Spatiotemporal evolution and transmission dynamics of Alpha and Delta SARS-CoV-2 variants contributing to sequential outbreaks in Cambodia during 2021.

Background: Tracking the emergence, introduction and spread of SARS-CoV-2 variants of concern are essential for informing public health strategies. In 2021, Cambodia faced two major epidemic waves of SARS-CoV-2 triggered by the successive rise of the Alpha and Delta variants.

Methods: Phylodynamic analysis of 1,163 complete SARS-CoV-2 genomes from Cambodia, along with global sequences, were conducted between February and September 2021 to infer viral introductions, molecular epidemiology and population dynamics.

Humoral Immunity Profiling to Pandemic and Bat-Derived Coronavirus Variants: A Geographical Comparison.

Dynamic pathogen exposure may impact the immunological response to SARS-CoV-2 (SCV2). One potential explanation for the lack of severe SCV2-related morbidity and mortality in Southeast Asia is prior exposure to related betacoronaviruses. Recent discoveries of SCV2-related betacoronaviruses from horseshoe bats (Rhinolophus sinicus) in Thailand, Laos, and Cambodia suggest the potential for bat-to-human spillover exposures in the region.

Bacterial Genomics for National Antimicrobial Resistance Surveillance in Cambodia.

Background: Antimicrobial resistance (AMR) surveillance in low- and middle-income countries (LMICs) often relies on poorly resourced laboratory processes. Centralized sequencing was combined with cloud-based, open-source bioinformatics solutions for national AMR surveillance in Cambodia.

Methods: Blood cultures growing gram-negative bacteria were collected at six Cambodian hospitals (January 2021 - October 2022).

Case Report: Risk Factors Associated with Mortality in Adults with Burkholderia Pseudomallei Bacteremia: A Retrospective Case Series of Melioidosis in Cambodia.

In resource-scarce settings, melioidosis is associated with up to 80% mortality. Studies of melioidosis in Cambodia report primarily on pediatric populations with localized infection; however, literature describing Cambodian adults with severe melioidosis is lacking. We present a case series of 35 adults with sequence-confirmed Burkholderia pseudomallei bacteremia presenting to a provincial referral hospital in rural Cambodia.

Genomic epidemiology of SARS-CoV-2 in Cambodia, January 2020 to February 2021.

The first case of coronavirus disease 2019 (COVID-19) in Cambodia was confirmed on 27 January 2020 in a traveller from Wuhan. Cambodia subsequently implemented strict travel restrictions, and although intermittent cases were reported during the first year of the COVID-19 pandemic, no apparent widespread community transmission was detected. Investigating the routes of severe acute respiratory coronavirus 2 (SARS-CoV-2) introduction into the country was critical for evaluating the implementation of public health interventions and assessing the effectiveness of social control measures.

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.

Genetic and Antigenic Characterization of an Influenza A(H3N2) Outbreak in Cambodia and the Greater Mekong Subregion during the COVID-19 Pandemic, 2020.

Introduction of non-pharmaceutical interventions to control COVID-19 in early 2020 coincided with a global decrease in active influenza circulation. However, between July and November 2020, an influenza A(H3N2) epidemic occurred in Cambodia and in other neighboring countries in the Greater Mekong Subregion in Southeast Asia. We characterized the genetic and antigenic evolution of A(H3N2) in Cambodia and found that the 2020 epidemic comprised genetically and antigenically similar viruses of Clade3C2a1b/131K/94N, but they were distinct from the WHO recommended influenza A(H3N2) vaccine virus components for 2020-2021 Northern Hemisphere season.

Human Infection with Avian Influenza A(H9N2) Virus, Cambodia, February 2021.

In February 2021, routine sentinel surveillance for influenza-like illness in Cambodia detected a human avian influenza A(H9N2) virus infection. Investigations identified no recent H9N2 virus infections in 43 close contacts. One chicken sample from the infected child's house was positive for H9N2 virus and genetically similar to the human virus.

Update on and Nontyphoidal Salmonella Antimicrobial Drug Resistance: Implications on Empirical Treatment of Acute Infectious Diarrhea in Cambodia.

Information on causative diarrheal pathogens and their associated antimicrobial susceptibility remains limited for Cambodia. This study describes antimicrobial resistance patterns for and nontyphoidal Salmonella isolates collected in Cambodia over a 5-year period. Multidrug resistance was shown in 98% of isolates, with 70%, 11%, and 29% of isolates being resistant to fluoroquinolones, azithromycin, and cephalosporin, respectively.

