Two family outbreaks of Chlamydia pneumoniae infection (original) (raw)
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Epidemiology of Chlamydia pneumoniae
Clinical Microbiology and Infection, 1998
Chlamydia pneumoniae is the most commonly occurring intracellular bacterial pathogen. It is frequently involved in respiratory tract infections and to a lesser degree in extrapulmonary diseases. According to seroepidemiologic surveys, C. pneumoniae infection seems to be both endemic and epidemic. Such studies indicate that C. pneumoniae infection is widespread, with frequent reinfection during a lifetime. In Western countries the highest rate of new infections occurs between the ages of 5 and 15. The antibody prevalence worldwide is higher in adult males than in females. Currently available data suggest that C. pneumoniae is primarily transmitted from human to human without any animal reservoir. Transmission seems to be inefficient, although household outbreaks with high transmission rates are reported. Most reports rank C. pneumoniae among the three most common etiologic agents of community-acquired pneumonia, with an incidence ranging from 6% to 25%, and generally presenting a mild and, in some cases, self-limiting clinical course.
Incidence of community-acquired pneumonia caused byChlamydia pneumoniae in Italian patients
European Journal of Clinical Microbiology & Infectious Diseases, 1993
The incidence of Chlamydia pneumoniae as a cause of community-acquired pneumonia was evaluated in a one-year prospective study in 108 patients with community.acquired pneumonia. The bacteriological diagnosis was based on culture ofsputum or bronchial aspirate and examination of acute and convalescent phase sera for Mycoplasma pneumoniae, Legionella pneumophila and Chlamydla pneumoniae. A definitive microbiological diagnosis was obtained in 58 (54 %) patients. Chlamydiapneumoniae was the causative agent in 14 patients (13 %) on the basis of positive serological tests; in 10 of the 14 patients Chlamydia pneumoniae was also detected by means of an indirect immunofluorescence test using pharyngeal swab specimens. In conclusion, Chlamydla pneumonlae seems to be a common etiological agent of community-acquired pneumonia, as increasingly reported in the last six to seven years.
Serological studies on Chlamydia pneumoniae infections
2007
Chlamydia pneumoniae is a common, widespread pathogen that causes acute and chronic infections. Serological diagnosis of C. pneumoniae infection is primarily based on the microimmunofluorescence (MIF) method, but only a fourfold IgG antibody increase between paired sera and the presence of IgM antibodies have generally been accepted as markers of acute infection. At the present, no commonly accepted, reliable serological or other methods for the diagnosis of chronic C. pneumoniae infection exist. We evaluated C. pneumoniae specific serological tests in different populations, followed the kinetics of C. pneumoniae antibodies in multiple sera obtained from the same individuals, compared anti-human IgA FITC conjugates in MIF test and evaluated C. pneumoniae specific antibody tests before and after coronary events in case-control pairs matched for the time point of serum sampling, place of residence, and treatment. We showed that reinfection or reactivation is needed for the persistence of elevated IgG and IgA antibody levels. In chronic infections and upon reactivation, chronic processes may be better diagnosable based on IgA persistence than IgG levels because of the rapid disappearance of IgA levels after seroconversions. The cycle of reinfection and reactivation seems to be faster than previously thought in crowded conditions, such as in military service, since we recorded several antibody changes between the arrival and departure sera of military recruits during 6-month service. The presence of antibodies does not provide protection from reinfection. Commercial anti-human IgA conjugates act differently in MIF tests, and there is marked variation in their ability to detect IgA antibodies. The EIA test used here overestimated the prevalence and persistence of IgA antibodies when compared to MIF. The best compability between MIF and EIA antibody levels was seen in the participants with high titers. Only high IgA MIF titers to C. pneumoniae at the baseline predicted future coronary events. In the present study, seroconversions both in the participants who developed a coronary event and in the controls were detected by MIF and EIA, but mostly in different persons. Seroconversion suggesting reinfection or reactivation of persistent infection may have a role in accelerating chronic processes, because the participants with MIF seroconversion between consecutive sera had a slightly higher risk for coronary events than the controls. EIA seroconversions were more common in the controls than in the cases before the coronary event. The difference in the kinetics of EIA and MIF antibodies warrants future research and supports the use of the MIF method as a golden standard in the measurement of C. pneumoniae IgG and IgA antibody levels and seroconversions. In their diagnostic practice, laboratories should use, compare, and validate more C. pneumoniae IgA antibody tests in addition to IgG tests. Unspecific findings in C. pneumoniae EIA tests require re-estimation and a new way to interpret the results. Chlamydia experts should speak for MIF and rethink the meaning of IgA antibodies and recommendations in the diagnosis of C. pneumoniae infections.
Clinical Microbiology and Infection, 2009
Chlamydophila pneumoniae infection is ubiquitous. It accounts for 10% of community-acquired pneumonias and 5% of cases of pharyngitis, bronchitis and sinusitis in both immunocompetent and immunocompromised hosts. It is also involved in exacerbations of chronic bronchitis and asthma. Moreover, C. pneumoniae has been reported as a possible cause of atherosclerosis and central nervous system disorders. The current reference standard for serological diagnosis of acute infection is microimmunofluorescence testing, although molecular detection techniques may well become reference diagnostic tests in the near future. Tetracyclines and erythromycin show good in vitro activity, and so far have been the most commonly employed drugs in the treatment of C. pneumoniae infection. New macrolides, ketolides and fluoroquinolones are other potentially effective drugs. This review analyses the most recent data concerning the involvement of C. pneumoniae in human diseases.
