Treatment of Giardia Lamblia Infections in Children

Treatment of Giardia Lamblia Infections in Children: Randomized Open-labeled Trial Comparing Rectal Metronidazole With Oral Tinidazole

This study investigates the efficacy and safety of rectally administered metronidazole for pediatric Giardia lamblia infection, as well as the acceptance of this treatment regimen by patients/caregivers. The investigators hypothesize that rectal metronidazole is non-inferior to single-dose of oral tinidazole and will cure at least 72% of patients, a well as will be tolerated as good as tinidazole.

Approximately 180 children (age 6 months to 10 years) whose clinical symptoms could be explained by giardiasis and whose fecal samples will test positive for the presence of G.lamblia in Uusimaa laboratory (HUSLAB) will be recruited. The study will be performed as an open-label trial. Patients will be randomized during primary visits alternately into two groups by random allocation to receive either of the two study drugs. Patients from group 1 will be treated with a standard regimen of oral tinidazole (Fasigyn) at a single dose of 50 mg/kg, maximum 2 g/dose. Patients from group 2 will be given rectal metronidazole (Flagyl) 500 mg/dose for children weighing 10-14,9 kg, 1000 mg/dose for those weighing 15-29,9 kg and 1500 mg/dose for those weighing 30-44,9 kg. Suppositories will not be halved. Patients will be given 1 dose/day for 3 days. The first dose of metronidazole will be administered during the primary clinical visit and 2 additional doses will be provided to the parents for home administration. Fecal samples will be collected from the study patients on day 7-10 post-treatment and will be analyzed in HUSLAB for the presence of G.lamblia antigen by enzyme immunoassay (EIA). Early collection of samples on day 7-10 will help to avoid the risk of tests being positive due to reinfection. If any of the patients will not clear the infection by day 10, he/she will be invited to a second visit and re-treated. Patients from group 1 will be re-treated by rectal metronidazole and patients from group 2 by oral tinidazole, thus performing a cross-over. Follow-up stool samples will be collected. Criteria for clinical cure will be resolution of symptoms by day 10 and microbiological cure will be defined as negative G.lamblia antigen test from fecal samples collected on day 7-10 post-treatment.

Patients will be given rectal metronidazole (Flagyl) 500 mg/dose for children weighing 10-14,9 kg, 1000 mg/dose for those weighing 15-29,9 kg and 1500 mg/dose for those weighing 30-44,9 kg. Suppositories will not be halved. Patients will be given 1 dose/day for 3 days.

Patients will be treated with a standard regimen of oral tinidazole (Fasigyn) at a single dose of 50 mg/kg, maximum 2 g/dose

Clinical recovery was defined as the resolution of symptoms by day 10 post-treatment, assessed using a structured questionnaire by interviewing the parents/caregivers.

Microbiological recovery was defined as negative G.lamblia antigen test from fecal samples collected on day 10 post-treatment.

Inclusion Criteria: clinical symptoms could be explained by giardiasis AND fecal samples will test positive for the presence of G.lamblia in Uusimaa laboratory (HUSLAB) Exclusion Criteria: age <6 mo or >10 years weight <9.5 kg the absence of symptoms co-infection with another pathogen, which may cause giardiasis-like symptoms