Introduction: Intestinal protozoa are considered potential pathogens that could be a cause of recurrent abdominal pain (RAP).The aims of the study were to assess the prevalence of protozoal infection, especially with respect to Giardia lamblia (gl), Dientamoeba fragilis (df) and Blastocystis hominis (bh), in children with RAP, and to determine if these parasites have a causative role in some of the patients with RAP.
Methods: 100 consecutive patients (57 F, 43 M; mean age 8.76 [range 4.15–15.97] years) who were presented in the hospital of one of the authors (CG) with RAP were investigated for intestinal protozoa. Inclusion criteria: >4 years old, >3 episodes of abdominal pain in the last 3 months, severe enough to affect the daily activities of the child, and referral by a general practitioner. Three stool samples were collected on 3 separate days into 1 vial each. From the stool samples in the 1st and 3rd vial, containing sodium acetate acetic acid formalin (SAF) fixative, parasitological assessment was performed using an iron haematoxylin-Kinyoun (IHK) staining procedure and a Giardia lamblia specific ELISA. The unpreserved 2nd stool sample was examined for (oo)cysts and spores of protozoa. When parasites were detected, patients were treated with metronidazole (20 mg/kg/day for gl, 35–50 mg/kg/day for df and bh) for 10 days. Because of intolerance or refusal of metronidazole some children were treated with tinida-zole (two dosages of 75 mg/kg 1 week apart) or, in case of df, paromomycine (25–35 mg/kg/day for 7 days). At least 1 week after the end of treatment stool examination was repeated, followed by evaluation of complaints during at least 6 months.
Results: 6 patients failed to bring stool samples. Of the remaining 94 patients 34 carried parasites (gl , df , bh , df+bh , gl+df+bh ). 8 patients had spontaneous resolution of abdominal pain. The remaining 26 patients were treated. Faecal control thereafter was negative in 22 patients (gl , df , bh , df+bh , gl+df+bh ). Of these 22, 12 patients showed resolution of abdominal pain after treatment (gl , df , bh , df+bh , gl+df+bh ); 11 of these carried df.
Conclusion: A significant proportion of children with abdominal pain (34 out of 94) was infected with intestinal parasites. Spontaneous resolution of abdominal pain without eradication of parasites is not unusual. In slightly over half of the patients eradication of parasites resulted in persistent disappearance of abdominal pain; the prevalence of df in these patients suggests a potential role for this parasite in RAP.