avian & livestock assay data sheet

Atoxoplasmosis

Test code: X0021 - Ultrasensitive qualitative detection of Atoxoplasma species by real time PCR

Atoxoplasmosis is a parasitic disease primarily of passerine birds, especially canaries, finches, sparrows, grosbeaks, starlings and mynahs. The disease is caused by infection with various species of the coccidian protozoan genus Atoxoplasma. The parasite is host-specific and is transmitted via the fecal-oral route.

Infection with this parasite can cause rapid and fatal disease in fledgling birds. Affected young birds may develop diarrhea, anorexia, depression, ruffled feathers, ataxia and hepatic enlargement that may be grossly visible through the living bird’s skin as "black spot." Mortality rates for atoxoplasmosis can reach 80% in young passerines. Infected adult birds are usually asymptomatic but continue to shed oocysts. The infection can last for up to eight months. Oocysts are very stable in the environment and are not inactivated by most disinfectants. Thus, routine environmental monitoring may be required to completely remove these parasites from a facility. In addition, new birds which are introduced into a flock or facility should be repeatedly screened to ensure no parasites are being introduced.

Diagnosis of atoxoplasmosis has traditionally been through postmortem examination and histopathology of fledglings that die acutely, or by fecal floatation on persistently infected adult birds. Identification of Atoxoplasma oocysts is extremely difficult because the oocysts are very similar to those of Isospora species and the shedding of the oocysts by infected birds is often sporadic. Blood smear testing can be used, but sensitivity is low. Molecular detection by PCR has been found to be both sensitive and specific for detection and identification of the parasite (Adkesson et al., 2005).

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Atoxoplasma infection
• Ensure that flocks are free of Atoxoplasma
• Early prevention of spread of Atoxoplasma among birds, and between birds and other animals
• Minimize human exposure to Atoxoplasma

References:
Adkesson, M.J., Zdziarski, J.M. and Little, S.E. (2005) Atoxoplasmosis in tanagers. J. Zoo Wildl. Med. 36:265-272

Specimen requirement: 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top) tube, or 0.2 ml feces, or cloacal swab, or 0.2 ml fresh, frozen or fixed tissue.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected