We have been preparing this for an eventual overhaul of the Handbook, but there have been a number of requests, especially by new folks, to help clear up confusion.

note: edited to add a study 1pm PST
New work in the field of community acquired pneumonia caused by CPn had a really nice review of the cytokineⁱ profile caused by this pathogen. abstract text below:

Vitamin Dⁱ and prevention of breast cancer: pooled analysis.

* Garland CF,
* Gorham ED,
* Mohr SB,
* Grant WB,
* Giovannucci EL,
* Lipkin M,
* Newmark H,
* Holick MF,
* Garland FC.

Department of Family and Preventive Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA. cgarland@ucsd.edu

J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):793-8. Epub 2007 Jan 12.Click here to read Links
Vitamin Dⁱ in the treatment of pulmonary tuberculosis.

* Martineau AR,
* Honecker FU,
* Wilkinson RJ,
* Griffiths CJ.

Centre for Health Sciences, Institute of Health Sciences Education, Barts and The London School of Medicine and Dentistry, London E1 2AT, United Kingdom. a.martineau@qmul.ac.uk

BMC Infect Dis. 2007 May 30;7(1):48 [Epub ahead of print]
Higher incidence of persistent chronic infection of Chlamydia pneumoniae among coronary artery disease patients in India is a cause of concern.

* Jha HC,
* Vardhan H,
* Gupta R,
* Varma R,
* Prasad J,
* Mittal A.

Clin Diagn Lab Immunol. 2000 Sep;7(5):739-44.
Comparison of five serologic tests for diagnosis of acute infections by Chlamydia pneumoniae.
Persson K, Boman J. Department of Clinical Microbiology, Malmo University Hospital, S-205 02 Malmo, Sweden.

Georgian Med News. 2007 Apr;(145):58-62.

[The role of endothelial dysfunction and Chlamydia pneumoniae infection in patients with ischemic stroke.] [Article in Russian]

* Devidze E, * Sanikidze T, * Samadashvili D.

Department of Neurology, Tbilisi State Medical University.

J Neurosci Res. 2003 Mar 1;71(5):740-50. Links
Chlamydia pneumoniae infection promotes the transmigration of monocytes through human brain endothelial cells.MacIntyre A, Abramov R, Hammond CJ, Hudson AP, Arking EJ, Little CS, Appelt DM, Balin BJ.
Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, Pennsylvania, USA.

Antimicrob Agents Chemother. 2003 June; 47(6): 1972–1975.
doi: 10.1128/AAC.47.6.1972-1975.2003.
Copyright © 2003, American Society for Microbiology

Chlamydia pneumoniae Resists Antibioticsⁱ in Lymphocytes
Hiroyuki Yamaguchi,1 Herman Friedman,1 Mayumi Yamamoto,2 Keigo Yasuda,2 and Yoshimasa Yamamoto1,3*

Department of Medical Microbiology and Immunology, College of Medicine, University of South Florida, Tampa, Florida 33612,1 Third Department of Internal Medicine, School of Medicine, Gifu University, Gifu,2 Division of Molecular Microbiology, Department of Basic Laboratory Sciences, School of Allied Health Sciences, Faculty of Medicine, Osaka University, Osaka, Japan3

Chlamydia pneumoniae directly interferes with HIF-1alpha stabilization in human host cells.

Rupp J, et al

 Institute of Medical Microbiology and Hygiene, Center for Structural and Cell Biology in Medicine, University of Luebeck, 23538 Luebeck, Germany.

Here is a link to a little page from the American Centers for Disease Control (the CDC) which is an overview on chlamydia pneumoniae. It has a few factoids about CPn. One thing of interest to me since I have spent some time attempting to get specific epidemiological evidence on it (is it more prevalent in the northern states for example) is that much of that kind of information is simply not known.
Here is the link to the CDC page CDC Chlamydia pneumoniae page
marie