Published: 27-03-2024 15:52 | Updated: 27-03-2024 15:52

Towards elimination of Schistosomiasis and Soil-Transmitted Helminths- meet Dr Tigist Dires Gebreyesus

Tigist Dires Gebreyesus in white labcoat
Tigist Dires Gebreyesus doing genotyping in the lab. Photo: Private

Tigist Dires Gebreyesus is an Ethiopian public health specialist with a master’s in public health from University of Gondar, Ethiopia. She has been working within the Ethiopian Food and Drug Authority, the former Ethiopian Food, Medicine and Healthcare Administration and Control Authority. In December 2023, Dr Gebreyesus defended her doctoral thesis that was part of the PROFORMA project at Karolinska Institutet, Department of Global Public Health.

Titled “Pharmacovigilance of Preventive Chemotherapy for the Control of Schistosomiasis and Soil-Transmitted Helminths in Ethiopia” Dr Gebreyesus’ doctoral project focused on the safety and efficacy of medicines used for the control and elimination of the two most prevalent neglected tropical diseases Schistosomiasis and Soil-Transmitted Helminths (STHs) in Ethiopia.  

"These medicines are mainly used in school based preventive chemotherapy through mass drug administration (MDA) strategies for the control and elimination Schistosomiasis and STHs. The aim of my PhD project was to investigate the safety and efficacy of Praziquantel, a drug used for the treatment of Schistosomiasis and albendazole a drug used for the treatment of STHs through MDA. Additionally, we have investigated the diseases prevalence and pharmacogenetic and pharmacokinetic in the study area among school children" says Dr Gebreyesus.

Schistosomiasis MDA training in Ethiopia.
Training of trainers on active surveillance of mass drug administration in Ethiopia, 2018. Photo: Private

Six key findings from the PhD research

When asked about the main results from her study Dr Gebreyesus lists six findings:

  1. After several rounds of MDA in the study area, the diseases prevalence remained high indicating the continuous transmission of the diseases after treatment, requiring additional control measures in endemic areas.
  2. The drugs used in preventive chemotherapy were safe and tolerable among school children, however high rate of adverse events were observed among Schistosomiasis and STHs infected children underline the need for integration of pharmacovigilance in MDA programs. 
  3. Praziquantel is still efficacious for the treatment of Schistosomiasis though low cure rate was observed among moderate to heavily infected children.
  4. We observed reduced efficacy of albendazole for the treatment of ascaris lumbricoides and trichuris trichuria, which urges the need for investigating alternative treatment options for these helminths diseases.
  5. High re-infection after cure was also observed in STHs infected children which also require the integration of other control measures in endemic areas.
  6.  Finally in our PG/PK study we found sex, CYP2C19 and CYP2J2 genotypes significantly predicting PZQ plasma exposure among children.


Life after PhD- senior medicine safety expert

Dr Gebreyesus is currently working at Ethiopian Food and Drug Authority, as a senior medicine safety and post marketing surveillance expert. Her main role as a senior expert focuses on training of junior pharmacovigilance experts, conducting operational pharmacovigilance research, preparing active safety surveillance protocol, and writing their results are among others. 

"My PhD experience was a good learning opportunity with several ups and downs which helped me to become a confident researcher in my area. I have gained lots of knowledge in my research areas and developed skills on the process of conducting research from the planning to the end result. My research area being in the rural districts also helped in contextualizing research in rural areas. I have also developed data analysis and writing skills".

Tigist Dires Gebreyesus defended her docotral thesis December 15, 2023. 

The PROFORMA project is part of the EDCTP2 programme supported by the European Union (grant number CSA2016S-1618 - PROFORMA).