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Potential host range and spillover risk for novel viruses can be predicted using a network informed by known virus-host associations.

Intro: Cardamones variant Wēnzhōu virus (CVWV) is a rodent-borne virus and part of Arenaviridae family. It causes occasionally fatal hemorrhagic in human, but is generally neglected among others zoonotic disease. In Cambodia, the presence of CVWV was detected in 2009 in two Rattus species. It shares more than 85% of identity in S and L segments compared to Wenzhou Mammarenavirus from China, and was shown to be pathogenic in human. To assess the molecular epidemiology of CVWV amount rodents, and the seroprevalence in human and rodents populations in Cambodia Methods: The study was conducted using rodent's serum and pool of organs, and human serum samples, collected in Phnom Penh (the Capital city of Cambodia) and two provinces (Preah Sihanouk and Kampong Cham) representing rural setting, in 2020 and 2022. The presence of CVWV RNA was tested on rodent's pool organs using RT-PCR of GPC and L genes of Arenavirus and Sanger sequencing. The detection of anti-CVWV IgG antibody was performed on rodent and human serum samples using in-house ELISA. Findings: Between 2020 and 2022, 750 pools of organs from rodents and 788 human serum samples were collected. In rodents, the overall prevalence of CVWV was 5.2% (39/750) with the highest prevalence observed in Preah Sihanouk site 3.6% (27/750). Only Rattus exulans 15.4% (32/280) and Rattus norvegicus 4.9% (7/144) species were affected by CVWV. Seroprevalence of anti-CVWV IgG was significantly highest in Rattus norvegicus (58.1%, 72/124), followed by Rattus exulans (13.3%, 24/181) (p < 0.001). In human, seroprevalence of anti-CVWV IgG was between 12.7% (100/788) to 20.3% (112/555) among two visits of 788 participants. Twenty-eight participant remained sero-positive within 2 years period. Conclusion: Our findings provide updates on prevalence and genetic characterization diversity of Mammarenavirus in Cambodia. Further investigations are needed to determine the risk behavior and impact of Arenavirus infection at human-rodent interface.

Intro: Recent evidence shows the Greater Mekong Subregion to be a hotspot for Sarbecoviruses in bats, especially insectivorous Horseshoe bats (genus Rhinolophus). However, prevalence, maintenance, and evolution of these viruses in Rhinolophids is still poorly understood. Sampling efforts are still limited and generally only cover cross-sectional surveillance at single points in time. Following the detection of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2)-related viruses in Rhinolophus shameli from 2010 in Steung Treng, Cambodia, further active longitudinal surveillance in the same area between 2020-2021 continued the detection of these viruses. Methods: Live bat capture and sampling has been implemented in several sites located in Stung Treng province. All rectal swabs of bats were tested for the detection of SARS-CoV-2 or Sarbecoviruses by real time RT-PCR. RNA samples from positive RT-PCR bats were then sequenced using a highly multiplexed PCR amplicon approach using new designed primers set guided by the ARTIC Network multiplex PCR primers set (https://artic.network/ncov-2019), on Oxford Nanopore technology. Findings: The sarbecoviruses were detected in four Rhinolophus shameli bats, a percentage of similarity ranging at the nucleotide level between 98.8% - 99.1% when compared to two other Cambodian bat sarbecoviruses from 2010 and between 92.4% - 94.5% when compared to human SARS-CoV-2 across the whole genome. Discussion: The bat SARS-CoV-2 related virus recently detected in four positive bats in 2020-2021 are genetically homologous with the virus detected in 2010, indicating a geographically/host limited population that is stable over time in the past ten years. Conclusion: Overall, our findings indicate further complexity in the diversity and evolution of sarbecoviruses and add intricacy to the search for the origins of the Coronavirus Disease 2019 (COVID-19) pandemic.

