PART III. RECOMMENDATIONS AND REQUIREMENTS
Recommendations for Controlling Infection Among Humans and Birds [back to top]
- To prevent the transmission of C. psittaci to persons and other birds, the following control measures are recommended for physicians, veterinarians and their staffs, and members of the pet bird industry:
- Take measures to protect persons at high risk from becoming infected. All persons in contact with infected birds should be informed about the nature of the disease. If a person who has been exposed develops respiratory illness, the physician should initiate early and specific treatment for psittacosis. Persons at risk should be instructed to wear protective clothing, gloves, a paper surgical cap, and a respirator with an N95 rating or a higher-efficiency respirator when cleaning cages or handling infected birds. Surgical masks may not be effective in preventing transmission of C. psittaci. When necropsies are performed on potentially infected birds, additional precautions should be taken, including a) wetting the carcass with detergent and water to prevent aerosolization of infectious particles and b) working under an examining hood that has an exhaust fan.
- Maintain accurate records of all bird-related transactions to aid in identifying sources of infected birds and potentially exposed persons. Records should include the date of purchase, species of birds purchased, source of birds, and any identified illnesses or deaths among birds. In addition, when birds are sold by a store, the seller should record the name, address, and telephone number of the customer; the date of purchase; the species of birds purchased; and the band numbers if applicable.
- Do not purchase or sell birds that have signs of AC (e.g., ocular or nasal discharge, diarrhea, or low body weight).
- Quarantine newly acquired birds for 30–45 days, and test or prophylactically treat them before adding them to a group.
- Consider birds that have been to shows, exhibitions, fairs, and other events as newly acquired birds, and quarantine them upon return to the facility.
- Test birds for AC before they are to be boarded or sold on consignment, and house them in a room separate from other birds.
- Practice preventive husbandry. Position cages to prevent the transfer of fecal matter, feathers, food, and other materials from one cage to another. Do not stack cages, and be sure to use solid-sided cages or barriers if cages are adjoining. The bottom of the cage should be made of wire mesh, and litter that will not produce dust (e.g., newspapers) should be placed underneath the mesh. Clean all cages and food and water bowls daily. Soiled bowls should be emptied, cleaned with soap and water, rinsed, placed in a disinfectant solution, and rinsed again before reuse. Between occupancies by different birds, cages should be thoroughly scrubbed with soap and water, disinfected, and rinsed in clean, running water. Exhaust ventilation should be sufficient to prevent accumulation of aerosols.
- Prevent the spread of infection. If AC is confirmed, probable, or suspected, birds requiring treatment should be held in isolation. Rooms and cages where infected birds were housed should be cleaned immediately and disinfected thoroughly to eliminate chlamydial organisms from the environment. When the cage is being cleaned, transfer the bird to a clean cage. Thoroughly scrub the soiled cage with a detergent to remove all fecal debris, rinse the cage, disinfect it (allowing at least 5 minutes of contact with the disinfectant), and rerinse the cage to remove the disinfectant. Discard all items that cannot be adequately disinfected (e.g., wooden perches, nest material, and litter). While birds are being treated, minimize the circulation of feathers and dust by taking precautions such as wet-mopping the floor frequently with disinfectants and preventing air currents and drafts within the area. Reduce contamination from dust by spraying the floor with a disinfectant or water before sweeping it. Do not use a vacuum cleaner, because vacuuming can cause aerosolization of infectious particles. Frequently remove waste material from the cage (after moistening the material), and burn or double-bag the waste for disposal. When possible, care for healthy birds before handling isolated birds.
- Use disinfection measures. Because C. psittaci has a high lipid content, it is susceptible to most disinfectants and detergents. In the clinic or laboratory, a 1:1,000 dilution of quaternary ammonium compounds (e.g., Roccal ® or Zephiran ® ) is effective, as is 70% isopropyl alcohol, 1% Lysol ® , 1:100 dilution of household bleach (i.e., 2.5 tablespoons per gallon [10 mL/L]), or chlorophenols. ( C. psittaci is susceptible to heat but is resistant to acid and alkali.) Many disinfectants are respiratory irritants and should be used in a well-ventilated area. Avoid mixing disinfectants with any other product.
Recommendations for Treating and Caring for Infected Birds [back to top]
All birds with confirmed or probable AC should be isolated and treated, preferably under the supervision of a veterinarian (Appendix B). Birds with suspected AC or birds previously exposed to AC should be isolated and retested or treated. Because treated birds can be reinfected with C. psittaci after treatment, such birds should not be exposed to untreated birds or other potential sources of infection. To prevent reinfection from environmental sources, aviaries should be thoroughly cleaned and sanitized. No vaccine against chlamydiosis in birds is available.
The following general recommendations should be followed by bird owners and dealers when treating and caring for birds with confirmed, probable, or suspected cases of AC:
- Protect birds from undue stress (e.g., chilling or shipping), poor husbandry, or malnutrition. These problems reduce the effectiveness of treatment and promote the development of secondary infections with other bacteria or yeast.
