Parasitic Infections and Host Tissue Response in Histopathology: A Rare Retrospective Research Study from Rural India.

Objective: Parasite are living organisms which survive on another living being for their nourishment and survival. When these parasites resides on human body, they bring about inflammatory response. This inflammatory response leads to tissue reaction. Tissue response on microscopy appear as an eosinophilia, abscess and granulomas. This study was planned with the objective to know the frequency of parasite infection, tissue response in parasite infection and its comparison in terms of variables like age, sex and the type of parasite.

Methods: This is a retrospective study, conducted in the department of pathology. A total of 26 cases of parasitic infections in human specimens reported in our department from January 2008 to December 2019 were included in this study. On all archived cases hematoxylin and eosin and where ever required periodic acid schiff was applied. These slides were thoroughly examined and clinicopathological correlation was studied.

Results: Age range of patients was 5 years to 70 years. Maximum number of patients were belonging to 11-20 year age group. Male to female ratio was 1:2. Among the 26 cases, there were 9 cases (34.62%) of hydatid cyst, six cases of Entamoeba histolytica (23.07%), four cases of Enterobious vermicularis (15.38%), and two cases (7.69%) each of Ascaris lumbricoides, filaria and cysticercosis respectively. A specific tissue response seen in cysticercosis having chronic inflammatory cells, palisaded epithelioid cells granuloma and giant cell reaction while other showed inflammatory cells infiltration.

Conclusion: Clinically diagnosis of parasitic infection in each and every case is not possible, similarly radiological investigation is also suggestive only. Histopathology examination is the benchmark investigation to diagnose parasite infection and tissue reaction to the host. Histopathology examination must be implicated in every case to identify parasite and tissue reaction so that the patients can be managed accordingly before the complications rises.