Cambodia malaria indicator survey 2020: Implications for malaria elimination.

Background: Cambodia has made significant progress in controlling malaria in the past decade. It now aims to eliminate malaria from the country by 2025. It launched the Malaria Elimination Action Framework (MEAF 2016-2020) in 2015 with strong political commitment targeting appropriate interventions on high-risk populations, particularly mobile and migrant groups.

Methods: In 2020, the household-level Cambodia Malaria Survey 2020 (CMS 2020) was conducted with the objective to assess the performance of malaria control activities using the indicators outlined in MEAF 2016-2020. The survey used a cross-sectional probability proportional to size approach drawing 4,000 households from 100 villages across the malaria-endemic districts of the country.

Results: A total of 3,996 households with 17,415 inhabitants were interviewed. Of the surveyed households, 98.4% owned a long-lasting insecticide-treated bednet or hammock (LLIN/LLIHN). However, only 79.5% of these reported sleeping under a net the previous night, with only 45.7% sleeping under an insecticide treated net (ITN). Given that forest visitors are at the highest risk of getting malaria, the survey also targeted this group. Of the forest visitor respondents, 89.3% brought an ITN along and 88.9% reported to have used a net during their forest stay. About 10.8% of forest goers had received a forest kit for malaria prevention from mobile malaria workers the last time they went to the forest. Knowledge about mosquito repellents was high among forest goers (62.5%) but the actual use thereof during the last visit to the forest was low (22%). While awareness about malaria prevention with LLINs remained high among most respondents, knowledge about malaria diagnosis and treatment was not universal. Source of malaria knowledge and its treatment was usually from a household member, followed by a village malaria worker or a primary health care center staff. Of those who had fever during the previous two weeks, 93.6% sought advice or treatment outside the home, and the most commonly reported source for advice or treatment was private providers (39.4%) followed by health center/district hospital (31.3%).

Conclusions: ITN distribution and other malaria prevention interventions have largely benefited the high-risk groups including the forest visitors. Comparing the CMS 2020 results with the 2017 CMS results, it is clear that forest visitors' use of LLIN/LLIHN has improved considerably. However, more needs to be done to ensure forest visitors be protected either through using LLINs or repellents while working and staying in the forest areas. Also, given that sleeping under LLINs has decreased over the past several years among the at-risk populations, the programme will have to develop strategies to ensure that the communities do not lower their guard against malaria as cases further dwindle in malaria prone areas. Heightened awareness amongst the general population will be critical for eliminating malaria in Cambodia without any possibility of malaria re-emergence or re-establishment.