PRELIMINARY STUDY FOR DETECTION OF CAPILLARIA PHILIPPINENSIS COPRO-DNA IN DIARRHEIC PATIENTS

Abstract

Intestinal capillariasis is an emerging serious parasitic disease. Human infection occurs accidentally. Cases of human infection by C. philippinensis appear to be spreading geographically. It was first reported in 1963 in the Northern Philippines and subsequently in the surrounding areas. It was recorded in Egypt in 1989. Infection causes chronic diarrhea associated with abdominal pain, weight loss, vomiting, borborgymi, and oedema. The diagnosis of intestinal capillariasis is based on the detection of eggs, larvae, and/or adult worms of the parasite in the feces. The present study aimed to develop a molecular diagnostic tool to detect C. philippinensis copro-DNA using PCR-based assays in faecal samples of infected patients compared with conventional microscopic method. Stool samples of 250 studied individuals were examined by direct wet mount microscopy and by nPCR. For evaluation of the diagnostic effectiveness of microscopy, nPCR test was used as a reference standard method for detection of C. philippinensis infection. Based on the obtained results of the present study, nPCR was able to detect 43 C.philippinensis infected cases (28.6%) of the symptomatic group, while microscopic examination was able to detect 36 cases (24%). None of the 100 apparently healthy control subjects was found to be infected with C. philippinensis by any of both techniques. The age of cases detected ranged from 5 to 70 years with mean age of 28.4 (±13.7). The microscopic method had a high sensitivity (83.7%) and specificity (100%) and accuracy (95.3 %) using nPCR as a gold standard. Kappa test of agreement showed that there was a perfect agreement between it with nPCR findings (0.8). Among analyzed study variables, gender of nPCR positive cases was positively associated with risk of C.philippinensis infection. Females were estimated to be 5.05 times more than males in the risk of having C philippinensis infection. There was also statistical significant difference between prevalence of C.philippinensis and having chronic diarrhea. Among the associated clinical manifestations, vomiting, borborgymi, weight loss, lower limb edema and flatulence showed significant correlation between them and probability of having C.philippinensis infection. All were positively associated with risk of C. philippinensis infection. There was a significant correlation between presence of Charcot Leyden crystals in stool samples and probability of having C.philippinensis infection. From the obtained results, we can conclude that nPCR is a reliable standard diagnostic tool for early detection of intestinal capillariasis. Also in chronic cases missed by coproscopy.