Prevalence of Giardia intestinalis with other co-infecting parasites in Barak Valley, Assam, India: a molecular approach.

Giardia intestinalis was included in the World Health Organization's Neglected Disease Initiative in 2004 as it may range from asymptomatic to chronic or severe diarrhoea and chronic disorders post-infection. The present study aimed to find out the rate of sole infection of G. intestinalis and co-infection of this with other protozoan parasites among the inhabitants of Barak Valley region of Southern Assam by conventional and molecular detection. A total of 1168 samples were collected from different groups of individuals, all the collected samples were subjected to microscopy after specific staining by Lugol's iodine solution, Trichrome staining and modified ZN staining procedures. Microscopically positive samples were further confirmed by PCR using specific primer sets. Of the total no. of samples, 267 (22.85%) were positive by PCR for G. intestinalis with a little higher rate of infection in female (24.06%) (OR = 1.2192, CI = 0.9262 to 1.6049) than male (21.27%). The rate of infection is comparatively higher (25.93%) in the age group of 0-5 years (OR = 1.9149, CI = 1.2558 to 2.9200). In 196 samples G. intestinalis co-existence was observed and detected by PCR with some other protozoan parasites like Entamoeba spp., Cryptosporidium spp. and Blastocystis spp. The rate of infection was higher (31.96%) among the participants who collected water from river. Least of the participants showed diarrhoeal symptoms (18.18%) but majority (28.45%) complained for having abdominal cramps (OR = 1.3402, CI = 0.8815 to 1.7855). Among the human infective assemblages, assemblage specific molecular detection revealed the rate of infection of assemblage B was comparatively higher (60.30%) than assemblage A.