Chlamydophila pneumoniae: Infectious substances pathogen safety data sheet

For more information on Chlamydophila pneumoniae, see the following:

• Infection Control guideline for the Prevention of Healthcare-Associated Pneumonia

Section I – Infectious agent

Name

Chlamydophila pneumoniae

Agent type

Bacteria

Taxonomy

Family

Chlamydiaceae

Genus

Chlamydophila

Species

pneumoniae

Synonym or cross-reference

Originally named Chlamydia strain TWAR, in 1989 it was reclassified as a new species, Chlamydia pneumoniae^Footnote1. In 1999 the genus was renamed Chlamydophila, but the change was not universally adopted. C. pneumoniae is commonly referred to by both genus names^{Footnote 2}.

Characteristics

Brief description

C. pneumoniae is a non-motile, gram-negative obligate intracellular bacterium. The genome is approximately 1.23 Mbp^{Footnote 3}. C. pneumoniae has two developmental forms: a metabolically inactive and infectious elementary body, which is adapted for extracellular survival, and a metabolically active, non-infectious reproductive reticulate body^{Footnote 4}. C. pneumoniae elementary bodies are usually pear-shaped, whereas elementary bodies of other members of the genus are typically round^{Footnote 3}. The elementary bodies are smaller in size (0.2 µm) while the reticulate bodies are larger in size (0.8 µm)^{Footnote 5}. Three C. pneumoniae biovars have been identified: human, koala, and equine^{Footnote 3Footnote 6}.

Properties

C. pneumoniae can be cultured in yolk sacs of chicken embryos and some cell lines such as HL (human line) and Hep-2 cells^{Footnote 3}. C. pneumoniae replicate in the cytoplasm of host cells within membrane-bound vacuoles (inclusion), until they occupy most of the cytoplasm, C. pneumoniae is then released from the cell either by extrusion or cell host lysis to infect neighbouring cells^{Footnote 5}. C. pneumoniae is able to systematically spread to other tissues outside the lungs through peripheral blood mononuclear cells, and can multiply in various cell types^{Footnote 5}. C pneumoniae can survive under stressful conditions as a non-infectious persistent form and remain in the host cell as reticulate bodies before reactivation^{Footnote 5}.

Section II – Hazard identification

Pathogenicity and toxicity

C. pneumoniae causes upper and lower respiratory tract infections (e.g., pharyngitis, sinusitis, bronchitis, community-acquired pneumonia) in humans^Footnote1. In most individuals, infection is asymptomatic, or mild and self-limiting^{Footnote 7Footnote 8}. Initial symptoms include rhinorrhea, headache (25-60%), fever (25-45%), hoarseness (65-75%), and sore throat (70-80%)^Footnote8. These symptoms usually resolve after one week and are followed by a dry cough (75-90%) that can persist for weeks to months^{Footnote7Footnote8Footnote 9}. Although C. pneumoniae can cause a severe form of pneumonia, fatalities are rare^{Footnote 10Footnote 11}.

C. pneumoniae appears to be capable of persisting in the body after acute infection^Footnote7, and has been associated with various chronic conditions in adults including atherosclerosis^{Footnote 12Footnote 13Footnote 14}, cardiovascular disease^Footnote5, neck vein obstruction^{Footnote 15}, asthma onset and exacerbation^{Footnote 16Footnote 17}, chronic obstructive pulmonary disease^{Footnote 18}, late onset dementia^{Footnote 19}, arthritis^{Footnote 20Footnote 21}, multiple sclerosis^{Footnote 22} and, skin and mucous membrane eruptions^{Footnote 23}.

Atherosclerosis is the buildup of plaque in arteries and is a precursor to cardiovascular disease. In vascular cells, C. pneumoniae induces oxidative stress and inflammatory proteins which accelerates atherosclerotic lesion development^{Footnote 24}. The prevalence of C. pneumoniae in atherosclerotic plaques is 40-50%^{Footnote 25}.

C. pneumoniae can promote asthma onset by inducing high counts of eosinophils and neutrophils in the airways. If not treated, C. pneumoniae can cause chronic infection that induces more inflammatory responses. The reported prevalence of asthmatics with C. pneumoniae infection is variable, ranging from 15-92%^{Footnote 26}.

