Morphologic Diagnosis

In eosinophilic meningitis with A. cantonensis, the cerebrospinal fluid (CSF) is abnormal (elevated pressure, proteins, and leukocytes; eosinophilia). On rare occasions, larvae have been found in the CSF. In abdominal angiostrongyliasis with A. costaricensis, eggs and larvae can be identified in biopsy specimens.

Molecular Diagnosis

The CDC offers a real-time PCR assay for the specific detection of A. cantonensis in human CSF specimens. The CSF should be kept cold and shipped to CDC on ice pack as soon as possible; alternatively it can be kept frozen until shipment is arranged. Shipment on dry ice is optional. Recommended volume of CSF is at least 2 ml. Volumes less than 1 ml may lead to reduced test sensitivity.

No specific molecular tests are available for A. costaricensis. A conventional PCR followed by DNA sequencing can be performed for A. costaricensis on a case-by case basis. Acceptable specimen type is tissue biopsies.

References

Qvarnstrom Y, da Silva AQA, Teem JL, Hollingsworth R, Bishop H, Graeff-Teixeira C, and da Silva AJ: Improved Molecular Detection of Angiostrongylus cantonensis in Mollusks and Other Environmental Samples with a Species-Specific Internal Transcribed Spacer 1-Based TaqMan Assay. Appl. Envir. Microbiol.; 2010; 76: 5287 - 5289.

Qvarnstrom Y, Sullivan JJ, Bishop HS, Hollingsworth R, da Silva AJ: PCR-based detection of Angiostrongylus cantonensis in tissue and mucus secretions from molluscan hosts. Appl. Environ. Microbiol.; 2007; 73:1415-1419.

Eamsobhanaa P, Limb PE, Solano G, Zhange H, Ganf X, Yongc HS: Molecular differentiation of Angiostrongylus taxa (Nematoda: Angiostrongylidae) by cytochrome c oxidase subunit I (COI) gene sequences. Acta Tropica; 2010; 116: 152–156.