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Training Hematologists and Building Research Capacity in Tanzania

December 29, 2022

January 2023

Mary Ellen Schneider

Mary Ellen Schneider is a medical journalist based in Setauket, New York.

Dr. Jonathan Blackwell (third from left), from Australia, poses with clinicians in Dar es Salaam during a training visit. Photo courtesy Dr. Jonathan Blackwell and HVO
Dr. Jonathan Blackwell (third from left), from Australia, poses with
clinicians in Dar es Salaam during a training visit. Photo courtesy
Dr. Jonathan Blackwell and HVO.

In 2013, there were just six hematologists working in the United Republic of Tanzania, one of the largest countries in East Africa and then home to more than 48 million people.1 These specialists were all located in the port city of Dar es Salaam, forcing patients to travel hours to receive care for conditions like sickle cell disease (SCD), anemia, and hematologic malignancies and causing critical delays in diagnosis and treatment.

Since then, investments in graduate medical training are beginning to pay off. To date, the number of trained hematologists has risen to 28, and another 16 candidates are in training. While most hematologists are still concentrated in Dar es Salaam, there are now trained specialists in other regions of the country.

One of the drivers of this steady progress in expanding the hematology workforce has been a collaboration between Muhimbili University of Health and Allied Science (MUHAS) and Muhimbili National Hospital (MNH) in Dar es Salaam, the American Society of Hematology (ASH), and the nonprofit Health Volunteers Overseas (HVO). The program, which began in February 2013, brings volunteer hematologists and hematopathologists to Dar es Salaam to provide training and consulting at the university and its associated teaching hospital. Volunteers participate in ward rounds, clinics, bedside consults, lectures, and laboratory training.

“The aim of the program is strengthening skills in clinical management of hematologic conditions, laboratory hematology, and blood transfusion services, and overall capacity building through training, research, and consultancy,” said Ahlam Nasser, MD, the program’s on-site coordinator and a consultant hematologist and lecturer at MUHAS. “The ASH/HVO program has helped us along the way while we were building capacity and developing the training program for hematology.”

Over the years, the ASH/HVO program has recruited five or six volunteers annually to travel to Dar es Salaam for up to four weeks at a time, explained Enrico M. Novelli, MD, who served as longtime co-director of the program alongside Theresa Coetzer, PhD, from the program’s inception through July 2022. (Jared Block, MD, now serves as program director.) The goal of the program is to fill a gap in local training, Dr. Novelli said, so the program directors work with the local site leaders to figure out the needs and recruit volunteers with expertise in areas such as hematopathology, marrow failure syndromes, and bleeding disorders.

Health Care Needs

Tanzania has a population of more than 60 million with a number of critical hematology needs. It is considered a low-resource country with a strained health care system and poor access to specialized health care personnel. Access issues are compounded by high rates of maternal and child mortality and infectious diseases, such as malaria and HIV/AIDS. More than 60% of health care facilities in the country are run by the government, and Tanzania is moving toward a universal health care system, though only about a third of individuals were covered by some type of health insurance as of 2019, according to the U.S. International Trade Administration.2

In hematology specifically, SCD is a significant issue. Tanzania has about 11,000 children born with SCD each year, and an analysis of infants born in northwest Tanzania showed a prevalence of more than 20% for sickle cell trait and 1.2% for SCD.3,4

Dr. Nasser said patients who come to the teaching hospital in Dar es Salaam are in need of blood transfusions for many reasons, including acute or chronic blood loss, bone marrow failure, and nutritional deficiencies, such as iron deficiency or vitamin B12 deficiency from autoimmune conditions. They also treat a wide range of hematologic malignancies, including acute and chronic leukemias, lymphomas, and multiple myeloma.

Resources are strained at MNH, said Dr. Novelli, who is also the section chief of benign hematology at the University of Pittsburgh Medical Center (UPMC) and medical director of the UPMC Adult Sickle Cell Program. “You have to tailor the training to the local resources and the local medical landscape,” Dr. Novelli said.

