Hematological, biochemical, and serological parameters of experimentally infected rabbits with Trichinella nativa and Trichinella spiralis for early identification of trichinellosis

Abstract

Background and Aim: Trichinellosis remains a dangerous disease for humans and animals, which can lead to a lethal outcome. The study of specific body reactions in response to invasion by different types of Trichinella can help in the early diagnosis of the disease. This study aimed to investigate the hematological, biochemical, and serological characteristics of rabbits experimentally infected with trichinellosis, as well as the possibility of using changes in these parameters at various disease stages for early hematological, biochemical, and serological diagnosis of trichinellosis. Materials and Methods: Three groups of rabbits were orally infected with Trichinella nativa and Trichinella spiralis derived from encysted T. spirtalis larvae in pork muscle samples. The first and second groups were infected with T. nativa and T. spiralis, respectively, while the third group served as control by receiving a physiological solution. An ADVIA 2120i automatic hematology analyzer with a blood smear staining module was used to determine the hematological parameters of rabbits. Antigens were used in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies in the sera of infected rabbits that were supernatants containing excretory-secretory antigens (ES-Ag) and somatic antigen (S-Ag). Results: The detection of biochemical responses to the invasion of T. nativa and T. spiralis isolates was detected and hematological parameters were featured in two cases. Trichinella nativa increased the number of erythrocytes, neutrophils, eosinophils, monocytes, basophils, and thrombocytes on day 7 in rabbits. Creatine kinase (CK) is regarded as the most important indicator for the early detection of parasite invasion. Blood biochemistry showed no active response to T. spiralis infection. However, counts of erythrocytes, neutrophils, lymphocytes, and CK rose significantly. In both color indicators, the number of thrombocytes decreased. Enzyme-linked immunosorbent assay with ES-Ag and S-Ag of these isolates demonstrated the ability to detect antibodies as early as 7 days after infection, with a significant increase in the marker up to 70 days. Conclusion: On the 7th day after infection, blood tests of infected animals revealed CK-N-acetyl-cysteine (18.2%) and neutrophils (43%) when infected with T. nativa and neutrophils (26.7%) and lymphocytes (20%) when infected with T. spiralis. These indicators may serve as specific parameters for the early detection of Trichinella spp. invasion.