ABSTRACT
A survey was undertaken in the east district of Imphal valley of Manipur, India, using an intradermal test with saline extract of adult Paragonimus westermani as test antigen to find out the prevalence of paragonimiasis and some of the epidemiological factors attributable to it. A total of 3,467 individuals of both sexes aged five years and above were tested. A total of 2934 persons admitted eating crabs and among them 234 were found reactive to Paragonimus antigen. The prevalence rate observed was 6.7 per cent. The proportion of positive reactors (8.0%) among the crab eaters compared to 0.1 per cent among those who did not eat crabs was highly significant (P < 0.01). The difference in the prevalence rates in different age groups and different sexes was also found to be highly significant. The habit of eating raw and or undercooked crabs had significant correlation with skin reactivity. The intradermal test was found to be a good screening test for mass surveys due to its simplicity, low cost, high sensitivity and no known untoward reaction. Four persons among the skin positive reactors presented with cough, pain in the chest, recurrent haemoptysis as major clinical manifestations. Laboratory investigations revealed Paragonimus eggs in the sputum smears, raised erythrocyte sedimentation rate, and high absolute eosinophil count in their blood. Praziquantel, the drug of choice was given at a dose of 25 mg per kg body weight 3 times a day for three consecutive days to each patient for a cure.