Knowledge of hepatitis B infection, hepatitis B vaccine, and vaccination status with its associated factors among healthcare workers in Kampot and Kep Provinces, Cambodia.

BACKGROUND: Healthcare Workers (HCWs) are susceptible to hepatitis B virus (HBV) infection and are advised to receive vaccination. However, vaccination rates remain low in developing countries. There is little data concerning Hepatitis B (HepB) vaccination and information regarding HBV knowledge among HCWs in Cambodia. This study aimed to evaluate the knowledge of HBV infection, HepB vaccine, and vaccination status with its associated factors among HCWs in Cambodia. METHODS: A Cross-sectional study was conducted among HCWs in Kampot and Kep Provinces, Cambodia, from September to October 2023 using a questionnaire survey. A total of 261 HCWs were recruited from 1,309 individuals working in all 83 health facilities using systematic random sampling methods. Statistical analyses including the χ2-test and multivariate logistic regression were conducted to identify factors associated with vaccination among the participants. RESULTS: Among 259 participants, 62.9% showed good knowledge of HBV infection, and 65.6% demonstrated good knowledge of the HepB vaccine. 59.8% of the participants had received the HepB vaccine, while 40.2% remained unvaccinated. Analysis showed that HCWs working at Provincial Health Department/Operational Districts and Provincial Referral Hospital/Referral Hospitals were more likely to be vaccinated compared to those at Health Centers [AOR = 6.5; CI = 1.1-39.5, p = 0.0403; AOR = 2.8, CI = 1.0-7.8, p = 0.0412], respectively. Furthermore, individuals with good knowledge of the HBV infection and vaccine were more likely to receive the vaccine compared to those with inadequate knowledge [AOR = 6.3; CI = 3.3-12.3, p < .0001; AOR = 3.7, CI = 1.9-7.4, p = 0.0001], respectively. Within the unvaccinated HCWs, 32% reported high vaccine costs as a barrier, 33% mentioned workplace vaccine was not for adults, and 59% reported insufficient education on adult HepB vaccination. CONCLUSIONS: The HepB vaccination coverage among HCWs is at 59.8%, which is below the World Health Organization's (WHO) recommendation rate of 100%. Knowledge of HBV infection and HepB vaccine were good predictive factors for vaccination. The high cost of vaccine, workplace vaccine not for adults, and insufficient education on adult vaccination were found as barriers to vaccination. This study underscores the importance of providing education to HCWs on HBV infection and the HepB vaccine. Furthermore, it highlights the need for a policy that ensures free vaccination for HCWs.

Challenges for ticks and tick-borne diseases research in Southeast Asia: Insight from the first international symposium in Cambodia.

BACKGROUND: Ticks, as critical vectors of a variety of pathogens, pose a significant public health challenge globally. In Southeast Asia (SEA), ticks are responsible for transmitting a diverse array of pathogens affecting humans and animals. The geographical and ecological diversity of SEA provides a unique environment that supports a wide range of tick species, which complicates the management and study of tick-borne diseases (TBDs). METHODOLOGY/PRINCIPAL FINDINGS: This article synthesizes findings from the first international symposium on ticks and TBDs in Southeast Asia, held in Phnom Penh on June 22 and 23, 2023. It highlights regional efforts to understand tick ecology and pathogen transmission. This paper proposes to present a summary of the various presentations given during the symposium following 3 main parts. The first one is devoted to the state of knowledge regarding ticks and TBDs in SEA countries, with presentations from 6 different countries, namely Cambodia, Indonesia, Laos, Malaysia, Thailand, and Vietnam. The second part focuses on the development of new research approaches on tick-borne pathogens (TBPs) and TBDs. The last part is a summary of the round table discussion held on the final day, with the aim of defining the most important challenges and recommendations for researches on TBP and TBD in the SEA region. CONCLUSIONS/SIGNIFICANCE: Key topics discussed include advancements in diagnostic tools, such as MALDI-TOF MS and proteomics, and the development of sustainable strategies for tick management and disease prevention. The symposium facilitated the exchange of knowledge and collaborative networks among experts from various disciplines, promoting a unified approach to tackling TBDs in the region. The symposium underscored the need for enhanced surveillance, diagnostics, and inter-regional cooperation to manage the threat of TBDs effectively. Recommendations include the establishment of a regional database for tick identification and the expansion of vector competence studies. These initiatives are crucial for developing targeted interventions and understanding the broader implications of climate change and urbanization on the prevalence of TBDs.

