INTRODUCTION

Inflammatory conditions modulated by Chlamydophila (Chlamydia) pneumoniae are considered to play an important role in the onset of atherosclerosis. In this paper we present the results of progressive observation of C. pneumoniae antibody titres in patients who underwent coronary artery bypass graft (CABG).

MATERIAL AND METHODS

The objective of our research was a prospective observation of antibody titres in IgA and IgG class antibodies against C. pneumoniae using indirect immunofluorescence in a group of 155 post-surgery CABG patients suffering from heart ischaemia. The microbiological test results were compared with patients' present coronary complaints evaluated on the CCS scale during a six-year period.

RESULTS

Six years after CABG, 128 patients (82.6%) are still alive. During the study a positive serological conversion of antibody titres was observed in 36 patients in the IgA class antibodies, and in 26 patients in the IgG class. The group of patients with no antibodies against C. pneumoniae decreased from 23.2 to 3.4%, while the group of patients with antibodies in both IgG and IgA classes increased from 52.3 to 83.9%. The average CCS degree decreased from 3.18 before CABG to 1.65 in the present study.

CONCLUSIONS

These results show no connection between the serological symptoms of chronic C. pneumoniae infection and coronary complaints evaluated on the CCS scale during a six-year study on post-CABG patients suffering from heart ischaemia. The surgical treatment of heart ischaemia brought about long-term improvement in the coronary condition of the observed group of patients.

Comparative randomized trial of azithromycin versus erythromycin and amoxicillin for treatment of community-acquired pneumonia in children

Our objective was to compare the clinical efficacy of azithromycin vs. erythromycin and amoxicillin in the treatment of presumed bacterial community-acquired pneumonia in ambulatory children, and to evaluate the etiologies of these illnesses. One hundred and ten children, aged 1 month to 14 years, were enrolled between January 1996-January 1999. Children were distributed into two groups according to clinical and radiological patterns: classic or atypical pneumonia. Patients with classic pneumonia were randomly assigned to receive oral amoxicillin 75 mg/kg/day for 7 days, or azithromycin 10 mg/kg/day for 3 days; patients with atypical pneumonia received azithromycin 10 mg/kg/day for 3 days, or erythromycin 50 mg/kg/day for 14 days. Chest X-ray, clinical, and laboratory parameters were obtained on enrollment. Clinic visits were performed on days 3, 7, and 14, and chest X-ray follow-up on days 7 and 14. Microbiological diagnosis of classic pathogens was based on blood and bronchial secretion cultures. The diagnosis of atypical pathogens C. pneumoniae, C. trachomatis, and M. pneumoniae was based on PCR and serologic tests.Forty-seven children met the criteria for classic pneumonia (23 children received azithromycin, and 24 received amoxicillin), and 59 children had atypical pneumonia (33 children were treated with azithromycin, and 26 with erythromycin). Demographic characteristics at enrollment were similar between children with classic pneumonia treated with azithromycin and erythromycin and children treated with azithromycin and erythromycin for atypical pneumonia. However, on day 7, children with classic pneumonia who received azithromycin normalized their chest X-ray more often than those who received amoxicillin (81.0% vs. 60.9%, respectively, P = 0.009). The same was true for children with atypical pneumonia; their chest X-rays had normalized by day 14 (100% in those with azithromycin vs. 81% in those with erythromycin, P = 0.059). Also, children with atypical pneumonia treated with azithromycin had earlier cessation of cough than children treated with erythromycin (3.6 +/- 1.9 vs. 5.5 +/- 3.6 days respectively, P = 0.02). There were only three children with side effects (mild diarrhea, all in the erythromycin group). Etiological agents were identified in 41% of children. In conclusion, azithromycin is an effective therapeutic option for the treatment of community-acquired classic and atypical pneumonia in children.

Seroprevalence of IgG antibodies against Chlamydia pneumoniae in Chinese, Malays and Asian Indians in Singapore

BACKGROUND

Chlamydia pneumoniae, a bacterium that causes respiratory infections, is probably under-diagnosed. There is also interest in its possible role in the aetiology of coronary heart disease. This is the first population-based seroprevalence survey of C. pneumoniae infection in Singapore.

METHODS

A random sample of 1,068 people aged 18-69 years was selected from the participants of the Singapore National Health Survey conducted in 1998. Sera and data on certain clinical measurements and conditions had been collected. IgG antibodies for C. pneumoniae were detected using an indirect microimmunofluorescence test and positivity graded. Seropositivity was defined as IgG titre >/=1:16.

RESULTS

There were no statistically significant differences in the prevalence rates of seropositivity to C. pneumoniae for age group 18-69 years among the three ethnic groups, i.e. Chinese (males 76.7%, females 68.3%), Malays (males 75.4%, females 59.1%), and Asian Indians (males 74.6%, females 59.4%). The seropositivity rate for people aged 18-69 years in Singapore was 75.0% for males and 65.5% for females (difference of 9.5%, P < 0.001). In both genders combined, seropositivity increased from 46.5% in the age group 18-29 to reach a plateau of 78.9% in the age group 40-49, which remained stable to 60-69 years. There was no association of seropositivity with smoking, diabetes mellitus, hypertension or body mass index after adjustment for age and gender.

CONCLUSION

The high prevalence rates in our study population and the higher rate in males compared to females are consistent with studies from other parts of the world. No significant difference in prevalence rates was observed among Chinese, Malays and Indians. The pattern of rising and levelling off of seropositivity with age suggests that C. pneumoniae infection occurs early in life, and in older ages the high level of seropositivity is probably maintained by re-infections or chronic infections. Chlamydia pneumoniae infection was not found to be associated with the cardiovascular risk factors examined.

Antibodies anti-Chlamydia pneumoniae and anti-Mycoplasma pneumoniae in patients with negative serology for hantavirus. Retrospective study

The seroprevalence of Chlamydia pneumoniae and Mycoplasma pneumoniae in hantavirus seronegative patients, who had symptoms and signs compatible with pneumonia was established. For this purpose we used the indirect fluorescent antibody test. Titers > or = 1:16 for C. pneumoniae and M. pneumoniae were found in 8.6% and 17.1% of the serum, respectively, showing evidence of recent or current infection.