Investigation on children's handwashing behaviour and contamination levels in rural Cambodia

Contaminated water and poor sanitation are among the leading causes of death in children under the age of 5 years (UNICEF 2023a). Without adequate water, sanitation and hygiene (WASH), children are at a high risk of contracting preventable diseases. In addition, diarrhoea is a leading cause of death in children and accounted for about 9% of all deaths among children under age 5 worldwide, in 2019. Approximately 1,300 young children die each day due to diarrhea, which is about 484,000 children a year (UNICEF 2022). The Kingdom of Cambodia's population was around 16 million, of which approximately 4.5 million (28.2%) were children under the age of 15 (NIS 2021). According to the World Bank Report, the infant mortality rate of Cambodia was 21 per 1,000 live births in 2021, which was relatively high among ASEAN countries, and ranked Cambodia the third worst, followed by Lao as the second, and Myanmar as the first (World Bank 2021). The leading causes of children's deaths is infectious diseases including diarrhoea, pneumonia and malaria (UNICEF 2023b). Interventions to prevent diseases, appropriate vaccines, safe drinking water and effective hand hygiene can reduce disease risks. Diarrhoea in rural Cambodia was closely related to the form of water used. Acute diarrhoea daily occurred in rural areas because of drinking surface water without treatment (UNICEF Cambodia 2019). Following the adoption of the global goals in late 2015, the Royal Government of Cambodia assigned the Ministry of Planning as the focal point for taking forward the development of the future Cambodian Sustainable Development Goals (CSDGs) framework (RGC 2018). However, the level of adaption and innovation was low at the indicator level. For instance, only five targets and six indicators have been adopted in the CSDGs framework for SDG 6, while it is eight targets and 11 indicators in the global framework (RGC 2018). The Cambodian government has planned sustainable access to an improved water supply for 100% of the rural population by 2025 (MRD 2011). The percentages of urban and rural population having access to safely managed drinking water service in their homes are 55 and 16%, respectively (MRD 2019). The percentages of urban and rural residents having access to basic water services are 95 and 70%, respectively (MRD 2019). Approximately 58.7% of rural households have access to an improved water supply, while 79% of the total households reported always treat their water for drinking (MRD 2019). Although many Cambodian people lived along watersheds, shallow groundwater was still the main source of drinking water due to the lack of safe water supplies and water treatment systems (Phan et al. 2010). Shallow groundwater, which is used as a drinking water source in rural Cambodia, could be contaminated with bacteria from toilets (Manago 2013). Likewise, a recent study revealed that both total coliform and Escherichia coli are found in tube wells, dug wells, ponds, canals and lakes, while the Cambodian Drinking Water Quality Standard for total coliform and E. coli is not detectable per 100 mL (Sao et al. 2023). In addition, a recent study revealed that some inhabitants residing in the coastal area of Cambodia were exposed to contaminants of health concern (As, F⁻, NO₃⁻) (Phan et al. 2023), and experienced water salinization (Phan et al. 2021) and aesthetic properties through their water consumption (Phan et al. 2019). Drinking properly treated water is an effective measure against diarrheal disease, and at the same time, it is important to wash hands frequently with clean water (UNICEF Cambodia 2019). Several studies have been conducted on child hygiene and handwashing in Cambodia. One of them concerns the sanitation of primary school children. En & Gan (2011) surveyed the water sources and sanitation facilities of 40 primary schools and revealed that there was a correlation between educational level, gender and sanitary environment. Furthermore, this study suggested that hygiene education for uneducated parents was very important as well as for children. Nuki & Kitawaki (2016) investigated the economic situation and selection of handwashing agents in rural Cambodia by comparing the rate of reduction in handwashing contamination by using liquid soaps, bar soaps, dishwashing detergents, etc. It was found that the decontamination rate on hands was reduced by liquid and solid soaps to about 80%, while tableware and laundry detergents showed a degree of decontamination of about 60% (Nuki & Kitawaki 2016). Concurrently, it was found that the decontamination rate of handwashing with soap was approximately six times higher than that of handwashing with water, and households who could afford soaps for such handwashing were relatively wealthy (Nuki & Kitawaki 2016). A previous study investigated household practices related to disease transmission between animals and humans in rural Cambodia, and found that there was a correlation between washing hands with soap after handling live animals, and people with knowledge of zoonotic diseases had a habit of washing their hands before and after cooking (Osbjer et al. 2015). Likewise, Vong et al. (2009) showed that inadequate handwashing and contact with culled birds were risk factors for H5N1 virus infection. It needs collective efforts to get children to take these preventive actions daily. However, due to the effects of the COVID-19 pandemic, handwashing behaviour has changed significantly, and it is thought that a similar behavioural change has occurred in rural Cambodia too. This change in handwashing behaviour may have a lower mortality rate in children under the age of 5 years in the future. Therefore, the present study was to investigate children's handwashing behaviour and contamination level in rural Cambodia before the COVID-19 pandemic. This survey showed which water sources children used to wash their hands, the contamination level before/after washing and microbial qualities (coliform and E. coli) of water used for washing hands by rural Cambodian children.

The field survey was conducted by a simple random sampling technique. The respondents voluntarily participated in the present study. We interviewed children under the age of 15 years (n = 23) about their handwashing behaviour, analysed the degree of contamination of their hands and measured the water quality of the water source for handwashing, after informed consent was obtained from their guardians in 2014. In addition, we applied qualitative inquiry to observe child participants' handwashing behaviour before and after eating, after touching soil and after toileting. Moreover, information on water practice and handwashing behaviour was collected at the Institute of Technology of Cambodia, the Royal University of Phnom Penh, the JICA Cambodia Office, and the Cambodian Bureau of Statistics.

