1 April 2021 The 'last mile' of malaria elimination in Cambodia - World Health Organization

Ly Kanha inspects a mosquito net at the house of Em Noun, a recovered malaria patient in Peam L'vear village in Cambodia. WHO/C. Liu

The sand coloured health centers dotted across Cambodia's provinces are fairly recognizable, even to an untrained eye. Most sport a canopy of red tile roofs with verandas that serve as waiting areas for incoming patients. Ly Kanha grew up familiar with the ins and outs of Cambodia's health centres. She spent most of her childhood in the care of her grandparents who were both working as health professionals at the time. 

"When I was young, my grandfather took me to the health centre, and I saw medical staff wearing medical uniforms," says Kanha as she recounts memories of observing the staff administering medication to patients.

Ly Kanha poses outside the Cambodia-Japan Friendship Health Center of Chambok. WHO/C. Liu

The visits made enough of an impression that Kanha eventually followed in the steps of her grandmother to become a midwife. Having passed her exam two years ago, she now works and lives on-site in a room that overlooks the shaded veranda of her health centre. As the resident midwife she starts her mornings performing prenatal checkups to expectant mothers who arrive on motorbikes hailing from the areas surrounding Beng village, Kampong Speu. Last year she took on extra duties and was appointed as the health centre's malaria worker. This is no easy task considering that Kampong Speu has the highest malaria incidence rate among Cambodia's remaining endemic provinces.

"Being a midwife working at a health center where there is a high number of malaria cases, greater human resources were needed to help assist the malaria programme. That's why I decided to be a part of the ["last mile" of malaria elimination]." says Kanha.

Since the 2000s, Cambodia has been at the epicentre of resistance to multiple antimalarial medicines. The last major spike of artemisinin resistance emerged in the Greater Mekong subregion in 2006, prompting concerns of a new public health threat. As malaria cases continued to rise, Cambodia's National Center for Parasitology, Entomology and Malaria Control (CNM) launched a malaria intensification plan in 2018. The plan included a goal to deplete parasite reservoirs in high-risk populations by deploying technical support to Cambodia's provinces, strengthening coordination, and ensuring the full implementation of malaria interventions.

Ly Kanha, 25, prepares to perform a malaria rapid diagnostic test for a patient. WHO/ C. Liu

By 2020, malaria cases were steadily falling while malaria testing numbers continued to increase. The intensification plan was well on track; so much so, that Cambodia pushed forward its pledge to eliminate the deadly Plasmodium falciparum malaria parasite from 2025 to 2023. Despite the added complication of COVID-19, the ambitious target was announced in February 2020 along with the unveiling of new focalized aggressive approaches later that year. In Cambodia this has been dubbed as the "last mile" of malaria elimination.

In an elimination setting like Cambodia, the last pockets of malaria are found among hard-to-reach populations living and working in remote, forested or mountainous areas. In such conditions, communities must travel long distances to the nearest health centre. Accessing malaria services can be difficult and asymptomatic cases are simply not detected.

Ly Kanha visits the home of a recovered malaria patient in Peam L'vear village. WHO/C. Liu

This is where health centre malaria workers like Kanha come into the picture. Although health centre workers have always been involved in Cambodia's malaria programming, the focalized aggressive approach places them in a pivotal role within the CNM's nationwide intervention to reach isolated communities and drive malaria out of far-flung corners still harbouring the disease.

Health centre workers provide a wide range of care services in facilities which are scattered across the country. Malaria is one of the many ailments they treat, and they have typically been in charge of diagnosing and treating the malaria patients who come to their centres. Owing to the focalized aggressive approach, they have taken on a more proactive role to supervise the CNM's networks of village malaria workers and mobile malaria workers who are tasked with meticulously searching for undetected cases. Over the next year these workers will take over the lion's share of responsibility for eliminating malaria.

Thong Yim, 26, a recovered malaria patient, sits under a mosquito net in his house. WHO/C. Liu

In Cambodia the highest malaria risk is among adult men, who constituted 81% of all malaria cases in 2020. Household mapping through a village census allows the village malaria workers to identify and target potential transmitters by providing preventive anti-malarial medication to men between the ages of 15 and 49. In addition, men frequently visiting malaria risk areas, such as forests, are provided with a further full course of preventive treatment to reduce the risk of getting malaria.

The role of health centre malaria workers doesn't stop here. They also oversee weekly house-to-house fever screening. This means that village malaria workers visit each home to test anyone with malaria symptoms (such as a fever) and give them treatment if they are positive. To interrupt transmission, villagers also receive insecticide-treated mosquito nets. Anyone visiting the forest receives a treated hammock net.

Ly Kanha prepares to perform a malaria rapid diagnostic test for a patient. WHO/C. Liu

The focalized aggressive approach is supervised by World Health Organization (WHO) staff which includes a team of epidemiologists who have been deployed in Cambodia's malaria-endemic provinces. Their presence ensures the approach is based on evidence drawn from monthly epidemiological analyses. If a new malaria case appears, they are on-site to provide technical guidance to provincial and district malaria officers and make the call for any additional health centres or villages to be included in the intervention.

Ly Kanha leaves on her motorbike after visiting the house of a recovered malaria patient. WHO/C. Liu

Cambodia's approach represents an important milestone in the ongoing efforts to end multidrug resistance in the Greater Mekong subregion. If successful, it will not only reduce the malaria burden in Cambodia; it will also provide a blueprint for other focalized aggressive approaches which WHO's Mekong Malaria Elimination programme is coordinating across the subregion -in the Lao People's Democratic Republic, Myanmar, Thailand and Viet Nam.

Ly Kanha reads a malaria rapid diagnostic test and records the diagnosis result in the malaria book. WHO/C. Liu

"The key is sustaining a commitment to eliminate malaria in the Greater Mekong subregion by 2030," says Dr Luciano Tuseo, Hub Coordinator of the Mekong Malaria Elimination programme. "There's still a lot of work needed to get that point, but the immense efforts of individuals like Kanha mean that we are successfully navigating the last mile of malaria elimination. Last year the subregion recorded a 31% drop in annual cases. This is unprecedented, particularly when we consider that this has all been achieved in the context of COVID-19."

Cambodia's 'last mile' of malaria elimination is implemented by the Cambodia's National Center for Parasitology, Entomology and Malaria Control, Ministry of Health in partnership with the World Health Organization, the United Nations Office for Project Services and civil society organizations. The Mekong Malaria Elimination programme is funded by the Global Fund to Fight AIDS, Tuberculosis and Malaria and the Bill & Melinda Gates Foundation.