Commercially traded fish portfolios mask household utilization of biodiversity in wild food systems.

The global biodiversity that underpins wild food systems-including fisheries-is rapidly declining. Yet, we often have only a limited understanding of how households use and benefit from biodiversity in the ecosystems surrounding them. Explicating these relationships is critical to forestall and mitigate the effects of biodiversity declines on food and nutrition security. Here, we quantify how biodiversity filters from ecosystems to household harvest, consumption, and sale, and how ecological traits and household characteristics shape these relationships. We used a unique, integrated ecological (40 sites, quarterly data collection) and household survey (n = 414, every 2 mo data collection) dataset collected over 3 y in rice field fisheries surrounding Cambodia's Tonlé Sap, one of Earth's most productive and diverse freshwater systems. While ecosystem biodiversity was positively associated with household catch, consumption, and sold biodiversity, households consumed an average of 43% of the species present in the ecosystem and sold only 9%. Larger, less nutritious, and more common species were disproportionally represented in portfolios of commercially traded species, while consumed species mirrored catches. The relationship between ecosystem and consumed biodiversity was remarkably consistent across variation in household fishing effort, demographics, and distance to nearest markets. Poorer households also consumed more species, underscoring how wild food systems may most benefit the vulnerable. Our findings amplify concerns about the impacts of biodiversity loss on our global food systems and highlight that utilization of biodiversity for consumption may far exceed what is commercially traded.

World Health Organization Enhanced Gonococcal Antimicrobial Surveillance Programme, Cambodia, 2023.

To determine antimicrobial susceptibility of Neisseria gonorrhoeae, we analyzed phenotypes and genomes of 72 isolates collected in Cambodia in 2023. Of those, 9/72 (12.5%) were extensively drug resistant, a 3-fold increase from 2022. Genomic analysis confirmed expansion of newly emerging resistant clones and ongoing resistance emergence across new phylogenetic backbones.

Exploring minimum dietary diversity among cambodian children using four rounds of demographic and health survey.

Dietary diversity among children is a crucial factor influencing their nutritional status; therefore, this paper uses data from four rounds of the Cambodia Demographic and Health Survey (CDHS) to examine the minimum dietary diversity among children aged 6-23 months. Multilevel binary regression is used to evaluate the variation in minimum dietary diversity at the cluster and province levels. The results show that nearly half of Cambodian children consistently lacked access to vitamin A-rich fruits and vegetables. Although the prevalence of inadequate minimum dietary diversity (MDD) among children significantly dropped from 76% in 2005 to 51% in 2021-2022, it is still high and needs attention. A decomposition analysis (Blinder-Oaxaca decomposition) was further used to understand the drivers of this temporal change in dietary diversity. The empirical results show that clusters represented the most significant source of geographic variation with respect to all eight food groups and MDD. Nutritional policy should improve education and awareness, reduce socio-economic disparities, leverage media, and promote full antenatal care to improve dietary diversity in Cambodia. Initiatives targeting the enhancement of insufficient minimum dietary diversity intake should encompass individual aspects and be customized to suit geographic and community settings.

A Plasmodium falciparum genetic cross reveals the contributions of pfcrt and plasmepsin II/III to piperaquine drug resistance.