The Pandemic Experience in Southeast Asia: Interface Between SARS-CoV-2, Malaria, and Dengue.

Southeast Asia (SEA) emerged relatively unscathed from the first year of the global SARS-CoV-2 pandemic, but as of July 2021 the region is experiencing a surge in case numbers primarily driven by Alpha (B.1.1.

Rapid metagenomic characterization of a case of imported COVID-19 in Cambodia.

Rapid production and publication of pathogen genome sequences during emerging disease outbreaks provide crucial public health information. In resource-limited settings, especially near an outbreak epicenter, conventional deep sequencing or bioinformatics are often challenging. Here we successfully used metagenomic next generation sequencing on an iSeq100 Illumina platform paired with an open-source bioinformatics pipeline to quickly characterize Cambodia's first case of COVID-2019.

Cholera in selected countries in Asia.

Introduction: Although the current pandemic of cholera originated in Asia, reports of cholera cases and outbreaks in the region are sparse. To provide a sub-regional assessment of cholera in South and Southeast Asia, we collated published and unpublished data from existing surveillance systems from Bangladesh, Cambodia, India, Malaysia, Nepal, Pakistan, Philippines, Thailand and Vietnam.

Methods: Data from existing country surveillance systems on diarrhea, acute watery diarrhea, suspected cholera and/or confirmed cholera in nine selected Asian countries (Bangladesh, Cambodia, India, Malaysia, Nepal, Pakistan, Philippines, Thailand and Vietnam) from 2011 to 2015 (or 2016, when available) were collated.

Circulation and characterization of seasonal influenza viruses in Cambodia, 2012-2015.

Background: Influenza virus circulation is monitored through the Cambodian influenza-like illness (ILI) sentinel surveillance system and isolates are characterized by the National Influenza Centre (NIC). Seasonal influenza circulation has previously been characterized by year-round activity and a peak during the rainy season (June-November).

Objectives: We documented the circulation of seasonal influenza in Cambodia for 2012-2015 and investigated genetic, antigenic, and antiviral resistance characteristics of influenza isolates.

Cholera prevention and control in Asian countries.

Cholera remains a major public health problem in many countries. Poor sanitation and inappropriate clean water supply, insufficient health literacy and community mobilization, absence of national plans and cross-border collaborations are major factors impeding optimal control of cholera in endemic countries. In March 2017, a group of experts from 10 Asian cholera-prone countries that belong to the Initiative against Diarrheal and Enteric Diseases in Africa and Asia (IDEA), together with representatives from the World Health Organization, the US National Institutes of Health, International Vaccine Institute, Agence de médecine préventive, NGOs (Save the Children) and UNICEF, met in Hanoi (Vietnam) to share progress in terms of prevention and control interventions on water, sanitation and hygiene (WASH), surveillance and oral cholera vaccine use.

National burden of influenza-associated hospitalizations in Cambodia, 2015 and 2016.

Introduction: The burden of influenza in Cambodia is not well known, but it would be useful for understanding the impact of seasonal epidemics and pandemics and to design appropriate policies for influenza prevention and control. The severe acute respiratory infection (SARI) surveillance system in Cambodia was used to estimate the national burden of SARI hospitalizations in Cambodia.

Methods: We estimated age-specific influenza-associated SARI hospitalization rates in three sentinel sites in Svay Rieng, Siem Reap and Kampong Cham provinces.

Using a hospital admission survey to estimate the burden of influenza-associated severe acute respiratory infection in one province of Cambodia-methods used and lessons learned.

Background: Understanding the burden of influenza-associated severe acute respiratory infection (SARI) is important for setting national influenza surveillance and vaccine priorities. Estimating influenza-associated SARI rates requires hospital-based surveillance data and a population-based denominator, which can be challenging to determine.

Objectives: We present an application of the World Health Organization's recently developed manual (WHO Manual) including hospital admission survey (HAS) methods for estimating the burden of influenza-associated SARI, with lessons learned to help others calculate similar estimates.

Establishing seasonal and alert influenza thresholds in Cambodia using the WHO method: implications for effective utilization of influenza surveillance in the tropics and subtropics.

Objective: To establish seasonal and alert thresholds and transmission intensity categories for influenza to provide timely triggers for preventive measures or upscaling control measures in Cambodia.

Methods: Using Cambodia's influenza-like illness (ILI) and laboratory-confirmed influenza surveillance data from 2009 to 2015, three parameters were assessed to monitor influenza activity: the proportion of ILI patients among all outpatients, proportion of ILI samples positive for influenza and the product of the two. With these parameters, four threshold levels (seasonal, moderate, high and alert) were established and transmission intensity was categorized based on a World Health Organization alignment method.

