Validating Egg-based Diagnostics and Molecular Markers for the Spread of Anthelmintic Resistance
Status:
Completed
Trial end date:
2019-09-01
Target enrollment:
Participant gender:
Summary
Soil-transmitted helminths (STHs) are a group of parasitic worms that infect millions of
children in sub-tropical and tropical countries, resulting in malnutrition, growth stunting,
intellectual retardation and cognitive deficits. To control the morbidity due to these worms,
school-based deworming programs are implemented, in which anthelminthic drugs are
administered to children without prior diagnosis. The continued fight against these worms is
aided by the London declaration on neglected tropical diseases, which helps sustain and
expand global drug donation program, resulting in an unprecedented growth of deworming
programs. However, the high degree of drug pressure makes deworming programs vulnerable to
the development of anthelmintic resistance because they only rely on one drug with sometimes
suboptimal efficacy and there is no availability of alternative drugs. Moreover, at present,
there is no surveillance system to monitor the emergence and spread of anthelmintic
resistance. It remains unclear to what extent the efficacy of drugs may have dropped and
whether anthelmintic resistance is already present.
This project aims to strengthen the monitoring and surveillance of drug efficacy and
anthelmintic resistance in STH programs. As such, it will support deworming programs in their
quest to eliminate STHs as a public health problem.
The specific objectives of the first work package are to validate diagnostic tools to monitor
drug efficacy and the spread of anthelmintic resistance, and to validate molecular markers
for benzimidazole resistance.
This study will be conducted at four different sites (Ethiopia, Tanzania, Lao PDR and Brazil)
and will focus on school-aged children (age 5-14). At baseline subjects will be asked to
provide a recent stool sample which will be processed using 3 different microscopic
techniques (KK, Mini-Flotac and FECPAKG2). All children will be treated with a single-oral
dose of albendazole (ALB) 400 mg and 14-21 days after treatment, a second stool sample will
be collected from all children to again determine the fecal egg counts. At each sampling,
stool is stored in preservative. Stored stool will be shipped to Belgium for DNA extraction
and quantitative PCR (qPCR) analysis. A subset of the samples will be analysed by
pyrosequencing to evaluate the single nucleotide polymorphisms in the b-tubulin gene. Pooling
of the stored samples will also be performed to compare with the values obtained from
analysing individual samples.