Furthermore, C. pneumoniae can infect the brain and central nervous system, possibly through the olfactory nerves, and increase the risk factor for dementia by promoting amyloid beta deposits in the brain^{Footnote 27}. 80-90% of patients with late-onset dementia contained C. pneumoniae in their brain tissue^{Footnote 27}.

C. pneumoniae infections have been identified in koalas, horses, bandicoots, amphibians, and reptiles^{Footnote 18}. While clinical features in other animals are less known, C. pneumoniae causes respiratory tract infections in koalas; infections can be asymptomatic or koalas may present symptoms similar to those observed in humans^{Footnote3Footnote 28}.

Epidemiology

C. pneumoniae causes respiratory tract infections in children and adults worldwide. Primary infection occurs mainly in school-aged children, whereas reinfection occurs in adults. Seroprevalence is approximately 50% by age 20, 80% in elderly males, and 70% in elderly females^{Footnote 18}. Incidence of community-acquired pneumonia in adults requiring hospitalization in the United States is approximately 24.8 cases per 10,000 people per year^{Footnote 29}. C. pneumoniae is responsible for 6-20% of community-acquired pneumonia cases^{Footnote 8}, and 5% of bronchitis cases^{Footnote 7}. Individuals with untreated HIV have higher risk of C. pneumoniae infection than healthy individuals^{Footnote 30}. Disease can be more severe in elderly individuals and those with cardiopulmonary disease^{Footnote 8}. Fatalities due to C. pneumoniae respiratory infections are rare^{Footnote 10Footnote 11}. Sporadic outbreaks of respiratory tract infection caused by C. pneumoniae have been reported in long-term care facilities, correctional centres, and military bases^{Footnote 31Footnote 32Footnote 33}.

Host range

Natural host(s)

Humans^Footnote1, horses^{Footnote 6}, koalas^Footnote28, Western-barred bandicoots^{Footnote 34}, reptiles (snakes, iguanas, chameleons, turtles)^{Footnote 35}, birds^{Footnote 36} and amphibians (frogs)^Footnote36.

Other host(s)

Mice, rabbits, toads, hamsters and non-human primates have been experimentally infected^{Footnote 37Footnote 38Footnote 39Footnote 40}.

Infectious dose

Unknown.

Incubation period

Approximately 21 days^Footnote7.

Communicability

Transmission of C. pneumoniae occurs via exposure to contaminated surfaces and subsequent transfer to mucosal tissues^{Footnote 41Footnote 42}. Transmission can also occur via exposure to infectious aerosols through close person-to-person contact, but this does not appear to be an efficient mode of transmission^Footnote42.

Section III – Dissemination

Reservoir

Humans^{Footnote 43}.

Zoonosis

None. However, findings of animal genotypes in humans suggest the possibility of zoonosis^{Footnote 44}.

Vectors

None.

Section IV – Stability and viability

Drug susceptibility/resistance

C. pneumoniae growth is inhibited by tetracyclines, macrolides, azalides, ketolides, chloramphenicol, rifampin, and fluoroquinolones in vitro^Footnote3. The developmental cycle is interrupted in the presence of beta-lactam antibiotics^Footnote3. Recently, Lefamulin has been shown to effectively inhibit protein synthesis in pulmonary organisms, including C. pneumoniae, and has been approved by FDA (Food and Drug Administration), EMA (European Medicines Agency), and Health Canada to treat against community-acquired pneumonia^{Footnote 45}.

C. pneumoniae is not susceptible to sulphonamides^{Footnote2Footnote3Footnote 46}. The TW-183 strain of C. pneumoniae has shown some in-vitro resistance to rifampin and rifalazil due to gene mutations^{Footnote 47}. Mutated CV-6 strain of C. pneumoniae has shown in-vitro resistance to quinolones^{Footnote 48}.

Susceptibility to disinfectants

Topical application of the oxidant N-chlorotaurine (0.1%) has been shown to effectively inactivate intra-cellular C. pneumoniae in-vitro^{Footnote 49}. Bleach (0.25%), ethanol (70%), glutaraldehyde (2%), hydrogen peroxide (7.5%), peracetic acid (0.2%), and orthophthalaldehyde (0.55%) are effective against other members of the Chlamydophila genus^{Footnote 50}.

