Population genomics of ancient and modern Trichuris trichiura.

The neglected tropical disease trichuriasis is caused by the whipworm Trichuris trichiura, a soil-transmitted helminth that has infected humans for millennia. Today, T. trichiura infects as many as 500 million people, predominantly in communities with poor sanitary infrastructure enabling sustained faecal-oral transmission. Using whole-genome sequencing of geographically distributed worms collected from human and other primate hosts, together with ancient samples preserved in archaeologically-defined latrines and deposits dated up to one thousand years old, we present the first population genomics study of T. trichiura. We describe the continent-scale genetic structure between whipworms infecting humans and baboons relative to those infecting other primates. Admixture and population demographic analyses support a stepwise distribution of genetic variation that is highest in Uganda, consistent with an African origin and subsequent translocation with human migration. Finally, genome-wide analyses between human samples and between human and non-human primate samples reveal local regions of genetic differentiation between geographically distinct populations. These data provide insight into zoonotic reservoirs of human-infective T. trichiura and will support future efforts toward the implementation of genomic epidemiology of this globally important helminth.

Efficacy of single and double doses of albendazole and mebendazole alone and in combination in the treatment of Trichuris trichiura in school-age children in Uganda.

A randomised clinical trial was conducted in Kabale District, southwestern Uganda, to compare the efficacies of single and double doses of a combination of 400mg albendazole (ALB) and 500mg mebendazole (MBZ) with those of single and double doses of each drug given alone in the treatment of Trichuris trichiura. Infected pupils (n=611) were randomised to six treatment groups. Three groups received either a single dose of ALB, MBZ or the combination (ALB+MBZ). The other three groups received either a double dose of ALB (ALB/ALB), MBZ (MBZ/MBZ) or the combination (ALB+MBZ/ALB+MBZ). All double doses were given 8h apart. Children were followed-up weekly for 1 month. Cure rates were significantly higher using double doses compared with single doses (irrespective of drug; z=-4.02, P<0.0005) as well as using the drug combination compared with single drugs (irrespective of doses; z=-7.64, P<0.0005). Cure rates measured at Day 7 were significantly higher than on Days 14 and 21 after treatment (Day 14, z=9.90, P<0.0005; Day 21, z=7.36, P<0.0005). Geometric mean (GM) intensities of positives were significantly lower on Day 7 compared with all other subsequent days (P<0.00005), and on Day 28 GM intensities reached pre-treatment levels (P=0.096). Whilst there was no difference in egg excretion between single and double doses of the same drug or drug combination (F((df)(1))=0.28, P=0.60), the combination treatment resulted in lower egg excretion than use of single drugs (F((df)(2))=50.90, P<0.00005). All the tested regimens of ALB and MBZ had low cure rates against T. trichiura in Uganda, but both combination treatments showed satisfactory egg reduction rates 3 weeks after treatment.

A randomised controlled clinical trial on the safety of co-administration of albendazole, ivermectin and praziquantel in infected schoolchildren in Uganda.

Integrated chemotherapy of neglected tropical diseases (NTD) through mass drug administration given as a single dose would increase treatment coverage and cost-effectiveness. This study reports on the safety of a combination of albendazole, ivermectin and praziquantel in the treatment of lymphatic filariasis (LF), schistosomiasis and soil-transmitted helminthiasis (STH) in infected children. In this randomised, controlled, single-blinded clinical trial conducted in 235 primary school children aged 5-18 years in Yumbe District in Northern Uganda, the triple combination therapy was compared with the current NTD programme regimen. Liver function testing was performed for all children who received combined therapy. The study included 48 children with LF alone, 60 children with schistosomiasis (Schistosoma mansoni), 41 children with STH, 49 children with schistosomiasis + LF and 37 children with all three types of infection. Children were closely monitored by a paediatrician for any adverse reactions for 7 days. No serious adverse events were experienced. However, 4 of 18 children in the test group and 2 of 3 children in the control group who did not report any ill conditions before treatment developed adverse drug reactions. The combined and conventional therapies were found to be equally safe. The efficacies of both therapies were comparable and satisfactory. [ClinicalTrials.gov identifier: NCT01050517].

The acceptability and safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and soil-transmitted helminthiasis in children aged 1-4 years in Uganda.

OBJECTIVE: There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children. METHODS: A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years. RESULTS: A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone. CONCLUSION: Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.

Albendazole and mebendazole have low efficacy against Trichuristrichiura in school-age children in Kabale District, Uganda.

Three groups of Trichuris trichiura-infected school-age children were treated with one dose 400mg albendazole, 100mg mebendazole twice daily for 3 d, or 100mg mebendazole twice daily for 5 d. The albendazole study investigated cure and egg reduction rates and found that only 5 of 66 infected children were egg-negative 7 d post-treatment, giving a cure rate of 8% and a geometric mean egg reduction rate of 89%. However, at day 14 post-treatment, all children were again egg-positive with significantly higher egg counts than at day 7 (P<0.001). The two mebendazole studies aimed for the recovery of adult T. trichiura worms. After the 3 d course of mebendazole treatment, only four worms were recovered on days 3-5 after start of treatment from 2 of 34 infected children. With the 5 d course of mebendazole treatment, 10 of 21 infected children expelled a total of 27 worms. In the last case the first worm appeared on day 4 post-treatment, and the highest number of worms was recovered when the study ended at day 7. In conclusion, even with the longest treatment regimen and collecting stool samples over seven consecutive days, only very few worms were recovered. The results of this study suggest that alternative drugs and/or alternative regimens in current control programmes against T. trichiura need renewed attention.