Piperaquine (PPQ) is widely used in combination with dihydroartemisinin as a first-line treatment against malaria. Multiple genetic drivers of PPQ resistance have been reported, including mutations in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and increased copies of plasmepsin II/III (pm2/3). We generated a cross between a Cambodia-derived multidrug-resistant KEL1/PLA1 lineage isolate (KH004) and a drug-susceptible Malawian parasite (Mal31). Mal31 harbors a wild-type (3D7-like) pfcrt allele and a single copy of pm2/3, while KH004 has a chloroquine-resistant (Dd2-like) pfcrt allele with an additional G367C substitution and multiple copies of pm2/3. We recovered 104 unique recombinant parasites and examined a targeted set of progeny representing all possible combinations of variants at pfcrt and pm2/3. We performed a detailed analysis of competitive fitness and a range of PPQ susceptibility phenotypes with these progenies, including PPQ survival assay, area under the dose response curve, and a limited point IC50. We find that inheritance of the KH004 pfcrt allele is required for reduced PPQ sensitivity, whereas copy number variation in pm2/3 further decreases susceptibility but does not confer resistance in the absence of additional mutations in pfcrt. A deep investigation of genotype-phenotype relationships demonstrates that progeny clones from experimental crosses can be used to understand the relative contributions of pfcrt, pm2/3, and parasite genetic background to a range of PPQ-related traits. Additionally, we find that the resistance phenotype associated with parasites inheriting the G367C substitution in pfcrt is consistent with previously validated PPQ resistance mutations in this transporter.IMPORTANCEResistance to piperaquine, used in combination with dihydroartemisinin, has emerged in Cambodia and threatens to spread to other malaria-endemic regions. Understanding the causal mutations of drug resistance and their impact on parasite fitness is critical for surveillance and intervention and can also reveal new avenues to limiting the evolution and spread of drug resistance. An experimental genetic cross is a powerful tool for pinpointing the genetic determinants of key drug resistance and fitness phenotypes and has the distinct advantage of quantifying the effects of naturally evolved genetic variation. Our study was strengthened since the full range of copies of KH004 pm2/3 was inherited among the progeny clones, allowing us to directly test the role of the pm2/3 copy number on resistance-related phenotypes in the context of a unique pfcrt allele. Our multigene model suggests an important role for both loci in the evolution of this multidrug-resistant parasite lineage.

Antibiotic resistance profiles of sentinel bacteria isolated from aquaculture in Cambodia.

The misuse of antibiotics and the emergence of antimicrobial resistance (AMR) is a concern in the aquaculture industry because it contributes to global health risks and impacts the environment. This study analyzed the AMR of sentinel bacteria associated with striped catfish (Pangasisanodon hypophthalmus) and giant snakehead (Channa micropeltes), the two main fish species reared in the pond culture in Cambodia. Phenotypic and genotypic characterization of the recovered isolates from fish, water, and sediment samples revealed the presence of bacteria, such as 22 species belonging to families Aeromonadaceae, Enterobacteriaceae, and Pseudomonadaceae. Among 48 isolates, Aeromonas caviae (n = 2), Aeromonas hydrophila (n = 2), Aeromonas ichthiosmia (n = 1), Aeromonas salmonicida (n = 4) were detected. A. salmonicida and A. hydrophilla are known as fish pathogens that occur worldwide in both fresh and marine water aquaculture. Antibiotic susceptibility testing revealed antibiotic resistance patterns of 24 (50 %) isolates among 48 isolates with higher multiple antibiotic resistance index (> 0.2). All the isolates of Enterobacteriaceae were susceptible to ciprofloxacin. Ciprofloxacin is a frontline antibiotic that is not recommended to use in aquaculture. Therefore, its use has to be strictly controlled. This study expands our knowledge of the AMR status in aquaculture farms which is very limited in Cambodia.

Determinants of stunting among under-five children: Evidence from Cambodian Demographic and Health Survey 2021-2022.

BACKGROUND: Epidemiological and nutritional modifications are causing an increase in stunting in many low- and middle-income countries (LMIC), which will eventually result in juvenile diseases and mortality. Therefore, this study aimed to identify the influential factors contributing to stunting among under-five children in Cambodia. METHODS: A secondary dataset consisting of 3268 under-five children was extracted from the latest Cambodian Demographic and Health Survey (CDHS)-2021/2022 dataset. The Chi-square test and Boruta algorithm were used for covariate selection, and logistic regression approaches were used to determine the influence of demographic, socioeconomic and other factors on the presence of stunting. RESULTS: Findings revealed that about 21% of under-five children were stunted, and the prevalence of stunting was higher in rural areas than in urban areas. The prevalence of child stunting was lower in families with highly educated parents. A child whose father had a secondary education had 0.71 times lower (adjusted odds ratio [AOR]: 0.71, 95% CI: 0.520-0.969) chance of stunting than a child whose father had no education. Findings revealed that Ratnak Kiri, Mondul Kiri, Stung Treng, Pursat and Kampot had a greater prevalence of stunting than other places, ranging from 27.11% to 35.70%, whereas Banteay Meanchey, Phnom Penh and Kandal had the lowest rates, ranging from 12.80% to 16.00%. Results of the Boruta algorithm and logistic regression suggested that under-five stunting is significantly influenced by factors such as the child's age, size at birth, mother's age at first birth, mother's body mass index (BMI), father's educational status, cooking fuel, and wealth index. CONCLUSIONS: It is necessary to take initiatives for reducing the prevalence of stunted children prioritising the identified factors that ultimately help to reduce the burden of child health. The authors believed that the findings of this study will be helpful for policymakers in designing the appropriate policies and actions to achieve the Sustainable Development Goals (SDGs) by reducing stunting among under-five children in Cambodia.