Physical inactivation

C. pneumoniae is sensitive to heat and UV radiation^{Footnote 51}. C. pneumoniae can be inactivated by heat treatment at 90°C for 30 minutes and by exposure to 30W UV light source for 30 minutes from a distance of 15 cm^{Footnote51Footnote 52}.

Survival outside host

C. pneumoniae can persist on a dry inanimate surface for up to 30 hours^Footnote41. C. pneumoniae can survive in liquid medium at 15°C for 2 weeks^{Footnote 53}, and on hands for 10-15 minutes^Footnote41.

Section V – First aid/medical

Surveillance

C. pneumoniae can be detected in clinical specimens using culture-based, antigen detection, antibody detection, and molecular methods^{Footnote 54}. C. pneumoniae antigens can be detected in cells using a peroxidase or fluorescent marker^{Footnote 55}. Antibodies against C. pneumoniae can be detected using micro-immunofluorescence antibody assays (MIF) and ELISAs^{Footnote 9}. Commercial PCR assays such as FilmArray^® Respiratory Panel (BioFire Diagnostics, Salt Lake City, UT) and NxTag^® Respiratory Pathogen Panel (Luminex Inc., Austin, TX) have been approved by the FDA for C. pneumoniae detection^{Footnote9Footnote29Footnote55}. Molecular methods, including PCR assays, is considered the "gold standard"^{Footnote 56}.

Note: The specific recommendations for surveillance in the laboratory should come from the medical surveillance program, which is based on a local risk assessment of the pathogens and activities being undertaken, as well as an overarching risk assessment of the biosafety program as a whole. More information on medical surveillance is available in the Canadian Biosafety Handbook.

First aid/treatment

The first-line treatment for C. pneumoniae are macrolides. The most active is clarithromycin with a minimum inhibitory concentration of 0.004-0.03 µg/mL. Others include azithromycin (0.05-0.25 µg/mL) and erythromycin (0.015-0.25 µg/mL)^Footnote47. Infections are also commonly treated with tetracyclines, such as doxycycline and minocycline, which have a minimum inhibitory concentration of 0.015-0.25 µg/mL^Footnote47. Quinolones show inhibitory activity against C. pneumoniae as well with varying levels of inhibitory concentrations, such as garenoxacin (0.015-0.03 µg/L), gemifloxacin (0.06-0.25 µg/L), or levofloxacin (0.25-1 µg/L)^{Footnote 47}. Treatment regimens usually involve multiple drugs due to complexity of eradicating chronic infection^Footnote2.

Note: The specific recommendations for first aid/treatment in the laboratory should come from the post-exposure response plan, which is developed as part of the medical surveillance program. More information on the post-exposure response plan can be found in the Canadian Biosafety Handbook.

Immunization

None.

Note: More information on the medical surveillance program can be found in the Canadian Biosafety Handbook, and by consulting the Canadian Immunization Guide.

Prophylaxis

None.

Note: More information on prophylaxis as part of the medical surveillance program can be found in the Canadian Biosafety Handbook.

Section VI – Laboratory hazard

Laboratory-acquired infections

Two laboratory workers developed asymptomatic respiratory tract infection with C. pneumoniae after exposure to aerosolized infectious material^{Footnote 57}. Four laboratory technicians presented with C. pneumoniae pneumonia after cultivating an isolate in the laboratory^{Footnote 58}. One laboratory technician presented with fatigue, fever, and severe pneumonia after aerosol exposure^{Footnote 59}.

Note: Please consult the Canadian Biosafety Standard and Canadian Biosafety Handbook for additional details on requirements for reporting exposure incidents. A Canadian biosafety guideline describing notification and reporting procedures is also available.

Sources/specimens

Nasopharyngeal swab or aspirate, lung and vascular biopsy specimens, blood, atherosclerotic plaques, brain tissue^{Footnote2Footnote25Footnote27}.

Primary hazards

Autoinoculation with infectious material and exposure of mucous membranes to infectious material, including infectious aerosols^Footnote42.

Special hazards

None.

Section VII – Exposure controls/personal protection

Risk group classification

C. pneumoniae is a Risk Group 2 Human Pathogen and Risk Group 2 Animal Pathogen^{Footnote 60Footnote 61}.

Containment requirements

Containment Level 2 facilities, equipment, and operational practices outlined in the Canadian Biosafety Standard for work involving infectious or potentially infectious materials, animals, or cultures.

