Chantha Hou, head of the hematology and flow cytometry laboratory at Calmette Hospital in Phnom Penh, Cambodia has been working with HVO volunteer Dr. Luke Carter-Brzezinski since early 2024. Dr. Carter-Brzezinski is a UK-based hematologist who spent three months with Ms. Hou in her lab following his residency. Since then, he has continued to provide consultations online via Telegram and WhatsApp, and the two have developed not just a collegial working relationship but also a friendship, establishing trust and easy communication. “When I need help,” she says, “I can always send a message with a picture and ask a question. Even when he’s on holiday, Luke will sacrifice for me. Sometimes it’s very urgent, the clinicians need results, and I am not sure of them. Luke always replies immediately.”
Having a professional network is an essential resource. “Chantha taught herself an incredible amount of morphology with little help or support and has done an incredible job in her lab. But it’s very hard doing all of this by yourself,” said Dr. Carter-Brzezinski. “In my lab, I have two or three hematology colleagues I can go to and ask questions. Doing it all by yourself is incredibly hard.” Until recently, Ms. Hou was solely responsible for bone marrow exams and interpretation of flow cytometry for the hospital. After receiving training from Dr. Carter-Brzezinski and other HVO volunteers, she was able to train another staff member to help her in the lab. No longer feeling isolated is one of the biggest changes Ms. Hou feels has come from HVO partnership: “Before, I felt like I was alone. It didn’t feel good. I thought, what if I make a mistake? The clinicians depend on my analysis. Now, when I have difficult cases, I can discuss with HVO colleagues. I feel confident. I have a friend.”
During Dr. Carter-Brzezinski’s three-month trip in 2024, his teaching focused broadly on blood cancers, including leukemias and lymphomas, and how to analyze bone marrow and blood. “There are particular conditions that are quite common in Cambodia,” said Dr. Carter-Brzezinski. “Aplastic anemia, for example, where bone marrow is almost empty and doesn’t produce the blood cells it should.” After training, Ms. Hou is now absolutely sure she can accurately identify aplastic anemia, whereas before she was often in doubt. At Ms Hou’s request, Dr. Carter-Brzezinski provided a lecture on diagnosing myelodysplastic syndrome (MDS), another common condition in the region. While aplastic anemia and MDS are quite different diseases and require very different treatments, they can look very similar under examination. “Because Luke taught me what clues to look for to identify MDS, I can accurately diagnosis more patients than before and feel confident about treatment.”
In addition to lectures, Dr. Carter-Brzezinski and Ms. Hou worked on clinical cases together while he was there. “I remember when I first started, there was another patient who had been in intensive care for a few weeks with bleeding in the brain. He had had two operations, and when Chantha and I looked at the blood sample, we diagnosed him with acute promyelocytic leukemia (APL). APL is a type of blood cancer where if you don’t treat it within forty-eight hours, the death rate in the first week is incredibly high. It’s important to look at the morphology, so important to pick it up. The treatment is really good, and, if can you get the patient through the first week, the likelihood of survival is 90% over the next five years. This patient received his first cycle of chemo, went into remission, and left the intensive care department.” Ms. Hou learned from this experience – months after Dr. Carter-Brzezinski’s return home, she examined a sample from another patient and recognized the disease. She immediately sent the sample to Dr. Carter-Brzezinski for confirmation. She provided the clinician on her team with the diagnosis, and they were able to begin treating the patient right away. “Without Chantha’s intervention, that patient would have died,” said Dr. Carter-Brzezinski.
He and other HVO volunteers have formed a multidisciplinary case conference team, meeting every month for the last two years with Ms. Hou, hematologists, and histopathologists at Calmette. The Calmette team sends case details to the volunteers a few days in advance, and they then convene on Zoom to discuss. They typically go over four to five cases at each meeting. Then, in addition, they have a group chat on Telegram to easily discuss any difficult cases that come up between meetings in urgent need of consultation.
Recently, the hematology team at Calmette has been working more collaboratively. “In the UK,” said Dr. Carter-Brzezinski, “the same doctors who work on the ward work in the lab. But in Cambodia, the lab staff and the doctors are different teams. It’s helpful for Chantha to get more information on patients, like their age, how long symptoms have lasted. I’m happy to see the clinical team and the lab team together.” Ms. Hou agrees that this improved, collaborative approach provides more support and better care for patients.
In May of 2025, Ms. Hou traveled to the UK to spend time with Dr. Carter-Brzezinski in his lab. They reviewed bone marrow cases and practiced recognizing dyserythropoiesis and abnormal cells. She joined his multidisciplinary team meetings of pathologists, hematologists, and cytogeneticists. She had the opportunity to see how flow cytometry is done at his hospital.
Dr. Carter-Brzezinski will return to Calmette in-person in January 2026, this time for ten days. Their focus will be on improving diagnostic testing at the hospital. “There’s a lot of tests that need to be sent to another country,” he said, “so we want to think about how we can increase or start particular tests at Chantha’s lab with the hope that in the future they can provide more in-house services. We’ve gotten in touch with a biomedical scientist who will try to help us, so hopefully that’s a good start.” Ms. Hou is excited about the prospect of further developing her lab: “We’ll need new equipment, and there are lots of obstacles, but there is hope. But the first thing we need to do is to educate people about it, and that’s where I think HVO volunteers can help.” If they can acquire the necessary resources, volunteers would be needed to train Ms. Hou, her colleague in the lab, and the pathologists on these new molecular tests. Performing tests on-site would provide faster diagnoses, saving lives.
Ms. Hou says that Calmette has the best hematology lab in Cambodia, in part thanks to education provided by HVO volunteers. Ms. Hou is trained in flow cytometry, something other hospitals do not have. In addition to her responsibilities at the lab, she is also a lecturer at a nearby university and has had the opportunity to present at multiple conferences – opportunities organized by HVO project director Dr. Katharine Lowndes. “I hope that HVO continues to support me,” she said. “I hope HVO will continue to build education and support me in developing cytogenetics capabilities at my lab in the future. Thanks to my own training, I now feel confident training other people. I do not feel alone.”
Dr. Carter-Brzezinski feels the time he has spent has been equally rewarding: “It’s been a real pleasure and a privilege to go to Chantha’s lab. She does an incredible job with much fewer resources than we have in the UK. I have so much respect for the work she’s done. It’s very hard. I think HVO is very good at picking sites that match the opportunities and skill volunteers can provide. It’s a really good and efficient use of money and sets the organization apart from others.”
To learn more about the opportunities available with the hematology project at Calmette, contact Program Manager Lauren Franklin at l.franklin@hvousa.org.