We would like to thank Dr. McManus for his letter regarding his recently published method for distinguishing the four recognized species of Echinococcus using PCR and DNA sequencing. It is interesting to know that the modern genetic approaches confirm the morphological observations made by classical parasitologists. Although we do agree with Dr. McManus that the four “species are quite clearly distinct”, we are in slight disagreement with some of the minor points he raises in his letter.
We are not convinced that “morphological features alone must be open to considerable doubt.” Experienced helminthologists have no problems identifying any of the four species in either the larval or strobilar stages. However, admittedly, many physicians are unable to make reliable identifications. Therefore, the PCR-RFLP and RAPD-PCR methods of McManus may be useful in hospital situations when no experienced person is available to make the identification. Secondly, we question how simple and how inexpensive the PCR-RFLP method is to carry out.