A descriptive assessment of the National Institute of Public Health's contribution to the COVID-19 response in Cambodia, 2020-2021.

Objective: This paper examines the contributions made by the National Institute of Public Health to Cambodia's response to the coronavirus disease (COVID-19) pandemic during 2020-2021. Methods: The activities conducted by the Institute were compared with adaptations of the nine pillars of the World Health Organization's 2020 COVID-19 strategic preparedness and response plan. To gather relevant evidence, we reviewed national COVID-19 testing data, information about COVID-19-related events documented by Institute staff, and financial and technical reports of the Institute's activities. Results: The main contributions the Institute made were to the laboratory pillar and the incident management and planning pillar. The Institute tested more than 50% of the 2 575 391 samples for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing and provided technical advice about establishing 18 new laboratories for SARS-CoV-2 testing in the capital city of Phnom Penh and 11 provinces. The Institute had representatives on many national committees and coauthored national guidelines for implementing rapid COVID-19 testing, preventing transmission in health-care facilities and providing treatment. The Institute contributed to six other pillars, but had no active role in risk communication and community engagement. Discussion: The Institute's support was essential to the COVID-19 response in Cambodia, especially for laboratory services and incident management and planning. Based on the contributions made by the Institute during the COVID-19 pandemic, continued investment in it will be critical to allow it to support responses to future health emergencies in Cambodia.

Impact of oral intervention on the oral and overall health of children living with HIV in Cambodia: a randomized controlled trial.

BACKGROUND: Maintaining oral health is essential for improving overall health of children living with HIV. Therefore, we evaluated the effectiveness of an oral health intervention for improving their oral and overall health. In addition, we examined their longitudinal association between changes in oral and overall health. METHODS: We conducted a 2-year randomized controlled trial involving children living with HIV in Cambodia. Children aged 3-15 years and their caregivers were randomly allocated either to the intervention (group A) or control (group B) arm. A second control arm (group C) included children without HIV. The group A children received oral health education sessions and practiced home-based daily care. RESULTS: In the baseline survey, 482 children participated (group A: n = 160, group B: n = 168, group C: n = 154), and 350 completed the endline survey. An interaction effect in teeth brushing duration was observed in children in group A relative to group B (AOR = 2.69, 95% CI: 1.37-5.31) and group C (AOR = 3.78, 95% CI: 1.70-8.40). Longitudinal associations were observed between changes in oral hygiene and overall health, as presented by alterations in dental caries in permanent teeth with viral load detection (adjusted odds ratio = 3.58, 95% CI: 1.10 - 11.73), in salivary flow quantity with the overall quality of life (ß = 0.07, 95% CI: < 0.01 - 0.13), as well as in dental caries, salivary pH, debris index with body mass index for age among group A children. CONCLUSIONS: Oral health intervention may improve oral care behaviors and potentially enhance overall health among children living with HIV in antiretroviral therapy in a resource-constrained setting. TRIAL REGISTRATION: ISRCTN 15177479.

Descriptive assessment of COVID-19 responses and lessons learnt in Cambodia, January 2020 to June 2022.

As a member state of the International Health Regulations 2005, Cambodia is continuously strengthening its capacity to respond to health emergencies and prevent the international spread of diseases. Despite this, Cambodia's capacity to prevent, detect and rapidly respond to public health threats remained limited at the onset of the pandemic, as was the case in most countries. This paper describes epidemiological phases, response phases, strategy and lessons learnt in Cambodia between 27 January 2020 and 30 June 2022. We classified epidemiological phases in Cambodia into three phases, in which Cambodia responded using eight measures: (1) detect, isolate/quarantine; (2) face coverings, hand hygiene and physical distancing measures; (3) risk communication and community engagement; (4) school closures; (5) border closures; (6) public event and gathering cancellation; (7) vaccination; and (8) lockdown. The measures corresponded to six strategies: (1) setting up and managing a new response system, (2) containing the spread with early response, (3) strengthening the identification of cases and contacts, (4) strengthening care for patients with COVID-19, (5) boosting vaccination coverage and (6) supporting disadvantaged groups. Thirteen lessons were learnt for future health emergency responses. Findings suggest that Cambodia successfully contained the spread of SARS-CoV-2 in the first year and quickly attained high vaccine coverage by the second year of the response. The core of this success was the strong political will and high level of cooperation from the public. However, Cambodia needs to further improve its infrastructure for quarantining and isolating cases and close contacts and laboratory capacity for future health emergencies.