Intro: Rodent-borne hantaviruses are pathogenic in humans and remain a threat for public health. In Asia, data are available mostly from oriental countries, but limited in South-East Asia. In Cambodia, the presence of hantavirus was reported in rodents since 1998. Nevertheless, burden of infection in humans remains unknown. In our study, we aimed to document the presence and diversity of hantaviruses in rodents and to assess hantavirus seroprevalence in people living in urban and rural settings in Cambodia. Methods: This is a retrospective study conducted using pooled organs collected from 750 rodents in urban and rural settings in 2020 (rainy season) and 2022 (dry season). Concurrently, 788 people working or living at the vicinity of rodent trapping locations were requested for blood collection. Hantavirus RNA in rodents was assessed using RT-PCR and confirmed by Sanger sequencing. Human sera were tested for anti-Thailand hantavirus IgG and IgM using in-house ELISA. Findings: In rodents, hantavirus RNA was detected in 25 (3.3%) caught rodents all originated from urban area. Seoul orthohantavirus was the most predominant virus detected in 23 Rattus norvegicus and 1 Rattus rattus. Thottapalayam virus was detected in one Suncus murinus. In humans, the initial seroprevalence of anti-hantavirus IgG was 10.0% (79/788) in 2020. For 70.4% (555/788) of these study participants, a follow-up blood collection was performed in 2022. Out of these, six (1.1%) individuals turned seroconverted, and one even was positive for hantavirus IgM antibodies. Overall, the hantavirus seroprevalence was significantly higher in urban compared to rural area (13.8% vs. 8.9%, p=0.03). Conclusion: Our findings highlighted a new insight of hantavirus circulation at the rodent-human interface in Cambodia. Additional analyses are ongoing to identify potential factors associated with human exposure to hantavirus. Further investigations are also needed to determine the impact of hantavirus infection on human health in Cambodia.

Abstract Objectives To assess if admission screening for Carbapenem Resistant Enterobacteriaceae (CRE) and cohort care can reduce CRE acquisition (CRE colonization during hospital stay), Hospital Acquired Infections (HAI), hospital-stay, mortality, and costs in three Intensive Care Units (ICU’s) at the Vietnamese National Children’s Hospital. Method CRE screening using rectal swabs and ChromIDCarbas elective culture at admission and if CRE negative, once weekly. Patients were treated in cohorts based on CRE colonization status. Results CRE colonization at baseline point-prevalence screening was 76.9% (103/134). Of 941 CRE screened at admission, 337 (35.8%) were CREpos. 694 patients met inclusion criteria. The 244 patients CRE negative at admission and screened > 2 times were stratified in 8 similar size groups (periods), based on time of admission. CRE acquisition decreased significant (OR − 3.2, p

Purpose: This study aims to evaluate the implementation of a hospital-based integrated bite case management system (IBCM) in Phnom Penh to identify potential improvements and assess the risk of rabies in human victims to help guide animal health interventions and post-exposure treatment. Methods & Materials: The surveillance programme was initiated from human dog-bite patients presented to the Institute Pasteur du Cambodge (IPC) Vaccination Unit in Phnom Penh for post-exposure prophylactic treatment, or through public reports between October 2020 and June 2021. All identified individuals with knowledge of a biting dog were engaged during the investigation. The standardised questionnaires were administered by phone, or in-person where deemed necessary. Each case was assigned with a rabies status; rabid, probable, suspect/inconclusive, and non-case depending on the outcome of an investigation. Univariate logistic regression was performed with all inputs except for inconclusive cases to evaluate the risk factors in case demographics associated with rabid animals. Results: During the study period, 5,035 investigations were conducted. The surveillance system detected 17 rabid cases associated with human dog-bite patients, and 2 cases through other reports. Fifty-seven cases were defined as probable, and 2,745 biting dogs were considered not rabid at the time of the incidents. A definitive conclusion was not drawn in 2,214 cases. The vaccination rate of known biting dogs was 18.6%. Univariate analyses showed that case demographics from the earliest stage of an investigation including animals showing signs of sickness (OR: 135.8, 95%CI: 42.0 – 439.3), animals’ death described as spontaneous (OR: 111.2, 95%CI: 26.3 – 469.9), animals that were killed (OR: 126.3, 95%CI: 42.4 – 545.3), ownerless animals (OR: 33.5, 95%CI: 11.5 – 97.4), patients older than 15 years old (OR: 5.3, 95%CI: 1.5 – 18.9), and multiple bite victims in a case (OR: 6.8, 95%CI: 2.3 – 20.2) were associated with confirmed rabid cases. Conclusion: The study identified barriers to successful sample collection and thorough follow-up with patients which could impact on the system competency. The results of the study indicated that the initial case demographics could be used to assist not only prioritise cases for the IBCM investigation, but also spare PEP prescription for cases of low risk.