The Impact of COVID-19 on Children, Young People, and Families in Sihanoukville, Cambodia: The Mitigating Work of M'Lop Tapang.

Globally, children have been adversely affected by the wide variety of impacts of SARS-CoV-2 (Coronavirus | COVID-19). Vulnerable children who depend on the support of education and health and social care systems were left unprotected as these systems were weakened by the pandemic. COVID-19 has exposed the already fragile situations in which many children and young people live and that thousands of children and young people would need ongoing support but remained invisible to statutory authorities. COVID-19 has also been a stark reminder of the vulnerability of individuals and societies and it has exposed deep divisions, inequalities, and injustices between different countries and groups of people. M'Lop Tapang is a local nonprofit organization registered with the Royal Government of Cambodia. This report discusses the efforts of M'Lop Tapang following the declaration of the COVID-19 global pandemic in early 2020, to address the local community needs; to ensure the voices of children remained heard; and to promote children's rights remaining a priority throughout the remainder of the pandemic.What is already known on this topicVulnerable children are dependent on remaining visible to education and health and social care systems to ensure they are safeguarded and protected.Poor safety, financial instability, unemployment, challenges to children's rights and displacement all have the potential to increase vulnerabilities and intensify inequalities.The COVID-19 global pandemic has widened the global lens for the nursing profession and to effect change, children's nurses need to think globally and act locally.What this study addsThis study provides insights into the challenges faced by children and families in Sihanoukville, Cambodia, during the early part of the SARS-CoV-2 (COVID19) pandemic in 2020-2021.The economic impact of COVID-19 on children and families living in Sihanoukville, Cambodia, between 2020 and 2021 is reviewed.The learning from the pragmatic and rapid interventions of M'Lop Tapang, Sihanoukville during the early phase of the SARS-CoV-2 (COVID-19) pandemic, are of use in other countries around the world in future epidemic or pandemic situations.

Increased frequencies of highly activated regulatory T cells skewed to a T helper 1-like phenotype with reduced suppressive capacity in dengue patients.

The pathogenesis of dengue involves a complex interplay between the viral factor and the host immune response. A mismatch between the infecting serotype and the adaptive memory response is hypothesized to lead to exacerbated immune responses resulting in severe dengue. Here, we aim to define in detail the phenotype and function of different regulatory T cell (Treg) subsets and their association with disease severity in a cohort of acute dengue virus (DENV)-infected Cambodian children. Treg frequencies and proliferation of Tregs are increased in dengue patients compared to age-matched controls. Tregs from dengue patients are skewed to a Th1-type Treg phenotype. Interestingly, Tregs from severe dengue patients produce more interleukin-10 after in vitro stimulation compared to Tregs from classical dengue fever patients. Functionally, Tregs from dengue patients have reduced suppressive capacity, irrespective of disease severity. Taken together, these data suggest that even though Treg frequencies are increased in the blood of acute DENV-infected patients, Tregs fail to resolve inflammation and thereby could contribute to the immunopathology of dengue. IMPORTANCE: According to the World Health Organization, dengue is the fastest-spreading, epidemic-prone infectious disease. The extent of dengue virus infections increased over the years, mainly driven by globalization-including travel and trade-and environmental changes. Dengue is an immunopathology caused by an imbalanced immune response to a secondary heterotypic infection. As regulatory T cells (Tregs) are essential in maintaining immune homeostasis and dampening excessive immune activation, this study addressed the role of Tregs in dengue immunopathology. We show that Tregs from dengue patients are highly activated, skewed to a Th1-like Treg phenotype and less suppressive compared to healthy donor Tregs. Our data suggest that Tregs fail to resolve ongoing inflammation during dengue infection and hence contribute to the immunopathology of severe dengue disease. These data clarify the role of Tregs in dengue immunopathogenesis, emphasizing the need to develop T cell-based vaccines for dengue.