Protective clothing

The applicable Containment Level 2 requirements for personal protective equipment and clothing outlined in the Canadian Biosafety Standard are to be followed. The personal protective equipment could include the use of a labcoat and dedicated footwear (e.g., boots, shoes) or additional protective footwear (e.g., boot or shoe covers) where floors may be contaminated (e.g., animal cubicles, PM rooms), gloves when direct skin contact with infected materials or animals is unavoidable, and eye protection where there is a known or potential risk of exposure to splashes.

Note: A local risk assessment will identify the appropriate hand, foot, head, body, eye/face, and respiratory protection, and the personal protective equipment requirements for the containment zone and work activities must be documented.

Other precautions

A biological safety cabinet (BSC) or other primary containment devices to be used for activities with open vessels, based on the risks associated with the inherent characteristics of the regulated material, the potential to produce infectious aerosols or aerosolized toxins, the handling of high concentrations of regulated materials, or the handling of large volumes of regulated materials.

Use of needles and syringes to be strictly limited. Bending, shearing, re-capping, or removing needles from syringes to be avoided, and if necessary, performed only as specified in standard operating procedures (SOPs). Additional precautions are required with work involving animals or large-scale activities.

Additional information

For diagnostic laboratories handling primary specimens that may contain C. pneumoniae, the following resources may be consulted:

• Human Diagnostic Activities Biosafety Guideline
• Local Risk Assessment Biosafety Guideline

Section VIII – Handling and storage

Spills

Allow aerosols to settle. Wearing personal protective equipment, gently cover the spill with absorbent paper towel and apply suitable disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (Canadian Biosafety Handbook).

Disposal

All materials/substances that have come in contact with the regulated materials should be completely decontaminated before they are removed from the containment zone or standard operating procedures (SOPs) to be in place to safely and securely move or transport waste out of the containment zone to a designated decontamination area / third party. This can be achieved by using decontamination technologies and processes that have been demonstrated to be effective against the regulated material, such as chemical disinfectants, autoclaving, irradiation, incineration, an effluent treatment system, or gaseous decontamination (Canadian Biosafety Handbook).

Storage

Containment Level 2: The applicable Containment Level 2 requirements for storage outlined in the Canadian Biosafety Standard are to be followed. Primary containers of regulated materials removed from the containment zone to be labelled, leakproof, impact resistant, and kept either in locked storage equipment or within an area with limited access.

Section IX – Regulatory and other information

Canadian regulatory information

Controlled activities with C. pneumoniae require a Human Pathogens and Toxins licence issued by the Public Health Agency of Canada. C. pneumoniae is a terrestrial animal pathogen in Canada; therefore, importation of C. pneumoniae requires an import permit under the authority of the Health of Animals Regulations (HAR), issued by the Public Health Agency of Canada. The Agency issues a "Pathogen and Toxin Licence document" for both a Humans Pathogens and Toxins Licence and HAR importation permit.

The following is a non-exhaustive list of applicable designations, regulations, or legislations:

• Human Pathogen and Toxins Act and Human Pathogens and Toxins Regulations
• Health of Animals Act and Health of Animals Regulations
• Transportation of Dangerous Goods Regulations

Last file update

September, 2023

Prepared by

Centre for Biosecurity, Public Health Agency of Canada.

Disclaimer

The scientific information, opinions, and recommendations contained in this Pathogen Safety Data Sheet have been developed based on or compiled from trusted sources available at the time of publication. Newly discovered hazards are frequent and this information may not be completely up to date. The Government of Canada accepts no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information.

Persons in Canada are responsible for complying with the relevant laws, including regulations, directives and standards applicable to the import, transport, and use of pathogens and toxins in Canada set by relevant regulatory authorities, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment and Climate Change Canada, and Transport Canada. The risk classification and related regulatory requirements referenced in this Pathogen Safety Data Sheet, such as those found in the Canadian Biosafety Standard, may be incomplete and are specific to the Canadian context. Other jurisdictions will have their own requirements.

Copyright ^© Public Health Agency of Canada, 2023, Canada