Trainees in Dar es Salaam examine histopathology slides. Photo courtesy Dr. Jonathan Blackwell and HVO
Trainees in Dar es Salaam examine histopathology slides. Photo courtesy Dr.
Jonathan Blackwell and HVO.

Short Visits, Long-Term Impact

Volunteer assignments in Dar es Salaam may last just a few weeks, but these short assignments are often the beginning of a long-term relationship, with some volunteers coming for repeat visits and helping to build collaborations with their home institutions, Dr. Nasser said.

That was the case for Anna Schuh, MD, PhD, a consultant hematologist and professor of molecular diagnostics at Oxford University in the U.K. She first came to Dar es Salaam in 2017 as an ASH/HVO volunteer and stayed for two weeks.

“I realized during those two weeks that with little effort I could make a huge difference,” Dr. Schuh said. “I realized that there was a real lack of diagnostics and of quality control around diagnostics and that this led to delays in diagnoses and misdiagnosis, meaning that the wrong treatment was given at the wrong time.”

She quickly decided she wanted to return and began applying for funding to develop and adopt diagnostics that could be used in low-resource settings like Tanzania, with a focus on blood diseases. Dr. Schuh and her partners at Oxford and in Dar es Salaam have been successful in developing and validating a next-generation sequencing approach to the noninvasive prenatal diagnosis of sickle cell anemia, which does not require the paternal genotype.5 They also developed an assay using nanopore sequencing technology that provides a low-cost way to genetically characterize SCD and beta-hemoglobinopathies.6

Drs. Schuh and Nasser also worked on research assessing the effectiveness of treatment for patients in Tanzania with chronic myeloid leukemia (CML). In Tanzania, imatinib has been freely available to patients with CML since 2004 thanks to a sponsorship from an international patient assistance program from Novartis Pharma AG and the nonprofit Max Foundation. The study, which monitored response to imatinib therapy, showed that while more than 70% of patients had a complete hematologic response, less than 25% had an optimal molecular response. Over the course of the study, the researchers identified late presentation and cytopenias during treatment as influencing molecular response.7

“We’re looking forward to doing more research to learn about the mutations patients are expressing that are making them nonresponsive to treatment and to determine which will be the best second-line treatment,” Dr. Nasser said. “Through this research we also hope to further build local capacity in performing additional molecular diagnostic tests.”

Dr. Schuh and her colleagues in Dar es Salaam also received a large five-year Global Health Program grant from the U.K. government to evaluate liquid biopsy for the diagnosis of Epstein-Barr virus-positive Burkitt’s lymphoma, the most common childhood lymphoma in Sub-Saharan Africa. Under her mentorship, postgraduate hematologists in Dar es Salaam set up a DNA sequencing laboratory and work with colleagues in Moshi and Uganda to analyze circulating lymphoma DNA. This program, together with a Global Partnership grant from the International Workshop on Chronic Lymphocytic Leukemia, has helped build sustainable research capacity in the area.

Virtual Lessons

Jared Block, MD, a hematopathologist at Carolinas Pathology Group in Charlotte, made his first visit to Dar es Salaam in the summer of 2019. Like Dr. Schuh, one short trip was the start of a longer-term relationship.

During his 10-day visit, Dr. Block worked with hematologists and pathologists in reading bone marrow aspirate and biopsies. He also assisted them in interpreting results with flow cytometry, including identifying certain types of leukemia.

“I love teaching and I teach fellows now. But in Tanzania, all I did was teach and everybody appreciated it so much. There were people in the wards that I was able to do stuff for that nobody else there could have done,” Dr. Block said. “It was one of the most rewarding things I’ve ever done in my life.”

He had his ticket to return in March 2020 when global travel essentially shut down due to the COVID-19 pandemic. In-person volunteering through the ASH/HVO has been on hold in Dar es Salaam and other sites throughout the pandemic, but is expected to resume in 2023. In the meantime, Dr. Block pivoted to offer live online trainings, providing about 10 one-hour lectures over the course of several months. The virtual setup worked well for teaching hematopathology, he said. He focused on providing practical knowledge, showing images, and explaining what was normal or abnormal, then providing comparison images from the same patient. The live virtual format allowed trainees to bring up questions, and Dr. Block said he would frequently pull up other images from his files to provide context.

