The main objective of this study is to provide data on the efficacy profile of different doses of oxfendazole when used in Trichuris trichiura infection. The drug will be also be examined for efficacy against other common nematodes encountered in man (Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus). The study will also provide data on the safety and tolerability of the oxfendazole in patients.

This is an assessor blind, randomized, comparative study in adult patients with proven intestinal infection with Trichuris trichiura to be conducted as a field study. Patients meeting the study entry criteria will receive either 6 mg/kg or 15 mg/kg or 30 mg/kg of oxfendazole as a single oral dose, three single doses of oxfendazole on consecutive days, or albendazole 400mg as a single oral dose. Stool samples will be obtained and examined prior to treatment and at 7, 14 and 21 days after treatment.

Inclusion Criteria:

1. Male or female outpatient, more than 18 years and less than 65 years of age.
2. Written or witnessed oral informed consent has been obtained.
3. Trichuris trichiura demonstrated in stool samples obtained during the week before enrolment: The presence of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenalis or other helminths will not be a cause for exclusion.
4. Willingness to comply with the requirements of the protocol and particularly to provide 4 stool samples, pretreatment and 7, 14 and 21 days after treatment.
5. Female patients of child bearing potential, who are using an established method of birth control (surgically sterile, intra-uterine contraceptive device, oral contraceptives, diaphragm in combination with contraceptive cream or foam, or condom in combination with contraceptive cream or foam) may be included

Exclusion Criteria:

1. The patient has demonstrated a previous hypersensitivity reaction to benzimidazole or other related compound.
2. Presence of other helminths without Trichuris trichiura. Non-target species may be present and details of response will be recorded.
3. The patient has diarrhoeal disease that would interfere with the evaluation of stool samples.
4. The patient has received an anthelminthic in the 2 weeks prior to enrolment into the study.
5. The patient has received an investigational drug within 30 days or 5 half-lives (whichever is longer) of the screening visit or is scheduled to receive such a drug during the study period.
6. The patient has a concomitant infection or any other underlying disease that would compromise the diagnosis and the evaluation of the response to the study medication.
7. The patient has a known history of renal dysfunction or plasma creatinine ≥ 1.5 times upper limit of normal for age or a known history of hepatic dysfunction or liver enzymes ≥ 1.5 times upper limit of normal.
8. The patient is a female who is pregnant, lactating or planning a pregnancy during the study, or is not practicing any form of contraception (see inclusion criteria (4.2.5).
9. The patient is unwilling or unable to take part in this study.
10. The patient has previously been enrolled in the study.

The data will be uploaded to the clinicaltrials.gov website, and a publication will be prepared

Each patient's treatment condition will be masked by a code assigned at randomization. The study pharmacist will know this assignment. A person other than the investigator will administer the drug as directed by the pharmacists.