The contamination of hands was determined by a wiping test, using an adenosine triphosphate (ATP) test kit manufactured by Kikkoman Biochemifa Co., Ltd, Japan (Kikkoman Corporation 2023). The ATP wipe test not only measures bacteria and viruses, but also can quantitatively measure dirt and stains on fingers and hands. This method has been used in food manufacturing and services (Tanaka et al. 2020; Ching et al. 2021), hotels, cleaning and environmental hygiene fields (Aycicek et al. 2006; Omidbakhsh et al. 2014; Yi et al. 2020). This ATP test has also been used in the medical field (Bakke et al. 2019; Oie et al. 2020). The ATP wiping test is a technology that applies an enzymatic reaction to generate light by reacting with luciferase. The amount of ATP is proportional to the amount of luminescence. The amount of ATP is quantitatively analysed by measuring the amount of this luminescence with a measuring instrument. The kit was used to measure with approximately 5–10 wipes on the palms of children under the age of 15 years and was compared with the recommended value (Relative Light Unit – RLU) in Table 1.

A survey was conducted at children's homes about their water usage patterns (Table 3). At least one well has been installed on the premises of the residents and was used for washing hands, washing and cooking. A survey of seasonal water consumption patterns revealed that during rain seasons, people used the water source in rainwater tanks for handwashing. In Cambodia, traditional rainwater tanks (Figure 2) were used to collect rainwater for various purposes. It was reported that these rainwater tanks were cleaned regularly, but in fact, dust, leaves and garbage might have been on the roof and rainwater collector before it was stored in traditional tanks. This water might not be safe because the color of the water was not transparent. As a result, coliforms were detected in 52 out of 54 rainwater tanks. In addition, E. coli was detected in 35 rainwater tanks, which meant that about 65% of the rainwater tanks were contaminated (Table 4). The interviews revealed that rainwater jars were used as water storage tanks during the dry season because it does not rain. Since groundwater was pumped up and/or river water was purchased, these water sources were stored in rainwater jars. The water source in rainwater jars might be a combination of groundwater, surface water and/or rainwater. In order to use water hygienically from rainwater jars, safe water management, such as regular washing and sterilization using sodium hypochlorite, was required. In addition, it was necessary to take measures such as using a cover to prevent mosquitoes from laying eggs and fallen leaves from entering the jar, and boiling water before drinking. Furthermore, it was necessary to treat properly when using groundwater because it was contaminated with arsenic (Phan et al. 2010) and other chemical contaminants (Phan et al. 2019, 2023; Sao et al. 2023). The present study suggested that handwashing was not frequently being done in the surveyed villages. The COVID-19 pandemic may have changed handwashing behavior, but the infrastructure of water needed for handwashing may not have improved. Looking at developing countries as a whole, other viruses such as the Ebola virus are also still a problem. According to a previous study, the use of alcohol disinfectants like ABHR is better for hand hygiene (Prabhu et al. 2023). Although it is important to wash hands, alcohol is also effective for hand hygiene. It is used in medical settings, but is also available anywhere due to the COVID-19 pandemic. Therefore, the use of ABHR in the community, to supplement handwashing with soap and clean water, is recommended. There is a need for a global effort to improve water, sanitation and hygiene with a focus on hand hygiene to mitigate the still-emerging COVID-19 (MacLeod et al. 2023). However, further study is warranted because the present study has some limitations; the sample size was not large enough to represent rural children in Cambodia and we did not apply any inferential statistics in our data analysis.

The present study investigated handwashing behaviour among children under the age of 15 years in a rural village of Cambodia. As a result, approximately 27% of children in rural study areas were found not to wash their hands and 17.2% of children washed their hands more than four times a day. Approximately, 74% of the dirt could be removed from hands by washing with water. Concurrently, it was found that water sources for handwashing differed between the rainy season and the dry season; they used polluted rainwater for handwashing in the rainy season. Approximately, 96% of water from traditional rainwater tanks (Pieng) used for handwashing was contaminated with coliform, while 65% was contaminated with E. coli. Therefore, water sources for children's handwashing were undoubtedly not safe. In this study, the handwashing behaviour of children under the age of 15 years and the quality of the water sources for handwashing before COVID-19 have been documented. Appropriate handwashing requires safe water and educational programs on personal and environmental hygiene, for children and their parents. Moreover, ABHR is necessary for hand hygiene. A further study on handwashing should be conducted including the changes in children's handwashing and environmental hygiene behaviour after COVID-19 in rural Cambodia, frequency of ABHR use and time and place of handwashing.

In this research, we received the cooperation of students from Toyo University and the Royal University of Phnom Penh. We would also like to thank the coordinator, Mr Ke Sarath for his assistance in interpreting and arranging this research and survey. This work was supported by JSPS KAKENHI Grant Number JP24830084, and the Center for sustainable development Studies, Toyo University used research funds to conduct research. We would like to express our gratitude to everyone involved in this research.

This work was supported by JSPS KAKENHI Grant Number JP24830084 and the Center for sustainable development Studies, Toyo University, used research funds to conduct research.

All authors read and approved the content of the final manuscript.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.