TOPICAL ASPECTS OF THE LABORATORY DIAGNOSIS OF PARASITIC DISEASES

Objective. To estimate the diagnostic value of laboratory diagnostic techniques for parasitoses that are relevant to southern Russia. Materials and methods. For verification of parasite infestation in 1500 patients attending the Clinic of Infectious and Parasitic Diseases, Rostov Research Institute of Microbiology and Parasitology, Russian Federal Service for Supervision of Consumer Rights Protection and Human Well-Being, the investigators used laboratory diagnostic techniques regulated by the Methodological Guidelines (MG) 4.2.3145-13 «Laboratory diagnosis of helminthiasis and protozoan disease» and MG 3.2.1173-02 «Serological tests for laboratory diagnosis of parasitic diseases». Results. Parasitic diseases were found in 58.5% of the patients who had visited the clinic with a referral diagnosis of helminthic invasion. The most frequently recorded diseases were enterobiasis (35.5%), echinococcosis (18.7%), toxocariasis (15.5%), and taeniarhynchosis (5.8%). The most effective method for diagnosing enterobiasis was a triple examination of the material collected from the perianal folds, which could identify pinworm (Enterobius vermicularis) eggs in 91.7% of the patients. The permanent laboratory signs of toxocariasis were peripheral blood eosinophilia and a positive result of ELISA with Toxocara antigen. A one-month follow-up after etiotropic therapy showed that 65.0% of patients had a two-fold or greater increase in antibody titers with a reduction of eosinophilia and normalization of peripheral blood parameters. There were negative results of ELISA with Echinococcus antigen in 9 (42.9%) patients prior to surgery and only in 4 (19.1%) patients a month after surgery. Five patients had a high risk of recurrence due to larval dissemination during surgery. The diagnosis of taeniarhynchosis was based on the results of parasitological examination of helminth segments before and after antihelminthic therapy. Examination of the scrapped perianal material revealed taeniid eggs in 62.5% of the patients. Conclusion. One of the important factors in optimizing the diagnosis of parasitic diseases is the choice of a method and the frequency of examinations, as well as the parallel application of all direct and immunological methods for the laboratory and instrumental verification of a diagnosis.

laboratory diagnosis, parasitic invasions