Assessing nasal airway resistance and symmetry: An approach to global perspective through computational fluid dynamics.

This study aimed to explore the variability in nasal airflow patterns among different sexes and populations using computational fluid dynamics (CFD). We focused on evaluating the universality and applicability of dimensionless parameters R (bilateral nasal resistance) and ϕ (nasal flow asymmetry), initially established in a Caucasian Spanish cohort, across a broader spectrum of human populations to assess normal breathing function in healthy airways. In this retrospective study, CT scans from Cambodia (20 males, 20 females), Russia (20 males, 18 females), and Spain (19 males, 19 females) were analyzed. A standardized CFD workflow was implemented to calculate R-ϕ parameters from these scans. Statistical analyses were conducted to assess and compare these parameters across different sexes and populations, emphasizing their distribution and variances. Our results indicated no significant sex-based differences in the R parameter across the populations. However, moderate sexual dimorphism in the ϕ parameter was observed in the Cambodian group. Notably, no geographical differences were found in either R or ϕ parameters, suggesting consistent nasal airflow characteristics across the diverse human groups studied. The study also emphasized the importance of using dimensionless variables to effectively analyze the relationships between form and function in nasal airflow. The observed consistency of R-ϕ parameters across various populations highlights their potential as reliable indicators in both medical practice and further CFD research, particularly in diverse human populations. Our findings suggest the potential applicability of dimensionless CFD parameters in analyzing nasal airflow, highlighting their utility across diverse demographic and geographic contexts. This research advances our understanding of nasal airflow dynamics and underscores the need for additional studies to validate these parameters in broader population cohorts. The approach of employing dimensionless parameters paves the way for future research that eliminates confounding size effects, enabling more accurate comparisons across different populations and sexes. The implications of this study are significant for the advancement of personalized medicine and the development of diagnostic tools that accommodate individual variations in nasal airflow.

Determinants of postpartum depression among women in Kampong Chhnang Province, Cambodia.

OBJECTIVE: This study aimed to identify the prevalence of postpartum depression (PPD) and the factors associated with PPD in Kampong Chhnang Province, Cambodia. STUDY DESIGN: A cross-sectional study. PARTICIPANTS: This study included 440 Cambodian women at 6-8 weeks postpartum who visited health centers between July and September 2021. MATERIALS AND METHODS: Data were collected through face-to-face interviews by midwives and nurses using a structured questionnaire. The Edinburgh Postnatal Depression Scale (EPDS) in the Khmer language was used to screen for PPD, and suspected PPD was defined as a total EPDS score ≥ 10. Logistic regression analyses were performed to identify the factors associated with suspected PPD. FINDINGS: The average age of participants was 28.6 years old. The prevalence of suspected-PPD was 30.2 % (n = 133). Factors associated with suspected PPD were income dissatisfaction (adjusted odds ratio (AOR) = 2.66, 95 % confidence interval (CI) 1.27-5.56, P = 0.010), unintended pregnancy (AOR = 1.99, 95 % CI 1.10-3.61, P = 0.023), and a partner employed as a manual laborer (AOR = 3.85, 95 % CI 1.11-13.33, P = 0.034), farmer (AOR = 3.69, 95 % CI 1.11-12.31, P = 0.034), and factory worker (AOR = 5.43, 95 % CI 1.38-21.41, P = 0.016). In addition, poor relationship with partners (AOR = 2.14, 95 % CI 1.17-3.94, P = 0.014), poor relationship with mother-in-law (AOR = 3.51, 95 % CI 1.70-7.21, P < 0.001), and a history of depression before pregnancy (AOR = 6.34, 95 % CI 1.59-25.34, P = 0.009) were significantly associated with suspected-PPD. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: This study highlighted the need for mental health services in primary healthcare settings. Mental health training for healthcare workers, particularly primary-level nurses, should be prioritized and strengthened. Further clinical study on EPDS validation should be carried out to justify the appropriate cut-off EPDS score for Cambodian women. The EPDS should be integrated into routine PNC services to identify women with suspected-PPD. Education on PPD should be provided not only to the nurses and midwives, but also to the women and their families to support the mental health of pregnant and postpartum women.