Real-Time Polymerase Chain Reaction Detection of Angiostrongylus cantonensis DNA in Cerebrospinal Fluid from Patients with Eosinophilic Meningitis.

Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis. Timely diagnosis of these infections is difficult, partly because reliable laboratory diagnostic methods are unavailable. The aim of this study was to evaluate the usefulness of a real-time polymerase chain reaction (PCR) assay for the detection of A.

Epidemiological and virological characteristics of influenza viruses circulating in Cambodia from 2009 to 2011.

Background: The Cambodian National Influenza Center (NIC) monitored and characterized circulating influenza strains from 2009 to 2011.

Methodology/principal Findings: Sentinel and study sites collected nasopharyngeal specimens for diagnostic detection, virus isolation, antigenic characterization, sequencing and antiviral susceptibility analysis from patients who fulfilled case definitions for influenza-like illness, acute lower respiratory infections and event-based surveillance. Each year in Cambodia, influenza viruses were detected mainly from June to November, during the rainy season.

Identification of molecular markers associated with alteration of receptor-binding specificity in a novel genotype of highly pathogenic avian influenza A(H5N1) viruses detected in Cambodia in 2013.

Human infections with influenza A(H5N1) virus in Cambodia increased sharply during 2013. Molecular characterization of viruses detected in clinical specimens from human cases revealed the presence of mutations associated with the alteration of receptor-binding specificity (K189R, Q222L) and respiratory droplet transmission in ferrets (N220K with Q222L). Discovery of quasispecies at position 222 (Q/L), in addition to the absence of the mutations in poultry/environmental samples, suggested that the mutations occurred during human infection and did not transmit further.

Dynamic of H5N1 virus in Cambodia and emergence of a novel endemic sub-clade.

In Cambodia, the first detection of HPAI H5N1 virus in birds occurred in January 2004 and since then there have been 33 outbreaks in poultry while 21 human cases were reported. The origin and dynamics of these epizootics in Cambodia remain unclear. In this work we used a range of bioinformatics methods to analyze the Cambodian virus sequences together with those from neighboring countries.

In vitro generation of functional insulin-producing cells from lipoaspirated human adipose tissue-derived stem cells.

Background And Aims: Tissue engineering strategy has been considered as an alternative treatment for diabetes mellitus due to lack of permanent pharmaceutical treatment and islet donors for transplantation. Various cell lines have been used to generate functional insulin-producing cells (IPCs) including progenitor pancreatic cell lines, embryonic stem cells (ESCs), umbilical cord blood stem cells (UCB-SCs), adult bone marrow stem cells (BMSCs), and adipose tissue-derived stem cells (ADSCs).

Methods: Human ADSCs from lipoaspirated abdominal fat tissue was differentiated into IPCs following a two-step induction protocol based on a combination of alternating high and low glucose, nicotinamide, activin A and glucagon-like peptide 1 (GLP-1) for a duration of 3 weeks.

A cost-effectiveness analysis of Japanese encephalitis vaccine in Cambodia.

This study aimed to evaluate the cost and effectiveness of introducing a live, attenuated vaccine (SA 14-14-2) against Japanese encephalitis (JE) into the immunization program. The study demonstrated that SA 14-14-2 immunization is cost-effective in controlling JE in Cambodia compared to no vaccination. Averting one disability-adjusted life year, from a societal perspective, through the introduction of SA 14-14-2 through routine immunization, or a combination of routine immunization plus a campaign targeting children 1-5 or 1-10 years of age, costs US$22, US$34 and US$53, respectively.

Disability from Japanese encephalitis in Cambodia and Viet Nam.

A cohort of Japanese encephalitis (JE) survivors in Cambodia and Viet Nam were assessed at least 4 months after hospital discharge in order to understand the extent of disability after JE. We used a simple assessment tool which focuses on the impact on daily life. In total, 64 disability assessments were conducted: 38 in Cambodia and 26 in Viet Nam.

Influenza activity in Cambodia during 2006-2008.

Background: There is little information about influenza disease among the Cambodian population. To better understand the dynamics of influenza in Cambodia, the Cambodian National Influenza Center (NIC) was established in August 2006. To continuously monitor influenza activity, a hospital based sentinel surveillance system for ILI (influenza like illness) with a weekly reporting and sampling scheme was established in five sites in 2006.