Chlamydia sp. in hospitalised children with community acquired pneumonia
Indian pediatrics, 2007
Our aim was to document the prevalence of chlamydial infection in children less than five years of age with Community Acquired Pneumonia (CAP). Seventy three children, 1 month to 5 years of age, hospitalized with CAP were enrolled over a period of one year. Microimmunofluorescence (MIF) was done to detect IgM antibodies against Chlamydia sp. in sera of all patients; PCR was performed to detect C. pneumoniae DNA in nasopharyngeal aspirates. The prevalence of Chlamydia species infection in CAP in children < 5 years of age was 5.5% (4/73). Two cases were positive for C. trachomatis antibodies; one case was positive for C. pneumoniae antibodies and one case was positive for C. pneumoniae DNA. Chlamydia sp. have an important role in CAP in children < 5 years and for early diagnosis of infection, use of more than one method i.e. PCR and serology both is advisable.
Clinical Infectious Diseases, 2001
Chlamydia pneumoniae has been associated with atherosclerosis and several other chronic diseases, but reports from different laboratories are highly variable and "gold standards" are lacking, which has led to calls for more standardized approaches to diagnostic testing. Using leading researchers in the field, we reviewed the available approaches to serological testing, culture, DNA amplification, and tissue diagnostics to make specific recommendations. With regard to serological testing, only use of microimmunofluorescence is recommended, standardized definitions for "acute infection" and "past exposure" are proposed, and the use of single immunoglobulin (Ig) G titers for determining acute infection and IgA for determining chronic infection are discouraged. Confirmation of a positive culture result requires propagation of the isolate or confirmation by use of polymerase chain reaction (PCR). Four of 18 PCR assays described in published reports met the proposed validation criteria. More consistent use of control antibodies and tissues and improvement in skill at identifying staining artifacts are necessary to avoid false-positive results of immunohistochemical staining. These standards should be applied in future investigations and periodically modified as indicated. Chlamydia pneumoniae is a fastidious bacterium that was first established as a cause of acute respiratory infection 115 years ago; more recently, it has been associated with certain chronic diseases, including atherosclerotic cardiovascular disease. The ever-expanding spectrum of diseases associated with C. pneumoniae infection has led a
High frequency of Chlamydia pneumoniae and risk factors in children with acute respiratory infection
Brazilian Journal of Microbiology, 2020
This study was performed as a contribution for a better understanding of Chlamydia pneumoniae frequency in children with respiratory infections. A total of 416 children were recruited from two clinical centers in Sao Luis, Brazil. Of these patients, 165 children had upper respiratory tract infections (URTI), 150 had community-acquired pneumonia (CAP), and 101 were asymptomatic volunteer children. Clinical and epidemiological data from the participants were recorded. Nasopharyngeal swab samples were collected to extract DNA. C. pneumoniae DNA positivity and copy numbers were obtained by an absolute quantitative realtime PCR method. Results Positivity for C. pneumoniae DNA was higher in samples from URTI children (38.2%) and from CAP children (18.0%) than in those from the control group (7.9%; p < 0.001). Moreover, C. pneumoniae DNA was denser in children with URTI than in asymptomatic children. Considering the cutoff, the highest value of C. pneumoniae DNA found in asymptomatic children of the 3.98 log10 copies/mL, 8.5% (14/165) of the children with URTI, and 3.3% (5/150) with CAP presented high copy numbers of C. pneumoniae DNA. Conclusion Taken together, these results revealed a high frequency of C. pneumoniae in both children with URTI and CAP. Keywords Acute respiratory infection. Children. Chlamydia pneumoniae acquired pneumonia (CAP) is an acute lower respiratory tract infection leading to the deaths of approximately 1 million children under 5 years of age in 2015 alone [2]. This high incidence and mortality related to ARI in children is associated with the presence of risk factors that predispose individuals
Prevalence of antibodies to Chlamydia pneumoniae in Slovenia
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 1994
Aims: To estimate the occurrence of recent, past, and "persistent" infections with Chlamydia pneumoniae-as indicated by serology-in an Israeli population without clinical evidence of respiratory infection. Methods: Serum samples from 402 subjects (172 children and 230 adults), without known respiratory symptoms, were collected. Antibodies to C pneumoniae (IgG, IgA, and IgM) were evaluated using the microimmunofluorescence (MIF) assay. Antibody prevalence and indication of recent, past, and persistent infections were calculated and their distribution determined according to age, sex, and season. Results: Antibodies to C pneumoniae were detected in 53 children (31%) and 171 adults (74%). Recent infection was indicated in only one of 50 children under 5 years of age, in nine of 122 older children, and in 19 of 230 adults. IgM antibodies were detected in nine children, but only in three adults. Past infection was indicated in six of 96 young children (aged 1-10 years), in 28 of 76 teenagers, and in 128 of 230 adults. Persistent infection was indicated in three young children, in six teenagers, and in 24 adults, with a significantly higher frequency (p = 0.012) in men (18 of 117) than in women (six of 113). No seasonal differences could be detected. Conclusions: Infection with C pneumoniae was detected serologically in children and adults without clinical signs of respiratory disease. These results should serve as a basis for studies on the role of C pneumoniae infections and their sequelae in Israel and contribute to the general understanding of asymptomatic infection with C pneumoniae.