Factors influencing maternal death in Cambodia, Laos, Myanmar, and Vietnam countries: A systematic review.

BACKGROUND: A maternal mortality ratio is a sensitive indicator when comparing the overall maternal health between countries and its very high figure indicates the failure of maternal healthcare efforts. Cambodia, Laos, Myanmar, and Vietnam-CLMV countries are the low-income countries of the South-East Asia region where their maternal mortality ratios are disproportionately high. This systematic review aimed to summarize all possible factors influencing maternal mortality in CLMV countries. METHODS: This systematic review applied "The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist (2020)", Three key phrases: "Maternal Mortality and Health Outcome", "Maternal Healthcare Interventions" and "CLMV Countries" were used for the literature search. 75 full-text papers were systematically selected from three databases (PubMed, Google Scholar and Hinari). Two stages of data analysis were descriptive analysis of the general information of the included papers and qualitative analysis of key findings. RESULTS: Poor family income, illiteracy, low education levels, living in poor households, and agricultural and unskilled manual job types of mothers contributed to insufficient antenatal care. Maternal factors like non-marital status and sex-associated work were highly associated with induced abortions while being rural women, ethnic minorities, poor maternal knowledge and attitudes, certain social and cultural beliefs and husbands' influences directly contributed to the limitations of maternal healthcare services. Maternal factors that made more contributions to poor maternal healthcare outcomes included lower quintiles of wealth index, maternal smoking and drinking behaviours, early and elderly age at marriage, over 35 years pregnancies, unfavourable birth history, gender-based violence experiences, multigravida and higher parity. Higher unmet needs and lower demands for maternal healthcare services occurred among women living far from healthcare facilities. Regarding the maternal healthcare workforce, the quality and number of healthcare providers, the development of healthcare infrastructures and human resource management policy appeared to be arguable. Concerning maternal healthcare service use, the provisions of mobile and outreach maternal healthcare services were inconvenient and limited. CONCLUSION: Low utilization rates were due to several supply-side constraints. The results will advance knowledge about maternal healthcare and mortality and provide a valuable summary to policymakers for developing policies and strategies promoting high-quality maternal healthcare.

Discrimination and violence against women migrant workers in Thailand during the COVID-19 pandemic: A mixed-methods study.

BACKGROUND: Women migrant workers are vulnerable to discrimination and violence, which are significant public health problems. These situations may have been intensified during the COVID-19 pandemic. This study aimed to investigate discrimination against women migrant workers in Thailand during the COVID-19 pandemic and its intersection with their experiences of violence and associated factors. METHODS: A mixed-methods study design was employed to collect data from 572 women migrant workers from Myanmar, Lao People's Democratic Republic, and Cambodia. Face-to-face interviews were conducted with 494 participants using a structured questionnaire for quantitative data, whereas qualitative data was collected through 24 in-depth interviews and focus group discussions with 54 migrant women. Simple and multiple logistic regression and content analysis were employed. RESULTS: This study found that about one in five women migrant workers experienced discrimination during the COVID-19 pandemic. Among those who experienced discrimination, 63.2% had experienced intimate partner violence and 76.4% had experienced non-intimate partner violence in their lifetime. The multivariable analysis revealed that women migrant workers who had experienced any violence (AOR = 2.76, 95% CI = 1.49, 5.12), lost their jobs or income during the pandemic (AOR = 3.99, 95% CI = 2.09, 7.62), and were from Myanmar (AOR = 4.68, 95% CI = 1.79, 12.21) were more likely to have experienced discrimination. CONCLUSION: The results suggest that the intersection of discrimination and violence against women migrant workers in Thailand demands special interest to understand and address the problem. It is recommended that policymakers provide interventions and programs that are inclusive and responsive to the unique needs of women migrants depending on their country of origin and job profile.

Antibodies to Aedes aegypti D7L salivary proteins as a new serological tool to estimate human exposure to Aedes mosquitoes.

