TB is the second greatest killer worldwide after HIV, with 95% of these deaths occurring in low-and-middle income countries. Moreover, TB remains undiagnosed in up to 50% of the population in some areas, leading to untreated cases, uncontrolled spread, and avoidable deaths.
APOPO’s innovative TB screening techniques are employed at 17 TB centers in Tanzania and 8 in Mozambique and have improved case detection rates by over 40%! I had the opportunity to chat with Dr. Negussie Beyene, who is a Program Manager and has worked with APOPO’s Tanzania TB operation for five years.
Negussie Beyene, Program Manager at APOPO Tanzania
Gina Uppal: What is the role of rats in APOPOs TB detection program?
Negussie Beyene: At APOPO we have trained African giant pouched rats to accurately detect the scent of TB in human sputum samples. A rat can screen hundred samples in less than 20 minutes, a task which would take a lab technician more than two days. Furthermore, manual screenings are only 20-30% sensitive in poor settings, whereas rats have produced results with 70% sensitivity. As a second-line screening tool, samples are screened primarily at the diagnostic facilities of TB clinics and then screened for the second time by trained rats. In Tanzania alone we have already encountered over 3,500 misdiagnosed samples. This is very valuable for identifying misdiagnosed cases and controlling the spread of TB in Tanzania.
GU: How did APOPO begin its work with TB?
NB: Bart Weetjens, the founder of APOPO, loved all kinds of rodents as a young boy and kept them as pets. As a product design engineer, he became interested in the growing land-mine problem in Africa. After visiting Angola and Mozambique, he witnessed groups using dogs to detect landmines, and began to explore the potential of using smaller animals, such as rodents.
After overcoming many critics, his idea finally received a 1-year grant from the Development Corporation in Brussels and a small team began work on the idea. After about 2 years, the program was brought to Tanzania and research continued. In 2003, the World Bank Development Marketplace Global Competition provided the seed funding to expand this research. The first tests on a real mine field showed good results, which were published in the Journal for Mine Action. In 2008, proof of principle to utilize trained rats for the detection of TB in human sputum was presented at the International Union Against Tuberculosis and Lung Disease conference in Paris, and was published in the Journal of Tuberculosis and Lung Disease.
GU: How does APOPO work within the community networks to obtain TB samples? How has this improved the efficiency of TB screening at health facilities in Tanzania?
NB: We normally obtain sputum samples from collaborating TB centers and hospitals from patients who are suspected to have TB. Since we do our rat screening after the diagnosis by microscopy at the centers, it has been difficult to bring back those who were misdiagnosed by microscopy but found positive by our rats and confirmed. Recently, we started working with a local NGO called Mapambano ya Kifua Kikuu na Ukimwi Tanzania (MKUTA) which is composed of ex-TB patients. We essentially share the same goal as this NGO: we want to identify missed cases and the MKUTA works to promote health in communities and reduce the burden of TB. APOPO has been testing sputum samples from patients at 25 local NGOs and hospitals across Tanzia and Mozambique, such as Burguruni Health Center in Tanzania and Chamanculo General Hospital in Mozambique. Samples detected as positive are reported to partners who follow up with patients to start treatment. Our partners at these hospitals also track originally misdiagnosed cases to ensure individuals receive treatment.
A trained rat working on TB samples, Photo Credit: Sylvain Piraux
GU: You have been recognized by several prominent health development agencies (Ashoka, Skoll, World Bank etc) over the last few years. What scale is APOPO currently at and what are your plans for the next few years?
NB: The support of these organizations definitely helped APOPO gain recognition for our research methods which are ongoing alongside our operations. In the next five to seven years, we foresee the completion of a fine-tuned technique. Our hope is to become the front line screening tool for TB in high burden areas like prisons or refugee camps. Traditional methods are too resource intensive and time consuming, thus leaving these populations unscreened.
We have also received a three-year grant from the UBS Optimus Foundation from Switzerland and there is hope for another three years of funding after evaluations later this month. We are very excited about this partnership as APOPO’s TB program grows.
GU: Are there plans for expansion to other regions?
NB: Currently APOPO’s TB operations are active in Dar es Salaam, Tanzania, and Maputo, Mozambique. Our strategy moving forward is to expand to other major cities in Cambodia, which has a high TB burden. We hope to move into Myanmar to address the TB burden there as well. Aside from TB, we also see merit in using rats for cancer screening. However, at the moment, APOPO is focused on using rats for TB and landmine detection.
GU: What challenges do you face moving forward?
NB: Entering new regions is always difficult, especially as a program with such novel methods. In Cambodia, our success with landmine operations has laid a path for the potential use of rat detection to address TB. We must deal with preliminary resistance to our methods by publishing more research establishing the credibility of our methods. We are currently limited in how much we can scale our operations by our human resource and budget constraints.