Sexual and reproductive health services access and provision in Cambodia during the COVID-19 pandemic: a mixed-method study of urban-rural differences.

BACKGROUND: The COVID-19 pandemic pushed governments worldwide to implement unprecedented mitigation measures, including safe-distancing, lockdowns, disruption of non-essential services, border closures and travel restrictions, with both potential to affect rural and urban service-users differently and unintended consequences including reductions in sexual and reproductive health (SRH) services. We aimed to explore rural-urban differences in progress and challenges in SRH services provision in Cambodia, particularly during initial months of the COVID-19 pandemic. METHODS: We used a mixed-methods study design, including a household survey of 423 adolescents and women aged 18-49 and semi-structured interviews with 21 healthcare providers. We analysed survey data using multivariable logistic regression to identify associations between rural-urban setting and contraceptive perceptions or access. We analysed interview data thematically. RESULTS: Rural-urban residence was significantly associated with reported perceptions about and access to contraceptives. Rural participants had higher odds of stating it was possible to change contraceptive methods early in the COVID-19 pandemic, compared with urban participants. Qualitative data showed that although SRH services continued, health-workers faced differential challenges in rural and urban areas, e.g. service-users not attending due to job losses in urban areas and not complying with safe-distancing and mask-wearing requests in rural areas. CONCLUSIONS: COVID-19 and inadequate mitigation responses differentially affected rural and urban SRH service providers and service-users, exacerbating existing socioeconomic stressors while adding new fears of infection, transport constraints, and reduced livelihoods. Added financial support could help mitigate challenges in both rural and urban areas.

Using Relational Community Engagement within the Digital Health Intervention (DHI) to Improve Access and Retention among People Living with HIV (PLWH): Findings from a Mixed-Method Study in Cambodia.

We examined the impact of COVID-19-associated restrictive measures on the HIV care system in Cambodia through a complexity lens and aimed to use the findings to integrate social and relational processes into the design and implementation of proposed solutions that could support program outcomes during these times. Through a mixed-method design, we generated data on the strength of connection and quality of relationships between stakeholders and how this, in turn, provided a more holistic understanding of the challenges experienced during a pandemic. We interviewed 43 HIV care providers and 13 patients from eight HIV clinics and 13 policy-level stakeholders from relevant institutions involved in HIV care from April to May 2021. We identified several challenges, as well as an opportunity to improve HIV care access that built upon a strong foundation of trust between the HIV care providers and receivers in Cambodia. Trusting relationships between providers and patients provided the basis for intervention development aiming to improve the care experience and patients' engagement in care. Iterative research processes could better inform the intervention, and communication resources provided through relational skills training are key to their application and sustainability.

Residual risk of mother-to-child transmission of HBV despite timely Hepatitis B vaccination: a major challenge to eliminate hepatitis B infection in Cambodia.