Introduction: Aedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. Methods: We tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. Results: We found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. Discussion: The IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion.

Exploring the pediatric nasopharyngeal bacterial microbiota with culture-based MALDI-TOF mass spectrometry and targeted metagenomic sequencing.

The nasopharynx is an important reservoir of disease-associated and antimicrobial-resistant bacterial species. This proof-of-concept study assessed the utility of a combined culture, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and targeted metagenomic sequencing workflow for the study of the pediatric nasopharyngeal bacterial microbiota. Nasopharyngeal swabs and clinical metadata were collected from Cambodian children during a hospital outpatient visit and then biweekly for 12 weeks. Swabs were cultured on chocolate and blood-gentamicin agar, and all colony morphotypes were identified by MALDI-TOF MS. Metagenomic sequencing was done on a scrape of all colonies from a chocolate agar culture and processed using the mSWEEP pipeline. One hundred one children were enrolled, yielding 620 swabs. MALDI-TOF MS identified 106 bacterial species/40 genera: 20 species accounted for 88.5% (2,190/2,474) of isolates. Colonization by Moraxella catarrhalis (92.1% of children on ≥1 swab), Haemophilus influenzae (87.1%), and Streptococcus pneumoniae (83.2%) was particularly common. In S. pneumoniae-colonized children, a median of two serotypes [inter-quartile range (IQR) 1-2, range 1-4] was detected. For the 21 bacterial species included in the mSWEEP database and identifiable by MALDI-TOF, detection by culture + MALDI-TOF MS and culture + mSWEEP was highly concordant with a median species-level agreement of 96.9% (IQR 86.8%-98.8%). mSWEEP revealed highly dynamic lineage-level colonization patterns for S. pneumoniae which were quite different to those for S. aureus. A combined culture, MALDI-TOF MS, targeted metagenomic sequencing approach for the exploration of the young child nasopharyngeal microbiome was technically feasible, and each component yielded complementary data. IMPORTANCE: The human upper respiratory tract is an important source of disease-causing and antibiotic-resistant bacteria. However, understanding the interactions and stability of these bacterial populations is technically challenging. We used a combination of approaches to determine colonization patterns over a 3-month period in 101 Cambodian children. The combined approach was feasible to implement, and each component gave complementary data to enable a better understanding of the complex patterns of bacterial colonization.

Detecting orphanage trafficking and exploitation.

BACKGROUND: There is growing awareness that a proportion of children in orphanages have been recruited or transferred into the facility for a purpose of exploitation and/or profit. These children are often falsely presented as orphans to evoke sympathy and solicit funding. This process is known as orphanage trafficking. Although orphanage trafficking can be prosecuted under legal frameworks in some jurisdictions, including Cambodia, there have been limited prosecutions to date. One factor that likely contributes to a lack of prosecution is poor detection, yet the indicators of orphanage trafficking have not been considered by extant research. OBJECTIVE: The current study was conducted as a first step towards providing evidence-based indicators of orphanage trafficking. PARTICIPANTS AND SETTING: Professionals who had identified or responded to cases of orphanage-based exploitation in Cambodia were interviewed. Participants included criminal justice professionals, investigators from civil society organisations, and child protection social workers. METHODS: Professionals' perspectives on how to identify orphanage trafficking were explored via in-depth interviews, and the data were analysed via thematic analysis. RESULTS: The analysis revealed a distinct set of indicators that may be used to detect orphanage trafficking, including the operation of an unauthorised facility, orphanage tourism and volunteering, and an overt focus on fundraising. CONCLUSION: The indicators revealed in this study point to the need for an effective and thorough monitoring system for orphanages, as well as adequate education and training of relevant personnel to aid in the detection of orphanage trafficking.

Bayesian modeling of post-vaccination serological data suggests that yearly vaccination of dog aged <2 years old is efficient to stop rabies circulation in Cambodia.

