Malaria in Cambodia: A Retrospective Analysis of a Changing Epidemiology 2006-2019.

BACKGROUND: In Cambodia, malaria persists with changing epidemiology and resistance to antimalarials. This study aimed to describe how malaria has evolved spatially from 2006 to 2019 in Cambodia. METHODS: We undertook a secondary analysis of existing malaria data from all government healthcare facilities in Cambodia. The epidemiology of malaria was described by sex, age, seasonality, and species. Spatial clusters at the district level were identified with a Poisson model. RESULTS: Overall, incidence decreased from 7.4 cases/1000 population in 2006 to 1.9 in 2019. The decrease has been drastic for females, from 6.7 to 0.6/1000. Adults aged 15-49 years had the highest malaria incidence among all age groups. The proportion of Plasmodium (P.) falciparum + Mixed among confirmed cases declined from 87.9% (n = 67,489) in 2006 to 16.6% (n = 5290) in 2019. Clusters of P. falciparum + Mixed and P. vivax + Mixed were detected in forested provinces along all national borders. CONCLUSIONS: There has been a noted decrease in P. falciparum cases in 2019, suggesting that an intensification plan should be maintained. A decline in P. vivax cases was also noted, although less pronounced. Interventions aimed at preventing new infections of P. vivax and relapses should be prioritized. All detected malaria cases should be captured by the national surveillance system to avoid misleading trends.

Determinants of Exclusive Breastfeeding of Infants under Six Months among Cambodian Mothers.

INTRODUCTION: Practicing exclusive breastfeeding (EBF) in an infant's first six months of life is recommended by the World Health Organization because of its proven effectiveness as a method to support the infant's short- and long-term physical and cognitive development. However, many countries, including Cambodia, face contextually driven challenges in meeting this optimum standard of breastfeeding. The recent declining EBF rate in Cambodia is a concerning indicator of the impact of these challenges. METHODS: We used existing data from the 2014 Cambodian Demographic and Health Survey (CDHS) to analyze 717 Cambodian mother-infant pairs. CDHS 2014 used a two-stage stratified cluster sampling approach to select samples. A multivariable logistic regression analysis was used to assess determinants of EBF, taking into account the sampling weight in the analysis. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) were calculated, and significance level was considered at p value < 0.05. RESULTS: Our findings indicate that among mothers with infants under six months, EBF was more likely if they resided rurally (AOR = 2.28; 95% CI 1.23-4.23) and if they delivered at a public hospital (AOR = 2.64; 95% CI 1.28-5.47). On the other hand, mothers of middle wealth index practiced EBF less than mothers of low wealth index (AOR = 0.58; 95% CI 0.34-0.99). And as expected, our analysis confirmed that the older the infants grew, the less likely they were to be exclusively breastfed than those younger than one month old (2-3 months: AOR = 0.49; 95% CI 0.26-0.92; 4-5 months: AOR = 0.25; 95% CI 0.15-0.43). CONCLUSION: The findings emphasize the need to address these determinants adequately by appropriate interventions to halt the declining trend of EBF practice. We recommend a multifaceted approach to improve EBF rates in Cambodia. Advocacy around EBF at public hospitals should continue, and private hospital staff should receive training to provide EBF counselling and support to mothers.

Efficacy and Safety of Pyronaridine-Artesunate for Treatment of Uncomplicated Plasmodium falciparum Malaria in Western Cambodia.

Pyronaridine-artesunate efficacy for the treatment of uncomplicated Plasmodium falciparum malaria was assessed in an area of artemisinin resistance in western Cambodia. This nonrandomized, single-arm, observational study was conducted between 2014 and 2015. Eligible patients were adults or children with microscopically confirmed P. falciparum infection and fever. Patients received pyronaridine-artesunate once daily for 3 days, dosed according to body weight. The primary outcome was an adequate clinical and parasitological response (ACPR) on day 42, estimated by using Kaplan-Meier analysis, PCR adjusted to exclude reinfection. One hundred twenty-three patients were enrolled. Day 42 PCR-crude ACPRs were 87.2% (95% confidence interval [CI], 79.7 to 92.6%) for the overall study, 89.8% (95% CI, 78.8 to 95.3%) for Pursat, and 82.1% (95% CI, 68.4 to 90.2%) for Pailin. Day 42 PCR-adjusted ACPRs were 87.9% (95% CI, 80.6 to 93.2%) for the overall study, 89.8% (95% CI, 78.8 to 95.3%) for Pursat, and 84.0% (95% CI, 70.6 to 91.7%) for Pailin (P = 0.353 by a log rank test). Day 28 PCR-crude and -adjusted ACPRs were 93.2% (95% CI, 82.9 to 97.4%) and 88.1% (95% CI, 75.3 to 94.5%) for Pursat and Pailin, respectively. A significantly lower proportion of patients achieved day 3 parasite clearance in Pailin (56.4% [95% CI, 43.9 to 69.6%]) than in Pursat (86.7% [95% CI, 76.8 to 93.8%]; P = 0.0019). Fever clearance was also extended at Pailin versus Pursat (P < 0.0001). Most patients (95.9% [116/121]) harbored P. falciparum kelch13 C580Y mutant parasites. Pyronaridine-artesunate was well tolerated; mild increases in hepatic transaminase levels were consistent with data from previous reports. Pyronaridine-artesunate efficacy was below the World Health Organization-recommended threshold at day 42 for medicines with a long half-life (90%) for first-line treatment of P. falciparum malaria in western Cambodia despite high efficacy elsewhere in Asia and Africa. (This study has been registered at ClinicalTrials.gov under registration number NCT02389439.).