BACKGROUND: In countries with intermediate or high hepatitis B virus (HBV) endemicity, mother-to-child transmission (MTCT) represents the main route of chronic HBV infection. There is a paucity of information on HBV MTCT in Cambodia. This study aimed to investigate the prevalence of HBV infection among pregnant women and its MTCT rate in Siem Reap, Cambodia. METHODS: This longitudinal study included two parts, study-1 to screen HBsAg among pregnant women and study-2 to follow up babies of all HBsAg-positive and one-fourth of HBsAg-negative mothers at their delivery and six-month post-partum. Serum or dried blood spot (DBS) samples were collected to examine HBV sero-markers by chemiluminescent enzyme immunoassay (CLEIA), and molecular analyses were performed on HBsAg-positive samples. Structured questionnaires and medical records were used to examine the risk factors for HBV infection. MTCT rate was calculated by HBsAg positivity of 6-month-old babies born to HBsAg-positive mothers and ascertained by the homology of HBV genomes in mother-child pair at 6-month-old. RESULTS: A total of 1,565 pregnant women were screened, and HBsAg prevalence was 4.28% (67/1565). HBeAg positivity was 41.8% and was significantly associated with high viral load (p < 0.0001). Excluding subjects who dropped out due to restrictions during COVID-19, one out of 35 babies born to HBsAg-positive mothers tested positive for HBsAg at 6 months of age, despite receiving timely HepB birth dose and HBIG, followed by 3 doses of HepB vaccine. Hence the MTCT rate was 2.86%. The mother of the infected baby was positive for HBeAg and had a high HBV viral load (1.2 × 109 copies/mL). HBV genome analysis showed 100% homology between the mother and the child. CONCLUSIONS: Our findings illustrate the intermediate endemicity of HBV infection among pregnant women in Siem Reap, Cambodia. Despite full HepB vaccination, a residual risk of HBV MTCT was observed. This finding supports the recently updated guidelines for the prevention of HBV MTCT in 2021, which integrated screening and antiviral prophylaxis for pregnant women at risk of HBV MTCT. Furthermore, we strongly recommend the urgent implementation of these guidelines nationwide to effectively combat HBV in Cambodia.

Social contact patterns relevant for infectious disease transmission in Cambodia.

Social mixing patterns are key determinants of infectious disease transmission. Mathematical models parameterised with empirical data from contact pattern surveys have played an important role in understanding epidemic dynamics and informing control strategies, including for SARS-CoV-2. However, there is a paucity of data on social mixing patterns in many settings. We conducted a community-based survey in Cambodia in 2012 to characterise mixing patterns and generate setting-specific contact matrices according to age and urban/rural populations. Data were collected using a diary-based approach from 2016 participants, selected by stratified random sampling. Contact patterns were highly age-assortative, with clear intergenerational mixing between household members. Both home and school were high-intensity contact settings, with 27.7% of contacts occurring at home with non-household members. Social mixing patterns differed between rural and urban residents; rural participants tended to have more intergenerational mixing, and a higher number of contacts outside of home, work or school. Participants had low spatial mobility, with 88% of contacts occurring within 1 km of the participants' homes. These data broaden the evidence-base on social mixing patterns in low and middle-income countries and Southeast Asia, and highlight within-country heterogeneities which may be important to consider when modelling the dynamics of pathogens transmitted via close contact.

Influx of Backyard Farming with Limited Biosecurity Due to the COVID-19 Pandemic Carries an Increased Risk of Zoonotic Spillover in Cambodia.

Backyard farming with limited biosecurity creates a massive potential for zoonotic spillover. Cambodia, a developing nation in Southeast Asia, is a hub for emerging and endemic infectious diseases. Due to pandemic-induced job losses in the tourism sector, rumors suggest that many former Cambodian tour guides have turned to backyard farming as a source of income and food security. A cross-sectional study including 331 tour guides and 69 poultry farmers in Cambodia before and during the novel coronavirus disease 2019 (COVID-19) pandemic was conducted. Participants were administered a survey to assess food security, income, and general farming practices. Survey data were collected to evaluate the risk perceptions for avian influenza virus (AIV), antimicrobial resistance (AMR), and general biosecurity management implemented on these poultry farms. Overall, food security decreased for 80.1% of the tour guides during the COVID-19 pandemic. Approximately 21% of the tour guides interviewed used backyard poultry farming to supplement losses of income and food insecurity during the COVID-19 pandemic, with a significantly higher risk than for traditional poultry farmers. Agricultural intensification in Cambodia due to the COVID-19 pandemic has caused an influx of makeshift farms with limited biosecurity. Inadequate biosecurity measures in animal farms can facilitate spillover and contribute to future pandemics. Improved biosecurity and robust viral surveillance systems are critical for reducing the risk of spillover from backyard farms. IMPORTANCE While this study highlights COVID-19-associated changes in poultry production at a small scale in Cambodia, poultry production is expected to expand due to an increase in the global demand for poultry protein during the pandemic, changes in urbanization, and the reduction of the global pork supply caused by African swine fever (ASF). The global demand and surge in poultry products, combined with inadequate biosecurity methods, can lead to an increased risk of domestic animal and human spillovers of zoonotic pathogens such as avian influenza. Countries in regions of endemicity are often plagued by complex emergency situations (i.e., food insecurity and economic fallouts) that hinder efforts to effectively address the emergence (or reemergence) of zoonotic diseases. Thus, novel surveillance strategies for endemic and emerging infectious diseases require robust surveillance systems and biosecurity training programs to prevent future global pandemics.

