1.Assessing progress and challenges towards malaria elimination in Kampong Speu, Cambodia: analysis of Plasmodium vivax and mixed infections, 2019–2023
Kanha Ly ; Sophanith Ung ; Maria Concepcion Roces ; Dysoley Lek ; Po Ly
Western Pacific Surveillance and Response 2025;16(4):99-108
Malaria is a life-threatening but preventable disease caused by Plasmodium parasites transmitted through bites of infected female Anopheles mosquitoes. According to the World Health Organization, the Western Pacific Region reported 1.7 million malaria cases in 2023, of which Plasmodium vivax accounted for 28.9% of cases and approximately 3500 malaria-related deaths. This reflects a decrease in the incidence of malaria cases and associated mortality compared to 2022, highlighting progress but underscoring persistent challenges. Cambodia, with its goal to eliminate malaria by 2025, continues to face public health challenges, particularly from P. vivax and mixed-species infections. This report provides an in-depth epidemiological analysis of malaria cases and radical cure treatment outcomes for P. vivax and mixed-species infections in Kampong Speu Province from 2019 to 2023. Data were drawn from Cambodia’s national Malaria Information System and radical cure treatment records. The analysis demonstrated a substantial increase in malaria screening, primarily conducted by village malaria workers, while the number of confirmed malaria cases continued to decline. The annual parasite incidence dropped from 23.8 per 1000 at-risk individuals in 2019 to 0.7 per 1000 in 2023. Radical cure treatment completion rates among eligible cases improved from 78% in 2019 to 98% in 2023. Significant progress has been made towards malaria elimination. However, males aged 15–49 years, particularly forest-goers in the Kampong Speu operational district, remain the most at-risk group. In support of malaria elimination, it is recommended to enhance prevention measures, increase screening and ensure 100% radical cure treatment for all eligible cases in high-risk populations.
2.Emergence of vaccine-derived poliovirus type 2 after using monovalent type 2 oral poliovirus vaccine in an outbreak response, Philippines
SweetC B Alipon ; Yoshihiro Takashima ; Tigran Avagyan ; Varja Grabovac ; Syeda Kanwal Aslam ; Benjamin Bayutas ; Josephine Logronio ; Xiaojun Wang ; Achyut Shrestha ; Sukadeo Neupane ; Maria Concepcion Roces ; Lea Necitas Apostol ; Nemia Sucaldito
Western Pacific Surveillance and Response 2022;13(2):01-07
Objective:
In response to an outbreak of circulating vaccine-derived poliovirus (cVDPV) type 2 in the Philippines in 2019–2020, several rounds of supplementary immunization activities using the monovalent type 2 oral poliovirus vaccine (OPV) were conducted for the first time in the Western Pacific Region. After use of the monovalent vaccine, the emergence of vaccine-derived poliovirus unrelated to the outbreak virus was detected in healthy children and environmental samples. This report describes the detection of this poliovirus in the Philippines after use of the monovalent type 2 OPV for outbreak response.
Methods:
We describe the emergence of vaccine-derived poliovirus unrelated to the outbreak detected after supplementary immunization activities using the monovalent type 2 OPV. This analysis included virus characterization, phylogenetic analyses and epidemiological investigations.
Results:
Three environmental samples and samples from six healthy children tested positive for the emergent vaccine-derived poliovirus. All isolates differed from the Sabin type 2 reference strain by 6–13 nucleotide changes, and all were detected in the National Capital Region and Region 4, which had conducted supplementary immunization activities.
Discussion
Since the 2016 removal of type 2 strains from the OPV, vaccine-derived poliovirus outbreaks have occurred in communities that are immunologically naive to poliovirus type 2 and in areas with recent use of monovalent OPV. To prevent the emergence and further spread of cVDPV type 2, several interventions could be implemented including optimizing outbreak responses by using the monovalent type 2 OPV, accelerating the availability of the novel type 2 OPV, strengthening routine immunization using inactivated polio vaccine and eventually replacing OPV with inactivated poliovirus vaccine for routine immunization.
3.Field epidemiology training programmes in the Asia-Pacific: what is best practice for supervision?
Owen Forbes ; Stephanie Davis ; Amalie Dyda ; Alexander Rosewell ; Stephanie Williams ; Martyn Kirk ; Maria Concepcion Roces ; Consorcia Lim-Quizon ; Kerri Viney
Western Pacific Surveillance and Response 2019;10(4):9-17
Introduction:
Field epidemiology training programmes (FETPs) emphasize competency-based training and learning by doing. Supervision of FETP trainees is critical for programmes to achieve learning outcomes. We sought to address a knowledge gap regarding what constitutes effective FETP supervision.
Methods:
We investigated FETP supervision using a mixed-methods approach. Quantitative data were collected through a survey of FETP directors. Qualitative data included written feedback from the survey and a focus group discussion (FGD) conducted with FETP supervisors at the 8th South-East Asia and Western Pacific Bi-regional TEPHINET Conference. FGD questions focused on effective supervisory qualities and activities and challenges to effective supervision. We calculated descriptive statistics for quantitative data and analysed qualitative data using a deductive content analysis approach.
Results:
Eleven FETP directors responded to the survey and 23 participated in the FGD. Overall, supervision was seen as very important for trainee outcomes. Participants identified the different roles of academic and field supervisors but emphasized the importance of an enabling and supporting attitude towards trainees. Soft skills and interpersonal abilities were among the most important qualities identified for effective supervision. Key challenges identified included a lack of consistency in supervisors’ technical knowledge and the difficulty of finding candidate supervisors with sufficient interest, availability and motivation for supervision.
Discussion
Several practical recommendations arose from this study for supervision in FETPs, including recruiting and training supervisors with a more holistic range of skills. Our findings also provide key points for current FETP supervisors to consider to improve their own practice.


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