Rabies control remains challenging in low and middle-income countries, mostly due to lack of financial resources, rapid turnover of dog populations and poor accessibility to dogs. Rabies is endemic in Cambodia, where no national rabies vaccination program is implemented. The objective of this study was to assess the short and long-term vaccination-induced immunity in Cambodian dogs under field conditions, and to propose optimized vaccination strategies. A cohort of 351 dogs was followed at regular time points following primary vaccination only (PV) or PV plus single booster (BV). Fluorescent antibody virus neutralization test (FAVNT) was implemented to determine the neutralizing antibody titer against rabies and an individual titer ≥0·5 IU/mL indicated protection. Bayesian modeling was used to evaluate the individual duration of protection against rabies and the efficacy of two different vaccination strategies. Overall, 61% of dogs had a protective immunity one year after PV. In dogs receiving a BV, this protective immunity remained for up to one year after the BV in 95% of dogs. According to the best Bayesian model, a PV conferred a protective immunity in 82% of dogs (95% CI: 75-91%) for a mean duration of 4.7 years, and BV induced a lifelong protective immunity. Annual PV of dogs less than one year old and systematic BV solely of dogs vaccinated the year before would allow to achieve the 70% World Health Organization recommended threshold to control rabies circulation in a dog population in three to five years of implementation depending on dog population dynamics. This vaccination strategy would save up to about a third of vaccine doses, reducing cost and time efforts of mass dog vaccination campaigns. These results can contribute to optimize rabies control measures in Cambodia moving towards the global goal of ending human death from dog-mediated rabies by 2030.

Adherence and acceptability of multiple micronutrient supplementation during pregnancy: Study protocol for a cluster-randomized non-inferiority trial in Cambodia.

BACKGROUND: Iron and folic acid (IFA) supplements are currently provided to Cambodian women during pregnancy. However, recent research has found benefits of a multiple micronutrient supplement (MMS) over just IFA alone on several outcomes of perinatal and infant health. The Ministry of Health in Cambodia has proposed a transition from IFA to MMS but to effectively guide this transition requires implementation research on the acceptability and adherence to MMS (over IFA). METHODS: This non-inferiority trial aims to assess the adherence and acceptability of IFA (60 mg elemental iron and 400 µg folic acid) compared to MMS (standard UNIMMAP formulation including 15 micronutrients) during antenatal care in Cambodia. A prospective cohort of 1545 pregnant women will be assigned to one of three trial arms: (1) IFA for 90 days [IFA-90]; (2) MMS for 180 days with two distributions of 90-count tablet bottles [MMS-90]; or (3) MMS for 180 days with one 180-count tablet bottle [MMS-180]. Each arm will enroll 515 women across 48 health centers (clusters) in Kampong Thom Province in Cambodia. The primary outcome is the non-inferiority of adherence rates of MMS-180 compared to IFA-90, as assessed by tablet counts. Mixed-effects logistic and linear regression models will be used to estimate the difference in the adherence rate between the two groups, with an 'a priori' determined non-inferiority margin of 15%. Acceptability of MMS and IFA will be measured using a quantitative survey conducted with enrolled pregnant women at 30-day, 90-day, and 180-day time-points. DISCUSSION: Findings from this study will guide an effective and feasible MMS scale-up strategy for Cambodia. Additionally, the findings will be shared globally with other stakeholders planning to scale up MMS in other countries. TRIAL REGISTRATION: NCT05867836 ( ClinicalTrials.gov , registered May 18, 2023).

Cambodia's Imminent Graduation from Least Developed Country Status: What Will be the Impact of the TRIPS Agreement on Access to HIV and Hepatitis C Medicines in Cambodia?

Cambodia has experienced exponential economic growth in recent years and is expected to graduate from least developed country (LDC) status within the next decade. Membership of the World Trade Organization (WTO) will require Cambodia to grant product and process patents for pharmaceuticals upon LDC graduation. This study aims to measure the impact of the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) on the price of HIV and hepatitis C medicine in Cambodia once it graduates from LDC status and is obliged to make patents available for pharmaceutical products and processes. Using scenarios based on likely outcomes of accession to the TRIPS Agreement, it measures the impact on the price of the HIV treatment program and compares that impact with the hepatitis C treatment program. Graduation from LDC status would be expected to result in a modest increase in the cost of the antiretroviral (ARV) treatment program and very large increases in the cost of the direct acting antivirals (DAA) treatment program. If annual treatment budgets remain constant, patent protection could see 1,515 fewer people living with HIV able to access ARV treatment and 2,577 fewer people able to access DAA treatment (a drop in treatment coverage of 93%).