Income loss and gender-based violence during the COVID-19 pandemic among female entertainment workers in Cambodia: a cross-sectional phone survey.

BACKGROUND: In Cambodia, female entertainment workers (FEWs) are disproportionately affected by global and local disasters, such as the COVID-19 pandemic. To prevent the spread of COVID-19, the government imposed tight restrictions, including closures of entertainment venues, such as karaoke bars, beer gardens, nightclubs, or massage parlors, leading FEWs to face economic and social disruptions. This study aims to assess the relationship between income loss during the pandemic and gender-based violence (GBV) among FEWs in Cambodia to inform future disaster response programs. METHODS: We conducted a phone survey in August 2021 with 369 randomly sampled FEWs from a national organization's email list. We used a structured questionnaire to ask the participants about job and income loss, food security, mental health, access to health services, and GBV. We fit a linear regression model to examine the differences in GBV experience between FEWs who lost all their income and those who lost partial income due to the COVID-19 pandemic. Key covariables comprised the number of dependents, smartphone ownership, internet access, food security, and mental health. Multivariable linear regression analysis was conducted. RESULTS: The mean age (31.6 vs. 30.6), years of formal education (6.3 vs. 6.3), marital status (24.2 vs. 23.8 never married), and the number of children (1.3 vs. 1.1) of women reporting having lost all income were not significantly different from those who experienced partial income loss. Overall, GBV experiences were significantly higher in FEWs who lost all income than in those who lost partial income (62.9% vs. 47.4%, p = 0.03). Controlling for the number of dependents, smartphone ownership, and food security, the adjusted odds ratio for GBV was significant in the adjusted model (AOR = 1.23 (1.08-1.40), p = 0.001) indicating that those who experienced total income loss were more likely to experience GBV than those who experienced partial income loss. In addition, they were significantly less likely to be food secure (p = 0.04), less likely to own a smartphone (p = 0.02), and had more dependents (p < 0.001). CONCLUSION: Disaster response programs should consider the implications of safety measures and government support for both formal and informal workers regarding safety, food access, and mental health support. Food assistance programs should target the most vulnerable informal sector workers during crises.

The Role of Food Literacy in Managing Nutritional Precarity in the Migrant Experience: Dietary Lifestyles of Cambodia Migrants in Thailand.

The paper explores the dietary lifestyles of young Cambodian migrants in Thailand to illuminate the role of food literacy in determining nutritional outcomes and well-being, including during crises, such as the COVID-19 pandemic. In this context, food literacy is defined as food skills and abilities to plan, select, and prepare to achieve adequate consumption under new or adverse social and culinary contexts of the migrant experience. In this paper, we consider both how nutritional precarity arises in the migrant experience, and to what extent food literacy can mitigate it under various conditions. The research approach involves a combination of qualitative and quantitative approaches that were adjusted to address the limited mobility for social science research during the COVID-19 pandemic in Thailand. Data collection was conducted through hybrid (online and in-person) ethnography, focus group discussions, food literacy questionnaires, and key informant interviews, often facilitated through internet messaging clients. The findings indicate that, while generally high food literacy may facilitate the transition to the foreign food systems found in migration destinations, optimizing nutrition and well-being requires reinforcement by context-specific food literacy, such as openness to foreign flavors and recipes. Contextual food literacy most directly leads to positive social and health outcomes while simultaneously expanding universal food literacy in the long-term.