Dr. Block is planning to return to Tanzania in early 2023. He has done some fundraising in the interim and plans to bring microscopes and lenses with him to assist the clinicians in Dar es Salaam.

“By just doing what you do every day at work here [in the U.S.], the contribution that you can make to their lives and the lives of all the patients is tremendous. We do that with more people here, but it doesn’t quite feel as personal,” he said.

Dr. Jared Block (center left) and Dr. Jonathan Blackwell (center right) are surrounded by trainees and hematologists in Dar es Salaam. Dr. Ahlam Nasser, the program on-site coordinator, poses at the front. Photo courtesy Dr. Jonathan Blackwell and HVO
Dr. Jared Block (center left) and Dr. Jonathan Blackwell (center right)
are surrounded by trainees and hematologists in Dar es Salaam. Dr.
Ahlam Nasser, the program on-site coordinator, poses at the front.
Photo courtesy Dr. Jonathan Blackwell and HVO.

Future Needs

Traditionally, virtual training through HVO was informal and ad hoc, but the pandemic pushed those efforts into high gear, explained April Pinner, HVO’s director of programs. HVO now has an e-learning platform specially designed for use in low-resource settings, and many of the local partner institutions have made investments in their technology infrastructure. Although this platform has not yet been rolled out in Tanzania, there is an interest in scaling e-learning there in the future, Ms. Pinner said. “It just expands the opportunities that we’re able to offer volunteers and our international partners, and ultimately our capacity for sustainable impact,” she said.

HVO is working to reopen its programs to in-person volunteering as it embraces a new hybrid education model, with hematologists returning to Dar es Salaam possibly in early 2023. Exactly what that reopening looks like will depend on the needs of the local site, Ms. Pinner said, and how they have been impacted by COVID-19.

Hematopathology continues to be a pressing need in Tanzania, Dr. Nasser said, and the program is seeking volunteers with that experience, as well laboratory training in flow cytometry and molecular diagnostics. They are also looking for volunteers with bone marrow transplant experience who can help MUHAS establish a hematopoietic cell transplantation training program to complement the hospital’s efforts to build capacity in this area.

Dr. Schuh described her experience in Tanzania as “life changing” and urged hematologists to consider the opportunity to volunteer with the ASH/HVO program.

“If you get frustrated by your work because of the little change you feel you make and the complexity of the medicine we practice, then it’s really valuable to go to a place like MNH and get your hands dirty because you come out as a different person,” she said.

For more information on volunteer opportunities in Dar es Salaam and other locations around the world, visit

—By Mary Ellen Schneider


  1. The World Bank. Population, total – Tanzania, 1960-2021. Accessed October 4, 2022.
  2. US International Trade Administration. Tanzania – Country Commercial Guide, Healthcare. December 2, 2021. Accessed October 4, 2022.
  3. Makani J, Tluway F, Makubi A, et al. A ten year review of the sickle cell program in Muhimbili National Hospital, Tanzania. BMC Hematol. 2018;18:33.
  4. Ambrose EE, Smart LR, Charles M, et al. Geospatial mapping of sickle cell disease in Northwest Tanzania: the Tanzania Sickle Surveillance Study (TS3). Blood. 2018;132(Supplement 1):3662.
  5. Cutts A, Vavoulis DV, Petrou M, et al. A method for noninvasive prenatal diagnosis of monogenic autosomal recessive disorders. Blood. 2019;134(14):1190-1193.
  6. Christopher H, Burns A, Josephat E, Makani J, Schuh A, Nkya S. Using DNA testing for the precise, definite, and low-cost diagnosis of sickle cell disease and other haemoglobinopathies: findings from Tanzania. BMC Genomics. 2021;22:902.
  7. Nasser A, Hussein A, Chamba C, et al. Molecular response to imatinib in patients with chronic myeloid leukemia in Tanzania. Blood Adv. 2021;5(5):1403-1411.

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