STOP Spillover in Cambodia works closely with partner institutions of the Royal Government of Cambodia as part of a One Health Design, Research, and Mentorship Working Group (OH-DReaM WG). With support from the USAID-funded STOP Spillover project, OH-DReaM WG members have been trained in participatory epidemiology, active syndromic surveillance, and biosafety practices. As a result of training, and after developing officially approved terms of reference, the OH-DReaM WG has been transformed into a Syndromic and Active Surveillance (SAS) team.
The SAS team uses symptom-based case definitions and active surveillance. At two local health centers (Roka Ar and Khchau Health Centers) and a referral hospital (Kang Meas Referral Hospital), SAS teams identified patients with signs suggestive of viral infections. Team members collected samples from those patients, their family members, livestock, and community environments for virus PCR testing. During the first round of sampling in January 2024, the SAS team collected 22 samples from patients, 74 from livestock, and 59 from bat guano and urine. By analyzing findings from active syndromic surveillance of humans, the environment, and livestock, understanding of transmission dynamics and potential spillover agents can be greatly improved.
Through sampling and testing, bat guano is an indicator of bat viral infection and shedding. Sampling across different targets (guano, surfaces, livestock, humans) helps determine if the same virus is circulating in bats, other animals, and people in guano farming communities. Laboratory results detected a positive case of coronavirus HKU1 strain S2628, a common human coronavirus (HCoV). Common human coronaviruses such as this typically cause mild to moderate upper respiratory illness often referred to as a “common cold.” In rare cases, they can progress to pneumonia. Zoonotic transmission of HKU1 has not been recorded (as of March 2024). This virus has only been found in human samples to date. It is not closely related to SARS-CoV-2, the causative agent of COVID-19. Findings from the samples were reported to public health authorities and shared with study participants. Arrangements with the national animal laboratory are being finalized for testing samples from livestock, bat guano, and urine.
Through close collaboration and communication between One Health actors at all levels and with local government and community actors, the SAS team successfully identified respiratory illnesses and tested patients for coronaviruses by using syndromic and active surveillance techniques. As a result of this collaborative effort, a case of coronavirus HKU1 infection was detected in a human patient, proving these efforts successful.
The OH-DReaM WG sentinel surveillance team consists of multiple institutions, including the Communicable Disease Control Department of the Ministry of Health; the General Department of Animal Health and Production of the Ministry of Agriculture, Forestry and Fisheries; the Provincial Department of Health; the Provincial Department of Agriculture, Forestry and Fisheries; the Health Operational District; the Kang Meas district referral hospital; and Kchao and Roka Ar Commune Health Centers.
Bringing these diverse and disparate voices together to co-create a local surveillance system is an innovative approach to address some of the underlying causes of zoonotic spillover, amplification, and spread, including the lack of intersectoral communication and insufficient attention and surveillance in high-risk interfaces. This is a novel risk-based participatory surveillance system implemented at a potentially high-risk interface for virus spillover using a One Health approach. The system brings surveillance capacity to the point where spillovers may occur and samples across human, animal, and environmental domains in real-time, creating the conditions to detect a zoonotic coronavirus spillover should it occur in the community.