A controlled before-and-after study of a multi-modal intervention to improve hand hygiene during the peri-natal period in Cambodia.

Adequate hand hygiene practices throughout the continuum of care of maternal and newborn health are essential for infection prevention. However, the hand hygiene compliance of facility-based birth attendants, parents and other caregivers along this continuum is low and behavioural-science informed interventions targeting the range of caregivers in both the healthcare facility and home environments are scarce. We assessed the limited efficacy of a novel multimodal behaviour change intervention, delivered at the facility, to improve the hand hygiene practices among midwives and caregivers during childbirth through the return to the home environment. The 6-month intervention was implemented in 4 of 8 purposively selected facilities and included environmental restructuring, hand hygiene infrastructure provision, cues and reminders, and participatory training. In this controlled before-and-after study, the hand hygiene practices of all caregivers present along the care continuum of 99 women and newborns were directly observed. Direct observations took place during three time periods; labour, delivery and immediate aftercare in the facility delivery room, postnatal care in the facility ward and in the home environment within the first 48 h following discharge. Multilevel logistic regression models, adjusted for baseline measures, assessed differences in hand hygiene practices between intervention and control facilities. The intervention was associated with increased odds of improved practice of birth attendants during birth and newborn care in the delivery room (Adjusted odds ratio [AOR] = 4.7; 95% confidence interval [CI] = 2.7, 7.7), and that of parental and non-parental caregivers prior to newborn care in the post-natal care ward (AOR = 9.2; CI = 1.3, 66.2); however, the absolute magnitude of improvements was limited. Intervention effects were not presented for the home environment due COVID-19 related restrictions on observation duration at endline which resulted in too low observation numbers to warrant testing. Our results suggest the potential of a facility-based multimodal behaviour change intervention to improve hand hygiene practices that are critical to maternal and neonatal infection along the continuum of care.

Comparison of Routine Hematology, Coagulation, and Clinical Chemistry Parameters of Cynomolgus Macaques of Mauritius Origin With Cynomolgus Macaques of Cambodia, China, and Vietnam Origin.

Cynomolgus macaques (Macaca fascicularis) are commonly used in safety assessment and as translational models for drug development. Recent supply chain pressures, exportation bans, and increased demand for drug safety assessment studies exacerbated by the COVID-19 pandemic have prompted the investigation of utilizing macaques of different geographic origin in preclinical toxicity studies. This study compares routine hematology, coagulation, and clinical chemistry endpoints of 3 distinct subpopulations of mainland Asia origin (Cambodia, China, and Vietnam) with Mauritius origin macaques compiling results of 3,225 animals from 123 regulatory toxicology studies conducted at North American and European Union contract research organization facilities between 2016 and 2019. Results were generally similar amongst the subpopulations compared in this study. Few notable differences in hematology test results and several minor differences in serum biochemistry and coagulation test results were identified when 3 distinct subpopulations of mainland Asia origin macaques were compared with Mauritius origin macaques. Our findings support the use of different origin macaques in drug development programs; however, emphasizes the importance of maintaining consistency in geographic origin of animals within a study.

Qualitative evaluation of enabling factors and barriers to the success and sustainability of national public health institutes in Cambodia, Colombia, Liberia, Mozambique, Nigeria, Rwanda and Zambia.