- Observe the birds daily, and weigh them every 3–7 days. If the birds are not maintaining weight, have them reevaluated by a veterinarian.
- Do not administer antimicrobial agents to birds through drinking water, and avoid the use of high dietary concentrations of calcium or other divalent cations.
- Isolate birds that are to be treated in clean, uncrowded cages, segregated by sex.
- Clean up all spilled food promptly; wash food and water containers daily.
- Provide fresh water and appropriate vitamins daily.
- Continue medication for the full treatment period to avoid relapses. Birds may appear clinically improved and have reduced shedding after 1 week.
Responsibilities of Veterinarians and Physicians [back to top]
Veterinarians should be aware that AC is not a rare disease among pet birds and should consider a diagnosis of AC for any lethargic bird that has nonspecific signs of illness, especially if the bird was purchased recently. If AC is suspected, the veterinarian should submit appropriate laboratory specimens to a veterinary diagnostic laboratory to confirm the diagnosis. Both laboratories and attending veterinarians should follow local and state regulations or guidelines regarding case reporting. Veterinarians should work closely with authorities who conduct investigations in their jurisdictions. When appropriate, veterinarians should inform clients that infected birds should be isolated and treated. In addition, they should educate clients about the public health hazard posed by AC and the appropriate precautions that should be taken to avoid the risk for transmission. Persons exposed to the birds should seek medical attention if they develop influenza-like symptoms or other respiratory illness.
Most states require physicians to report cases of psittacosis among humans to the appropriate health authorities. Timely diagnosis and reporting may help identify the source of infection and control the spread of disease. Because single-serum titers are both insensitive and nonspecific for diagnosis of psittacosis, confirmation with paired acute- and convalescent-phase sera is recommended. Birds that are suspected sources of human infection should be referred to veterinarians for evaluation and treatment. Local and state authorities may conduct epidemiologic investigations and institute additional disease-control measures (see Local and State Epidemiologic Investigations).
Quarantine of Birds [back to top]
The appropriate animal and public health authorities may issue a quarantine for all affected and susceptible birds on a premises where C. psittaci infection has been identified. The purpose of imposing a quarantine is not to discourage disease reporting but to prevent further disease transmission ( 3 ). Because of the severe economic impact of quarantines, reasonable economic options should be made available to the owners and operators of pet stores. For example, with the approval of state or local authorities, the owner of quarantined birds may choose to a) treat the birds in a separate quarantine area to prevent exposure to the public and other birds or b) euthanize the infected birds. After completion of the treatment or removal of the birds, a quarantine can be lifted when the infected premises are thoroughly cleaned and disinfected. The area can then be restocked with birds.
Bird Importation Regulations [back to top]
The Veterinary Services of the Animal and Plant Health Inspection Service, U.S. Department of Agriculture (USDA), regulates the importation of pet birds to ensure that exotic poultry diseases are not introduced into the United States. These regulations are set forth in the Code of Federal Regulations, Title 9, Chapter 1 ( 3 ). Because of the possibility of smuggled pet birds, these import measures do not guarantee that AC cannot enter the United States. In general, current USDA regulations regarding the importation of birds include the following requirements:
- Before shipping the birds, the importer must obtain an import permit from the USDA and a health certificate issued and/or endorsed by a veterinarian of the national government of the exporting country.
- A USDA veterinary inspection must be conducted at the first port of entry in the United States and a quarantine be imposed for a minimum of 30 days at a USDA-approved facility, to determine whether the birds are free of evidence of communicable diseases of poultry. In addition, the birds must be tested to ensure they are free of exotic Newcastle disease and pathogenic avian influenza.
- During the 30-day U.S. quarantine, psittacine birds must receive a balanced, medicated feed ration containing ³ 1% chlortetracycline (CTC) with £ 0.7% calcium for the entire quarantine period as a precautionary measure against AC. The USDA recommends that importers continue CTC prophylactic treatment of psittacine birds for an additional 15 days (i.e., for 45 continuous days).
Local and State Epidemiologic Investigations [back to top]
Public health or animal health authorities at the local or state level may need to conduct epidemiologic investigations to help control the transmission of C. psittaci to humans and birds. An epidemiologic investigation should be initiated if a) a bird with confirmed or probable AC was procured from a pet store, b sis, or c) several suspect avian cases have been identified from the same source. Other situations may be investigated at the discretion of the appropriate local or state public health departments or animal health authorities.
Investigations involving recently purchased birds should include a visit to the site where the infected bird is located and identification of the location where the bird was originally procured (e.g., pet shop, dealer, breeder, or quarantine station). During such investigations, authorities should consider documenting the number and types of birds involved, the health status of potentially affected persons and birds, locations of facilities where birds were housed, relevant ventilation-related factors, the treatment protocol, and the source of medicated feed, if such treatment is initiated. To help identify multistate outbreaks of C. psittaci infection, local and state authorities should report suspected outbreaks to the Respiratory Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, CDC, telephone (404) 639-2215.