This study was conducted as a baseline survey for an intervention study, which is currently carried out to integrate community-based malaria control and Maternal, Neonatal, and Child Health (MNCH) services in the Ratanakiri Province, Cambodia. Data were collected from December 23 to 30, 2015, through face-to-face interviews with mothers with children under 2 years of age living in 62 VMW villages.
This study was conducted in Ratanakiri Province in the north-eastern part of the country, which shares its borders with Lao People’s Democratic Republic (PDR) and Vietnam. Residents consist of 13 ethnic minority groups and the Khmer group, which is the major ethnic group in Cambodia. People generally live in villages which consist of 20–60 families and mainly engage in subsistence shifting agriculture, rice farming, and plantation of rubber, cashew, and cassava. As the majority of ethnic minority groups live on subsistence slash-and-burn farming and rice cultivation, many of them own farm huts (plot huts) near or inside the forest, where they stay to plant, guard, and harvest crops [10, 11].
Out of 27 health centers in Ratanakiri province, 12 that cover villages where Village Malaria Workers (VMWs) are engaged in malaria control activities, were included in this study (VMW villages). Seven out of the 12 health centers were then selected based on accessibility by vehicles or motorcycles throughout the year (purposive sampling). These included Andaung Meas, Chomrom Bay Sruk, Kachanh, Lumphat, Ochum, Oyadav, and Taveng. Of the 73 VMW villages serviced by the seven health centers, ten villages under the Ochum health center and one village under the Andaung Meas health center were excluded, considering the geographical difficulty in conducting a long-term intervention program scheduled after the survey, and absence of eligible interviewees at the time of the survey. Therefore, in total 62 VMW villages were selected for inclusion in this study.
A semi-structured questionnaire was developed to conduct the face-to-face interviews. Most of the questions were drawn from existing questionnaires, including the Cambodia Demographic Health Survey 2014  and questionnaires that were already used in Cambodia for previous studies on VMWs and mothers with children under five [13,14,15]. The questionnaire contained questions regarding a) mothers’ and their families’ socio-demographic characteristics; b) agricultural practices; c) history of fever and infectious diseases (malaria, diarrhea, and pneumonia, etc.); d) knowledge and actions for malaria prevention; e) treatment-seeking behavior of mothers for themselves and their children under two; f) mothers’ complications during pregnancy and childbirth (fever, anemia, bleeding, etc.); and g) children’s complications (fever, difficulty breathing, etc.). The questionnaire was developed in English, translated into Khmer by Cambodian health experts, and then verified by other Khmer health experts to ensure the accuracy of the translation.
Indices to measure mothers’ knowledge on malaria epidemiology and vector ecology and actions for malaria prevention and vector control were developed based on mothers’ answers to the survey questions, as described in previous publications [13, 16]. Knowledge indices measured to quantify understanding of malaria epidemiology and vector ecology included: malaria symptoms, malaria transmission, vector species, vector active time, vector development time, breeding places, and natural enemies. Regarding malaria symptoms, mothers were asked if the following are correct: stomach ache, diarrhoea, nausea, fever, and shivering. Choices given to answer malaria transmission included cough or sneeze, touching blood, touching utensils, sharing food, coming close to mosquitoes, and mosquito bites. Choices on mosquito genera and sex were given for vector species. For vector’s most active time, the following time periods were given, morning, afternoon, and dusk to dawn. Vector development time was asked by an open-ended question. Regarding vector breeding places, trees, on the ground, and water pools around houses, water pools in the forest were given. For natural enemies of the vector, four choices were given: dogs, birds, aquatic insects, and small fish. Correct answer for each item was given one point.
Action indices were developed to quantify different malaria preventive and vector control measures taken by mothers. Each measure that mothers undertook was given one or two points, according to its effectiveness and frequency [13, 16]. A maximum of two points were given to effective measures (always/most of the time = 2, sometimes/rarely =1, never = 0), including “come back home before dusk,” “wear long-sleeved shirts/pants”, “sleep under bed nets at home”, “refrain from going to the forest”, “bring hammock nets to the forest”, “fill in water pools” “burn trash around house”, “seal holes/cracks on walls/ceilings”, and “cover water jars/tanks”. A maximum of one point (always/most of the time/sometimes = 1, rarely/never = 0) was given to less effective measures including “kill mosquitoes by hands”, “use mosquito coils”, “spray house”, and “clear bush around house”. For a wrong measure “plant flowers/grasses around house”, 0 points (always/most of the time/sometimes/rarely = 0, never = 1) were given. The total points for five malaria preventive measures and nine vector control measures became index scores, ranging from 0 to 10 and 0 to 13, respectively. Using each index, study population was divided into tertiles, namely least active, active, and most active groups.
Seventeen surveyors visited each participant’s residence and conducted face-to-face interviews. Before conducting the interviews, malaria experts of the National Center for Parasitology, Entomology, and Malaria Control, Cambodia (CNM) and lead researchers conducted a one-day training for the surveyors to explain each question in the questionnaire and how to conduct the interviews.
We recruited all mothers with children under two residing in 62 VMW villages, who were available at the time of the survey, in order to capture malaria knowledge, preventive actions, and treatment-seeking behavior of mothers in the study site as accurately as possible. Although 388 mothers were interviewed, 11 were excluded from analysis because of missing data. In total, 377 mothers were included in the analysis.
GPS data collection and analysis
GPS data were collected to measure actual travel distance between the 62 villages and their nearest health centers. Four GPS data collectors traveled from each village to its nearest health center with Holux m-241 (a wireless GPS logger). GPS data were recorded every 5 seconds during each trip. Data were entered into Excel 2016 through the Holux exTour for Logger v2.1 software, and then into Arc Map 10.4, which was used to calculate the actual distance traveled.
Data management and statistical analysis
All data were coded, entered into data analysis software, and double-checked by the authors to ensure accuracy. Data analysis was done by STATA version 14. Descriptive analyses were conducted to describe sociodemographic characteristics, knowledge and actions for malaria prevention, and treatment-seeking behavior for fever management among participants. Mothers were classified into socio-economic status quartiles based on household assets and housing characteristics determined using a principal component analysis [15, 17].
Basic descriptive statistics such as frequency and percentages were used to describe mothers with correct knowledge on malaria epidemiology and vector ecology as well as those who took each measure for malaria prevention and vector control. Knowledge and action indices were compared between mothers who had fever and those who did not have fever during the most recent pregnancy as well as between mothers with a child who had fever and those with a child who did not have fever during the last 3 months.
To identify determinants of fever during the most recent pregnancy and fever among their children less than 2 years of age, two multiple logistic regression analyses were conducted. Outcomes of these analyses were reported occurrence of fever during pregnancy and that of fever among children during the last 3 months. Also, the following independent variables were included: mother’s age, education, wealth quartiles, ethnicity, having other children or not, age and gender of the child, experience of child loss, whether water was treated prior to consumption, whether there was a toilet at home, whether the family owned livestock, indices to describe malaria preventive measures and vector control measures undertaken, and whether the mother had an agricultural practice which required staying overnight at a farm hut.
Of the sociodemographic characteristics investigated, literacy was excluded from the analysis because of multicollinearity with education (r = 0.89). Mother’s marital status and occupation were excluded because of the small sub-group sample sizes (most of the mothers were married and were farmers). Child age and child gender were also excluded from the analysis for fever during pregnancy because they were unknown factors during pregnancy. P-values < 0.05 were considered statistically significant.