OBJECTIVES: The success of National Public Health Institutes (NPHIs) in low-income and middle-income countries (LMICs) is critical to countries' ability to deliver public health services to their populations and effectively respond to public health emergencies. However, empirical data are limited on factors that promote or are barriers to the sustainability of NPHIs. This evaluation explored stakeholders' perceptions about enabling factors and barriers to the success and sustainability of NPHIs in seven countries where the U.S. Centers for Disease Control and Prevention (CDC) has supported NPHI development and strengthening. DESIGN: Qualitative study. SETTING: Cambodia, Colombia, Liberia, Mozambique, Nigeria, Rwanda and Zambia. PARTICIPANTS: NPHI staff, non-NPHI government staff, and non-governmental and international organisation staff. METHODS: We conducted semistructured, in-person interviews at a location chosen by the participants in the seven countries. We analysed data using a directed content analysis approach. RESULTS: We interviewed 43 NPHI staff, 29 non-NPHI government staff and 24 staff from non-governmental and international organisations. Participants identified five enabling factors critical to the success and sustainability of NPHIs: (1) strong leadership, (2) financial autonomy, (3) political commitment and country ownership, (4) strengthening capacity of NPHI staff and (5) forming strategic partnerships. Three themes emerged related to major barriers or threats to the sustainability of NPHIs: (1) reliance on partner funding to maintain key activities, (2) changes in NPHI leadership and (3) staff attrition and turnover. CONCLUSIONS: Our findings contribute to the scant literature on sustainability of NPHIs in LMICs by identifying essential components of sustainability and types of support needed from various stakeholders. Integrating these components into each step of NPHI development and ensuring sufficient support will be critical to strengthening public health systems and safeguarding their continuity. Our findings offer potential approaches for country leadership to direct efforts to strengthen and sustain NPHIs.

Robust and Functional Immune Memory Up to 9 Months After SARS-CoV-2 Infection: A Southeast Asian Longitudinal Cohort.

The duration of humoral and cellular immune memory following SARS-CoV-2 infection in populations in least developed countries remains understudied but is key to overcome the current SARS-CoV-2 pandemic. Sixty-four Cambodian individuals with laboratory-confirmed infection with asymptomatic or mild/moderate clinical presentation were evaluated for Spike (S)-binding and neutralizing antibodies and antibody effector functions during acute phase of infection and at 6-9 months follow-up. Antigen-specific B cells, CD4+ and CD8+ T cells were characterized, and T cells were interrogated for functionality at late convalescence. Anti-S antibody titers decreased over time, but effector functions mediated by S-specific antibodies remained stable. S- and nucleocapsid (N)-specific B cells could be detected in late convalescence in the activated memory B cell compartment and are mostly IgG+. CD4+ and CD8+ T cell immune memory was maintained to S and membrane (M) protein. Asymptomatic infection resulted in decreased antibody-dependent cellular cytotoxicity (ADCC) and frequency of SARS-CoV-2-specific CD4+ T cells at late convalescence. Whereas anti-S antibodies correlated with S-specific B cells, there was no correlation between T cell response and humoral immune memory. Hence, all aspects of a protective immune response are maintained up to nine months after SARS-CoV-2 infection and in the absence of re-infection.

SARS-CoV-2 Cross-Reactivity in Prepandemic Serum from Rural Malaria-Infected Persons, Cambodia.

Inhabitants of the Greater Mekong Subregion in Cambodia are exposed to pathogens that might influence serologic cross-reactivity with severe acute respiratory syndrome coronavirus 2. A prepandemic serosurvey of 528 malaria-infected persons demonstrated higher-than-expected positivity of nonneutralizing IgG to spike and receptor-binding domain antigens. These findings could affect interpretation of large-scale serosurveys.

Presence of Recombinant Bat Coronavirus GCCDC1 in Cambodian Bats.

Bats have been recognized as an exceptional viral reservoir, especially for coronaviruses. At least three bat zoonotic coronaviruses (SARS-CoV, MERS-CoV and SARS-CoV-2) have been shown to cause severe diseases in humans and it is expected more will emerge. One of the major features of CoVs is that they are all highly prone to recombination. An extreme example is the insertion of the P10 gene from reoviruses in the bat CoV GCCDC1, first discovered in Rousettus leschenaultii bats in China. Here, we report the detection of GCCDC1 in four different bat species (Eonycteris spelaea, Cynopterus sphinx, Rhinolophus shameli and Rousettus sp.) in Cambodia. This finding demonstrates a much broader geographic and bat species range for this virus and indicates common cross-species transmission. Interestingly, one of the bat samples showed a co-infection with an Alpha CoV most closely related to RsYN14, a virus recently discovered in the same genus (Rhinolophus) of bat in Yunnan, China, 2020. Taken together, our latest findings highlight the need to conduct active surveillance in bats to assess the risk of emerging CoVs, especially in Southeast Asia.