Cambodia has made impressive progress in malaria control and elimination in recent years. No malaria-related deaths have been reported in Cambodia since 2018, and incidence has decreased to historically low levels. This achievement has taken considerable effort, yet challenges remain to achieve malaria elimination. Since the 1970s, Cambodia has been the epicenter of emerging malaria multidrug resistance, including resistance to artemisinin combination therapies (ACT). The high failure rates of ACTs used in Cambodia constitute a regional and global threat to malaria control and elimination efforts. That is why WHO and its partners, including the Global Fund, the Gates Foundation, the United States Agency for International Development (USAID)/President’s Malaria Initiative (PMI), the United Nations Office for Project Services (UNOPS) as well as several civil society organizations, are focused on supporting the National Malaria Programme, which aims to eliminate malaria in Cambodia and the Greater Mekong Subregion. In response to an appeal by the WHO Country Office in Cambodia to place the elimination of malaria at the highest level of the country’s health agenda, the Government of Cambodia has strengthened its commitment to eliminating malaria.

WHO in the Western Pacific Region set out long-term goals and new ways of working in a vision called For the future: towards the healthiest and safest region. WHO support in Cambodia was in line with the thematic priority of “Reaching the Unreached” as it worked to target specific populations for malaria control and elimination interventions. Given that most malaria transmission (greater than 90%) occurs in forested areas among migrant and mobile populations and forest goers, an intensified approach to reach these populations was deemed a priority. In 2017, Cambodia experienced a significant increase in malaria cases. Discrepancies between the typical site of transmission (forested areas) and the location of available human and technical resources, primarily at the central and at the district level, required Cambodia to reorient malaria control and elimination efforts to reach the unreached.

How did Cambodia do it, and how did the WHO Secretariat support Cambodia? 

The “For the Future” vision also outlines “how” WHO, Member States, and partners can work to achieve the thematic priorities outlined in the vision. In Cambodia, innovation, “grounds-up” approaches, and partnerships were just a few ways of working that supported Cambodia’s malaria control efforts. An innovative anthropological approach (including focus groups with forest goers and brainstorming for tailored solutions) was piloted by the WHO Country Office in collaboration with the National Center for Parasitology, Entomology and Malaria Control, provincial health departments and partners in several provinces in Cambodia. Working with forest goers to understand behaviours and identify community-based interventions was a grounds-up approach that improved planning and implementation to address local challenges.

Photo Credit: © WHO

Photo Caption: WHO staff and partners visit village malaria workers in Cambodia’s Mondulkiri Province.

WHO worked together as one team, deploying epidemiologists and health staff from the WHO Regional Office for the Western Pacific and the Country Office in Cambodia to the provincial level. Technical support was provided to malaria staff in provincial health departments, operational districts, and civil society organizations to strengthen programming and coordination of case detection and management, surveillance, vector control measures, and supply chain in the six targeted provinces responsible for the majority of cases in Cambodia. Additionally, village malaria workers were recruited in targeted areas, and 120 mobile malaria workers were deployed in areas close to the forest to: reinforce case management by performing active case detection in the forests and passive case detection at home; distribute forest packs to forest goers, including long-lasting insecticide-treated hammock nets, boots, and backpacks; and reinforce information education communication. WHO epidemiologists performed routine epidemiological analyses and mapping of cases and areas where malaria transmission occurs to guide and reinforce malaria activities where and when needed with a problem-solving approach based on evidence. Joint visits every three to six months were organized by WHO with all partners from provincial health departments, operational districts, health facilities and village levels to assess progress and identify gaps and challenges to be addressed.

The emergence of COVID-19 in 2020 posed a risk to an already fragile health system. WHO worked closely with the National Malaria Programme and partners to conduct risk assessments of the potential impact of the COVID-19 pandemic on malaria elimination efforts and to tailor malaria interventions in the context of COVID-19. Community engagement was a key intervention used to share messages for malaria elimination strategies while at the same time conveying COVID-19 risk and prevention measures. In this way, COVID-19 served as a window of opportunity to cement commitment to malaria elimination in Cambodia.

The National Center for Parasitology, Entomology and Malaria Control set the elimination target to 2023 for a specific parasite, Plasmodium falciparum, and set the target for all other species to be eliminated by 2025. To accomplish these targets, with support from the WHO Country Office, intensive elimination operations are in place countrywide to detect, investigate and clear all cases and foci. Once a locally acquired case is identified, a focus investigation is carried out to determine what interventions are necessary to interrupt transmission. Targeted vector control measures, rigorous case management and more localized approaches, such as targeted drug administration for at-risk populations and intermittent preventive treatment for travellers to malaria-risk areas, are implemented in villages where malaria transmission is high. In addition, monitoring of antimalarial drug resistance is routinely implemented through therapeutic efficacy studies and integrated drug efficacy surveillance.

WHO plays a critical role in supporting Cambodia to identify, develop and implement adapted and evidence-based strategies toward malaria elimination. Through continued partnerships, technical, strategic and operational support to the Ministry of Health, National Center for Parasitology, Entomology and Malaria Control and malaria partners have put Cambodia on track to achieve malaria elimination targets. With an engaged and motivated network, early diagnosis, treatment, and vector control measures are ensured for at-risk populations. Malaria control and elimination strategies are delivered hand-in-hand with the community, government and partners through tailor-made, innovative interventions to reach the unreached and work towards the “For the Future” vision of the broader Western Pacific Region.

Photo Credit: © WHO Malaria Team in Cambodia/2021

Photo Caption: Malaria elimination. Case management: weekly house-to-house fever screening.